[v2] tree-object-size: Support strndup and strdup
Checks
Commit Message
Use string length of input to strdup to determine the usable size of the
resulting object. Avoid doing the same for strndup since there's a
chance that the input may be too large, resulting in an unnecessary
overhead or worse, the input may not be NULL terminated, resulting in a
crash where there would otherwise have been none.
gcc/ChangeLog:
* tree-object-size.cc (todo): New variable.
(object_sizes_execute): Use it.
(strdup_object_size): New function.
(call_object_size): Use it.
gcc/testsuite/ChangeLog:
* gcc.dg/builtin-dynamic-object-size-0.c (test_strdup,
test_strndup, test_strdup_min, test_strndup_min): New tests.
(main): Call them.
* gcc.dg/builtin-dynamic-object-size-1.c: Silence overread
warnings.
* gcc.dg/builtin-dynamic-object-size-2.c: Likewise.
* gcc.dg/builtin-dynamic-object-size-3.c: Likewise.
* gcc.dg/builtin-dynamic-object-size-4.c: Likewise.
* gcc.dg/builtin-object-size-1.c: Silence overread warnings.
Declare free, strdup and strndup.
(test11): New test.
(main): Call it.
* gcc.dg/builtin-object-size-2.c: Silence overread warnings.
Declare free, strdup and strndup.
(test9): New test.
(main): Call it.
* gcc.dg/builtin-object-size-3.c: Silence overread warnings.
Declare free, strdup and strndup.
(test11): New test.
(main): Call it.
* gcc.dg/builtin-object-size-4.c: Silence overread warnings.
Declare free, strdup and strndup.
(test9): New test.
(main): Call it.
---
Tested:
- x86_64 bootstrap and testsuite run
- i686 build and testsuite run
- ubsan bootstrap
.../gcc.dg/builtin-dynamic-object-size-0.c | 43 +++++++++
.../gcc.dg/builtin-dynamic-object-size-1.c | 2 +-
.../gcc.dg/builtin-dynamic-object-size-2.c | 2 +-
.../gcc.dg/builtin-dynamic-object-size-3.c | 2 +-
.../gcc.dg/builtin-dynamic-object-size-4.c | 2 +-
gcc/testsuite/gcc.dg/builtin-object-size-1.c | 94 +++++++++++++++++-
gcc/testsuite/gcc.dg/builtin-object-size-2.c | 94 +++++++++++++++++-
gcc/testsuite/gcc.dg/builtin-object-size-3.c | 95 ++++++++++++++++++-
gcc/testsuite/gcc.dg/builtin-object-size-4.c | 94 +++++++++++++++++-
gcc/tree-object-size.cc | 84 +++++++++++++++-
10 files changed, 502 insertions(+), 10 deletions(-)
Comments
On Fri, 4 Nov 2022 at 18:18, Siddhesh Poyarekar <siddhesh@gotplt.org> wrote:
>
> Use string length of input to strdup to determine the usable size of the
> resulting object. Avoid doing the same for strndup since there's a
> chance that the input may be too large, resulting in an unnecessary
> overhead or worse, the input may not be NULL terminated, resulting in a
> crash where there would otherwise have been none.
>
> gcc/ChangeLog:
>
> * tree-object-size.cc (todo): New variable.
> (object_sizes_execute): Use it.
> (strdup_object_size): New function.
> (call_object_size): Use it.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/builtin-dynamic-object-size-0.c (test_strdup,
> test_strndup, test_strdup_min, test_strndup_min): New tests.
> (main): Call them.
> * gcc.dg/builtin-dynamic-object-size-1.c: Silence overread
> warnings.
> * gcc.dg/builtin-dynamic-object-size-2.c: Likewise.
> * gcc.dg/builtin-dynamic-object-size-3.c: Likewise.
> * gcc.dg/builtin-dynamic-object-size-4.c: Likewise.
> * gcc.dg/builtin-object-size-1.c: Silence overread warnings.
> Declare free, strdup and strndup.
> (test11): New test.
> (main): Call it.
> * gcc.dg/builtin-object-size-2.c: Silence overread warnings.
> Declare free, strdup and strndup.
> (test9): New test.
> (main): Call it.
> * gcc.dg/builtin-object-size-3.c: Silence overread warnings.
> Declare free, strdup and strndup.
> (test11): New test.
> (main): Call it.
> * gcc.dg/builtin-object-size-4.c: Silence overread warnings.
> Declare free, strdup and strndup.
> (test9): New test.
> (main): Call it.
> ---
> Tested:
>
> - x86_64 bootstrap and testsuite run
> - i686 build and testsuite run
> - ubsan bootstrap
>
> .../gcc.dg/builtin-dynamic-object-size-0.c | 43 +++++++++
> .../gcc.dg/builtin-dynamic-object-size-1.c | 2 +-
> .../gcc.dg/builtin-dynamic-object-size-2.c | 2 +-
> .../gcc.dg/builtin-dynamic-object-size-3.c | 2 +-
> .../gcc.dg/builtin-dynamic-object-size-4.c | 2 +-
> gcc/testsuite/gcc.dg/builtin-object-size-1.c | 94 +++++++++++++++++-
> gcc/testsuite/gcc.dg/builtin-object-size-2.c | 94 +++++++++++++++++-
> gcc/testsuite/gcc.dg/builtin-object-size-3.c | 95 ++++++++++++++++++-
> gcc/testsuite/gcc.dg/builtin-object-size-4.c | 94 +++++++++++++++++-
> gcc/tree-object-size.cc | 84 +++++++++++++++-
> 10 files changed, 502 insertions(+), 10 deletions(-)
>
> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c
> index 01a280b2d7b..4f1606a486b 100644
> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c
> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c
> @@ -479,6 +479,40 @@ test_loop (int *obj, size_t sz, size_t start, size_t end, int incr)
> return __builtin_dynamic_object_size (ptr, 0);
> }
>
> +/* strdup/strndup. */
> +
> +size_t
> +__attribute__ ((noinline))
> +test_strdup (const char *in)
> +{
> + char *res = __builtin_strdup (in);
> + return __builtin_dynamic_object_size (res, 0);
> +}
> +
> +size_t
> +__attribute__ ((noinline))
> +test_strndup (const char *in, size_t bound)
> +{
> + char *res = __builtin_strndup (in, bound);
> + return __builtin_dynamic_object_size (res, 0);
> +}
> +
> +size_t
> +__attribute__ ((noinline))
> +test_strdup_min (const char *in)
> +{
> + char *res = __builtin_strdup (in);
> + return __builtin_dynamic_object_size (res, 2);
> +}
> +
> +size_t
> +__attribute__ ((noinline))
> +test_strndup_min (const char *in, size_t bound)
> +{
> + char *res = __builtin_strndup (in, bound);
> + return __builtin_dynamic_object_size (res, 2);
> +}
> +
> /* Other tests. */
>
> struct TV4
> @@ -651,6 +685,15 @@ main (int argc, char **argv)
> int *t = test_pr105736 (&val3);
> if (__builtin_dynamic_object_size (t, 0) != -1)
> FAIL ();
> + const char *str = "hello world";
> + if (test_strdup (str) != __builtin_strlen (str) + 1)
> + FAIL ();
> + if (test_strndup (str, 4) != 5)
> + FAIL ();
> + if (test_strdup_min (str) != __builtin_strlen (str) + 1)
> + FAIL ();
> + if (test_strndup_min (str, 4) != 1)
> + FAIL ();
>
> if (nfails > 0)
> __builtin_abort ();
> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-1.c b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-1.c
> index 7cc8b1c9488..8f17c8edcaf 100644
> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-1.c
> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-1.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -Wno-stringop-overread" } */
> /* { dg-require-effective-target alloca } */
>
> #define __builtin_object_size __builtin_dynamic_object_size
> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-2.c b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-2.c
> index 267dbf48ca7..3677782ff1c 100644
> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-2.c
> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-2.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -Wno-stringop-overread" } */
> /* { dg-require-effective-target alloca } */
>
> #define __builtin_object_size __builtin_dynamic_object_size
> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-3.c b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-3.c
> index fb9dc56da7e..5b6987b7773 100644
> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-3.c
> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-3.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -Wno-stringop-overread" } */
> /* { dg-require-effective-target alloca } */
>
> #define __builtin_object_size __builtin_dynamic_object_size
> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-4.c b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-4.c
> index 870548b4206..9d796224e96 100644
> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-4.c
> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-4.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -Wno-stringop-overread" } */
> /* { dg-require-effective-target alloca } */
>
> #define __builtin_object_size __builtin_dynamic_object_size
> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-1.c b/gcc/testsuite/gcc.dg/builtin-object-size-1.c
> index b772e2da9b9..c6e5b4c29f8 100644
> --- a/gcc/testsuite/gcc.dg/builtin-object-size-1.c
> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-1.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -Wno-stringop-overread" } */
> /* { dg-require-effective-target alloca } */
>
> typedef __SIZE_TYPE__ size_t;
> @@ -7,10 +7,13 @@ extern void abort (void);
> extern void exit (int);
> extern void *malloc (size_t);
> extern void *calloc (size_t, size_t);
> +extern void free (void *);
> extern void *alloca (size_t);
> extern void *memcpy (void *, const void *, size_t);
> extern void *memset (void *, int, size_t);
> extern char *strcpy (char *, const char *);
> +extern char *strdup (const char *);
> +extern char *strndup (const char *, size_t);
>
> struct A
> {
> @@ -629,6 +632,94 @@ test10 (void)
> }
> }
>
> +/* Tests for strdup/strndup. */
> +size_t
> +__attribute__ ((noinline))
> +test11 (void)
> +{
> + int i = 0;
> + const char *ptr = "abcdefghijklmnopqrstuvwxyz";
> + char *res = strndup (ptr, 21);
> + if (__builtin_object_size (res, 0) != 22)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr, 32);
> + if (__builtin_object_size (res, 0) != 27)
> + abort ();
> +
> + free (res);
> +
> + res = strdup (ptr);
> + if (__builtin_object_size (res, 0) != 27)
> + abort ();
> +
> + free (res);
> +
> + char *ptr2 = malloc (64);
> + strcpy (ptr2, ptr);
> +
> + res = strndup (ptr2, 21);
> + if (__builtin_object_size (res, 0) != 22)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr2, 32);
> + if (__builtin_object_size (res, 0) != 33)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr2, 128);
> + if (__builtin_object_size (res, 0) != 64)
> + abort ();
> +
> + free (res);
> +
> + res = strdup (ptr2);
> +#ifdef __builtin_object_size
> + if (__builtin_object_size (res, 0) != 27)
> +#else
> + if (__builtin_object_size (res, 0) != (size_t) -1)
> +#endif
> + abort ();
> + free (res);
> + free (ptr2);
> +
> + ptr = "abcd\0efghijklmnopqrstuvwxyz";
> + res = strdup (ptr);
> + if (__builtin_object_size (res, 0) != 5)
> + abort ();
> + free (res);
> +
> + res = strndup (ptr, 24);
> + if (__builtin_object_size (res, 0) != 5)
> + abort ();
> + free (res);
> +
> + res = strndup (ptr, 2);
> + if (__builtin_object_size (res, 0) != 3)
> + abort ();
> + free (res);
> +
> + res = strdup (&ptr[4]);
> + if (__builtin_object_size (res, 0) != 1)
> + abort ();
> + free (res);
> +
> + res = strndup (&ptr[4], 4);
> + if (__builtin_object_size (res, 0) != 1)
> + abort ();
> + free (res);
> +
> + res = strndup (&ptr[4], 1);
> + if (__builtin_object_size (res, 0) != 1)
> + abort ();
> + free (res);
> +}
> +
> int
> main (void)
> {
> @@ -644,5 +735,6 @@ main (void)
> test8 ();
> test9 (1);
> test10 ();
> + test11 ();
> exit (0);
> }
> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-2.c b/gcc/testsuite/gcc.dg/builtin-object-size-2.c
> index 2729538da17..639a83cfd39 100644
> --- a/gcc/testsuite/gcc.dg/builtin-object-size-2.c
> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-2.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -Wno-stringop-overread" } */
> /* { dg-require-effective-target alloca } */
>
> typedef __SIZE_TYPE__ size_t;
> @@ -7,10 +7,13 @@ extern void abort (void);
> extern void exit (int);
> extern void *malloc (size_t);
> extern void *calloc (size_t, size_t);
> +extern void free (void *);
> extern void *alloca (size_t);
> extern void *memcpy (void *, const void *, size_t);
> extern void *memset (void *, int, size_t);
> extern char *strcpy (char *, const char *);
> +extern char *strdup (const char *);
> +extern char *strndup (const char *, size_t);
>
> struct A
> {
> @@ -544,6 +547,94 @@ test8 (unsigned cond)
> #endif
> }
>
> +/* Tests for strdup/strndup. */
> +size_t
> +__attribute__ ((noinline))
> +test9 (void)
> +{
> + const char *ptr = "abcdefghijklmnopqrstuvwxyz";
> + char *res = strndup (ptr, 21);
> + if (__builtin_object_size (res, 1) != 22)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr, 32);
> + if (__builtin_object_size (res, 1) != 27)
> + abort ();
> +
> + free (res);
> +
> + res = strdup (ptr);
> + if (__builtin_object_size (res, 1) != 27)
> + abort ();
> +
> + free (res);
> +
> + char *ptr2 = malloc (64);
> + strcpy (ptr2, ptr);
> +
> + res = strndup (ptr2, 21);
> + if (__builtin_object_size (res, 1) != 22)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr2, 32);
> + if (__builtin_object_size (res, 1) != 33)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr2, 128);
> + if (__builtin_object_size (res, 1) != 64)
> + abort ();
> +
> + free (res);
> +
> + res = strdup (ptr2);
> +#ifdef __builtin_object_size
> + if (__builtin_object_size (res, 1) != 27)
> +#else
> + if (__builtin_object_size (res, 1) != (size_t) -1)
> +#endif
> + abort ();
> +
> + free (res);
> + free (ptr2);
> +
> + ptr = "abcd\0efghijklmnopqrstuvwxyz";
> + res = strdup (ptr);
> + if (__builtin_object_size (res, 1) != 5)
> + abort ();
> + free (res);
> +
> + res = strndup (ptr, 24);
> + if (__builtin_object_size (res, 1) != 5)
> + abort ();
> + free (res);
> +
> + res = strndup (ptr, 2);
> + if (__builtin_object_size (res, 1) != 3)
> + abort ();
> + free (res);
> +
> + res = strdup (&ptr[4]);
> + if (__builtin_object_size (res, 1) != 1)
> + abort ();
> + free (res);
> +
> + res = strndup (&ptr[4], 4);
> + if (__builtin_object_size (res, 1) != 1)
> + abort ();
> + free (res);
> +
> + res = strndup (&ptr[4], 1);
> + if (__builtin_object_size (res, 1) != 1)
> + abort ();
> + free (res);
> +}
> +
> int
> main (void)
> {
> @@ -557,5 +648,6 @@ main (void)
> test6 ();
> test7 ();
> test8 (1);
> + test9 ();
> exit (0);
> }
> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-3.c b/gcc/testsuite/gcc.dg/builtin-object-size-3.c
> index 44a99189776..ff4f1747334 100644
> --- a/gcc/testsuite/gcc.dg/builtin-object-size-3.c
> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-3.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -Wno-stringop-overread" } */
> /* { dg-require-effective-target alloca } */
>
> typedef __SIZE_TYPE__ size_t;
> @@ -7,10 +7,13 @@ extern void abort (void);
> extern void exit (int);
> extern void *malloc (size_t);
> extern void *calloc (size_t, size_t);
> +extern void free (void *);
> extern void *alloca (size_t);
> extern void *memcpy (void *, const void *, size_t);
> extern void *memset (void *, int, size_t);
> extern char *strcpy (char *, const char *);
> +extern char *strdup (const char *);
> +extern char *strndup (const char *, size_t);
>
> struct A
> {
> @@ -636,6 +639,95 @@ test10 (void)
> }
> }
>
> +/* Tests for strdup/strndup. */
> +size_t
> +__attribute__ ((noinline))
> +test11 (void)
> +{
> + const char *ptr = "abcdefghijklmnopqrstuvwxyz";
> + char *res = strndup (ptr, 21);
> + if (__builtin_object_size (res, 2) != 22)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr, 32);
> + if (__builtin_object_size (res, 2) != 27)
> + abort ();
> +
> + free (res);
> +
> + res = strdup (ptr);
> + if (__builtin_object_size (res, 2) != 27)
> + abort ();
> +
> + free (res);
> +
> + char *ptr2 = malloc (64);
> + strcpy (ptr2, ptr);
> +
> + res = strndup (ptr2, 21);
> + if (__builtin_object_size (res, 2) != 1)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr2, 32);
> + if (__builtin_object_size (res, 2) != 1)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr2, 128);
> + if (__builtin_object_size (res, 2) != 1)
> + abort ();
> +
> + free (res);
> +
> + res = strdup (ptr2);
> +
> +#ifdef __builtin_object_size
> + if (__builtin_object_size (res, 2) != 27)
> +#else
> + if (__builtin_object_size (res, 2) != 1)
> +#endif
> + abort ();
> +
> + free (res);
> + free (ptr2);
> +
> + ptr = "abcd\0efghijklmnopqrstuvwxyz";
> + res = strdup (ptr);
> + if (__builtin_object_size (res, 2) != 5)
> + abort ();
> + free (res);
> +
> + res = strndup (ptr, 24);
> + if (__builtin_object_size (res, 2) != 5)
> + abort ();
> + free (res);
> +
> + res = strndup (ptr, 2);
> + if (__builtin_object_size (res, 2) != 3)
> + abort ();
> + free (res);
> +
> + res = strdup (&ptr[4]);
> + if (__builtin_object_size (res, 2) != 1)
> + abort ();
> + free (res);
> +
> + res = strndup (&ptr[4], 4);
> + if (__builtin_object_size (res, 2) != 1)
> + abort ();
> + free (res);
> +
> + res = strndup (&ptr[4], 1);
> + if (__builtin_object_size (res, 2) != 1)
> + abort ();
> + free (res);
> +}
> +
> int
> main (void)
> {
> @@ -651,5 +743,6 @@ main (void)
> test8 ();
> test9 (1);
> test10 ();
> + test11 ();
> exit (0);
> }
> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-4.c b/gcc/testsuite/gcc.dg/builtin-object-size-4.c
> index b9fddfed036..4c007c364b7 100644
> --- a/gcc/testsuite/gcc.dg/builtin-object-size-4.c
> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-4.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -Wno-stringop-overread" } */
> /* { dg-require-effective-target alloca } */
>
> typedef __SIZE_TYPE__ size_t;
> @@ -7,10 +7,13 @@ extern void abort (void);
> extern void exit (int);
> extern void *malloc (size_t);
> extern void *calloc (size_t, size_t);
> +extern void free (void *);
> extern void *alloca (size_t);
> extern void *memcpy (void *, const void *, size_t);
> extern void *memset (void *, int, size_t);
> extern char *strcpy (char *, const char *);
> +extern char *strdup (const char *);
> +extern char *strndup (const char *, size_t);
>
> struct A
> {
> @@ -517,6 +520,94 @@ test8 (unsigned cond)
> #endif
> }
>
> +/* Tests for strdup/strndup. */
> +size_t
> +__attribute__ ((noinline))
> +test9 (void)
> +{
> + const char *ptr = "abcdefghijklmnopqrstuvwxyz";
> + char *res = strndup (ptr, 21);
> + if (__builtin_object_size (res, 3) != 22)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr, 32);
> + if (__builtin_object_size (res, 3) != 27)
> + abort ();
> +
> + free (res);
> +
> + res = strdup (ptr);
> + if (__builtin_object_size (res, 3) != 27)
> + abort ();
> +
> + free (res);
> +
> + char *ptr2 = malloc (64);
> + strcpy (ptr2, ptr);
> +
> + res = strndup (ptr2, 21);
> + if (__builtin_object_size (res, 3) != 1)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr2, 32);
> + if (__builtin_object_size (res, 3) != 1)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr2, 128);
> + if (__builtin_object_size (res, 3) != 1)
> + abort ();
> +
> + free (res);
> +
> + res = strdup (ptr2);
> +#ifdef __builtin_object_size
> + if (__builtin_object_size (res, 3) != 27)
> +#else
> + if (__builtin_object_size (res, 3) != 1)
> +#endif
> + abort ();
> +
> + free (res);
> + free (ptr2);
> +
> + ptr = "abcd\0efghijklmnopqrstuvwxyz";
> + res = strdup (ptr);
> + if (__builtin_object_size (res, 3) != 5)
> + abort ();
> + free (res);
> +
> + res = strndup (ptr, 24);
> + if (__builtin_object_size (res, 3) != 5)
> + abort ();
> + free (res);
> +
> + res = strndup (ptr, 2);
> + if (__builtin_object_size (res, 3) != 3)
> + abort ();
> + free (res);
> +
> + res = strdup (&ptr[4]);
> + if (__builtin_object_size (res, 3) != 1)
> + abort ();
> + free (res);
> +
> + res = strndup (&ptr[4], 4);
> + if (__builtin_object_size (res, 3) != 1)
> + abort ();
> + free (res);
> +
> + res = strndup (&ptr[4], 1);
> + if (__builtin_object_size (res, 3) != 1)
> + abort ();
> + free (res);
> +}
> +
> int
> main (void)
> {
> @@ -530,5 +621,6 @@ main (void)
> test6 ();
> test7 ();
> test8 (1);
> + test9 ();
> exit (0);
> }
> diff --git a/gcc/tree-object-size.cc b/gcc/tree-object-size.cc
> index 1f04cb80fd0..08e5731617d 100644
> --- a/gcc/tree-object-size.cc
> +++ b/gcc/tree-object-size.cc
> @@ -89,6 +89,10 @@ static bitmap computed[OST_END];
> /* Maximum value of offset we consider to be addition. */
> static unsigned HOST_WIDE_INT offset_limit;
>
> +/* Tell the generic SSA updater what kind of update is needed after the pass
> + executes. */
> +static unsigned todo;
> +
> /* Return true if VAL represents an initial size for OBJECT_SIZE_TYPE. */
>
> static inline bool
> @@ -787,6 +791,73 @@ alloc_object_size (const gcall *call, int object_size_type)
> return bytes ? bytes : size_unknown (object_size_type);
> }
>
> +/* Compute __builtin_object_size for CALL, which is a call to either
> + BUILT_IN_STRDUP or BUILT_IN_STRNDUP; IS_STRNDUP indicates which it is.
> + OBJECT_SIZE_TYPE is the second argument from __builtin_object_size.
> + If unknown, return size_unknown (object_size_type). */
> +
> +static tree
> +strdup_object_size (const gcall *call, int object_size_type, bool is_strndup)
> +{
> + tree src = gimple_call_arg (call, 0);
> + tree sz = size_unknown (object_size_type);
> + tree n = NULL_TREE;
> +
> + if (is_strndup)
> + n = fold_build2 (PLUS_EXPR, sizetype, size_one_node,
> + gimple_call_arg (call, 1));
> +
> +
> + /* For strdup, simply emit strlen (SRC) + 1 and let the optimizer fold it the
> + way it likes. */
> + if (!is_strndup)
Sorry to nitpick, should this just be under else ? Since this
condition will be false if the above if (is_strndup)
is true.
Thanks,
Prathamesh
> + {
> + tree strlen_fn = builtin_decl_implicit (BUILT_IN_STRLEN);
> + if (strlen_fn)
> + {
> + sz = fold_build2 (PLUS_EXPR, sizetype, size_one_node,
> + build_call_expr (strlen_fn, 1, src));
> + todo = TODO_update_ssa_only_virtuals;
> + }
> + }
> +
> + /* In all other cases, return the size of SRC since the object size cannot
> + exceed that. We cannot do this for OST_MINIMUM unless SRC points into a
> + string constant since otherwise the object size could go all the way down
> + to zero. */
> + if (!size_valid_p (sz, object_size_type)
> + || size_unknown_p (sz, object_size_type))
> + {
> + tree wholesrc = NULL_TREE;
> + if (TREE_CODE (src) == ADDR_EXPR)
> + wholesrc = get_base_address (TREE_OPERAND (src, 0));
> +
> + /* If the source points within a string constant, we try to get its
> + length. */
> + if (wholesrc && TREE_CODE (wholesrc) == STRING_CST)
> + {
> + tree len = c_strlen (src, 0);
> + if (len)
> + sz = fold_build2 (PLUS_EXPR, sizetype, size_one_node, len);
> + }
> +
> + /* For maximum estimate, our next best guess is the object size of the
> + source. */
> + if (size_unknown_p (sz, object_size_type)
> + && !(object_size_type & OST_MINIMUM))
> + compute_builtin_object_size (src, object_size_type, &sz);
> + }
> +
> + /* String duplication allocates at least one byte, so we should never fail
> + for OST_MINIMUM. */
> + if ((!size_valid_p (sz, object_size_type)
> + || size_unknown_p (sz, object_size_type))
> + && (object_size_type & OST_MINIMUM))
> + sz = size_one_node;
> +
> + /* Factor in the N. */
> + return n ? fold_build2 (MIN_EXPR, sizetype, n, sz) : sz;
> +}
>
> /* If object size is propagated from one of function's arguments directly
> to its return value, return that argument for GIMPLE_CALL statement CALL.
