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-rw-r--r--arch/ia64/kernel/jprobes.S27
-rw-r--r--arch/ia64/kernel/kprobes.c57
-rw-r--r--include/asm-ia64/kprobes.h6
3 files changed, 90 insertions, 0 deletions
diff --git a/arch/ia64/kernel/jprobes.S b/arch/ia64/kernel/jprobes.S
index 2323377e369..5cd6226f44f 100644
--- a/arch/ia64/kernel/jprobes.S
+++ b/arch/ia64/kernel/jprobes.S
@@ -60,3 +60,30 @@ END(jprobe_break)
GLOBAL_ENTRY(jprobe_inst_return)
br.call.sptk.many b0=jprobe_break
END(jprobe_inst_return)
+
+GLOBAL_ENTRY(invalidate_stacked_regs)
+ movl r16=invalidate_restore_cfm
+ ;;
+ mov b6=r16
+ ;;
+ br.ret.sptk.many b6
+ ;;
+invalidate_restore_cfm:
+ mov r16=ar.rsc
+ ;;
+ mov ar.rsc=r0
+ ;;
+ loadrs
+ ;;
+ mov ar.rsc=r16
+ ;;
+ br.cond.sptk.many rp
+END(invalidate_stacked_regs)
+
+GLOBAL_ENTRY(flush_register_stack)
+ // flush dirty regs to backing store (must be first in insn group)
+ flushrs
+ ;;
+ br.ret.sptk.many rp
+END(flush_register_stack)
+
diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c
index 346fedf9ea4..50ae8c7d453 100644
--- a/arch/ia64/kernel/kprobes.c
+++ b/arch/ia64/kernel/kprobes.c
@@ -766,11 +766,56 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
return ret;
}
+struct param_bsp_cfm {
+ unsigned long ip;
+ unsigned long *bsp;
+ unsigned long cfm;
+};
+
+static void ia64_get_bsp_cfm(struct unw_frame_info *info, void *arg)
+{
+ unsigned long ip;
+ struct param_bsp_cfm *lp = arg;
+
+ do {
+ unw_get_ip(info, &ip);
+ if (ip == 0)
+ break;
+ if (ip == lp->ip) {
+ unw_get_bsp(info, (unsigned long*)&lp->bsp);
+ unw_get_cfm(info, (unsigned long*)&lp->cfm);
+ return;
+ }
+ } while (unw_unwind(info) >= 0);
+ lp->bsp = 0;
+ lp->cfm = 0;
+ return;
+}
+
int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
{
struct jprobe *jp = container_of(p, struct jprobe, kp);
unsigned long addr = ((struct fnptr *)(jp->entry))->ip;
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ struct param_bsp_cfm pa;
+ int bytes;
+
+ /*
+ * Callee owns the argument space and could overwrite it, eg
+ * tail call optimization. So to be absolutely safe
+ * we save the argument space before transfering the control
+ * to instrumented jprobe function which runs in
+ * the process context
+ */
+ pa.ip = regs->cr_iip;
+ unw_init_running(ia64_get_bsp_cfm, &pa);
+ bytes = (char *)ia64_rse_skip_regs(pa.bsp, pa.cfm & 0x3f)
+ - (char *)pa.bsp;
+ memcpy( kcb->jprobes_saved_stacked_regs,
+ pa.bsp,
+ bytes );
+ kcb->bsp = pa.bsp;
+ kcb->cfm = pa.cfm;
/* save architectural state */
kcb->jprobe_saved_regs = *regs;
@@ -792,8 +837,20 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
{
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ int bytes;
+ /* restoring architectural state */
*regs = kcb->jprobe_saved_regs;
+
+ /* restoring the original argument space */
+ flush_register_stack();
+ bytes = (char *)ia64_rse_skip_regs(kcb->bsp, kcb->cfm & 0x3f)
+ - (char *)kcb->bsp;
+ memcpy( kcb->bsp,
+ kcb->jprobes_saved_stacked_regs,
+ bytes );
+ invalidate_stacked_regs();
+
preempt_enable_no_resched();
return 1;
}
diff --git a/include/asm-ia64/kprobes.h b/include/asm-ia64/kprobes.h
index a74b6810455..8c0fc227f0f 100644
--- a/include/asm-ia64/kprobes.h
+++ b/include/asm-ia64/kprobes.h
@@ -68,10 +68,14 @@ struct prev_kprobe {
unsigned long status;
};
+#define MAX_PARAM_RSE_SIZE (0x60+0x60/0x3f)
/* per-cpu kprobe control block */
struct kprobe_ctlblk {
unsigned long kprobe_status;
struct pt_regs jprobe_saved_regs;
+ unsigned long jprobes_saved_stacked_regs[MAX_PARAM_RSE_SIZE];
+ unsigned long *bsp;
+ unsigned long cfm;
struct prev_kprobe prev_kprobe;
};
@@ -118,5 +122,7 @@ extern int kprobe_exceptions_notify(struct notifier_block *self,
static inline void jprobe_return(void)
{
}
+extern void invalidate_stacked_regs(void);
+extern void flush_register_stack(void);
#endif /* _ASM_KPROBES_H */