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- Remove unncessary type casts

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- Make kernel backtrace routine more robust by refusing to backtrace
    further when encountered function that is possibly modifies SP
    value
This commit is contained in:
Oleksandr Tymoshenko 2012-03-14 23:46:07 +00:00
parent 96ec27d42b
commit d43022a1b3
1 changed files with 15 additions and 6 deletions
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21
sys/dev/hwpmc/hwpmc_mips.c
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@ -150,6 +150,15 @@ pmc_next_frame(register_t *pc, register_t *sp)
case OP_SW:
case OP_SD:
/*
* SP is being saved using S8(FP). Most likely it indicates
* that SP is modified in the function and we can't get
* its value safely without emulating code backward
* So just bail out on functions like this
*/
if ((i.IType.rs == 30) && (i.IType.rt = 29))
return (-1);
/* look for saved registers on the stack */
if (i.IType.rs != 29)
break;
@ -327,9 +336,9 @@ pmc_save_kernel_callchain(uintptr_t *cc, int nframes,
register_t pc, ra, sp;
int frames = 0;
pc = (uint64_t)tf->pc;
sp = (uint64_t)tf->sp;
ra = (uint64_t)tf->ra;
pc = tf->pc;
sp = tf->sp;
ra = tf->ra;
/*
* Unwind, and unwind, and unwind
@ -353,9 +362,9 @@ pmc_save_user_callchain(uintptr_t *cc, int nframes,
register_t pc, ra, sp;
int frames = 0;
pc = (uint64_t)tf->pc;
sp = (uint64_t)tf->sp;
ra = (uint64_t)tf->ra;
pc = tf->pc;
sp = tf->sp;
ra = tf->ra;
/*
* Unwind, and unwind, and unwind