> @@ -1233,12 +1304,19 @@ call_object_size (struct object_size_info *osi, tree ptr, gcall *call)
> {
> int object_size_type = osi->object_size_type;
> unsigned int varno = SSA_NAME_VERSION (ptr);
> + tree bytes = NULL_TREE;
>
> gcc_assert (is_gimple_call (call));
>
> gcc_assert (!object_sizes_unknown_p (object_size_type, varno));
> gcc_assert (osi->pass == 0);
> - tree bytes = alloc_object_size (call, object_size_type);
> +
> + bool is_strdup = gimple_call_builtin_p (call, BUILT_IN_STRDUP);
> + bool is_strndup = gimple_call_builtin_p (call, BUILT_IN_STRNDUP);
> + if (is_strdup || is_strndup)
> + bytes = strdup_object_size (call, object_size_type, is_strndup);
> + else
> + bytes = alloc_object_size (call, object_size_type);
>
> if (!size_valid_p (bytes, object_size_type))
> bytes = size_unknown (object_size_type);
> @@ -1998,6 +2076,8 @@ dynamic_object_sizes_execute_one (gimple_stmt_iterator *i, gimple *call)
> static unsigned int
> object_sizes_execute (function *fun, bool early)
> {
> + todo = 0;
> +
> basic_block bb;
> FOR_EACH_BB_FN (bb, fun)
> {
> @@ -2094,7 +2174,7 @@ object_sizes_execute (function *fun, bool early)
> }
>
> fini_object_sizes ();
> - return 0;
> + return todo;
> }
>
> /* Simple pass to optimize all __builtin_object_size () builtins. */
> --
> 2.37.3
>
On 2022-11-04 09:43, Prathamesh Kulkarni wrote:
> On Fri, 4 Nov 2022 at 18:18, Siddhesh Poyarekar <siddhesh@gotplt.org> wrote:
>>
>> Use string length of input to strdup to determine the usable size of the
>> resulting object. Avoid doing the same for strndup since there's a
>> chance that the input may be too large, resulting in an unnecessary
>> overhead or worse, the input may not be NULL terminated, resulting in a
>> crash where there would otherwise have been none.
>>
>> gcc/ChangeLog:
>>
>> * tree-object-size.cc (todo): New variable.
>> (object_sizes_execute): Use it.
>> (strdup_object_size): New function.
>> (call_object_size): Use it.
>>
>> gcc/testsuite/ChangeLog:
>>
>> * gcc.dg/builtin-dynamic-object-size-0.c (test_strdup,
>> test_strndup, test_strdup_min, test_strndup_min): New tests.
>> (main): Call them.
>> * gcc.dg/builtin-dynamic-object-size-1.c: Silence overread
>> warnings.
>> * gcc.dg/builtin-dynamic-object-size-2.c: Likewise.
>> * gcc.dg/builtin-dynamic-object-size-3.c: Likewise.
>> * gcc.dg/builtin-dynamic-object-size-4.c: Likewise.
>> * gcc.dg/builtin-object-size-1.c: Silence overread warnings.
>> Declare free, strdup and strndup.
>> (test11): New test.
>> (main): Call it.
>> * gcc.dg/builtin-object-size-2.c: Silence overread warnings.
>> Declare free, strdup and strndup.
>> (test9): New test.
>> (main): Call it.
>> * gcc.dg/builtin-object-size-3.c: Silence overread warnings.
>> Declare free, strdup and strndup.
>> (test11): New test.
>> (main): Call it.
>> * gcc.dg/builtin-object-size-4.c: Silence overread warnings.
>> Declare free, strdup and strndup.
>> (test9): New test.
>> (main): Call it.
>> ---
>> Tested:
>>
>> - x86_64 bootstrap and testsuite run
>> - i686 build and testsuite run
>> - ubsan bootstrap
>>
>> .../gcc.dg/builtin-dynamic-object-size-0.c | 43 +++++++++
>> .../gcc.dg/builtin-dynamic-object-size-1.c | 2 +-
>> .../gcc.dg/builtin-dynamic-object-size-2.c | 2 +-
>> .../gcc.dg/builtin-dynamic-object-size-3.c | 2 +-
>> .../gcc.dg/builtin-dynamic-object-size-4.c | 2 +-
>> gcc/testsuite/gcc.dg/builtin-object-size-1.c | 94 +++++++++++++++++-
>> gcc/testsuite/gcc.dg/builtin-object-size-2.c | 94 +++++++++++++++++-
>> gcc/testsuite/gcc.dg/builtin-object-size-3.c | 95 ++++++++++++++++++-
>> gcc/testsuite/gcc.dg/builtin-object-size-4.c | 94 +++++++++++++++++-
>> gcc/tree-object-size.cc | 84 +++++++++++++++-
>> 10 files changed, 502 insertions(+), 10 deletions(-)
>>
>> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c
>> index 01a280b2d7b..4f1606a486b 100644
>> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c
>> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c
>> @@ -479,6 +479,40 @@ test_loop (int *obj, size_t sz, size_t start, size_t end, int incr)
>> return __builtin_dynamic_object_size (ptr, 0);
>> }
>>
>> +/* strdup/strndup. */
>> +
>> +size_t
>> +__attribute__ ((noinline))
>> +test_strdup (const char *in)
>> +{
>> + char *res = __builtin_strdup (in);
>> + return __builtin_dynamic_object_size (res, 0);
>> +}
>> +
>> +size_t
>> +__attribute__ ((noinline))
>> +test_strndup (const char *in, size_t bound)
>> +{
>> + char *res = __builtin_strndup (in, bound);
>> + return __builtin_dynamic_object_size (res, 0);
>> +}
>> +
>> +size_t
>> +__attribute__ ((noinline))
>> +test_strdup_min (const char *in)
>> +{
>> + char *res = __builtin_strdup (in);
>> + return __builtin_dynamic_object_size (res, 2);
>> +}
>> +
>> +size_t
>> +__attribute__ ((noinline))
>> +test_strndup_min (const char *in, size_t bound)
>> +{
>> + char *res = __builtin_strndup (in, bound);
>> + return __builtin_dynamic_object_size (res, 2);
>> +}
>> +
>> /* Other tests. */
>>
>> struct TV4
>> @@ -651,6 +685,15 @@ main (int argc, char **argv)
>> int *t = test_pr105736 (&val3);
>> if (__builtin_dynamic_object_size (t, 0) != -1)
>> FAIL ();
>> + const char *str = "hello world";
>> + if (test_strdup (str) != __builtin_strlen (str) + 1)
>> + FAIL ();
>> + if (test_strndup (str, 4) != 5)
>> + FAIL ();
>> + if (test_strdup_min (str) != __builtin_strlen (str) + 1)
>> + FAIL ();
>> + if (test_strndup_min (str, 4) != 1)
>> + FAIL ();
>>
>> if (nfails > 0)
>> __builtin_abort ();
>> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-1.c b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-1.c
>> index 7cc8b1c9488..8f17c8edcaf 100644
>> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-1.c
>> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-1.c
>> @@ -1,5 +1,5 @@
>> /* { dg-do run } */
>> -/* { dg-options "-O2" } */
>> +/* { dg-options "-O2 -Wno-stringop-overread" } */
>> /* { dg-require-effective-target alloca } */
>>
>> #define __builtin_object_size __builtin_dynamic_object_size
>> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-2.c b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-2.c
>> index 267dbf48ca7..3677782ff1c 100644
>> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-2.c
>> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-2.c
>> @@ -1,5 +1,5 @@
>> /* { dg-do run } */
>> -/* { dg-options "-O2" } */
>> +/* { dg-options "-O2 -Wno-stringop-overread" } */
>> /* { dg-require-effective-target alloca } */
>>
>> #define __builtin_object_size __builtin_dynamic_object_size
>> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-3.c b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-3.c
>> index fb9dc56da7e..5b6987b7773 100644
>> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-3.c
>> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-3.c
>> @@ -1,5 +1,5 @@
>> /* { dg-do run } */
>> -/* { dg-options "-O2" } */
>> +/* { dg-options "-O2 -Wno-stringop-overread" } */
>> /* { dg-require-effective-target alloca } */
>>
>> #define __builtin_object_size __builtin_dynamic_object_size
>> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-4.c b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-4.c
>> index 870548b4206..9d796224e96 100644
>> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-4.c
>> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-4.c
>> @@ -1,5 +1,5 @@
>> /* { dg-do run } */
>> -/* { dg-options "-O2" } */
>> +/* { dg-options "-O2 -Wno-stringop-overread" } */
>> /* { dg-require-effective-target alloca } */
>>
>> #define __builtin_object_size __builtin_dynamic_object_size
>> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-1.c b/gcc/testsuite/gcc.dg/builtin-object-size-1.c
>> index b772e2da9b9..c6e5b4c29f8 100644
>> --- a/gcc/testsuite/gcc.dg/builtin-object-size-1.c
>> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-1.c
>> @@ -1,5 +1,5 @@
>> /* { dg-do run } */
>> -/* { dg-options "-O2" } */
>> +/* { dg-options "-O2 -Wno-stringop-overread" } */
>> /* { dg-require-effective-target alloca } */
>>
>> typedef __SIZE_TYPE__ size_t;
>> @@ -7,10 +7,13 @@ extern void abort (void);
>> extern void exit (int);
>> extern void *malloc (size_t);
>> extern void *calloc (size_t, size_t);
>> +extern void free (void *);
>> extern void *alloca (size_t);
>> extern void *memcpy (void *, const void *, size_t);
>> extern void *memset (void *, int, size_t);
>> extern char *strcpy (char *, const char *);
>> +extern char *strdup (const char *);
>> +extern char *strndup (const char *, size_t);
>>
>> struct A
>> {
>> @@ -629,6 +632,94 @@ test10 (void)
>> }
>> }
>>
>> +/* Tests for strdup/strndup. */
>> +size_t
>> +__attribute__ ((noinline))
>> +test11 (void)
>> +{
>> + int i = 0;
>> + const char *ptr = "abcdefghijklmnopqrstuvwxyz";
>> + char *res = strndup (ptr, 21);
>> + if (__builtin_object_size (res, 0) != 22)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strndup (ptr, 32);
>> + if (__builtin_object_size (res, 0) != 27)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strdup (ptr);
>> + if (__builtin_object_size (res, 0) != 27)
>> + abort ();
>> +
>> + free (res);
>> +
>> + char *ptr2 = malloc (64);
>> + strcpy (ptr2, ptr);
>> +
>> + res = strndup (ptr2, 21);
>> + if (__builtin_object_size (res, 0) != 22)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strndup (ptr2, 32);
>> + if (__builtin_object_size (res, 0) != 33)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strndup (ptr2, 128);
>> + if (__builtin_object_size (res, 0) != 64)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strdup (ptr2);
>> +#ifdef __builtin_object_size
>> + if (__builtin_object_size (res, 0) != 27)
>> +#else
>> + if (__builtin_object_size (res, 0) != (size_t) -1)
>> +#endif
>> + abort ();
>> + free (res);
>> + free (ptr2);
>> +
>> + ptr = "abcd\0efghijklmnopqrstuvwxyz";
>> + res = strdup (ptr);
>> + if (__builtin_object_size (res, 0) != 5)
>> + abort ();
>> + free (res);
>> +
>> + res = strndup (ptr, 24);
>> + if (__builtin_object_size (res, 0) != 5)
>> + abort ();
>> + free (res);
>> +
>> + res = strndup (ptr, 2);
>> + if (__builtin_object_size (res, 0) != 3)
>> + abort ();
>> + free (res);
>> +
>> + res = strdup (&ptr[4]);
>> + if (__builtin_object_size (res, 0) != 1)
>> + abort ();
>> + free (res);
>> +
>> + res = strndup (&ptr[4], 4);
>> + if (__builtin_object_size (res, 0) != 1)
>> + abort ();
>> + free (res);
>> +
>> + res = strndup (&ptr[4], 1);
>> + if (__builtin_object_size (res, 0) != 1)
>> + abort ();
>> + free (res);
>> +}
>> +
>> int
>> main (void)
>> {
>> @@ -644,5 +735,6 @@ main (void)
>> test8 ();
>> test9 (1);
>> test10 ();
>> + test11 ();
>> exit (0);
>> }
>> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-2.c b/gcc/testsuite/gcc.dg/builtin-object-size-2.c
>> index 2729538da17..639a83cfd39 100644
>> --- a/gcc/testsuite/gcc.dg/builtin-object-size-2.c
>> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-2.c
>> @@ -1,5 +1,5 @@
>> /* { dg-do run } */
>> -/* { dg-options "-O2" } */
>> +/* { dg-options "-O2 -Wno-stringop-overread" } */
>> /* { dg-require-effective-target alloca } */
>>
>> typedef __SIZE_TYPE__ size_t;
>> @@ -7,10 +7,13 @@ extern void abort (void);
>> extern void exit (int);
>> extern void *malloc (size_t);
>> extern void *calloc (size_t, size_t);
>> +extern void free (void *);
>> extern void *alloca (size_t);
>> extern void *memcpy (void *, const void *, size_t);
>> extern void *memset (void *, int, size_t);
>> extern char *strcpy (char *, const char *);
>> +extern char *strdup (const char *);
