x86: print which shared library/executable faulted in segfault etc. messages v3

They now look like:

hal-resmgr[13791]: segfault at 3c rip 2b9c8caec182 rsp 7fff1e825d30 error 4 in libacl.so.1.1.0[2b9c8caea000+6000]

This makes it easier to pinpoint bugs to specific libraries.

And printing the offset into a mapping also always allows to find the
correct fault point in a library even with randomized mappings. Previously
there was no way to actually find the correct code address inside
the randomized mapping.

Relies on earlier patch to shorten the printk formats.

They are often now longer than 80 characters, but I think that's worth it.

[includes fix from Eric Dumazet to check d_path error value]

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 5 insertions, 2 deletions

diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps_32.c
index 6f3bb287c702..270cfd483160 100644
--- a/arch/x86/kernel/traps_32.c
+++ b/arch/x86/kernel/traps_32.c
@@ -609,11 +609,14 @@ void __kprobes do_general_protection(struct pt_regs * regs,
         current->thread.error_code = error_code;
         current->thread.trap_no = 13;
         if (show_unhandled_signals && unhandled_signal(current, SIGSEGV) &&
-            printk_ratelimit())
+            printk_ratelimit()) {
                 printk(KERN_INFO
-                    "%s[%d] general protection ip:%lx sp:%lx error:%lx\n",
+                    "%s[%d] general protection ip:%lx sp:%lx error:%lx",
                     current->comm, task_pid_nr(current),
                     regs->ip, regs->sp, error_code);
+                print_vma_addr(" in ", regs->ip);
+                printk("\n");
+        }
 
         force_sig(SIGSEGV, current);
         return;