kernel/git/stable/linux.git/arch/arm, branch linux-2.6.32.y

ARM: 7670/1: fix the memset fix

2014-11-23T09:55:51+00:00

Commit 455bd4c430b0 ("ARM: 7668/1: fix memset-related crashes caused by recent GCC (4.7.2) optimizations") attempted to fix a compliance issue with the memset return value. However the memset itself became broken by that patch for misaligned pointers. This fixes the above by branching over the entry code from the misaligned fixup code to avoid reloading the original pointer. Also, because the function entry alignment is wrong in the Thumb mode compilation, that fixup code is moved to the end. While at it, the entry instructions are slightly reworked to help dual issue pipelines. Signed-off-by: Nicolas Pitre Tested-by: Alexander Holler Signed-off-by: Russell King (cherry picked from commit 418df63adac56841ef6b0f1fcf435bc64d4ed177) Signed-off-by: Willy Tarreau

ARM: 7668/1: fix memset-related crashes caused by recent GCC (4.7.2) optimizations

2014-11-23T09:55:50+00:00

Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on assumptions about the implementation of memset and similar functions. The current ARM optimized memset code does not return the value of its first argument, as is usually expected from standard implementations. For instance in the following function: void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) { memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter)); waiter->magic = waiter; INIT_LIST_HEAD(&waiter->list); } compiled as: 800554d0 : 800554d0: e92d4008 push {r3, lr} 800554d4: e1a00001 mov r0, r1 800554d8: e3a02010 mov r2, #16 ; 0x10 800554dc: e3a01011 mov r1, #17 ; 0x11 800554e0: eb04426e bl 80165ea0 800554e4: e1a03000 mov r3, r0 800554e8: e583000c str r0, [r3, #12] 800554ec: e5830000 str r0, [r3] 800554f0: e5830004 str r0, [r3, #4] 800554f4: e8bd8008 pop {r3, pc} GCC assumes memset returns the value of pointer 'waiter' in register r0; causing register/memory corruptions. This patch fixes the return value of the assembly version of memset. It adds a 'mov' instruction and merges an additional load+store into existing load/store instructions. For ease of review, here is a breakdown of the patch into 4 simple steps: Step 1 ====== Perform the following substitutions: ip -> r8, then r0 -> ip, and insert 'mov ip, r0' as the first statement of the function. At this point, we have a memset() implementation returning the proper result, but corrupting r8 on some paths (the ones that were using ip). Step 2 ====== Make sure r8 is saved and restored when (! CALGN(1)+0) == 1: save r8: - str lr, [sp, #-4]! + stmfd sp!, {r8, lr} and restore r8 on both exit paths: - ldmeqfd sp!, {pc} @ Now <64 bytes to go. + ldmeqfd sp!, {r8, pc} @ Now <64 bytes to go. (...) tst r2, #16 stmneia ip!, {r1, r3, r8, lr} - ldr lr, [sp], #4 + ldmfd sp!, {r8, lr} Step 3 ====== Make sure r8 is saved and restored when (! CALGN(1)+0) == 0: save r8: - stmfd sp!, {r4-r7, lr} + stmfd sp!, {r4-r8, lr} and restore r8 on both exit paths: bgt 3b - ldmeqfd sp!, {r4-r7, pc} + ldmeqfd sp!, {r4-r8, pc} (...) tst r2, #16 stmneia ip!, {r4-r7} - ldmfd sp!, {r4-r7, lr} + ldmfd sp!, {r4-r8, lr} Step 4 ====== Rewrite register list "r4-r7, r8" as "r4-r8". Signed-off-by: Ivan Djelic Reviewed-by: Nicolas Pitre Signed-off-by: Dirk Behme Signed-off-by: Russell King (cherry picked from commit 455bd4c430b0c0a361f38e8658a0d6cb469942b5) Signed-off-by: Willy Tarreau

signal: Define __ARCH_HAS_SA_RESTORER so we know whether to clear sa_restorer

2013-06-10T09:42:21+00:00

Vaguely based on upstream commit 574c4866e33d 'consolidate kernel-side struct sigaction declarations'. flush_signal_handlers() needs to know whether sigaction::sa_restorer is defined, not whether SA_RESTORER is defined. Define the __ARCH_HAS_SA_RESTORER macro to indicate this. Signed-off-by: Ben Hutchings Cc: Al Viro Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau

ARM: 7410/1: Add extra clobber registers for assembly in kernel_execve

2012-10-07T21:37:48+00:00

commit e787ec1376e862fcea1bfd523feb7c5fb43ecdb9 upstream. The inline assembly in kernel_execve() uses r8 and r9. Since this code sequence does not return, it usually doesn't matter if the register clobber list is accurate. However, I saw a case where a particular version of gcc used r8 as an intermediate for the value eventually passed to r9. Because r8 is used in the inline assembly, and not mentioned in the clobber list, r9 was set to an incorrect value. This resulted in a kernel panic on execution of the first user-space program in the system. r9 is used in ret_to_user as the thread_info pointer, and if it's wrong, bad things happen. Signed-off-by: Tim Bird Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman Signed-off-by: Willy Tarreau

ARM: 7325/1: fix v7 boot with lockdep enabled

2012-03-04T17:49:21+00:00

commit 8e43a905dd574f54c5715d978318290ceafbe275 upstream. Bootup with lockdep enabled has been broken on v7 since b46c0f74657d ("ARM: 7321/1: cache-v7: Disable preemption when reading CCSIDR"). This is because v7_setup (which is called very early during boot) calls v7_flush_dcache_all, and the save_and_disable_irqs added by that patch ends up attempting to call into lockdep C code (trace_hardirqs_off()) when we are in no position to execute it (no stack, MMU off). Fix this by using a notrace variant of save_and_disable_irqs. The code already uses the notrace variant of restore_irqs. Reviewed-by: Nicolas Pitre Acked-by: Stephen Boyd Cc: Catalin Marinas Signed-off-by: Rabin Vincent Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman

ARM: 7321/1: cache-v7: Disable preemption when reading CCSIDR

2012-03-04T17:49:21+00:00

commit b46c0f74657d1fe1c1b0c1452631cc38a9e6987f upstream. armv7's flush_cache_all() flushes caches via set/way. To determine the cache attributes (line size, number of sets, etc.) the assembly first writes the CSSELR register to select a cache level and then reads the CCSIDR register. The CSSELR register is banked per-cpu and is used to determine which cache level CCSIDR reads. If the task is migrated between when the CSSELR is written and the CCSIDR is read the CCSIDR value may be for an unexpected cache level (for example L1 instead of L2) and incorrect cache flushing could occur. Disable interrupts across the write and read so that the correct cache attributes are read and used for the cache flushing routine. We disable interrupts instead of disabling preemption because the critical section is only 3 instructions and we want to call v7_dcache_flush_all from __v7_setup which doesn't have a full kernel stack with a struct thread_info. This fixes a problem we see in scm_call() when flush_cache_all() is called from preemptible context and sometimes the L2 cache is not properly flushed out. Signed-off-by: Stephen Boyd Acked-by: Catalin Marinas Reviewed-by: Nicolas Pitre Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman

ARM:imx:fix pwm period value

2012-01-06T23:38:02+00:00

commit 5776ac2eb33164c77cdb4d2b48feee15616eaba3 upstream. According to imx pwm RM, the real period value should be PERIOD value in PWMPR plus 2. PWMO (Hz) = PCLK(Hz) / (period +2) Signed-off-by: Jason Chen Signed-off-by: Sascha Hauer Signed-off-by: Greg Kroah-Hartman

MXC PWM: should active during DOZE/WAIT/DBG mode

2012-01-06T23:38:01+00:00

commit c0d96aed8c6dd925afe9ea35491a0cd458642a86 upstream. Signed-off-by: Jason Chen Signed-off-by: Sascha Hauer Signed-off-by: Greg Kroah-Hartman

ARM: davinci: dm646x evm: wrong register used in setup_vpif_input_channel_mode

2011-12-21T21:04:51+00:00

commit 83713fc9373be2e943f82e9d36213708c6b0050e upstream. The function setup_vpif_input_channel_mode() used the VSCLKDIS register instead of VIDCLKCTL. This meant that when in HD mode videoport channel 0 used a different clock from channel 1. Clearly a copy-and-paste error. Signed-off-by: Hans Verkuil Acked-by: Manjunath Hadli Signed-off-by: Sekhar Nori Signed-off-by: Greg Kroah-Hartman

ARM: 7161/1: errata: no automatic store buffer drain

2011-12-09T17:21:36+00:00

commit 11ed0ba1754841316d4095478944300acf19acc3 upstream. This patch implements a workaround for PL310 erratum 769419. On revisions of the PL310 prior to r3p2, the Store Buffer does not automatically drain. This can cause normal, non-cacheable writes to be retained when the memory system is idle, leading to suboptimal I/O performance for drivers using coherent DMA. This patch adds an optional wmb() call to the cpu_idle loop. On systems with an outer cache, this causes an explicit flush of the store buffer. Acked-by: Catalin Marinas Tested-by: Marc Zyngier Signed-off-by: Will Deacon Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman