[v2,4/8] objtool/LoongArch: Enable orc to be built
Commit Message
Implement arch-specific init_orc_entry(), reg_name(), orc_type_name(),
print_reg() and orc_print_dump(), then set BUILD_ORC as y to build the
orc related files.
Co-developed-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Co-developed-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
tools/arch/loongarch/include/asm/orc_types.h | 58 ++++++++++
tools/objtool/Makefile | 4 +
tools/objtool/arch/loongarch/Build | 1 +
tools/objtool/arch/loongarch/decode.c | 16 +++
tools/objtool/arch/loongarch/orc.c | 155 +++++++++++++++++++++++++++
5 files changed, 234 insertions(+)
create mode 100644 tools/arch/loongarch/include/asm/orc_types.h
create mode 100644 tools/objtool/arch/loongarch/orc.c
Comments
Hi, Tiezhu,
On Mon, Oct 9, 2023 at 9:03 PM Tiezhu Yang <yangtiezhu@loongson.cn> wrote:
>
> Implement arch-specific init_orc_entry(), reg_name(), orc_type_name(),
> print_reg() and orc_print_dump(), then set BUILD_ORC as y to build the
> orc related files.
>
> Co-developed-by: Jinyang He <hejinyang@loongson.cn>
> Signed-off-by: Jinyang He <hejinyang@loongson.cn>
> Co-developed-by: Youling Tang <tangyouling@loongson.cn>
> Signed-off-by: Youling Tang <tangyouling@loongson.cn>
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> ---
> tools/arch/loongarch/include/asm/orc_types.h | 58 ++++++++++
> tools/objtool/Makefile | 4 +
> tools/objtool/arch/loongarch/Build | 1 +
> tools/objtool/arch/loongarch/decode.c | 16 +++
> tools/objtool/arch/loongarch/orc.c | 155 +++++++++++++++++++++++++++
> 5 files changed, 234 insertions(+)
> create mode 100644 tools/arch/loongarch/include/asm/orc_types.h
> create mode 100644 tools/objtool/arch/loongarch/orc.c
>
> diff --git a/tools/arch/loongarch/include/asm/orc_types.h b/tools/arch/loongarch/include/asm/orc_types.h
> new file mode 100644
> index 0000000..1d37e62
> --- /dev/null
> +++ b/tools/arch/loongarch/include/asm/orc_types.h
> @@ -0,0 +1,58 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +#ifndef _ORC_TYPES_H
> +#define _ORC_TYPES_H
> +
> +#include <linux/types.h>
> +
> +/*
> + * The ORC_REG_* registers are base registers which are used to find other
> + * registers on the stack.
> + *
> + * ORC_REG_PREV_SP, also known as DWARF Call Frame Address (CFA), is the
> + * address of the previous frame: the caller's SP before it called the current
> + * function.
> + *
> + * ORC_REG_UNDEFINED means the corresponding register's value didn't change in
> + * the current frame.
> + *
> + * The most commonly used base registers are SP and BP -- which the previous SP
> + * is usually based on -- and PREV_SP and UNDEFINED -- which the previous BP is
> + * usually based on.
> + *
> + * The rest of the base registers are needed for special cases like entry code
> + * and GCC realigned stacks.
> + */
> +#define ORC_REG_UNDEFINED 0
> +#define ORC_REG_PREV_SP 1
> +#define ORC_REG_SP 2
> +#define ORC_REG_BP 3
There is no BP register for LoongArch, so I think all 'BP' should be
'FP' in this patch.
Huacai
> +#define ORC_REG_MAX 4
> +
> +#define ORC_TYPE_UNDEFINED 0
> +#define ORC_TYPE_END_OF_STACK 1
> +#define ORC_TYPE_CALL 2
> +#define ORC_TYPE_REGS 3
> +#define ORC_TYPE_REGS_PARTIAL 4
> +
> +#ifndef __ASSEMBLY__
> +/*
> + * This struct is more or less a vastly simplified version of the DWARF Call
> + * Frame Information standard. It contains only the necessary parts of DWARF
> + * CFI, simplified for ease of access by the in-kernel unwinder. It tells the
> + * unwinder how to find the previous SP and BP (and sometimes entry regs) on
> + * the stack for a given code address. Each instance of the struct corresponds
> + * to one or more code locations.
