diff options
| author | Jan Beulich <jbeulich@novell.com> | 2006-01-11 22:43:00 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-11 19:01:13 -0800 |
| commit | b556b35e98ad2b9174a7a623d152cdf412d1a999 (patch) | |
| tree | 10f99d70e719fba811dee85d2f3a82b26d7a4ce8 /arch/x86_64/kernel/entry.S | |
| parent | ed8388a5d9db0445322f86ee8381b0f04a2057ee (diff) | |
[PATCH] x86_64: Move int 3 handler to debug stack and allow to increase it.
This
- switches the INT3 handler to run on an IST stack (to cope with
breakpoints set by a kernel debugger on places where the kernel's
%gs base hasn't been set up, yet); the IST stack used is shared with
the INT1 handler's
[AK: this also allows setting a kprobe on the interrupt/exception entry
points]
- allows nesting of INT1/INT3 handlers so that one can, with a kernel
debugger, debug (at least) the user-mode portions of the INT1/INT3
handling; the nesting isn't actively enabled here since a kernel-
debugger-free kernel doesn't need it
Signed-Off-By: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/x86_64/kernel/entry.S')
| -rw-r--r-- | arch/x86_64/kernel/entry.S | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S index bd21ebafaf66..28b3c8e6b044 100644 --- a/arch/x86_64/kernel/entry.S +++ b/arch/x86_64/kernel/entry.S @@ -673,7 +673,10 @@ ENTRY(spurious_interrupt) /* error code is on the stack already */ /* handle NMI like exceptions that can happen everywhere */ - .macro paranoidentry sym +#ifndef DEBUG_IST +# define DEBUG_IST 0 +#endif + .macro paranoidentry sym, ist=0 SAVE_ALL cld movl $1,%ebx @@ -683,10 +686,20 @@ ENTRY(spurious_interrupt) js 1f swapgs xorl %ebx,%ebx -1: movq %rsp,%rdi +1: + .if \ist + movq %gs:pda_data_offset, %rbp + .endif + movq %rsp,%rdi movq ORIG_RAX(%rsp),%rsi movq $-1,ORIG_RAX(%rsp) + .if \ist + subq $EXCEPTION_STACK_SIZE, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp) + .endif call \sym + .if \ist + addq $EXCEPTION_STACK_SIZE, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp) + .endif cli .endm @@ -904,7 +917,7 @@ KPROBE_ENTRY(debug) INTR_FRAME pushq $0 CFI_ADJUST_CFA_OFFSET 8 - paranoidentry do_debug + paranoidentry do_debug, DEBUG_IST jmp paranoid_exit CFI_ENDPROC .previous .text @@ -959,7 +972,12 @@ paranoid_schedule: CFI_ENDPROC KPROBE_ENTRY(int3) - zeroentry do_int3 + INTR_FRAME + pushq $0 + CFI_ADJUST_CFA_OFFSET 8 + paranoidentry do_int3, DEBUG_IST + jmp paranoid_exit + CFI_ENDPROC .previous .text ENTRY(overflow) |