>> +extern char *strndup (const char *, size_t);
>>
>> struct A
>> {
>> @@ -544,6 +547,94 @@ test8 (unsigned cond)
>> #endif
>> }
>>
>> +/* Tests for strdup/strndup. */
>> +size_t
>> +__attribute__ ((noinline))
>> +test9 (void)
>> +{
>> + const char *ptr = "abcdefghijklmnopqrstuvwxyz";
>> + char *res = strndup (ptr, 21);
>> + if (__builtin_object_size (res, 1) != 22)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strndup (ptr, 32);
>> + if (__builtin_object_size (res, 1) != 27)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strdup (ptr);
>> + if (__builtin_object_size (res, 1) != 27)
>> + abort ();
>> +
>> + free (res);
>> +
>> + char *ptr2 = malloc (64);
>> + strcpy (ptr2, ptr);
>> +
>> + res = strndup (ptr2, 21);
>> + if (__builtin_object_size (res, 1) != 22)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strndup (ptr2, 32);
>> + if (__builtin_object_size (res, 1) != 33)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strndup (ptr2, 128);
>> + if (__builtin_object_size (res, 1) != 64)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strdup (ptr2);
>> +#ifdef __builtin_object_size
>> + if (__builtin_object_size (res, 1) != 27)
>> +#else
>> + if (__builtin_object_size (res, 1) != (size_t) -1)
>> +#endif
>> + abort ();
>> +
>> + free (res);
>> + free (ptr2);
>> +
>> + ptr = "abcd\0efghijklmnopqrstuvwxyz";
>> + res = strdup (ptr);
>> + if (__builtin_object_size (res, 1) != 5)
>> + abort ();
>> + free (res);
>> +
>> + res = strndup (ptr, 24);
>> + if (__builtin_object_size (res, 1) != 5)
>> + abort ();
>> + free (res);
>> +
>> + res = strndup (ptr, 2);
>> + if (__builtin_object_size (res, 1) != 3)
>> + abort ();
>> + free (res);
>> +
>> + res = strdup (&ptr[4]);
>> + if (__builtin_object_size (res, 1) != 1)
>> + abort ();
>> + free (res);
>> +
>> + res = strndup (&ptr[4], 4);
>> + if (__builtin_object_size (res, 1) != 1)
>> + abort ();
>> + free (res);
>> +
>> + res = strndup (&ptr[4], 1);
>> + if (__builtin_object_size (res, 1) != 1)
>> + abort ();
>> + free (res);
>> +}
>> +
>> int
>> main (void)
>> {
>> @@ -557,5 +648,6 @@ main (void)
>> test6 ();
>> test7 ();
>> test8 (1);
>> + test9 ();
>> exit (0);
>> }
>> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-3.c b/gcc/testsuite/gcc.dg/builtin-object-size-3.c
>> index 44a99189776..ff4f1747334 100644
>> --- a/gcc/testsuite/gcc.dg/builtin-object-size-3.c
>> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-3.c
>> @@ -1,5 +1,5 @@
>> /* { dg-do run } */
>> -/* { dg-options "-O2" } */
>> +/* { dg-options "-O2 -Wno-stringop-overread" } */
>> /* { dg-require-effective-target alloca } */
>>
>> typedef __SIZE_TYPE__ size_t;
>> @@ -7,10 +7,13 @@ extern void abort (void);
>> extern void exit (int);
>> extern void *malloc (size_t);
>> extern void *calloc (size_t, size_t);
>> +extern void free (void *);
>> extern void *alloca (size_t);
>> extern void *memcpy (void *, const void *, size_t);
>> extern void *memset (void *, int, size_t);
>> extern char *strcpy (char *, const char *);
>> +extern char *strdup (const char *);
>> +extern char *strndup (const char *, size_t);
>>
>> struct A
>> {
>> @@ -636,6 +639,95 @@ test10 (void)
>> }
>> }
>>
>> +/* Tests for strdup/strndup. */
>> +size_t
>> +__attribute__ ((noinline))
>> +test11 (void)
>> +{
>> + const char *ptr = "abcdefghijklmnopqrstuvwxyz";
>> + char *res = strndup (ptr, 21);
>> + if (__builtin_object_size (res, 2) != 22)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strndup (ptr, 32);
>> + if (__builtin_object_size (res, 2) != 27)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strdup (ptr);
>> + if (__builtin_object_size (res, 2) != 27)
>> + abort ();
>> +
>> + free (res);
>> +
>> + char *ptr2 = malloc (64);
>> + strcpy (ptr2, ptr);
>> +
>> + res = strndup (ptr2, 21);
>> + if (__builtin_object_size (res, 2) != 1)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strndup (ptr2, 32);
>> + if (__builtin_object_size (res, 2) != 1)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strndup (ptr2, 128);
>> + if (__builtin_object_size (res, 2) != 1)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strdup (ptr2);
>> +
>> +#ifdef __builtin_object_size
>> + if (__builtin_object_size (res, 2) != 27)
>> +#else
>> + if (__builtin_object_size (res, 2) != 1)
>> +#endif
>> + abort ();
>> +
>> + free (res);
>> + free (ptr2);
>> +
>> + ptr = "abcd\0efghijklmnopqrstuvwxyz";
>> + res = strdup (ptr);
>> + if (__builtin_object_size (res, 2) != 5)
>> + abort ();
>> + free (res);
>> +
>> + res = strndup (ptr, 24);
>> + if (__builtin_object_size (res, 2) != 5)
>> + abort ();
>> + free (res);
>> +
>> + res = strndup (ptr, 2);
>> + if (__builtin_object_size (res, 2) != 3)
>> + abort ();
>> + free (res);
>> +
>> + res = strdup (&ptr[4]);
>> + if (__builtin_object_size (res, 2) != 1)
>> + abort ();
>> + free (res);
>> +
>> + res = strndup (&ptr[4], 4);
>> + if (__builtin_object_size (res, 2) != 1)
>> + abort ();
>> + free (res);
>> +
>> + res = strndup (&ptr[4], 1);
>> + if (__builtin_object_size (res, 2) != 1)
>> + abort ();
>> + free (res);
>> +}
>> +
>> int
>> main (void)
>> {
>> @@ -651,5 +743,6 @@ main (void)
>> test8 ();
>> test9 (1);
>> test10 ();
>> + test11 ();
>> exit (0);
>> }
>> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-4.c b/gcc/testsuite/gcc.dg/builtin-object-size-4.c
>> index b9fddfed036..4c007c364b7 100644
>> --- a/gcc/testsuite/gcc.dg/builtin-object-size-4.c
>> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-4.c
>> @@ -1,5 +1,5 @@
>> /* { dg-do run } */
>> -/* { dg-options "-O2" } */
>> +/* { dg-options "-O2 -Wno-stringop-overread" } */
>> /* { dg-require-effective-target alloca } */
>>
>> typedef __SIZE_TYPE__ size_t;
>> @@ -7,10 +7,13 @@ extern void abort (void);
>> extern void exit (int);
>> extern void *malloc (size_t);
>> extern void *calloc (size_t, size_t);
>> +extern void free (void *);
>> extern void *alloca (size_t);
>> extern void *memcpy (void *, const void *, size_t);
>> extern void *memset (void *, int, size_t);
>> extern char *strcpy (char *, const char *);
>> +extern char *strdup (const char *);
>> +extern char *strndup (const char *, size_t);
>>
>> struct A
>> {
>> @@ -517,6 +520,94 @@ test8 (unsigned cond)
>> #endif
>> }
>>
>> +/* Tests for strdup/strndup. */
>> +size_t
>> +__attribute__ ((noinline))
>> +test9 (void)
>> +{
>> + const char *ptr = "abcdefghijklmnopqrstuvwxyz";
>> + char *res = strndup (ptr, 21);
>> + if (__builtin_object_size (res, 3) != 22)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strndup (ptr, 32);
>> + if (__builtin_object_size (res, 3) != 27)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strdup (ptr);
>> + if (__builtin_object_size (res, 3) != 27)
>> + abort ();
>> +
>> + free (res);
>> +
>> + char *ptr2 = malloc (64);
>> + strcpy (ptr2, ptr);
>> +
>> + res = strndup (ptr2, 21);
>> + if (__builtin_object_size (res, 3) != 1)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strndup (ptr2, 32);
>> + if (__builtin_object_size (res, 3) != 1)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strndup (ptr2, 128);
>> + if (__builtin_object_size (res, 3) != 1)
>> + abort ();
>> +
>> + free (res);
>> +
>> + res = strdup (ptr2);
>> +#ifdef __builtin_object_size
>> + if (__builtin_object_size (res, 3) != 27)
>> +#else
>> + if (__builtin_object_size (res, 3) != 1)
>> +#endif
>> + abort ();
>> +
>> + free (res);
>> + free (ptr2);
>> +
>> + ptr = "abcd\0efghijklmnopqrstuvwxyz";
>> + res = strdup (ptr);
>> + if (__builtin_object_size (res, 3) != 5)
>> + abort ();
>> + free (res);
>> +
>> + res = strndup (ptr, 24);
>> + if (__builtin_object_size (res, 3) != 5)
>> + abort ();
>> + free (res);
>> +
>> + res = strndup (ptr, 2);
>> + if (__builtin_object_size (res, 3) != 3)
>> + abort ();
>> + free (res);
>> +
>> + res = strdup (&ptr[4]);
>> + if (__builtin_object_size (res, 3) != 1)
>> + abort ();
>> + free (res);
>> +
>> + res = strndup (&ptr[4], 4);
>> + if (__builtin_object_size (res, 3) != 1)
>> + abort ();
>> + free (res);
>> +
>> + res = strndup (&ptr[4], 1);
>> + if (__builtin_object_size (res, 3) != 1)
>> + abort ();
>> + free (res);
>> +}
>> +
>> int
>> main (void)
>> {
>> @@ -530,5 +621,6 @@ main (void)
>> test6 ();
>> test7 ();
>> test8 (1);
>> + test9 ();
>> exit (0);
>> }
>> diff --git a/gcc/tree-object-size.cc b/gcc/tree-object-size.cc
>> index 1f04cb80fd0..08e5731617d 100644
>> --- a/gcc/tree-object-size.cc
>> +++ b/gcc/tree-object-size.cc
>> @@ -89,6 +89,10 @@ static bitmap computed[OST_END];
>> /* Maximum value of offset we consider to be addition. */
>> static unsigned HOST_WIDE_INT offset_limit;
>>
>> +/* Tell the generic SSA updater what kind of update is needed after the pass
>> + executes. */
>> +static unsigned todo;
>> +
>> /* Return true if VAL represents an initial size for OBJECT_SIZE_TYPE. */
>>
>> static inline bool
>> @@ -787,6 +791,73 @@ alloc_object_size (const gcall *call, int object_size_type)
>> return bytes ? bytes : size_unknown (object_size_type);
>> }
>>
>> +/* Compute __builtin_object_size for CALL, which is a call to either
>> + BUILT_IN_STRDUP or BUILT_IN_STRNDUP; IS_STRNDUP indicates which it is.
>> + OBJECT_SIZE_TYPE is the second argument from __builtin_object_size.
>> + If unknown, return size_unknown (object_size_type). */
>> +
>> +static tree
>> +strdup_object_size (const gcall *call, int object_size_type, bool is_strndup)
>> +{
>> + tree src = gimple_call_arg (call, 0);
>> + tree sz = size_unknown (object_size_type);
>> + tree n = NULL_TREE;
>> +
>> + if (is_strndup)
>> + n = fold_build2 (PLUS_EXPR, sizetype, size_one_node,
>> + gimple_call_arg (call, 1));
>> +
>> +
>> + /* For strdup, simply emit strlen (SRC) + 1 and let the optimizer fold it the
>> + way it likes. */
>> + if (!is_strndup)
> Sorry to nitpick, should this just be under else ? Since this
> condition will be false if the above if (is_strndup)
> is true.
Fixed locally. I'll resend once I have more comments on the rest of the
patch.
Thanks,
Sid
Ping!
On 2022-11-04 08:48, Siddhesh Poyarekar wrote:
> Use string length of input to strdup to determine the usable size of the
> resulting object. Avoid doing the same for strndup since there's a
> chance that the input may be too large, resulting in an unnecessary
> overhead or worse, the input may not be NULL terminated, resulting in a
> crash where there would otherwise have been none.
>
> gcc/ChangeLog:
>
> * tree-object-size.cc (todo): New variable.
> (object_sizes_execute): Use it.
> (strdup_object_size): New function.
> (call_object_size): Use it.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/builtin-dynamic-object-size-0.c (test_strdup,
> test_strndup, test_strdup_min, test_strndup_min): New tests.
> (main): Call them.
> * gcc.dg/builtin-dynamic-object-size-1.c: Silence overread
> warnings.
> * gcc.dg/builtin-dynamic-object-size-2.c: Likewise.
> * gcc.dg/builtin-dynamic-object-size-3.c: Likewise.
> * gcc.dg/builtin-dynamic-object-size-4.c: Likewise.
> * gcc.dg/builtin-object-size-1.c: Silence overread warnings.
> Declare free, strdup and strndup.
> (test11): New test.
> (main): Call it.
> * gcc.dg/builtin-object-size-2.c: Silence overread warnings.
> Declare free, strdup and strndup.
> (test9): New test.
> (main): Call it.
> * gcc.dg/builtin-object-size-3.c: Silence overread warnings.
> Declare free, strdup and strndup.
> (test11): New test.
> (main): Call it.
> * gcc.dg/builtin-object-size-4.c: Silence overread warnings.
> Declare free, strdup and strndup.
> (test9): New test.
> (main): Call it.