> + */
> +struct orc_entry {
> + s16 sp_offset;
> + s16 bp_offset;
> + s16 ra_offset;
> + unsigned int sp_reg:4;
> + unsigned int bp_reg:4;
> + unsigned int ra_reg:4;
> + unsigned int type:3;
> + unsigned int signal:1;
> +};
> +#endif /* __ASSEMBLY__ */
> +
> +#endif /* _ORC_TYPES_H */
> diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
> index 83b100c..bf7f7f8 100644
> --- a/tools/objtool/Makefile
> +++ b/tools/objtool/Makefile
> @@ -57,6 +57,10 @@ ifeq ($(SRCARCH),x86)
> BUILD_ORC := y
> endif
>
> +ifeq ($(SRCARCH),loongarch)
> + BUILD_ORC := y
> +endif
> +
> export BUILD_ORC
> export srctree OUTPUT CFLAGS SRCARCH AWK
> include $(srctree)/tools/build/Makefile.include
> diff --git a/tools/objtool/arch/loongarch/Build b/tools/objtool/arch/loongarch/Build
> index d24d563..1d4b784 100644
> --- a/tools/objtool/arch/loongarch/Build
> +++ b/tools/objtool/arch/loongarch/Build
> @@ -1,2 +1,3 @@
> objtool-y += decode.o
> objtool-y += special.o
> +objtool-y += orc.o
> diff --git a/tools/objtool/arch/loongarch/decode.c b/tools/objtool/arch/loongarch/decode.c
> index 3a426e4..1c96759 100644
> --- a/tools/objtool/arch/loongarch/decode.c
> +++ b/tools/objtool/arch/loongarch/decode.c
> @@ -3,6 +3,8 @@
> #include <objtool/check.h>
> #include <objtool/warn.h>
> #include <asm/inst.h>
> +#include <asm/orc_types.h>
> +#include <linux/objtool_types.h>
>
> int arch_ftrace_match(char *name)
> {
> @@ -38,6 +40,20 @@ bool arch_callee_saved_reg(unsigned char reg)
>
> int arch_decode_hint_reg(u8 sp_reg, int *base)
> {
> + switch (sp_reg) {
> + case ORC_REG_UNDEFINED:
> + *base = CFI_UNDEFINED;
> + break;
> + case ORC_REG_SP:
> + *base = CFI_SP;
> + break;
> + case ORC_REG_BP:
> + *base = CFI_FP;
> + break;
> + default:
> + return -1;
> + }
> +
> return 0;
> }
>
> diff --git a/tools/objtool/arch/loongarch/orc.c b/tools/objtool/arch/loongarch/orc.c
> new file mode 100644
> index 0000000..7d7ecee
> --- /dev/null
> +++ b/tools/objtool/arch/loongarch/orc.c
> @@ -0,0 +1,155 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +#include <linux/objtool_types.h>
> +#include <asm/orc_types.h>
> +
> +#include <objtool/check.h>
> +#include <objtool/orc.h>
> +#include <objtool/warn.h>
> +#include <objtool/endianness.h>
> +
> +int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruction *insn)
> +{
> + struct cfi_reg *bp = &cfi->regs[CFI_BP];
> + struct cfi_reg *ra = &cfi->regs[CFI_RA];
> +
> + memset(orc, 0, sizeof(*orc));
> +
> + if (!cfi) {
> + /*
> + * This is usually either unreachable nops/traps (which don't
> + * trigger unreachable instruction warnings), or
> + * STACK_FRAME_NON_STANDARD functions.
