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authorJan Beulich <jbeulich@novell.com>2006-12-07 02:14:13 +0100
committerAndi Kleen <andi@basil.nowhere.org>2006-12-07 02:14:13 +0100
commit359ad0d4015a9ab39243f2ebc4eb07915bd618b2 (patch)
tree90f05d8d9ab048029bfe1e451a012b4d5896aafe /kernel/unwind.c
parenteef5e0d185fc049bda11fa14ba286fbd357da896 (diff)
[PATCH] unwinder: more sanity checks in Dwarf2 unwinder
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>
Diffstat (limited to 'kernel/unwind.c')
-rw-r--r--kernel/unwind.c16
1 files changed, 15 insertions, 1 deletions
diff --git a/kernel/unwind.c b/kernel/unwind.c
index af48168a3afb..7e721f104105 100644
--- a/kernel/unwind.c
+++ b/kernel/unwind.c
@@ -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

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