> ---
> Tested:
>
> - x86_64 bootstrap and testsuite run
> - i686 build and testsuite run
> - ubsan bootstrap
>
> .../gcc.dg/builtin-dynamic-object-size-0.c | 43 +++++++++
> .../gcc.dg/builtin-dynamic-object-size-1.c | 2 +-
> .../gcc.dg/builtin-dynamic-object-size-2.c | 2 +-
> .../gcc.dg/builtin-dynamic-object-size-3.c | 2 +-
> .../gcc.dg/builtin-dynamic-object-size-4.c | 2 +-
> gcc/testsuite/gcc.dg/builtin-object-size-1.c | 94 +++++++++++++++++-
> gcc/testsuite/gcc.dg/builtin-object-size-2.c | 94 +++++++++++++++++-
> gcc/testsuite/gcc.dg/builtin-object-size-3.c | 95 ++++++++++++++++++-
> gcc/testsuite/gcc.dg/builtin-object-size-4.c | 94 +++++++++++++++++-
> gcc/tree-object-size.cc | 84 +++++++++++++++-
> 10 files changed, 502 insertions(+), 10 deletions(-)
>
> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c
> index 01a280b2d7b..4f1606a486b 100644
> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c
> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-0.c
> @@ -479,6 +479,40 @@ test_loop (int *obj, size_t sz, size_t start, size_t end, int incr)
> return __builtin_dynamic_object_size (ptr, 0);
> }
>
> +/* strdup/strndup. */
> +
> +size_t
> +__attribute__ ((noinline))
> +test_strdup (const char *in)
> +{
> + char *res = __builtin_strdup (in);
> + return __builtin_dynamic_object_size (res, 0);
> +}
> +
> +size_t
> +__attribute__ ((noinline))
> +test_strndup (const char *in, size_t bound)
> +{
> + char *res = __builtin_strndup (in, bound);
> + return __builtin_dynamic_object_size (res, 0);
> +}
> +
> +size_t
> +__attribute__ ((noinline))
> +test_strdup_min (const char *in)
> +{
> + char *res = __builtin_strdup (in);
> + return __builtin_dynamic_object_size (res, 2);
> +}
> +
> +size_t
> +__attribute__ ((noinline))
> +test_strndup_min (const char *in, size_t bound)
> +{
> + char *res = __builtin_strndup (in, bound);
> + return __builtin_dynamic_object_size (res, 2);
> +}
> +
> /* Other tests. */
>
> struct TV4
> @@ -651,6 +685,15 @@ main (int argc, char **argv)
> int *t = test_pr105736 (&val3);
> if (__builtin_dynamic_object_size (t, 0) != -1)
> FAIL ();
> + const char *str = "hello world";
> + if (test_strdup (str) != __builtin_strlen (str) + 1)
> + FAIL ();
> + if (test_strndup (str, 4) != 5)
> + FAIL ();
> + if (test_strdup_min (str) != __builtin_strlen (str) + 1)
> + FAIL ();
> + if (test_strndup_min (str, 4) != 1)
> + FAIL ();
>
> if (nfails > 0)
> __builtin_abort ();
> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-1.c b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-1.c
> index 7cc8b1c9488..8f17c8edcaf 100644
> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-1.c
> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-1.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -Wno-stringop-overread" } */
> /* { dg-require-effective-target alloca } */
>
> #define __builtin_object_size __builtin_dynamic_object_size
> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-2.c b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-2.c
> index 267dbf48ca7..3677782ff1c 100644
> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-2.c
> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-2.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -Wno-stringop-overread" } */
> /* { dg-require-effective-target alloca } */
>
> #define __builtin_object_size __builtin_dynamic_object_size
> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-3.c b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-3.c
> index fb9dc56da7e..5b6987b7773 100644
> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-3.c
> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-3.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -Wno-stringop-overread" } */
> /* { dg-require-effective-target alloca } */
>
> #define __builtin_object_size __builtin_dynamic_object_size
> diff --git a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-4.c b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-4.c
> index 870548b4206..9d796224e96 100644
> --- a/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-4.c
> +++ b/gcc/testsuite/gcc.dg/builtin-dynamic-object-size-4.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -Wno-stringop-overread" } */
> /* { dg-require-effective-target alloca } */
>
> #define __builtin_object_size __builtin_dynamic_object_size
> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-1.c b/gcc/testsuite/gcc.dg/builtin-object-size-1.c
> index b772e2da9b9..c6e5b4c29f8 100644
> --- a/gcc/testsuite/gcc.dg/builtin-object-size-1.c
> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-1.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -Wno-stringop-overread" } */
> /* { dg-require-effective-target alloca } */
>
> typedef __SIZE_TYPE__ size_t;
> @@ -7,10 +7,13 @@ extern void abort (void);
> extern void exit (int);
> extern void *malloc (size_t);
> extern void *calloc (size_t, size_t);
> +extern void free (void *);
> extern void *alloca (size_t);
> extern void *memcpy (void *, const void *, size_t);
> extern void *memset (void *, int, size_t);
> extern char *strcpy (char *, const char *);
> +extern char *strdup (const char *);
> +extern char *strndup (const char *, size_t);
>
> struct A
> {
> @@ -629,6 +632,94 @@ test10 (void)
> }
> }
>
> +/* Tests for strdup/strndup. */
> +size_t
> +__attribute__ ((noinline))
> +test11 (void)
> +{
> + int i = 0;
> + const char *ptr = "abcdefghijklmnopqrstuvwxyz";
> + char *res = strndup (ptr, 21);
> + if (__builtin_object_size (res, 0) != 22)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr, 32);
> + if (__builtin_object_size (res, 0) != 27)
> + abort ();
> +
> + free (res);
> +
> + res = strdup (ptr);
> + if (__builtin_object_size (res, 0) != 27)
> + abort ();
> +
> + free (res);
> +
> + char *ptr2 = malloc (64);
> + strcpy (ptr2, ptr);
> +
> + res = strndup (ptr2, 21);
> + if (__builtin_object_size (res, 0) != 22)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr2, 32);
> + if (__builtin_object_size (res, 0) != 33)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr2, 128);
> + if (__builtin_object_size (res, 0) != 64)
> + abort ();
> +
> + free (res);
> +
> + res = strdup (ptr2);
> +#ifdef __builtin_object_size
> + if (__builtin_object_size (res, 0) != 27)
> +#else
> + if (__builtin_object_size (res, 0) != (size_t) -1)
> +#endif
> + abort ();
> + free (res);
> + free (ptr2);
> +
> + ptr = "abcd\0efghijklmnopqrstuvwxyz";
> + res = strdup (ptr);
> + if (__builtin_object_size (res, 0) != 5)
> + abort ();
> + free (res);
> +
> + res = strndup (ptr, 24);
> + if (__builtin_object_size (res, 0) != 5)
> + abort ();
> + free (res);
> +
> + res = strndup (ptr, 2);
> + if (__builtin_object_size (res, 0) != 3)
> + abort ();
> + free (res);
> +
> + res = strdup (&ptr[4]);
> + if (__builtin_object_size (res, 0) != 1)
> + abort ();
> + free (res);
> +
> + res = strndup (&ptr[4], 4);
> + if (__builtin_object_size (res, 0) != 1)
> + abort ();
> + free (res);
> +
> + res = strndup (&ptr[4], 1);
> + if (__builtin_object_size (res, 0) != 1)
> + abort ();
> + free (res);
> +}
> +
> int
> main (void)
> {
> @@ -644,5 +735,6 @@ main (void)
> test8 ();
> test9 (1);
> test10 ();
> + test11 ();
> exit (0);
> }
> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-2.c b/gcc/testsuite/gcc.dg/builtin-object-size-2.c
> index 2729538da17..639a83cfd39 100644
> --- a/gcc/testsuite/gcc.dg/builtin-object-size-2.c
> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-2.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -Wno-stringop-overread" } */
> /* { dg-require-effective-target alloca } */
>
> typedef __SIZE_TYPE__ size_t;
> @@ -7,10 +7,13 @@ extern void abort (void);
> extern void exit (int);
> extern void *malloc (size_t);
> extern void *calloc (size_t, size_t);
> +extern void free (void *);
> extern void *alloca (size_t);
> extern void *memcpy (void *, const void *, size_t);
> extern void *memset (void *, int, size_t);
> extern char *strcpy (char *, const char *);
> +extern char *strdup (const char *);
> +extern char *strndup (const char *, size_t);
>
> struct A
> {
> @@ -544,6 +547,94 @@ test8 (unsigned cond)
> #endif
> }
>
> +/* Tests for strdup/strndup. */
> +size_t
> +__attribute__ ((noinline))
> +test9 (void)
> +{
> + const char *ptr = "abcdefghijklmnopqrstuvwxyz";
> + char *res = strndup (ptr, 21);
> + if (__builtin_object_size (res, 1) != 22)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr, 32);
> + if (__builtin_object_size (res, 1) != 27)
> + abort ();
> +
> + free (res);
> +
> + res = strdup (ptr);
> + if (__builtin_object_size (res, 1) != 27)
> + abort ();
> +
> + free (res);
> +
> + char *ptr2 = malloc (64);
> + strcpy (ptr2, ptr);
> +
> + res = strndup (ptr2, 21);
> + if (__builtin_object_size (res, 1) != 22)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr2, 32);
> + if (__builtin_object_size (res, 1) != 33)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr2, 128);
> + if (__builtin_object_size (res, 1) != 64)
> + abort ();
> +
> + free (res);
> +
> + res = strdup (ptr2);
> +#ifdef __builtin_object_size
> + if (__builtin_object_size (res, 1) != 27)
> +#else
> + if (__builtin_object_size (res, 1) != (size_t) -1)
> +#endif
> + abort ();
> +
> + free (res);
> + free (ptr2);
> +
> + ptr = "abcd\0efghijklmnopqrstuvwxyz";
> + res = strdup (ptr);
> + if (__builtin_object_size (res, 1) != 5)
> + abort ();
> + free (res);
> +
> + res = strndup (ptr, 24);
> + if (__builtin_object_size (res, 1) != 5)
> + abort ();
> + free (res);
> +
> + res = strndup (ptr, 2);
> + if (__builtin_object_size (res, 1) != 3)
> + abort ();
> + free (res);
> +
> + res = strdup (&ptr[4]);
> + if (__builtin_object_size (res, 1) != 1)
> + abort ();
> + free (res);
> +
> + res = strndup (&ptr[4], 4);
> + if (__builtin_object_size (res, 1) != 1)
> + abort ();
> + free (res);
> +
> + res = strndup (&ptr[4], 1);
> + if (__builtin_object_size (res, 1) != 1)
> + abort ();
> + free (res);
> +}
> +
> int
> main (void)
> {
> @@ -557,5 +648,6 @@ main (void)
> test6 ();
> test7 ();
> test8 (1);
> + test9 ();
> exit (0);
> }
> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-3.c b/gcc/testsuite/gcc.dg/builtin-object-size-3.c
> index 44a99189776..ff4f1747334 100644
> --- a/gcc/testsuite/gcc.dg/builtin-object-size-3.c
> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-3.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -Wno-stringop-overread" } */
> /* { dg-require-effective-target alloca } */
>
> typedef __SIZE_TYPE__ size_t;
> @@ -7,10 +7,13 @@ extern void abort (void);
> extern void exit (int);
> extern void *malloc (size_t);
> extern void *calloc (size_t, size_t);
> +extern void free (void *);
> extern void *alloca (size_t);
> extern void *memcpy (void *, const void *, size_t);
> extern void *memset (void *, int, size_t);
> extern char *strcpy (char *, const char *);
> +extern char *strdup (const char *);
> +extern char *strndup (const char *, size_t);
>
> struct A
> {
> @@ -636,6 +639,95 @@ test10 (void)
> }
> }
>
> +/* Tests for strdup/strndup. */
> +size_t
> +__attribute__ ((noinline))
> +test11 (void)
> +{
> + const char *ptr = "abcdefghijklmnopqrstuvwxyz";
> + char *res = strndup (ptr, 21);
> + if (__builtin_object_size (res, 2) != 22)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr, 32);
> + if (__builtin_object_size (res, 2) != 27)
> + abort ();
> +
> + free (res);
> +
> + res = strdup (ptr);
> + if (__builtin_object_size (res, 2) != 27)
> + abort ();
> +
> + free (res);
> +
> + char *ptr2 = malloc (64);
> + strcpy (ptr2, ptr);
> +
> + res = strndup (ptr2, 21);
> + if (__builtin_object_size (res, 2) != 1)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr2, 32);
> + if (__builtin_object_size (res, 2) != 1)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr2, 128);
> + if (__builtin_object_size (res, 2) != 1)
> + abort ();
> +
> + free (res);
> +
> + res = strdup (ptr2);
> +
> +#ifdef __builtin_object_size
> + if (__builtin_object_size (res, 2) != 27)
> +#else
> + if (__builtin_object_size (res, 2) != 1)
> +#endif