> + */
> + orc->type = ORC_TYPE_UNDEFINED;
> + return 0;
> + }
> +
> + switch (cfi->type) {
> + case UNWIND_HINT_TYPE_UNDEFINED:
> + orc->type = ORC_TYPE_UNDEFINED;
> + return 0;
> + case UNWIND_HINT_TYPE_END_OF_STACK:
> + orc->type = ORC_TYPE_END_OF_STACK;
> + return 0;
> + case UNWIND_HINT_TYPE_CALL:
> + orc->type = ORC_TYPE_CALL;
> + break;
> + case UNWIND_HINT_TYPE_REGS:
> + orc->type = ORC_TYPE_REGS;
> + break;
> + case UNWIND_HINT_TYPE_REGS_PARTIAL:
> + orc->type = ORC_TYPE_REGS_PARTIAL;
> + break;
> + default:
> + WARN_INSN(insn, "unknown unwind hint type %d", cfi->type);
> + return -1;
> + }
> +
> + orc->signal = cfi->signal;
> +
> + switch (cfi->cfa.base) {
> + case CFI_SP:
> + orc->sp_reg = ORC_REG_SP;
> + break;
> + case CFI_BP:
> + orc->sp_reg = ORC_REG_BP;
> + break;
> + default:
> + WARN_INSN(insn, "unknown CFA base reg %d", cfi->cfa.base);
> + return -1;
> + }
> +
> + switch (bp->base) {
> + case CFI_UNDEFINED:
> + orc->bp_reg = ORC_REG_UNDEFINED;
> + orc->bp_offset = 0;
> + break;
> + case CFI_CFA:
> + orc->bp_reg = ORC_REG_PREV_SP;
> + orc->bp_offset = bp->offset;
> + break;
> + case CFI_BP:
> + orc->bp_reg = ORC_REG_BP;
> + break;
> + default:
> + WARN_INSN(insn, "unknown BP base reg %d", bp->base);
> + return -1;
> + }
> +
> + switch (ra->base) {
> + case CFI_UNDEFINED:
> + orc->ra_reg = ORC_REG_UNDEFINED;
> + orc->ra_offset = 0;
> + break;
> + case CFI_CFA:
> + orc->ra_reg = ORC_REG_PREV_SP;
> + orc->ra_offset = ra->offset;
> + break;
> + case CFI_BP:
> + orc->ra_reg = ORC_REG_BP;
> + break;
> + default:
> + WARN_INSN(insn, "unknown RA base reg %d", ra->base);
> + return -1;
> + }
> +
> + orc->sp_offset = cfi->cfa.offset;
> +
> + return 0;
> +}
> +
> +static const char *reg_name(unsigned int reg)
> +{
> + switch (reg) {
> + case ORC_REG_SP:
> + return "sp";
> + case ORC_REG_BP:
> + return "fp";
> + case ORC_REG_PREV_SP:
> + return "prevsp";
> + default:
> + return "?";
> + }
> +}
> +
> +static const char *orc_type_name(unsigned int type)
> +{
> + switch (type) {
> + case UNWIND_HINT_TYPE_CALL:
> + return "call";
> + case UNWIND_HINT_TYPE_REGS:
> + return "regs";
> + case UNWIND_HINT_TYPE_REGS_PARTIAL:
> + return "regs (partial)";
> + default:
> + return "?";
> + }
> +}
> +
> +static void print_reg(unsigned int reg, int offset)
> +{
> + if (reg == ORC_REG_UNDEFINED)
> + printf(" (und) ");
> + else
> + printf("%s + %3d", reg_name(reg), offset);
> +
> +}
> +
> +void orc_print_dump(struct elf *dummy_elf, struct orc_entry *orc, int i)
> +{
> + printf("type:%s", orc_type_name(orc[i].type));
> +
> + printf(" sp:");
> +
> + print_reg(orc[i].sp_reg, bswap_if_needed(dummy_elf, orc[i].sp_offset));
> +
> + printf(" bp:");
> +
> + print_reg(orc[i].bp_reg, bswap_if_needed(dummy_elf, orc[i].bp_offset));
> +
> + printf(" ra:");
> +
> + print_reg(orc[i].ra_reg, bswap_if_needed(dummy_elf, orc[i].ra_offset));
> +
> + printf(" signal:%d\n", orc[i].signal);
> +}
> --
> 2.1.0
>
On 10/10/2023 08:52 PM, Huacai Chen wrote:
> Hi, Tiezhu,
>
> On Mon, Oct 9, 2023 at 9:03 PM Tiezhu Yang <yangtiezhu@loongson.cn> wrote:
>>
>> Implement arch-specific init_orc_entry(), reg_name(), orc_type_name(),
>> print_reg() and orc_print_dump(), then set BUILD_ORC as y to build the
>> orc related files.
...
>> +#define ORC_REG_SP 2
>> +#define ORC_REG_BP 3
> There is no BP register for LoongArch, so I think all 'BP' should be
> 'FP' in this patch.
Makes sense, thank you, will do it.
>> +#define ORC_REG_MAX 4
...
