From d95bc2501da97e2884b957c48df37c258a34db8d Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 19 Sep 2013 10:32:20 +0100 Subject: ARM: 7839/1: entry: fix tracing of ARM-private syscalls Commit 377747c40657 ("ARM: entry: allow ARM-private syscalls to be restarted") reworked the low-level syscall dispatcher to allow restarting of ARM-private syscalls. Unfortunately, this relocated the label used to dispatch a private syscall from the trace path, so that the invocation would be bypassed altogether! This causes applications to fail under strace as soon as they rely on a private syscall (e.g. set_tls): set_tls(0xb6fad4c0, 0xb6fadb98, 0xb6fb1050, 0xb6fad4c0, 0xb6fb1050) = -1 ENOSYS (Function not implemented) This patch fixes the label so that we correctly dispatch private syscalls from the trace path. Reported-by: Jason Gunthorpe Tested-by: Jason Gunthorpe Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/kernel/entry-common.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 74ad15d1a065..bc6bd9683ba4 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -442,10 +442,10 @@ local_restart: ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine add r1, sp, #S_OFF - cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE) +2: cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE) eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back bcs arm_syscall -2: mov why, #0 @ no longer a real syscall + mov why, #0 @ no longer a real syscall b sys_ni_syscall @ not private func #if defined(CONFIG_OABI_COMPAT) || !defined(CONFIG_AEABI) -- cgit v1.2.3 From 0c06a5d4b13cd66c833805a0d1db76b977944aac Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 10 Sep 2013 00:54:17 +0200 Subject: arm: Fix build error with context tracking calls ad65782fba50 (context_tracking: Optimize main APIs off case with static key) converted context tracking main APIs to inline function and left ARM asm callers behind. This can be easily fixed by making ARM calling the post static keys context tracking function. We just need to replicate the static key checks there. We'll remove these later when ARM will support the context tracking static keys. Reported-by: Guenter Roeck Reported-by: Russell King Signed-off-by: Frederic Weisbecker Tested-by: Kevin Hilman Cc: Nicolas Pitre Cc: Anil Kumar Cc: Tony Lindgren Cc: Benoit Cousson Cc: Guenter Roeck Cc: Russell King Cc: Kevin Hilman --- arch/arm/kernel/entry-header.S | 8 ++++---- kernel/context_tracking.c | 12 ++++++++++++ 2 files changed, 16 insertions(+), 4 deletions(-) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S index de23a9beed13..39f89fbd5111 100644 --- a/arch/arm/kernel/entry-header.S +++ b/arch/arm/kernel/entry-header.S @@ -329,10 +329,10 @@ #ifdef CONFIG_CONTEXT_TRACKING .if \save stmdb sp!, {r0-r3, ip, lr} - bl user_exit + bl context_tracking_user_exit ldmia sp!, {r0-r3, ip, lr} .else - bl user_exit + bl context_tracking_user_exit .endif #endif .endm @@ -341,10 +341,10 @@ #ifdef CONFIG_CONTEXT_TRACKING .if \save stmdb sp!, {r0-r3, ip, lr} - bl user_enter + bl context_tracking_user_enter ldmia sp!, {r0-r3, ip, lr} .else - bl user_enter + bl context_tracking_user_enter .endif #endif .endm diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c index 247091bf0587..859c8dfd78a1 100644 --- a/kernel/context_tracking.c +++ b/kernel/context_tracking.c @@ -50,6 +50,15 @@ void context_tracking_user_enter(void) { unsigned long flags; + /* + * Repeat the user_enter() check here because some archs may be calling + * this from asm and if no CPU needs context tracking, they shouldn't + * go further. Repeat the check here until they support the static key + * check. + */ + if (!static_key_false(&context_tracking_enabled)) + return; + /* * Some contexts may involve an exception occuring in an irq, * leading to that nesting: @@ -151,6 +160,9 @@ void context_tracking_user_exit(void) { unsigned long flags; + if (!static_key_false(&context_tracking_enabled)) + return; + if (in_interrupt()) return; -- cgit v1.2.3