[PATCH] kdump: Save trap information for later analysis
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>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index e458463..c6077a5 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -369,6 +369,10 @@
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;
@@ -379,9 +383,6 @@
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
@@ -494,6 +495,9 @@
}
put_cpu();
+ current->thread.error_code = error_code;
+ current->thread.trap_no = 13;
+
if (regs->eflags & VM_MASK)
goto gp_in_vm86;
@@ -897,9 +901,9 @@
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 --git a/arch/i386/mm/fault.c b/arch/i386/mm/fault.c
index a509237..92ed6c0 100644
--- a/arch/i386/mm/fault.c
+++ b/arch/i386/mm/fault.c
@@ -463,6 +463,9 @@
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);