>> +struct orc_entry {
>> + s16 sp_offset;
>> + s16 bp_offset;
>> + s16 ra_offset;
>> + unsigned int sp_reg:4;
>> + unsigned int bp_reg:4;
>> + unsigned int ra_reg:4;
>> + unsigned int type:3;
>> + unsigned int signal:1;
>> +};
At the same time, I will replace bp_offset with fp_offset and
replace bp_reg with fp_reg, then modify the related code.
Thanks,
Tiezhu
new file mode 100644
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _ORC_TYPES_H
+#define _ORC_TYPES_H
+
+#include <linux/types.h>
+
+/*
+ * The ORC_REG_* registers are base registers which are used to find other
+ * registers on the stack.
+ *
+ * ORC_REG_PREV_SP, also known as DWARF Call Frame Address (CFA), is the
+ * address of the previous frame: the caller's SP before it called the current
+ * function.
+ *
+ * ORC_REG_UNDEFINED means the corresponding register's value didn't change in
+ * the current frame.
+ *
+ * The most commonly used base registers are SP and BP -- which the previous SP
+ * is usually based on -- and PREV_SP and UNDEFINED -- which the previous BP is
+ * usually based on.
+ *
+ * The rest of the base registers are needed for special cases like entry code
+ * and GCC realigned stacks.
+ */
+#define ORC_REG_UNDEFINED 0
+#define ORC_REG_PREV_SP 1
+#define ORC_REG_SP 2
+#define ORC_REG_BP 3
+#define ORC_REG_MAX 4
+
+#define ORC_TYPE_UNDEFINED 0
+#define ORC_TYPE_END_OF_STACK 1
+#define ORC_TYPE_CALL 2
+#define ORC_TYPE_REGS 3
+#define ORC_TYPE_REGS_PARTIAL 4
+
+#ifndef __ASSEMBLY__
+/*
+ * This struct is more or less a vastly simplified version of the DWARF Call
+ * Frame Information standard. It contains only the necessary parts of DWARF
+ * CFI, simplified for ease of access by the in-kernel unwinder. It tells the
+ * unwinder how to find the previous SP and BP (and sometimes entry regs) on
+ * the stack for a given code address. Each instance of the struct corresponds
+ * to one or more code locations.
+ */
+struct orc_entry {
+ s16 sp_offset;
+ s16 bp_offset;
+ s16 ra_offset;
+ unsigned int sp_reg:4;
+ unsigned int bp_reg:4;
+ unsigned int ra_reg:4;
+ unsigned int type:3;
+ unsigned int signal:1;
+};
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ORC_TYPES_H */
@@ -57,6 +57,10 @@ ifeq ($(SRCARCH),x86)
BUILD_ORC := y
endif
+ifeq ($(SRCARCH),loongarch)
+ BUILD_ORC := y
+endif
+
export BUILD_ORC
export srctree OUTPUT CFLAGS SRCARCH AWK
include $(srctree)/tools/build/Makefile.include
@@ -1,2 +1,3 @@
objtool-y += decode.o
objtool-y += special.o
+objtool-y += orc.o
@@ -3,6 +3,8 @@
#include <objtool/check.h>
#include <objtool/warn.h>
#include <asm/inst.h>
+#include <asm/orc_types.h>
+#include <linux/objtool_types.h>
int arch_ftrace_match(char *name)
{
@@ -38,6 +40,20 @@ bool arch_callee_saved_reg(unsigned char reg)
int arch_decode_hint_reg(u8 sp_reg, int *base)
{
+ switch (sp_reg) {
+ case ORC_REG_UNDEFINED:
+ *base = CFI_UNDEFINED;
+ break;
+ case ORC_REG_SP:
+ *base = CFI_SP;
+ break;
+ case ORC_REG_BP:
+ *base = CFI_FP;
+ break;
+ default:
+ return -1;
+ }
+
return 0;
}
new file mode 100644
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <linux/objtool_types.h>
+#include <asm/orc_types.h>
+
+#include <objtool/check.h>
+#include <objtool/orc.h>
+#include <objtool/warn.h>
+#include <objtool/endianness.h>
+
+int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruction *insn)
+{
+ struct cfi_reg *bp = &cfi->regs[CFI_BP];
+ struct cfi_reg *ra = &cfi->regs[CFI_RA];
+
+ memset(orc, 0, sizeof(*orc));
+
+ if (!cfi) {
+ /*
+ * This is usually either unreachable nops/traps (which don't
+ * trigger unreachable instruction warnings), or
+ * STACK_FRAME_NON_STANDARD functions.
