linux-kernel - [PATCH 2/2] ARM: Enable tracing around vfp preemption enable/disable

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1362436983-28988-3-git-send-email-sboyd@codeaurora.org>
Date:	Mon,  4 Mar 2013 14:43:03 -0800
From:	Stephen Boyd <sboyd@...eaurora.org>
To:	linux-arm-kernel@...ts.infradead.org
Cc:	linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org
Subject: [PATCH 2/2] ARM: Enable tracing around vfp preemption enable/disable

The VFP code enables and disables preemption but doesn't call
into the tracer except for in the VFP bounce code to say that
preemption has been enabled again. Trace the preemption disable
and enable calls made in assembly so that we can accurately
measure how long preemption is disabled while handling VFP
exceptions.

Signed-off-by: Stephen Boyd <sboyd@...eaurora.org>
---
 arch/arm/kernel/entry-header.S | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index 130e6a6..75bcb18 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -165,19 +165,33 @@
 
 	.macro preempt_enable_no_resched, tsk, cnt
 #ifdef CONFIG_PREEMPT_COUNT
+#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
+	stmdb   sp!, {r0-r3, ip, lr}
+	mov	r0, #1
+	bl	sub_preempt_count
+	ldmia	sp!, {r0-r3, ip, lr}
+#else
 	get_thread_info	\tsk
 	ldr	\cnt, [\tsk, #TI_PREEMPT]	@ get preempt count
 	sub	\cnt, \cnt, #1			@ decrement it
 	str	\cnt, [\tsk, #TI_PREEMPT]
 #endif
+#endif
 	.endm
 
 	.macro preempt_disable, tsk, cnt
 #ifdef CONFIG_PREEMPT_COUNT
+#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
+	stmdb   sp!, {r0-r3, ip, lr}
+	mov	r0, #1
+	bl	add_preempt_count
+	ldmia	sp!, {r0-r3, ip, lr}
+#else
 	ldr	\cnt, [\tsk, #TI_PREEMPT]	@ get preempt count
 	add	\cnt, \cnt, #1			@ increment it
 	str	\cnt, [\tsk, #TI_PREEMPT]
 #endif
+#endif
 	.endm
 
 /*
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/