> + abort ();
> +
> + free (res);
> + free (ptr2);
> +
> + ptr = "abcd\0efghijklmnopqrstuvwxyz";
> + res = strdup (ptr);
> + if (__builtin_object_size (res, 2) != 5)
> + abort ();
> + free (res);
> +
> + res = strndup (ptr, 24);
> + if (__builtin_object_size (res, 2) != 5)
> + abort ();
> + free (res);
> +
> + res = strndup (ptr, 2);
> + if (__builtin_object_size (res, 2) != 3)
> + abort ();
> + free (res);
> +
> + res = strdup (&ptr[4]);
> + if (__builtin_object_size (res, 2) != 1)
> + abort ();
> + free (res);
> +
> + res = strndup (&ptr[4], 4);
> + if (__builtin_object_size (res, 2) != 1)
> + abort ();
> + free (res);
> +
> + res = strndup (&ptr[4], 1);
> + if (__builtin_object_size (res, 2) != 1)
> + abort ();
> + free (res);
> +}
> +
> int
> main (void)
> {
> @@ -651,5 +743,6 @@ main (void)
> test8 ();
> test9 (1);
> test10 ();
> + test11 ();
> exit (0);
> }
> diff --git a/gcc/testsuite/gcc.dg/builtin-object-size-4.c b/gcc/testsuite/gcc.dg/builtin-object-size-4.c
> index b9fddfed036..4c007c364b7 100644
> --- a/gcc/testsuite/gcc.dg/builtin-object-size-4.c
> +++ b/gcc/testsuite/gcc.dg/builtin-object-size-4.c
> @@ -1,5 +1,5 @@
> /* { dg-do run } */
> -/* { dg-options "-O2" } */
> +/* { dg-options "-O2 -Wno-stringop-overread" } */
> /* { dg-require-effective-target alloca } */
>
> typedef __SIZE_TYPE__ size_t;
> @@ -7,10 +7,13 @@ extern void abort (void);
> extern void exit (int);
> extern void *malloc (size_t);
> extern void *calloc (size_t, size_t);
> +extern void free (void *);
> extern void *alloca (size_t);
> extern void *memcpy (void *, const void *, size_t);
> extern void *memset (void *, int, size_t);
> extern char *strcpy (char *, const char *);
> +extern char *strdup (const char *);
> +extern char *strndup (const char *, size_t);
>
> struct A
> {
> @@ -517,6 +520,94 @@ test8 (unsigned cond)
> #endif
> }
>
> +/* Tests for strdup/strndup. */
> +size_t
> +__attribute__ ((noinline))
> +test9 (void)
> +{
> + const char *ptr = "abcdefghijklmnopqrstuvwxyz";
> + char *res = strndup (ptr, 21);
> + if (__builtin_object_size (res, 3) != 22)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr, 32);
> + if (__builtin_object_size (res, 3) != 27)
> + abort ();
> +
> + free (res);
> +
> + res = strdup (ptr);
> + if (__builtin_object_size (res, 3) != 27)
> + abort ();
> +
> + free (res);
> +
> + char *ptr2 = malloc (64);
> + strcpy (ptr2, ptr);
> +
> + res = strndup (ptr2, 21);
> + if (__builtin_object_size (res, 3) != 1)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr2, 32);
> + if (__builtin_object_size (res, 3) != 1)
> + abort ();
> +
> + free (res);
> +
> + res = strndup (ptr2, 128);
> + if (__builtin_object_size (res, 3) != 1)
> + abort ();
> +
> + free (res);
> +
> + res = strdup (ptr2);
> +#ifdef __builtin_object_size
> + if (__builtin_object_size (res, 3) != 27)
> +#else
> + if (__builtin_object_size (res, 3) != 1)
> +#endif
> + abort ();
> +
> + free (res);
> + free (ptr2);
> +
> + ptr = "abcd\0efghijklmnopqrstuvwxyz";
> + res = strdup (ptr);
> + if (__builtin_object_size (res, 3) != 5)
> + abort ();
> + free (res);
> +
> + res = strndup (ptr, 24);
> + if (__builtin_object_size (res, 3) != 5)
> + abort ();
> + free (res);
> +
> + res = strndup (ptr, 2);
> + if (__builtin_object_size (res, 3) != 3)
> + abort ();
> + free (res);
> +
> + res = strdup (&ptr[4]);
> + if (__builtin_object_size (res, 3) != 1)
> + abort ();
> + free (res);
> +
> + res = strndup (&ptr[4], 4);
> + if (__builtin_object_size (res, 3) != 1)
> + abort ();
> + free (res);
> +
> + res = strndup (&ptr[4], 1);
> + if (__builtin_object_size (res, 3) != 1)
> + abort ();
> + free (res);
> +}
> +
> int
> main (void)
> {
> @@ -530,5 +621,6 @@ main (void)
> test6 ();
> test7 ();
> test8 (1);
> + test9 ();
> exit (0);
> }
> diff --git a/gcc/tree-object-size.cc b/gcc/tree-object-size.cc
> index 1f04cb80fd0..08e5731617d 100644
> --- a/gcc/tree-object-size.cc
> +++ b/gcc/tree-object-size.cc
> @@ -89,6 +89,10 @@ static bitmap computed[OST_END];
> /* Maximum value of offset we consider to be addition. */
> static unsigned HOST_WIDE_INT offset_limit;
>
> +/* Tell the generic SSA updater what kind of update is needed after the pass
> + executes. */
> +static unsigned todo;
> +
> /* Return true if VAL represents an initial size for OBJECT_SIZE_TYPE. */
>
> static inline bool
> @@ -787,6 +791,73 @@ alloc_object_size (const gcall *call, int object_size_type)
> return bytes ? bytes : size_unknown (object_size_type);
> }
>
> +/* Compute __builtin_object_size for CALL, which is a call to either
> + BUILT_IN_STRDUP or BUILT_IN_STRNDUP; IS_STRNDUP indicates which it is.
> + OBJECT_SIZE_TYPE is the second argument from __builtin_object_size.
> + If unknown, return size_unknown (object_size_type). */
> +
> +static tree
> +strdup_object_size (const gcall *call, int object_size_type, bool is_strndup)
> +{
> + tree src = gimple_call_arg (call, 0);
> + tree sz = size_unknown (object_size_type);
> + tree n = NULL_TREE;
> +
> + if (is_strndup)
> + n = fold_build2 (PLUS_EXPR, sizetype, size_one_node,
> + gimple_call_arg (call, 1));
> +
> +
> + /* For strdup, simply emit strlen (SRC) + 1 and let the optimizer fold it the
> + way it likes. */
> + if (!is_strndup)
> + {
> + tree strlen_fn = builtin_decl_implicit (BUILT_IN_STRLEN);
> + if (strlen_fn)
> + {
> + sz = fold_build2 (PLUS_EXPR, sizetype, size_one_node,
> + build_call_expr (strlen_fn, 1, src));
> + todo = TODO_update_ssa_only_virtuals;
> + }
> + }
> +
> + /* In all other cases, return the size of SRC since the object size cannot
> + exceed that. We cannot do this for OST_MINIMUM unless SRC points into a
> + string constant since otherwise the object size could go all the way down
> + to zero. */
> + if (!size_valid_p (sz, object_size_type)
> + || size_unknown_p (sz, object_size_type))
> + {
> + tree wholesrc = NULL_TREE;
> + if (TREE_CODE (src) == ADDR_EXPR)
> + wholesrc = get_base_address (TREE_OPERAND (src, 0));
> +
> + /* If the source points within a string constant, we try to get its
> + length. */
> + if (wholesrc && TREE_CODE (wholesrc) == STRING_CST)
> + {
> + tree len = c_strlen (src, 0);
> + if (len)
> + sz = fold_build2 (PLUS_EXPR, sizetype, size_one_node, len);
> + }
> +
> + /* For maximum estimate, our next best guess is the object size of the
> + source. */
> + if (size_unknown_p (sz, object_size_type)
> + && !(object_size_type & OST_MINIMUM))
> + compute_builtin_object_size (src, object_size_type, &sz);
> + }
> +
> + /* String duplication allocates at least one byte, so we should never fail
> + for OST_MINIMUM. */
> + if ((!size_valid_p (sz, object_size_type)
> + || size_unknown_p (sz, object_size_type))
> + && (object_size_type & OST_MINIMUM))
> + sz = size_one_node;
> +
> + /* Factor in the N. */
> + return n ? fold_build2 (MIN_EXPR, sizetype, n, sz) : sz;
> +}
>
> /* If object size is propagated from one of function's arguments directly
> to its return value, return that argument for GIMPLE_CALL statement CALL.
> @@ -1233,12 +1304,19 @@ call_object_size (struct object_size_info *osi, tree ptr, gcall *call)
> {
> int object_size_type = osi->object_size_type;
> unsigned int varno = SSA_NAME_VERSION (ptr);
> + tree bytes = NULL_TREE;
>
> gcc_assert (is_gimple_call (call));
>
> gcc_assert (!object_sizes_unknown_p (object_size_type, varno));
> gcc_assert (osi->pass == 0);
> - tree bytes = alloc_object_size (call, object_size_type);
> +
> + bool is_strdup = gimple_call_builtin_p (call, BUILT_IN_STRDUP);
> + bool is_strndup = gimple_call_builtin_p (call, BUILT_IN_STRNDUP);
> + if (is_strdup || is_strndup)
> + bytes = strdup_object_size (call, object_size_type, is_strndup);
> + else
> + bytes = alloc_object_size (call, object_size_type);
>
> if (!size_valid_p (bytes, object_size_type))
> bytes = size_unknown (object_size_type);
> @@ -1998,6 +2076,8 @@ dynamic_object_sizes_execute_one (gimple_stmt_iterator *i, gimple *call)
> static unsigned int
> object_sizes_execute (function *fun, bool early)
> {
> + todo = 0;
> +
> basic_block bb;
> FOR_EACH_BB_FN (bb, fun)
> {
> @@ -2094,7 +2174,7 @@ object_sizes_execute (function *fun, bool early)
> }
>
> fini_object_sizes ();
> - return 0;
> + return todo;
> }
>
> /* Simple pass to optimize all __builtin_object_size () builtins. */
On 11/4/22 06:48, Siddhesh Poyarekar wrote:
> Use string length of input to strdup to determine the usable size of the
> resulting object. Avoid doing the same for strndup since there's a
> chance that the input may be too large, resulting in an unnecessary
> overhead or worse, the input may not be NULL terminated, resulting in a
> crash where there would otherwise have been none.
>
> gcc/ChangeLog:
>
> * tree-object-size.cc (todo): New variable.
> (object_sizes_execute): Use it.
> (strdup_object_size): New function.
> (call_object_size): Use it.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/builtin-dynamic-object-size-0.c (test_strdup,
> test_strndup, test_strdup_min, test_strndup_min): New tests.
> (main): Call them.
> * gcc.dg/builtin-dynamic-object-size-1.c: Silence overread
> warnings.
> * gcc.dg/builtin-dynamic-object-size-2.c: Likewise.
> * gcc.dg/builtin-dynamic-object-size-3.c: Likewise.
> * gcc.dg/builtin-dynamic-object-size-4.c: Likewise.
> * gcc.dg/builtin-object-size-1.c: Silence overread warnings.
> Declare free, strdup and strndup.
> (test11): New test.
> (main): Call it.
> * gcc.dg/builtin-object-size-2.c: Silence overread warnings.
> Declare free, strdup and strndup.
> (test9): New test.
> (main): Call it.
> * gcc.dg/builtin-object-size-3.c: Silence overread warnings.
> Declare free, strdup and strndup.
> (test11): New test.
> (main): Call it.
> * gcc.dg/builtin-object-size-4.c: Silence overread warnings.
> Declare free, strdup and strndup.
> (test9): New test.
> (main): Call it.
I'm struggling to see how the SSA updating is correct. Yes we need to
update the virtuals due to the introduction of the call to strlen,
particularly when SRC is not a string constant. But do we need to do more?
Don't we end up gimplifying the 1 + strlenfn (src) expression? Can that
possibly create new SSA_NAMEs? Do those need to be put into SSA form?
I feel like I'm missing something here...
jeff
On 2022-11-20 10:42, Jeff Law wrote:
>
> On 11/4/22 06:48, Siddhesh Poyarekar wrote:
>> Use string length of input to strdup to determine the usable size of the
>> resulting object. Avoid doing the same for strndup since there's a
>> chance that the input may be too large, resulting in an unnecessary
>> overhead or worse, the input may not be NULL terminated, resulting in a
>> crash where there would otherwise have been none.
>>
>> gcc/ChangeLog:
>>
>> * tree-object-size.cc (todo): New variable.
>> (object_sizes_execute): Use it.
>> (strdup_object_size): New function.
>> (call_object_size): Use it.
>>
>> gcc/testsuite/ChangeLog:
>>
>> * gcc.dg/builtin-dynamic-object-size-0.c (test_strdup,
>> test_strndup, test_strdup_min, test_strndup_min): New tests.
>> (main): Call them.
>> * gcc.dg/builtin-dynamic-object-size-1.c: Silence overread
>> warnings.
>> * gcc.dg/builtin-dynamic-object-size-2.c: Likewise.
>> * gcc.dg/builtin-dynamic-object-size-3.c: Likewise.
>> * gcc.dg/builtin-dynamic-object-size-4.c: Likewise.
>> * gcc.dg/builtin-object-size-1.c: Silence overread warnings.
>> Declare free, strdup and strndup.
>> (test11): New test.
>> (main): Call it.
>> * gcc.dg/builtin-object-size-2.c: Silence overread warnings.
>> Declare free, strdup and strndup.
>> (test9): New test.
>> (main): Call it.
>> * gcc.dg/builtin-object-size-3.c: Silence overread warnings.
>> Declare free, strdup and strndup.
>> (test11): New test.
>> (main): Call it.
>> * gcc.dg/builtin-object-size-4.c: Silence overread warnings.
>> Declare free, strdup and strndup.
>> (test9): New test.
>> (main): Call it.
>
> I'm struggling to see how the SSA updating is correct. Yes we need to
> update the virtuals due to the introduction of the call to strlen,
> particularly when SRC is not a string constant. But do we need to do more?