+ */
+ orc->type = ORC_TYPE_UNDEFINED;
+ return 0;
+ }
+
+ switch (cfi->type) {
+ case UNWIND_HINT_TYPE_UNDEFINED:
+ orc->type = ORC_TYPE_UNDEFINED;
+ return 0;
+ case UNWIND_HINT_TYPE_END_OF_STACK:
+ orc->type = ORC_TYPE_END_OF_STACK;
+ return 0;
+ case UNWIND_HINT_TYPE_CALL:
+ orc->type = ORC_TYPE_CALL;
+ break;
+ case UNWIND_HINT_TYPE_REGS:
+ orc->type = ORC_TYPE_REGS;
+ break;
+ case UNWIND_HINT_TYPE_REGS_PARTIAL:
+ orc->type = ORC_TYPE_REGS_PARTIAL;
+ break;
+ default:
+ WARN_INSN(insn, "unknown unwind hint type %d", cfi->type);
+ return -1;
+ }
+
+ orc->signal = cfi->signal;
+
+ switch (cfi->cfa.base) {
+ case CFI_SP:
+ orc->sp_reg = ORC_REG_SP;
+ break;
+ case CFI_BP:
+ orc->sp_reg = ORC_REG_BP;
+ break;
+ default:
+ WARN_INSN(insn, "unknown CFA base reg %d", cfi->cfa.base);
+ return -1;
+ }
+
+ switch (bp->base) {
+ case CFI_UNDEFINED:
+ orc->bp_reg = ORC_REG_UNDEFINED;
+ orc->bp_offset = 0;
+ break;
+ case CFI_CFA:
+ orc->bp_reg = ORC_REG_PREV_SP;
+ orc->bp_offset = bp->offset;
+ break;
+ case CFI_BP:
+ orc->bp_reg = ORC_REG_BP;
+ break;
+ default:
+ WARN_INSN(insn, "unknown BP base reg %d", bp->base);
+ return -1;
+ }
+
+ switch (ra->base) {
+ case CFI_UNDEFINED:
+ orc->ra_reg = ORC_REG_UNDEFINED;
+ orc->ra_offset = 0;
+ break;
+ case CFI_CFA:
+ orc->ra_reg = ORC_REG_PREV_SP;
+ orc->ra_offset = ra->offset;
+ break;
+ case CFI_BP:
+ orc->ra_reg = ORC_REG_BP;
+ break;
+ default:
+ WARN_INSN(insn, "unknown RA base reg %d", ra->base);
+ return -1;
+ }
+
+ orc->sp_offset = cfi->cfa.offset;
+
+ return 0;
+}
+
+static const char *reg_name(unsigned int reg)
+{
+ switch (reg) {
+ case ORC_REG_SP:
+ return "sp";
+ case ORC_REG_BP:
+ return "fp";
+ case ORC_REG_PREV_SP:
+ return "prevsp";
+ default:
+ return "?";
+ }
+}
+
+static const char *orc_type_name(unsigned int type)
+{
+ switch (type) {
+ case UNWIND_HINT_TYPE_CALL:
+ return "call";
+ case UNWIND_HINT_TYPE_REGS:
+ return "regs";
+ case UNWIND_HINT_TYPE_REGS_PARTIAL:
+ return "regs (partial)";
+ default:
+ return "?";
+ }
+}
+
+static void print_reg(unsigned int reg, int offset)
+{
+ if (reg == ORC_REG_UNDEFINED)
+ printf(" (und) ");
+ else
+ printf("%s + %3d", reg_name(reg), offset);
+
+}
+
+void orc_print_dump(struct elf *dummy_elf, struct orc_entry *orc, int i)
+{
+ printf("type:%s", orc_type_name(orc[i].type));
+
+ printf(" sp:");
+
+ print_reg(orc[i].sp_reg, bswap_if_needed(dummy_elf, orc[i].sp_offset));
+
+ printf(" bp:");
+
+ print_reg(orc[i].bp_reg, bswap_if_needed(dummy_elf, orc[i].bp_offset));
+
+ printf(" ra:");
+
+ print_reg(orc[i].ra_reg, bswap_if_needed(dummy_elf, orc[i].ra_offset));
+
+ printf(" signal:%d\n", orc[i].signal);
+}