From 1e7e3211854507d6c2695126d6d30a7762cf4006 Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 4 Jul 2014 14:32:43 +0100 Subject: ARM: alignment: save last kernel aligned fault location Save and report (via the procfs file) the last kernel unaligned fault location. This allows us to trivially inspect where the last fault happened for cases which we don't expect to occur. Since we expect the kernel to generate misalignment faults (due to the networking layer), even when warnings are enabled, we don't log them for the kernel. Tested-by: Tony Lindgren Acked-by: Catalin Marinas Signed-off-by: Russell King --- arch/arm/mm/alignment.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/arm/mm/alignment.c') diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c index b8cb1a2688a0..0c1ab49e5f7b 100644 --- a/arch/arm/mm/alignment.c +++ b/arch/arm/mm/alignment.c @@ -76,6 +76,7 @@ static unsigned long ai_user; static unsigned long ai_sys; +static void *ai_sys_last_pc; static unsigned long ai_skipped; static unsigned long ai_half; static unsigned long ai_word; @@ -130,7 +131,7 @@ static const char *usermode_action[] = { static int alignment_proc_show(struct seq_file *m, void *v) { seq_printf(m, "User:\t\t%lu\n", ai_user); - seq_printf(m, "System:\t\t%lu\n", ai_sys); + seq_printf(m, "System:\t\t%lu (%pF)\n", ai_sys, ai_sys_last_pc); seq_printf(m, "Skipped:\t%lu\n", ai_skipped); seq_printf(m, "Half:\t\t%lu\n", ai_half); seq_printf(m, "Word:\t\t%lu\n", ai_word); @@ -794,6 +795,7 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs) goto user; ai_sys += 1; + ai_sys_last_pc = (void *)instruction_pointer(regs); fixup: -- cgit v1.2.3 From 5ca918e5e3f9df4634077c06585c42bc6a8d699a Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Thu, 25 Sep 2014 11:56:19 +0100 Subject: ARM: 8165/1: alignment: don't break misaligned NEON load/store The alignment fixup incorrectly decodes faulting ARM VLDn/VSTn instructions (where the optional alignment hint is given but incorrect) as LDR/STR, leading to register corruption. Detect these and correctly treat them as unhandled, so that userspace gets the fault it expects. Reported-by: Simon Hosie Signed-off-by: Robin Murphy Cc: Signed-off-by: Russell King --- arch/arm/mm/alignment.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/arm/mm/alignment.c') diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c index 0c1ab49e5f7b..83792f4324ea 100644 --- a/arch/arm/mm/alignment.c +++ b/arch/arm/mm/alignment.c @@ -41,6 +41,7 @@ * This code is not portable to processors with late data abort handling. */ #define CODING_BITS(i) (i & 0x0e000000) +#define COND_BITS(i) (i & 0xf0000000) #define LDST_I_BIT(i) (i & (1 << 26)) /* Immediate constant */ #define LDST_P_BIT(i) (i & (1 << 24)) /* Preindex */ @@ -821,6 +822,8 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs) break; case 0x04000000: /* ldr or str immediate */ + if (COND_BITS(instr) == 0xf0000000) /* NEON VLDn, VSTn */ + goto bad; offset.un = OFFSET_BITS(instr); handler = do_alignment_ldrstr; break; -- cgit v1.2.3