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[PATCH] unwinder: more sanity checks in Dwarf2 unwinder

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Tighten the requirements on both input to and output from the Dwarf2
unwinder.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
This commit is contained in:
Jan Beulich
2006-12-07 02:14:13 +01:00
committed by Andi Kleen
parent eef5e0d185
commit 359ad0d401
5 changed files with 35 additions and 15 deletions
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kernel/unwind.c
+15 -1
View File
@@ -95,6 +95,7 @@ static const struct {
typedef unsigned long uleb128_t;
typedef signed long sleb128_t;
#define sleb128abs __builtin_labs
static struct unwind_table {
struct {
@@ -787,7 +788,7 @@ int unwind(struct unwind_frame_info *frame)
#define FRAME_REG(r, t) (((t *)frame)[reg_info[r].offs])
const u32 *fde = NULL, *cie = NULL;
const u8 *ptr = NULL, *end = NULL;
unsigned long pc = UNW_PC(frame) - frame->call_frame;
unsigned long pc = UNW_PC(frame) - frame->call_frame, sp;
unsigned long startLoc = 0, endLoc = 0, cfa;
unsigned i;
signed ptrType = -1;
@@ -936,6 +937,9 @@ int unwind(struct unwind_frame_info *frame)
state.dataAlign = get_sleb128(&ptr, end);
if (state.codeAlign == 0 || state.dataAlign == 0 || ptr >= end)
cie = NULL;
else if (UNW_PC(frame) % state.codeAlign
|| UNW_SP(frame) % sleb128abs(state.dataAlign))
return -EPERM;
else {
retAddrReg = state.version <= 1 ? *ptr++ : get_uleb128(&ptr, end);
/* skip augmentation */
@@ -968,6 +972,8 @@ int unwind(struct unwind_frame_info *frame)
#ifdef CONFIG_FRAME_POINTER
unsigned long top, bottom;
if ((UNW_SP(frame) | UNW_FP(frame)) % sizeof(unsigned long))
return -EPERM;
top = STACK_TOP(frame->task);
bottom = STACK_BOTTOM(frame->task);
# if FRAME_RETADDR_OFFSET < 0
@@ -1018,6 +1024,7 @@ int unwind(struct unwind_frame_info *frame)
|| state.regs[retAddrReg].where == Nowhere
|| state.cfa.reg >= ARRAY_SIZE(reg_info)
|| reg_info[state.cfa.reg].width != sizeof(unsigned long)
|| FRAME_REG(state.cfa.reg, unsigned long) % sizeof(unsigned long)
|| state.cfa.offs % sizeof(unsigned long))
return -EIO;
/* update frame */
@@ -1038,6 +1045,8 @@ int unwind(struct unwind_frame_info *frame)
#else
# define CASES CASE(8); CASE(16); CASE(32); CASE(64)
#endif
pc = UNW_PC(frame);
sp = UNW_SP(frame);
for (i = 0; i < ARRAY_SIZE(state.regs); ++i) {
if (REG_INVALID(i)) {
if (state.regs[i].where == Nowhere)
@@ -1118,6 +1127,11 @@ int unwind(struct unwind_frame_info *frame)
}
}
if (UNW_PC(frame) % state.codeAlign
|| UNW_SP(frame) % sleb128abs(state.dataAlign)
|| (pc == UNW_PC(frame) && sp == UNW_SP(frame)))
return -EIO;
return 0;
#undef CASES
#undef FRAME_REG