[PATCH] rt: x86: extend signal send delay to 32 bit

From: Yang Shi
Date: Thu Dec 10 2015 - 14:18:51 EST


When running some ptrace single step tests on x86-32 machine, the below problem
is triggered:

BUG: sleeping function called from invalid context at linux-rt/kernel/locking/rtmutex.c:917
in_atomic(): 1, irqs_disabled(): 0, pid: 1041, name: dummy2
INFO: lockdep is turned off.
Preemption disabled at:[<c100326f>] do_debug+0x1f/0x1a0

CPU: 10 PID: 1041 Comm: dummy2 Tainted: G W 4.1.13-rt13 #1
Hardware name: Intel Corporation S5520HC/S5520HC, BIOS S5500.86B.01.10.0025.030220091519 03/02/2009
00000000 00000000 e1811e80 c1aa8306 00000000 e1811ea8 c1080517 c1d8b2e8
c100326f c100326f 00000411 e5b7d5b4 e1d521c4 00000005 e1811f74 e1811ec4
c1ab0eff e1d51cc0 e5b7d180 c1081403 e5b7d180 e5b7d180 e1811ee4 c1064b5a
Call Trace:
[<c1aa8306>] dump_stack+0x46/0x5c
[<c1080517>] ___might_sleep+0x137/0x220
[<c100326f>] ? do_debug+0x1f/0x1a0
[<c100326f>] ? do_debug+0x1f/0x1a0
[<c1ab0eff>] rt_spin_lock+0x1f/0x80
[<c1081403>] ? preempt_count_sub+0xb3/0x110
[<c1064b5a>] do_force_sig_info+0x2a/0xc0
[<c106567d>] force_sig_info+0xd/0x10
[<c1010cff>] send_sigtrap+0x6f/0x80
[<c10033b1>] do_debug+0x161/0x1a0
[<c1ab2921>] debug_stack_correct+0x2e/0x35

Signal send delay is just available for x86-64, x86-32 needs it too.

Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxx>
---
arch/x86/include/asm/signal.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/signal.h b/arch/x86/include/asm/signal.h
index b1b08a2..0e7bfe9 100644
--- a/arch/x86/include/asm/signal.h
+++ b/arch/x86/include/asm/signal.h
@@ -32,7 +32,7 @@ typedef struct {
* TIF_NOTIFY_RESUME and set up the signal to be sent on exit of the
* trap.
*/
-#if defined(CONFIG_PREEMPT_RT_FULL) && defined(CONFIG_X86_64)
+#if defined(CONFIG_PREEMPT_RT_FULL)
#define ARCH_RT_DELAYS_SIGNAL_SEND
#endif

--
2.0.2

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