>
> Don't we end up gimplifying the 1 + strlenfn (src) expression? Can that
> possibly create new SSA_NAMEs? Do those need to be put into SSA form? I
> feel like I'm missing something here...
We do all of that manually in gimplify_size_expressions, the only thing
left to do is updating virtuals AFAICT.
Thanks,
Sid
On 11/21/22 07:27, Siddhesh Poyarekar wrote:
> On 2022-11-20 10:42, Jeff Law wrote:
>>
>> On 11/4/22 06:48, Siddhesh Poyarekar wrote:
>>> Use string length of input to strdup to determine the usable size of
>>> the
>>> resulting object. Avoid doing the same for strndup since there's a
>>> chance that the input may be too large, resulting in an unnecessary
>>> overhead or worse, the input may not be NULL terminated, resulting in a
>>> crash where there would otherwise have been none.
>>>
>>> gcc/ChangeLog:
>>>
>>> * tree-object-size.cc (todo): New variable.
>>> (object_sizes_execute): Use it.
>>> (strdup_object_size): New function.
>>> (call_object_size): Use it.
>>>
>>> gcc/testsuite/ChangeLog:
>>>
>>> * gcc.dg/builtin-dynamic-object-size-0.c (test_strdup,
>>> test_strndup, test_strdup_min, test_strndup_min): New tests.
>>> (main): Call them.
>>> * gcc.dg/builtin-dynamic-object-size-1.c: Silence overread
>>> warnings.
>>> * gcc.dg/builtin-dynamic-object-size-2.c: Likewise.
>>> * gcc.dg/builtin-dynamic-object-size-3.c: Likewise.
>>> * gcc.dg/builtin-dynamic-object-size-4.c: Likewise.
>>> * gcc.dg/builtin-object-size-1.c: Silence overread warnings.
>>> Declare free, strdup and strndup.
>>> (test11): New test.
>>> (main): Call it.
>>> * gcc.dg/builtin-object-size-2.c: Silence overread warnings.
>>> Declare free, strdup and strndup.
>>> (test9): New test.
>>> (main): Call it.
>>> * gcc.dg/builtin-object-size-3.c: Silence overread warnings.
>>> Declare free, strdup and strndup.
>>> (test11): New test.
>>> (main): Call it.
>>> * gcc.dg/builtin-object-size-4.c: Silence overread warnings.
>>> Declare free, strdup and strndup.
>>> (test9): New test.
>>> (main): Call it.
>>
>> I'm struggling to see how the SSA updating is correct. Yes we need
>> to update the virtuals due to the introduction of the call to strlen,
>> particularly when SRC is not a string constant. But do we need to do
>> more?
>>
>> Don't we end up gimplifying the 1 + strlenfn (src) expression? Can
>> that possibly create new SSA_NAMEs? Do those need to be put into SSA
>> form? I feel like I'm missing something here...
>
> We do all of that manually in gimplify_size_expressions, the only
> thing left to do is updating virtuals AFAICT.
I guess it's actually buried down in force_gimple_operand and I guess
for temporaries they're not going to be alive across the new gimple
sequence and each destination gets its own SSA_NAME, so it ought to be
safe. Just had to work a bit further through things.
OK for the trunk.
Thanks,
jeff
On 2022-11-22 15:43, Jeff Law wrote:
>
> On 11/21/22 07:27, Siddhesh Poyarekar wrote:
>> On 2022-11-20 10:42, Jeff Law wrote:
>>>
>>> On 11/4/22 06:48, Siddhesh Poyarekar wrote:
>>>> Use string length of input to strdup to determine the usable size of
>>>> the
>>>> resulting object. Avoid doing the same for strndup since there's a
>>>> chance that the input may be too large, resulting in an unnecessary
>>>> overhead or worse, the input may not be NULL terminated, resulting in a
>>>> crash where there would otherwise have been none.
>>>>
>>>> gcc/ChangeLog:
>>>>
>>>> * tree-object-size.cc (todo): New variable.
>>>> (object_sizes_execute): Use it.
>>>> (strdup_object_size): New function.
>>>> (call_object_size): Use it.
>>>>
>>>> gcc/testsuite/ChangeLog:
>>>>
>>>> * gcc.dg/builtin-dynamic-object-size-0.c (test_strdup,
>>>> test_strndup, test_strdup_min, test_strndup_min): New tests.
>>>> (main): Call them.
>>>> * gcc.dg/builtin-dynamic-object-size-1.c: Silence overread
>>>> warnings.
>>>> * gcc.dg/builtin-dynamic-object-size-2.c: Likewise.
>>>> * gcc.dg/builtin-dynamic-object-size-3.c: Likewise.
>>>> * gcc.dg/builtin-dynamic-object-size-4.c: Likewise.
>>>> * gcc.dg/builtin-object-size-1.c: Silence overread warnings.
>>>> Declare free, strdup and strndup.
>>>> (test11): New test.
>>>> (main): Call it.
>>>> * gcc.dg/builtin-object-size-2.c: Silence overread warnings.
>>>> Declare free, strdup and strndup.
>>>> (test9): New test.
>>>> (main): Call it.
>>>> * gcc.dg/builtin-object-size-3.c: Silence overread warnings.
>>>> Declare free, strdup and strndup.
>>>> (test11): New test.
>>>> (main): Call it.
>>>> * gcc.dg/builtin-object-size-4.c: Silence overread warnings.
>>>> Declare free, strdup and strndup.
>>>> (test9): New test.
>>>> (main): Call it.
>>>
>>> I'm struggling to see how the SSA updating is correct. Yes we need
>>> to update the virtuals due to the introduction of the call to strlen,
>>> particularly when SRC is not a string constant. But do we need to do
>>> more?
>>>
>>> Don't we end up gimplifying the 1 + strlenfn (src) expression? Can
>>> that possibly create new SSA_NAMEs? Do those need to be put into SSA
>>> form? I feel like I'm missing something here...
>>
>> We do all of that manually in gimplify_size_expressions, the only
>> thing left to do is updating virtuals AFAICT.
>
> I guess it's actually buried down in force_gimple_operand and I guess
> for temporaries they're not going to be alive across the new gimple
> sequence and each destination gets its own SSA_NAME, so it ought to be
> safe. Just had to work a bit further through things.
>
> OK for the trunk.
Thanks, pushed with the trivial fixup that Prathamesh suggested, i.e.
replaced 'if (!strndup)' with 'else'.
Sid
@@ -479,6 +479,40 @@ test_loop (int *obj, size_t sz, size_t start, size_t end, int incr)
return __builtin_dynamic_object_size (ptr, 0);
}
+/* strdup/strndup. */
+
+size_t
+__attribute__ ((noinline))
+test_strdup (const char *in)
+{
+ char *res = __builtin_strdup (in);
+ return __builtin_dynamic_object_size (res, 0);
+}
+
+size_t
+__attribute__ ((noinline))
+test_strndup (const char *in, size_t bound)
+{
+ char *res = __builtin_strndup (in, bound);
+ return __builtin_dynamic_object_size (res, 0);
+}
+
+size_t
+__attribute__ ((noinline))
+test_strdup_min (const char *in)
+{
+ char *res = __builtin_strdup (in);
+ return __builtin_dynamic_object_size (res, 2);
+}
+
+size_t
+__attribute__ ((noinline))
+test_strndup_min (const char *in, size_t bound)
+{
+ char *res = __builtin_strndup (in, bound);
+ return __builtin_dynamic_object_size (res, 2);
+}
+
/* Other tests. */
struct TV4
@@ -651,6 +685,15 @@ main (int argc, char **argv)
int *t = test_pr105736 (&val3);
if (__builtin_dynamic_object_size (t, 0) != -1)
FAIL ();
+ const char *str = "hello world";
+ if (test_strdup (str) != __builtin_strlen (str) + 1)
+ FAIL ();
+ if (test_strndup (str, 4) != 5)
+ FAIL ();
+ if (test_strdup_min (str) != __builtin_strlen (str) + 1)
+ FAIL ();
+ if (test_strndup_min (str, 4) != 1)
+ FAIL ();
if (nfails > 0)
__builtin_abort ();
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-O2" } */
+/* { dg-options "-O2 -Wno-stringop-overread" } */
/* { dg-require-effective-target alloca } */
#define __builtin_object_size __builtin_dynamic_object_size
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-O2" } */
+/* { dg-options "-O2 -Wno-stringop-overread" } */
/* { dg-require-effective-target alloca } */
#define __builtin_object_size __builtin_dynamic_object_size
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-O2" } */
+/* { dg-options "-O2 -Wno-stringop-overread" } */
/* { dg-require-effective-target alloca } */
#define __builtin_object_size __builtin_dynamic_object_size
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-O2" } */
+/* { dg-options "-O2 -Wno-stringop-overread" } */
/* { dg-require-effective-target alloca } */
#define __builtin_object_size __builtin_dynamic_object_size
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-O2" } */
+/* { dg-options "-O2 -Wno-stringop-overread" } */
/* { dg-require-effective-target alloca } */
typedef __SIZE_TYPE__ size_t;
@@ -7,10 +7,13 @@ extern void abort (void);
extern void exit (int);
extern void *malloc (size_t);
extern void *calloc (size_t, size_t);
+extern void free (void *);
extern void *alloca (size_t);
extern void *memcpy (void *, const void *, size_t);
extern void *memset (void *, int, size_t);
extern char *strcpy (char *, const char *);
+extern char *strdup (const char *);
+extern char *strndup (const char *, size_t);
struct A
{
@@ -629,6 +632,94 @@ test10 (void)
}
}
+/* Tests for strdup/strndup. */
+size_t
+__attribute__ ((noinline))
+test11 (void)
+{
+ int i = 0;
+ const char *ptr = "abcdefghijklmnopqrstuvwxyz";
+ char *res = strndup (ptr, 21);
+ if (__builtin_object_size (res, 0) != 22)
+ abort ();
+
+ free (res);
+
+ res = strndup (ptr, 32);
+ if (__builtin_object_size (res, 0) != 27)
+ abort ();
+
+ free (res);
+
+ res = strdup (ptr);
+ if (__builtin_object_size (res, 0) != 27)
+ abort ();
+
+ free (res);
+
+ char *ptr2 = malloc (64);
+ strcpy (ptr2, ptr);
+
+ res = strndup (ptr2, 21);
+ if (__builtin_object_size (res, 0) != 22)
+ abort ();
+
+ free (res);
+
+ res = strndup (ptr2, 32);
+ if (__builtin_object_size (res, 0) != 33)
+ abort ();
+
+ free (res);
+
+ res = strndup (ptr2, 128);
+ if (__builtin_object_size (res, 0) != 64)
+ abort ();
+
+ free (res);
+
+ res = strdup (ptr2);
+#ifdef __builtin_object_size
+ if (__builtin_object_size (res, 0) != 27)
+#else
+ if (__builtin_object_size (res, 0) != (size_t) -1)
+#endif
+ abort ();
+ free (res);
+ free (ptr2);
+
+ ptr = "abcd\0efghijklmnopqrstuvwxyz";
+ res = strdup (ptr);
+ if (__builtin_object_size (res, 0) != 5)
+ abort ();
+ free (res);
+
+ res = strndup (ptr, 24);
+ if (__builtin_object_size (res, 0) != 5)
+ abort ();
+ free (res);
+
+ res = strndup (ptr, 2);
+ if (__builtin_object_size (res, 0) != 3)
+ abort ();
+ free (res);
+
+ res = strdup (&ptr[4]);
+ if (__builtin_object_size (res, 0) != 1)
+ abort ();
+ free (res);
+
+ res = strndup (&ptr[4], 4);
+ if (__builtin_object_size (res, 0) != 1)
+ abort ();
+ free (res);
+
+ res = strndup (&ptr[4], 1);
+ if (__builtin_object_size (res, 0) != 1)
+ abort ();
+ free (res);
+}
+
int
main (void)
{
@@ -644,5 +735,6 @@ main (void)
test8 ();
test9 (1);
test10 ();
+ test11 ();
exit (0);
}
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-O2" } */
+/* { dg-options "-O2 -Wno-stringop-overread" } */
/* { dg-require-effective-target alloca } */
typedef __SIZE_TYPE__ size_t;
@@ -7,10 +7,13 @@ extern void abort (void);
extern void exit (int);
extern void *malloc (size_t);
extern void *calloc (size_t, size_t);
+extern void free (void *);
extern void *alloca (size_t);
extern void *memcpy (void *, const void *, size_t);
extern void *memset (void *, int, size_t);
extern char *strcpy (char *, const char *);
+extern char *strdup (const char *);
