2016-03-10 12:20:17

by Jianyu Zhan

[permalink] [raw]
Subject: [PATCH RFC] x86/traps: show unhandled signal for i386 in do_trap()

Commit abd4f7505baf ("x86: i386-show-unhandled-signals-v3") did turn on
the showing-unhandled-signal behaviour for i386 for some exception handlers,
but for no reason do_trap() is left out(my naive guess is because turning it on
for do_trap() would be too noisy since do_trap() is shared by several exceptions).

And since the same commit make "show_unhandled_signals" a debug tunable(in
/proc/sys/debug/exception-trace), and x86 by default turning it on. So it would be
strange for i386 users who turing it on manually and expect seeing the unhandled signal
output in log, but nothing.

This patch turns it on for i386 in do_trap().

Signed-off-by: Jianyu Zhan <[email protected]>
---
arch/x86/kernel/traps.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index ade185a..ef54dbb 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -262,7 +262,6 @@ do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
tsk->thread.error_code = error_code;
tsk->thread.trap_nr = trapnr;

-#ifdef CONFIG_X86_64
if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
printk_ratelimit()) {
pr_info("%s[%d] trap %s ip:%lx sp:%lx error:%lx",
@@ -271,7 +270,6 @@ do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
print_vma_addr(" in ", regs->ip);
pr_cont("\n");
}
-#endif

force_sig_info(signr, info ?: SEND_SIG_PRIV, tsk);
}
--
2.4.3


2016-03-10 13:40:41

by Jan Beulich

[permalink] [raw]
Subject: Re: [PATCH RFC] x86/traps: show unhandled signal for i386 in do_trap()

>>> On 10.03.16 at 13:19, <[email protected]> wrote:
> Commit abd4f7505baf ("x86: i386-show-unhandled-signals-v3") did turn on
> the showing-unhandled-signal behaviour for i386 for some exception handlers,
> but for no reason do_trap() is left out(my naive guess is because turning it
> on
> for do_trap() would be too noisy since do_trap() is shared by several
> exceptions).
>
> And since the same commit make "show_unhandled_signals" a debug tunable(in
> /proc/sys/debug/exception-trace), and x86 by default turning it on. So it
> would be
> strange for i386 users who turing it on manually and expect seeing the
> unhandled signal
> output in log, but nothing.
>
> This patch turns it on for i386 in do_trap().
>
> Signed-off-by: Jianyu Zhan <[email protected]>

I've been carrying this patch for years, without ever being able to
decide whether the distinction between 32-bit and 64-bit was
intentional.

Reviewed-by: Jan Beulich <[email protected]>

Subject: [tip:x86/asm] x86/entry/traps: Show unhandled signal for i386 in do_trap()

Commit-ID: 10ee73865e9e4705ba8b3f4d6149e8e68d902bb7
Gitweb: http://git.kernel.org/tip/10ee73865e9e4705ba8b3f4d6149e8e68d902bb7
Author: Jianyu Zhan <[email protected]>
AuthorDate: Thu, 10 Mar 2016 20:19:58 +0800
Committer: Ingo Molnar <[email protected]>
CommitDate: Thu, 10 Mar 2016 18:37:25 +0100

x86/entry/traps: Show unhandled signal for i386 in do_trap()

Commit abd4f7505baf ("x86: i386-show-unhandled-signals-v3") did turn on
the showing-unhandled-signal behaviour for i386 for some exception handlers,
but for no reason do_trap() is left out (my naive guess is because turning it on
for do_trap() would be too noisy since do_trap() is shared by several exceptions).

And since the same commit make "show_unhandled_signals" a debug tunable(in
/proc/sys/debug/exception-trace), and x86 by default turning it on.

So it would be strange for i386 users who turing it on manually and expect
seeing the unhandled signal output in log, but nothing.

This patch turns it on for i386 in do_trap() as well.

Signed-off-by: Jianyu Zhan <[email protected]>
Reviewed-by: Jan Beulich <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
arch/x86/kernel/traps.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 5fae2d8..1baf081 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -248,7 +248,6 @@ do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
tsk->thread.error_code = error_code;
tsk->thread.trap_nr = trapnr;

-#ifdef CONFIG_X86_64
if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
printk_ratelimit()) {
pr_info("%s[%d] trap %s ip:%lx sp:%lx error:%lx",
@@ -257,7 +256,6 @@ do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
print_vma_addr(" in ", regs->ip);
pr_cont("\n");
}
-#endif

force_sig_info(signr, info ?: SEND_SIG_PRIV, tsk);
}