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| author | H. Peter Anvin <hpa@zytor.com> | 2009-10-12 14:11:09 -0700 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2009-10-12 14:19:34 -0700 |
| commit | a343c75d338aa2afaea4a2a8e40de9e67b6fb4a7 (patch) | |
| tree | 1c6f6f764e01048a9d6b6155ce2cc23c92cad4be | |
| parent | def3c5d0a34e4b09b3cea4435c17209ad347104d (diff) | |
| download | op-kernel-dev-a343c75d338aa2afaea4a2a8e40de9e67b6fb4a7.zip op-kernel-dev-a343c75d338aa2afaea4a2a8e40de9e67b6fb4a7.tar.gz | |
x86: use kernel_stack_pointer() in dumpstack.c
The way to obtain a kernel-mode stack pointer from a struct pt_regs in
32-bit mode is "subtle": the stack doesn't actually contain the stack
pointer, but rather the location where it would have been marks the
actual previous stack frame. For clarity, use kernel_stack_pointer()
instead of coding this weirdness explicitly.
Furthermore, user_mode() is only valid when the process is known to
not run in V86 mode. Use the safer user_mode_vm() instead.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| -rw-r--r-- | arch/x86/kernel/dumpstack.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index 2d8a371..b8ce165 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -268,11 +268,12 @@ int __kprobes __die(const char *str, struct pt_regs *regs, long err) show_registers(regs); #ifdef CONFIG_X86_32 - sp = (unsigned long) (®s->sp); - savesegment(ss, ss); - if (user_mode(regs)) { + if (user_mode_vm(regs)) { sp = regs->sp; ss = regs->ss & 0xffff; + } else { + sp = kernel_stack_pointer(regs); + savesegment(ss, ss); } printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip); print_symbol("%s", regs->ip); |
