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authorDavid S. Miller <davem@davemloft.net>2008-12-28 20:19:47 -0800
committerDavid S. Miller <davem@davemloft.net>2008-12-28 20:19:47 -0800
commite3c6d4ee545e427b55882d97d3b663c6411645fe (patch)
tree294326663fb757739a98083c2ddd570d1eaf7337 /arch/arm/mm
parent5bc053089376217943187ed5153d0d1e5c5085b6 (diff)
parent3c92ec8ae91ecf59d88c798301833d7cf83f2179 (diff)
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts: arch/sparc64/kernel/idprom.c
Diffstat (limited to 'arch/arm/mm')
-rw-r--r--arch/arm/mm/alignment.c26
-rw-r--r--arch/arm/mm/fault.c1
2 files changed, 24 insertions, 3 deletions
diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c
index 133e65d166b..2d5884ce043 100644
--- a/arch/arm/mm/alignment.c
+++ b/arch/arm/mm/alignment.c
@@ -70,6 +70,10 @@ static unsigned long ai_dword;
static unsigned long ai_multi;
static int ai_usermode;
+#define UM_WARN (1 << 0)
+#define UM_FIXUP (1 << 1)
+#define UM_SIGNAL (1 << 2)
+
#ifdef CONFIG_PROC_FS
static const char *usermode_action[] = {
"ignored",
@@ -754,7 +758,7 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
user:
ai_user += 1;
- if (ai_usermode & 1)
+ if (ai_usermode & UM_WARN)
printk("Alignment trap: %s (%d) PC=0x%08lx Instr=0x%0*lx "
"Address=0x%08lx FSR 0x%03x\n", current->comm,
task_pid_nr(current), instrptr,
@@ -762,10 +766,10 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
thumb_mode(regs) ? tinstr : instr,
addr, fsr);
- if (ai_usermode & 2)
+ if (ai_usermode & UM_FIXUP)
goto fixup;
- if (ai_usermode & 4)
+ if (ai_usermode & UM_SIGNAL)
force_sig(SIGBUS, current);
else
set_cr(cr_no_alignment);
@@ -796,6 +800,22 @@ static int __init alignment_init(void)
res->write_proc = proc_alignment_write;
#endif
+ /*
+ * ARMv6 and later CPUs can perform unaligned accesses for
+ * most single load and store instructions up to word size.
+ * LDM, STM, LDRD and STRD still need to be handled.
+ *
+ * Ignoring the alignment fault is not an option on these
+ * CPUs since we spin re-faulting the instruction without
+ * making any progress.
+ */
+ if (cpu_architecture() >= CPU_ARCH_ARMv6 && (cr_alignment & CR_U)) {
+ cr_alignment &= ~CR_A;
+ cr_no_alignment &= ~CR_A;
+ set_cr(cr_alignment);
+ ai_usermode = UM_FIXUP;
+ }
+
hook_fault_code(1, do_alignment, SIGILL, "alignment exception");
hook_fault_code(3, do_alignment, SIGILL, "alignment exception");
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 2df8d9facf5..22c9530e91e 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -11,6 +11,7 @@
#include <linux/module.h>
#include <linux/signal.h>
#include <linux/mm.h>
+#include <linux/hardirq.h>
#include <linux/init.h>
#include <linux/kprobes.h>
#include <linux/uaccess.h>