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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-29 09:38:44 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-29 09:38:44 -0700
commita879cbbb34cbecfa9707fbb6e5a00c503ac1ecb9 (patch)
treefdf247f8dedea8f04d0989aeab6922ed073eee11 /arch/i386/kernel
parentc06fec5022ebe014af876da2df4a0eee836e97c8 (diff)
x86: make traps on 'iret' be debuggable in user space
This makes a trap on the 'iret' that returns us to user space cause a nice clean SIGSEGV, instead of just a hard (and silent) exit. That way a debugger can actually try to see what happened, and we also properly notify everybody who might be interested about us being gone. This loses the error code, but tells the debugger what happened with ILL_BADSTK in the siginfo.
Diffstat (limited to 'arch/i386/kernel')
-rw-r--r--arch/i386/kernel/entry.S8
-rw-r--r--arch/i386/kernel/traps.c1
2 files changed, 4 insertions, 5 deletions
diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index 3c73dc865ea..fe1918cc68d 100644
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -260,11 +260,9 @@ restore_nocheck:
.section .fixup,"ax"
iret_exc:
sti
- movl $__USER_DS, %edx
- movl %edx, %ds
- movl %edx, %es
- movl $11,%eax
- call do_exit
+ pushl $0 # no error code
+ pushl $do_iret_error
+ jmp error_code
.previous
.section __ex_table,"a"
.align 4
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index 6c0e383915b..d70819481f6 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -451,6 +451,7 @@ DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
+DO_ERROR_INFO(32, SIGSEGV, "iret exception", iret_error, ILL_BADSTK, 0)
fastcall void do_general_protection(struct pt_regs * regs, long error_code)
{