From: jistone@redhat.com (Josh Stone)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: enable_irq before ret_fast_syscall tracing
Date: Mon, 22 Jun 2015 17:08:54 -0700 [thread overview]
Message-ID: <1435018134-9653-1-git-send-email-jistone@redhat.com> (raw)
In-Reply-To: <20150604100625.GI7557@n2100.arm.linux.org.uk>
When reached via the slow path __sys_trace, __sys_trace_return and its
callees usually have interrupts still enabled. This is important if any
will schedule, like for a ptrace syscall-exit-stop.
In the rarer case where tracing was not enabled on syscall entry, and
then ret_fast_syscall sees tracing was enabled mid-syscall, then it
also ought to branch to __sys_trace_return with interrupts enabled.
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Josh Stone <jistone@redhat.com>
---
arch/arm/kernel/entry-common.S | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 4e7f40c577e6..5d8eb11b8571 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -35,7 +35,7 @@ ret_fast_syscall:
disable_irq @ disable interrupts
ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing
tst r1, #_TIF_SYSCALL_WORK
- bne __sys_trace_return
+ bne ret_fast_syscall_trace
tst r1, #_TIF_WORK_MASK
bne fast_work_pending
asm_trace_hardirqs_on
@@ -45,6 +45,10 @@ ret_fast_syscall:
ct_user_enter
restore_user_regs fast = 1, offset = S_OFF
+
+ret_fast_syscall_trace:
+ enable_irq @ enable interrupts
+ b __sys_trace_return
UNWIND(.fnend )
/*
--
2.4.2
next prev parent reply other threads:[~2015-06-23 0:08 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-14 19:13 arm syscall fast path can miss a ptrace syscall-exit Josh Stone
2015-05-14 19:35 ` Russell King - ARM Linux
2015-05-14 21:08 ` Josh Stone
2015-05-26 22:38 ` Josh Stone
2015-05-28 10:37 ` Russell King - ARM Linux
2015-05-29 20:13 ` Josh Stone
2015-06-01 10:24 ` Will Deacon
2015-06-03 1:01 ` [PATCH] arm64: fix missing syscall trace exit Josh Stone
2015-06-03 1:11 ` Josh Stone
2015-06-03 9:52 ` Will Deacon
2015-06-03 20:03 ` Josh Stone
2015-06-04 10:06 ` Russell King - ARM Linux
2015-06-04 17:14 ` Josh Stone
2015-06-04 23:17 ` Josh Stone
2015-06-05 15:38 ` Will Deacon
2015-06-05 17:52 ` Tom Lendacky
2015-06-05 21:28 ` Josh Stone
2015-06-08 10:21 ` Will Deacon
2015-06-08 16:37 ` Josh Stone
2015-06-08 16:43 ` Catalin Marinas
2015-06-23 0:08 ` Josh Stone [this message]
2015-06-23 0:15 ` [PATCH] ARM: enable_irq before ret_fast_syscall tracing Josh Stone
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