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Fix arm stack frame walking support:

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- Adjust stack offset for Clang
- Correctly fill registers for fake stack frame (soft PMC)

MFC after:	1 week
Sponsored by:	Stormshield
Differential Revision:	https://reviews.freebsd.org/D7396
This commit is contained in:
fabient 2017-03-14 16:06:57 +00:00
parent ead4920e1e
commit 74bd0be5e9
2 changed files with 17 additions and 4 deletions
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2
sys/arm/include/pmc_mdep.h
View File

@ -70,7 +70,9 @@ union pmc_md_pmc {
/* Build a fake kernel trapframe from current instruction pointer. */
#define PMC_FAKE_TRAPFRAME(TF) \
do { \
(TF)->tf_spsr = PSR_SVC32_MODE; \
__asm __volatile("mov %0, pc" : "=r" ((TF)->tf_pc)); \
__asm __volatile("mov %0, r11" : "=r" ((TF)->tf_r11)); \
} while (0)
/*

19
sys/dev/hwpmc/hwpmc_arm.c
View File

@ -42,6 +42,17 @@ __FBSDID("$FreeBSD$");
#include <vm/vm_param.h>
#include <vm/pmap.h>
/* XXX: Userland code compiled with gcc will need an heuristic
* to be correctly detected.
*/
#ifdef __clang__
#define PC_OFF 1
#define FP_OFF 0
#else
#define PC_OFF -1
#define FP_OFF -3
#endif
struct pmc_mdep *
pmc_md_initialize()
{
@ -100,7 +111,7 @@ pmc_save_kernel_callchain(uintptr_t *cc, int maxsamples,
for (count = 1; count < maxsamples; count++) {
/* Use saved lr as pc. */
r = fp - sizeof(uintptr_t);
r = fp + PC_OFF * sizeof(uintptr_t);
if (!PMC_IN_KERNEL_STACK(r, stackstart, stackend))
break;
pc = *(uintptr_t *)r;
@ -110,7 +121,7 @@ pmc_save_kernel_callchain(uintptr_t *cc, int maxsamples,
*cc++ = pc;
/* Switch to next frame up */
r = fp - 3 * sizeof(uintptr_t);
r = fp + FP_OFF * sizeof(uintptr_t);
if (!PMC_IN_KERNEL_STACK(r, stackstart, stackend))
break;
fp = *(uintptr_t *)r;
@ -147,7 +158,7 @@ pmc_save_user_callchain(uintptr_t *cc, int maxsamples,
for (count = 1; count < maxsamples; count++) {
/* Use saved lr as pc. */
r = fp - sizeof(uintptr_t);
r = fp + PC_OFF * sizeof(uintptr_t);
if (copyin((void *)r, &pc, sizeof(pc)) != 0)
break;
if (!PMC_IN_USERSPACE(pc))
@ -157,7 +168,7 @@ pmc_save_user_callchain(uintptr_t *cc, int maxsamples,
/* Switch to next frame up */
oldfp = fp;
r = fp - 3 * sizeof(uintptr_t);
r = fp + FP_OFF * sizeof(uintptr_t);
if (copyin((void *)r, &fp, sizeof(fp)) != 0)
break;
if (fp < oldfp || !PMC_IN_USERSPACE(fp))