diff mbox series

[1/4] libctf: fix assertion failure with no system qsort_r

Message ID 20230324133625.450723-1-nick.alcock@oracle.com
State Repeat Merge
Headers
Series [1/4] libctf: fix assertion failure with no system qsort_r |

Checks

Context Check Description
snail/binutils-gdb-check warning Git am fail log

Commit Message

Nick Alcock March 24, 2023, 1:36 p.m. UTC 
  If no suitable qsort_r is found in libc, we fall back to an
implementation in ctf-qsort.c.  But this implementation routinely calls
the comparison function with two identical arguments. The comparison
function that ensures that the order of output types is stable is not
ready for this, misinterprets it as a type appearing more that once (a
can-never-happen condition) and fails with an assertion failure.

Fixed, audited for further instances of the same failure (none found)
and added a no-qsort test to my regular testsuite run.

libctf/:
	PR libctf/30013
	* ctf-dedup.c (sort_output_mapping): Inputs are always equal to
	themselves.
---
 libctf/ctf-dedup.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/libctf/ctf-dedup.c b/libctf/ctf-dedup.c
index c46f69e7449..6297c45c84d 100644
--- a/libctf/ctf-dedup.c
+++ b/libctf/ctf-dedup.c
@@ -2306,6 +2306,10 @@  sort_output_mapping (const ctf_next_hkv_t *one, const ctf_next_hkv_t *two,
   ctf_id_t one_type;
   ctf_id_t two_type;
 
+  /* Inputs are always equal to themselves.  */
+  if (one == two)
+    return 0;
+
   one_gid = ctf_dynhash_lookup (d->cd_output_first_gid, one_hval);
   two_gid = ctf_dynhash_lookup (d->cd_output_first_gid, two_hval);