+extern char *strndup (const char *, size_t);
struct A
{
@@ -544,6 +547,94 @@ test8 (unsigned cond)
#endif
}
+/* Tests for strdup/strndup. */
+size_t
+__attribute__ ((noinline))
+test9 (void)
+{
+ const char *ptr = "abcdefghijklmnopqrstuvwxyz";
+ char *res = strndup (ptr, 21);
+ if (__builtin_object_size (res, 1) != 22)
+ abort ();
+
+ free (res);
+
+ res = strndup (ptr, 32);
+ if (__builtin_object_size (res, 1) != 27)
+ abort ();
+
+ free (res);
+
+ res = strdup (ptr);
+ if (__builtin_object_size (res, 1) != 27)
+ abort ();
+
+ free (res);
+
+ char *ptr2 = malloc (64);
+ strcpy (ptr2, ptr);
+
+ res = strndup (ptr2, 21);
+ if (__builtin_object_size (res, 1) != 22)
+ abort ();
+
+ free (res);
+
+ res = strndup (ptr2, 32);
+ if (__builtin_object_size (res, 1) != 33)
+ abort ();
+
+ free (res);
+
+ res = strndup (ptr2, 128);
+ if (__builtin_object_size (res, 1) != 64)
+ abort ();
+
+ free (res);
+
+ res = strdup (ptr2);
+#ifdef __builtin_object_size
+ if (__builtin_object_size (res, 1) != 27)
+#else
+ if (__builtin_object_size (res, 1) != (size_t) -1)
+#endif
+ abort ();
+
+ free (res);
+ free (ptr2);
+
+ ptr = "abcd\0efghijklmnopqrstuvwxyz";
+ res = strdup (ptr);
+ if (__builtin_object_size (res, 1) != 5)
+ abort ();
+ free (res);
+
+ res = strndup (ptr, 24);
+ if (__builtin_object_size (res, 1) != 5)
+ abort ();
+ free (res);
+
+ res = strndup (ptr, 2);
+ if (__builtin_object_size (res, 1) != 3)
+ abort ();
+ free (res);
+
+ res = strdup (&ptr[4]);
+ if (__builtin_object_size (res, 1) != 1)
+ abort ();
+ free (res);
+
+ res = strndup (&ptr[4], 4);
+ if (__builtin_object_size (res, 1) != 1)
+ abort ();
+ free (res);
+
+ res = strndup (&ptr[4], 1);
+ if (__builtin_object_size (res, 1) != 1)
+ abort ();
+ free (res);
+}
+
int
main (void)
{
@@ -557,5 +648,6 @@ main (void)
test6 ();
test7 ();
test8 (1);
+ test9 ();
exit (0);
}
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-O2" } */
+/* { dg-options "-O2 -Wno-stringop-overread" } */
/* { dg-require-effective-target alloca } */
typedef __SIZE_TYPE__ size_t;
@@ -7,10 +7,13 @@ extern void abort (void);
extern void exit (int);
extern void *malloc (size_t);
extern void *calloc (size_t, size_t);
+extern void free (void *);
extern void *alloca (size_t);
extern void *memcpy (void *, const void *, size_t);
extern void *memset (void *, int, size_t);
extern char *strcpy (char *, const char *);
+extern char *strdup (const char *);
+extern char *strndup (const char *, size_t);
struct A
{
@@ -636,6 +639,95 @@ test10 (void)
}
}
+/* Tests for strdup/strndup. */
+size_t
+__attribute__ ((noinline))
+test11 (void)
+{
+ const char *ptr = "abcdefghijklmnopqrstuvwxyz";
+ char *res = strndup (ptr, 21);
+ if (__builtin_object_size (res, 2) != 22)
+ abort ();
+
+ free (res);
+
+ res = strndup (ptr, 32);
+ if (__builtin_object_size (res, 2) != 27)
+ abort ();
+
+ free (res);
+
+ res = strdup (ptr);
+ if (__builtin_object_size (res, 2) != 27)
+ abort ();
+
+ free (res);
+
+ char *ptr2 = malloc (64);
+ strcpy (ptr2, ptr);
+
+ res = strndup (ptr2, 21);
+ if (__builtin_object_size (res, 2) != 1)
+ abort ();
+
+ free (res);
+
+ res = strndup (ptr2, 32);
+ if (__builtin_object_size (res, 2) != 1)
+ abort ();
+
+ free (res);
+
+ res = strndup (ptr2, 128);
+ if (__builtin_object_size (res, 2) != 1)
+ abort ();
+
+ free (res);
+
+ res = strdup (ptr2);
+
+#ifdef __builtin_object_size
+ if (__builtin_object_size (res, 2) != 27)
+#else
+ if (__builtin_object_size (res, 2) != 1)
+#endif
+ abort ();
+
+ free (res);
+ free (ptr2);
+
+ ptr = "abcd\0efghijklmnopqrstuvwxyz";
+ res = strdup (ptr);
+ if (__builtin_object_size (res, 2) != 5)
+ abort ();
+ free (res);
+
+ res = strndup (ptr, 24);
+ if (__builtin_object_size (res, 2) != 5)
+ abort ();
+ free (res);
+
+ res = strndup (ptr, 2);
+ if (__builtin_object_size (res, 2) != 3)
+ abort ();
+ free (res);
+
+ res = strdup (&ptr[4]);
+ if (__builtin_object_size (res, 2) != 1)
+ abort ();
+ free (res);
+
+ res = strndup (&ptr[4], 4);
+ if (__builtin_object_size (res, 2) != 1)
+ abort ();
+ free (res);
+
+ res = strndup (&ptr[4], 1);
+ if (__builtin_object_size (res, 2) != 1)
+ abort ();
+ free (res);
+}
+
int
main (void)
{
@@ -651,5 +743,6 @@ main (void)
test8 ();
test9 (1);
test10 ();
+ test11 ();
exit (0);
}
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-options "-O2" } */
+/* { dg-options "-O2 -Wno-stringop-overread" } */
/* { dg-require-effective-target alloca } */
typedef __SIZE_TYPE__ size_t;
@@ -7,10 +7,13 @@ extern void abort (void);
extern void exit (int);
extern void *malloc (size_t);
extern void *calloc (size_t, size_t);
+extern void free (void *);
extern void *alloca (size_t);
extern void *memcpy (void *, const void *, size_t);
extern void *memset (void *, int, size_t);
extern char *strcpy (char *, const char *);
+extern char *strdup (const char *);
+extern char *strndup (const char *, size_t);
struct A
{
@@ -517,6 +520,94 @@ test8 (unsigned cond)
#endif
}
+/* Tests for strdup/strndup. */
+size_t
+__attribute__ ((noinline))
+test9 (void)
+{
+ const char *ptr = "abcdefghijklmnopqrstuvwxyz";
+ char *res = strndup (ptr, 21);
+ if (__builtin_object_size (res, 3) != 22)
+ abort ();
+
+ free (res);
+
+ res = strndup (ptr, 32);
+ if (__builtin_object_size (res, 3) != 27)
+ abort ();
+
+ free (res);
+
+ res = strdup (ptr);
+ if (__builtin_object_size (res, 3) != 27)
+ abort ();
+
+ free (res);
+
+ char *ptr2 = malloc (64);
+ strcpy (ptr2, ptr);
+
+ res = strndup (ptr2, 21);
+ if (__builtin_object_size (res, 3) != 1)
+ abort ();
+
+ free (res);
+
+ res = strndup (ptr2, 32);
+ if (__builtin_object_size (res, 3) != 1)
+ abort ();
+
+ free (res);
+
+ res = strndup (ptr2, 128);
+ if (__builtin_object_size (res, 3) != 1)
+ abort ();
+
+ free (res);
+
+ res = strdup (ptr2);
+#ifdef __builtin_object_size
+ if (__builtin_object_size (res, 3) != 27)
+#else
+ if (__builtin_object_size (res, 3) != 1)
+#endif
+ abort ();
+
+ free (res);
+ free (ptr2);
+
+ ptr = "abcd\0efghijklmnopqrstuvwxyz";
+ res = strdup (ptr);
+ if (__builtin_object_size (res, 3) != 5)
+ abort ();
+ free (res);
+
+ res = strndup (ptr, 24);
+ if (__builtin_object_size (res, 3) != 5)
+ abort ();
+ free (res);
+
+ res = strndup (ptr, 2);
+ if (__builtin_object_size (res, 3) != 3)
+ abort ();
+ free (res);
+
+ res = strdup (&ptr[4]);
+ if (__builtin_object_size (res, 3) != 1)
+ abort ();
+ free (res);
+
+ res = strndup (&ptr[4], 4);
+ if (__builtin_object_size (res, 3) != 1)
+ abort ();
+ free (res);
+
+ res = strndup (&ptr[4], 1);
+ if (__builtin_object_size (res, 3) != 1)
+ abort ();
+ free (res);
+}
+
int
main (void)
{
@@ -530,5 +621,6 @@ main (void)
test6 ();
test7 ();
test8 (1);
+ test9 ();
exit (0);
}
@@ -89,6 +89,10 @@ static bitmap computed[OST_END];
/* Maximum value of offset we consider to be addition. */
static unsigned HOST_WIDE_INT offset_limit;
+/* Tell the generic SSA updater what kind of update is needed after the pass
+ executes. */
+static unsigned todo;
+
/* Return true if VAL represents an initial size for OBJECT_SIZE_TYPE. */
static inline bool
@@ -787,6 +791,73 @@ alloc_object_size (const gcall *call, int object_size_type)
return bytes ? bytes : size_unknown (object_size_type);
}
+/* Compute __builtin_object_size for CALL, which is a call to either
+ BUILT_IN_STRDUP or BUILT_IN_STRNDUP; IS_STRNDUP indicates which it is.
+ OBJECT_SIZE_TYPE is the second argument from __builtin_object_size.
+ If unknown, return size_unknown (object_size_type). */
+
+static tree
+strdup_object_size (const gcall *call, int object_size_type, bool is_strndup)
+{
+ tree src = gimple_call_arg (call, 0);
+ tree sz = size_unknown (object_size_type);
+ tree n = NULL_TREE;
+
+ if (is_strndup)
+ n = fold_build2 (PLUS_EXPR, sizetype, size_one_node,
+ gimple_call_arg (call, 1));
+
+
+ /* For strdup, simply emit strlen (SRC) + 1 and let the optimizer fold it the
+ way it likes. */
+ if (!is_strndup)
+ {
+ tree strlen_fn = builtin_decl_implicit (BUILT_IN_STRLEN);
+ if (strlen_fn)
+ {
+ sz = fold_build2 (PLUS_EXPR, sizetype, size_one_node,
+ build_call_expr (strlen_fn, 1, src));
+ todo = TODO_update_ssa_only_virtuals;
+ }
+ }
+
+ /* In all other cases, return the size of SRC since the object size cannot
+ exceed that. We cannot do this for OST_MINIMUM unless SRC points into a
+ string constant since otherwise the object size could go all the way down
+ to zero. */
+ if (!size_valid_p (sz, object_size_type)
+ || size_unknown_p (sz, object_size_type))
+ {
+ tree wholesrc = NULL_TREE;
+ if (TREE_CODE (src) == ADDR_EXPR)
+ wholesrc = get_base_address (TREE_OPERAND (src, 0));
+
+ /* If the source points within a string constant, we try to get its
+ length. */
+ if (wholesrc && TREE_CODE (wholesrc) == STRING_CST)
+ {
+ tree len = c_strlen (src, 0);
+ if (len)
+ sz = fold_build2 (PLUS_EXPR, sizetype, size_one_node, len);
+ }
+
+ /* For maximum estimate, our next best guess is the object size of the
+ source. */
+ if (size_unknown_p (sz, object_size_type)
+ && !(object_size_type & OST_MINIMUM))
+ compute_builtin_object_size (src, object_size_type, &sz);
+ }
+
+ /* String duplication allocates at least one byte, so we should never fail
+ for OST_MINIMUM. */
+ if ((!size_valid_p (sz, object_size_type)
+ || size_unknown_p (sz, object_size_type))
+ && (object_size_type & OST_MINIMUM))
+ sz = size_one_node;
+
+ /* Factor in the N. */
+ return n ? fold_build2 (MIN_EXPR, sizetype, n, sz) : sz;
+}
/* If object size is propagated from one of function's arguments directly
to its return value, return that argument for GIMPLE_CALL statement CALL.
@@ -1233,12 +1304,19 @@ call_object_size (struct object_size_info *osi, tree ptr, gcall *call)
{
int object_size_type = osi->object_size_type;
unsigned int varno = SSA_NAME_VERSION (ptr);
+ tree bytes = NULL_TREE;
gcc_assert (is_gimple_call (call));
gcc_assert (!object_sizes_unknown_p (object_size_type, varno));
gcc_assert (osi->pass == 0);
- tree bytes = alloc_object_size (call, object_size_type);
+
+ bool is_strdup = gimple_call_builtin_p (call, BUILT_IN_STRDUP);
+ bool is_strndup = gimple_call_builtin_p (call, BUILT_IN_STRNDUP);
+ if (is_strdup || is_strndup)
+ bytes = strdup_object_size (call, object_size_type, is_strndup);
+ else
+ bytes = alloc_object_size (call, object_size_type);
if (!size_valid_p (bytes, object_size_type))
bytes = size_unknown (object_size_type);
@@ -1998,6 +2076,8 @@ dynamic_object_sizes_execute_one (gimple_stmt_iterator *i, gimple *call)
static unsigned int
object_sizes_execute (function *fun, bool early)
{
+ todo = 0;
+
basic_block bb;
FOR_EACH_BB_FN (bb, fun)
{
@@ -2094,7 +2174,7 @@ object_sizes_execute (function *fun, bool early)
}
fini_object_sizes ();
- return 0;
+ return todo;
}
/* Simple pass to optimize all __builtin_object_size () builtins. */