diff options
| author | Visa Hankala <visa@cvs.openbsd.org> | 2022-01-25 07:10:20 +0000 |
|---|---|---|
| committer | Visa Hankala <visa@cvs.openbsd.org> | 2022-01-25 07:10:20 +0000 |
| commit | 1f70c54bdca729680634b6c5442c9f3997a308b0 (patch) | |
| tree | cc5a9586fa5426a8edf28852969104a67596b090 /sys/arch | |
| parent | 93abbe6d71e954c1b70a989b0319c291ae32a2c7 (diff) | |
Use unguarded loads in stack trace saving
The stack trace saver should see a system state that is not broken.
Therefore use unguarded memory accesses.
However, the unwinder is still haphazard. Terminate immediately if
the program counter or stack pointer look inconsistent.
Diffstat (limited to 'sys/arch')
| -rw-r--r-- | sys/arch/mips64/mips64/trap.c | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/sys/arch/mips64/mips64/trap.c b/sys/arch/mips64/mips64/trap.c index 1470522844f..f4adfb9b610 100644 --- a/sys/arch/mips64/mips64/trap.c +++ b/sys/arch/mips64/mips64/trap.c @@ -1,4 +1,4 @@ -/* $OpenBSD: trap.c,v 1.157 2022/01/21 16:39:56 visa Exp $ */ +/* $OpenBSD: trap.c,v 1.158 2022/01/25 07:10:19 visa Exp $ */ /* * Copyright (c) 1988 University of Utah. @@ -1136,6 +1136,9 @@ const char *fn_name(vaddr_t); #endif void stacktrace_subr(struct trapframe *, int, int (*)(const char*, ...)); +extern char kernel_text[]; +extern char etext[]; + /* * Print a stack backtrace. */ @@ -1349,12 +1352,9 @@ loop: end: if (ra) { - extern void *kernel_text; - extern void *etext; - if (pc == ra && stksize == 0) (*pr)("stacktrace: loop!\n"); - else if (ra < (vaddr_t)&kernel_text || ra > (vaddr_t)&etext) + else if (ra < (vaddr_t)kernel_text || ra > (vaddr_t)etext) (*pr)("stacktrace: ra corrupted!\n"); else { pc = ra; @@ -1395,7 +1395,10 @@ stacktrace_save_at(struct stacktrace *st, unsigned int skip) st->st_count = 0; while (st->st_count < STACKTRACE_MAX && pc != 0) { - if (!VALID_ADDRESS(pc) || !VALID_ADDRESS(sp)) + if ((pc & 0x3) != 0 || + pc < (vaddr_t)kernel_text || pc >= (vaddr_t)etext) + break; + if ((sp & 0x7) != 0 || !VALID_ADDRESS(sp)) break; if (!first) { @@ -1413,6 +1416,8 @@ stacktrace_save_at(struct stacktrace *st, unsigned int skip) db_symbol_values(sym, &name, NULL); subr = pc - (vaddr_t)diff; + if ((subr & 0x3) != 0) + break; if (subr == (vaddr_t)u_general || subr == (vaddr_t)u_intr) break; if (subr == (vaddr_t)k_general || subr == (vaddr_t)k_intr) { @@ -1430,11 +1435,11 @@ stacktrace_save_at(struct stacktrace *st, unsigned int skip) done = 0; framesize = 0; for (va = subr; va < pc && !done; va += 4) { - inst.word = kdbpeek(va); + inst.word = *(uint32_t *)va; if (inst_call(inst.word) || inst_return(inst.word)) { /* Check the delay slot and stop. */ va += 4; - inst.word = kdbpeek(va); + inst.word = *(uint32_t *)va; done = 1; } switch (inst.JType.op) { @@ -1448,7 +1453,7 @@ stacktrace_save_at(struct stacktrace *st, unsigned int skip) case OP_SD: if (inst.IType.rs == SP && inst.IType.rt == RA && ra == 0) - ra = kdbpeekd(sp + + ra = *(uint64_t *)(sp + (int16_t)inst.IType.imm); break; case OP_DADDI: |