arch/tile: support signal "exception-trace" hook
This change adds support for /proc/sys/debug/exception-trace to tile.
Like x86 and sparc, by default it is set to "1", generating a one-line
printk whenever a user process crashes. By setting it to "2", we get
a much more complete userspace diagnostic at crash time, including
a user-space backtrace, register dump, and memory dump around the
address of the crash.
Some vestiges of the Tilera-internal version of this support are
removed with this patch (the show_crashinfo variable and the
arch_coredump_signal function). We retain a "crashinfo" boot parameter
which allows you to set the boot-time value of exception-trace.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c
index 24ca54a..25b7b90 100644
--- a/arch/tile/mm/fault.c
+++ b/arch/tile/mm/fault.c
@@ -43,8 +43,11 @@
#include <arch/interrupts.h>
-static noinline void force_sig_info_fault(int si_signo, int si_code,
- unsigned long address, int fault_num, struct task_struct *tsk)
+static noinline void force_sig_info_fault(const char *type, int si_signo,
+ int si_code, unsigned long address,
+ int fault_num,
+ struct task_struct *tsk,
+ struct pt_regs *regs)
{
siginfo_t info;
@@ -59,6 +62,7 @@
info.si_code = si_code;
info.si_addr = (void __user *)address;
info.si_trapno = fault_num;
+ trace_unhandled_signal(type, regs, address, si_signo);
force_sig_info(si_signo, &info, tsk);
}
@@ -71,11 +75,12 @@
struct pt_regs *, regs)
{
if (address >= PAGE_OFFSET)
- force_sig_info_fault(SIGSEGV, SEGV_MAPERR, address,
- INT_DTLB_MISS, current);
+ force_sig_info_fault("atomic segfault", SIGSEGV, SEGV_MAPERR,
+ address, INT_DTLB_MISS, current, regs);
else
- force_sig_info_fault(SIGBUS, BUS_ADRALN, address,
- INT_UNALIGN_DATA, current);
+ force_sig_info_fault("atomic alignment fault", SIGBUS,
+ BUS_ADRALN, address,
+ INT_UNALIGN_DATA, current, regs);
/*
* Adjust pc to point at the actual instruction, which is unusual
@@ -471,8 +476,8 @@
*/
local_irq_enable();
- force_sig_info_fault(SIGSEGV, si_code, address,
- fault_num, tsk);
+ force_sig_info_fault("segfault", SIGSEGV, si_code, address,
+ fault_num, tsk, regs);
return 0;
}
@@ -547,7 +552,8 @@
if (is_kernel_mode)
goto no_context;
- force_sig_info_fault(SIGBUS, BUS_ADRERR, address, fault_num, tsk);
+ force_sig_info_fault("bus error", SIGBUS, BUS_ADRERR, address,
+ fault_num, tsk, regs);
return 0;
}