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authorPaul Mackerras <paulus@samba.org>2006-06-07 16:15:39 +1000
committerPaul Mackerras <paulus@samba.org>2006-06-09 21:24:16 +1000
commite9370ae15dc2f8ba1e1889ce26f13cda565b6ecb (patch)
tree338ed732f7a6607bc168795008e244f180876cda
parentfab5db97e44f76461f76b24adfa8ccb14d4df498 (diff)
[PATCH] powerpc: Implement PR_[GS]ET_UNALIGN prctls for powerpc
This gives the ability to control whether alignment exceptions get fixed up or reported to the process as a SIGBUS, using the existing PR_SET_UNALIGN and PR_GET_UNALIGN prctls. We do not implement the option of logging a message on alignment exceptions. Signed-off-by: Paul Mackerras <paulus@samba.org>
-rw-r--r--arch/powerpc/kernel/process.c11
-rw-r--r--arch/powerpc/kernel/traps.c6
-rw-r--r--include/asm-powerpc/processor.h7
3 files changed, 22 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 2d35d83961b..e4732459c48 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -752,6 +752,17 @@ int get_endian(struct task_struct *tsk, unsigned long adr)
return put_user(val, (unsigned int __user *)adr);
}
+int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
+{
+ tsk->thread.align_ctl = val;
+ return 0;
+}
+
+int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
+{
+ return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
+}
+
#define TRUNC_PTR(x) ((typeof(x))(((unsigned long)(x)) & 0xffffffff))
int sys_clone(unsigned long clone_flags, unsigned long usp,
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 03def571549..91a6e04d974 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -805,9 +805,11 @@ void __kprobes program_check_exception(struct pt_regs *regs)
void alignment_exception(struct pt_regs *regs)
{
- int fixed;
+ int fixed = 0;
- fixed = fix_alignment(regs);
+ /* we don't implement logging of alignment exceptions */
+ if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS))
+ fixed = fix_alignment(regs);
if (fixed == 1) {
regs->nip += 4; /* skip over emulated instruction */
diff --git a/include/asm-powerpc/processor.h b/include/asm-powerpc/processor.h
index fa616326815..d2c2c95f913 100644
--- a/include/asm-powerpc/processor.h
+++ b/include/asm-powerpc/processor.h
@@ -149,6 +149,7 @@ struct thread_struct {
unsigned int val; /* Floating point status */
} fpscr;
int fpexc_mode; /* floating-point exception mode */
+ unsigned int align_ctl; /* alignment handling control */
#ifdef CONFIG_PPC64
unsigned long start_tb; /* Start purr when proc switched in */
unsigned long accum_tb; /* Total accumilated purr for process */
@@ -217,6 +218,12 @@ extern int set_fpexc_mode(struct task_struct *tsk, unsigned int val);
extern int get_endian(struct task_struct *tsk, unsigned long adr);
extern int set_endian(struct task_struct *tsk, unsigned int val);
+#define GET_UNALIGN_CTL(tsk, adr) get_unalign_ctl((tsk), (adr))
+#define SET_UNALIGN_CTL(tsk, val) set_unalign_ctl((tsk), (val))
+
+extern int get_unalign_ctl(struct task_struct *tsk, unsigned long adr);
+extern int set_unalign_ctl(struct task_struct *tsk, unsigned int val);
+
static inline unsigned int __unpack_fe01(unsigned long msr_bits)
{
return ((msr_bits & MSR_FE0) >> 10) | ((msr_bits & MSR_FE1) >> 8);