From: Alexander Nyberg <alexn@telia.com>
If we are faulting in kernel it is quite possible this will lead to a
panic. Save trap number, cr2 (in case of page fault) and error_code in the
current thread (these fields already exist for signal delivery but are not
used here).
This helps later kdump crash analyzing from user-space (a script has been
submitted to dig this info out in gdb).
Signed-off-by: Alexander Nyberg <alexn@telia.com>
Cc: <fastboot@lists.osdl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
arch/i386/kernel/traps.c | 12 ++++++++----
arch/i386/mm/fault.c | 3 +++
2 files changed, 11 insertions(+), 4 deletions(-)
diff -puN arch/i386/kernel/traps.c~kdump-save-trap-information-for-later-analysis arch/i386/kernel/traps.c
--- 25/arch/i386/kernel/traps.c~kdump-save-trap-information-for-later-analysis 2005-06-18 02:55:57.000000000 -0700
+++ 25-akpm/arch/i386/kernel/traps.c 2005-06-18 02:55:57.000000000 -0700
@@ -411,6 +411,10 @@ static inline void die_if_kernel(const c
static void do_trap(int trapnr, int signr, char *str, int vm86,
struct pt_regs * regs, long error_code, siginfo_t *info)
{
+ struct task_struct *tsk = current;
+ tsk->thread.error_code = error_code;
+ tsk->thread.trap_no = trapnr;
+
if (regs->eflags & VM_MASK) {
if (vm86)
goto vm86_trap;
@@ -421,9 +425,6 @@ static void do_trap(int trapnr, int sign
goto kernel_trap;
trap_signal: {
- struct task_struct *tsk = current;
- tsk->thread.error_code = error_code;
- tsk->thread.trap_no = trapnr;
if (info)
force_sig_info(signr, info, tsk);
else
@@ -538,6 +539,9 @@ fastcall void do_general_protection(stru
}
put_cpu();
+ current->thread.error_code = error_code;
+ current->thread.trap_no = 13;
+
if (regs->eflags & VM_MASK)
goto gp_in_vm86;
@@ -983,9 +987,9 @@ fastcall void do_simd_coprocessor_error(
error_code);
return;
}
- die_if_kernel("cache flush denied", regs, error_code);
current->thread.trap_no = 19;
current->thread.error_code = error_code;
+ die_if_kernel("cache flush denied", regs, error_code);
force_sig(SIGSEGV, current);
}
}
diff -puN arch/i386/mm/fault.c~kdump-save-trap-information-for-later-analysis arch/i386/mm/fault.c
--- 25/arch/i386/mm/fault.c~kdump-save-trap-information-for-later-analysis 2005-06-18 02:55:57.000000000 -0700
+++ 25-akpm/arch/i386/mm/fault.c 2005-06-18 02:55:57.000000000 -0700
@@ -469,6 +469,9 @@ no_context:
printk(KERN_ALERT "*pte = %08lx\n", page);
}
#endif
+ tsk->thread.cr2 = address;
+ tsk->thread.trap_no = 14;
+ tsk->thread.error_code = error_code;
die("Oops", regs, error_code);
bust_spinlocks(0);
do_exit(SIGKILL);
_