[PARISC] unwinder improvements
Add special-case handling for "handle_interruption" so that we can rewind
past the interruption. This is useful for seeing what caused a BUG() or
WARN_ON(); otherwise the unwind stops at the interruption.
Signed-off-by: Randolph Chung <tausq@debian.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
diff --git a/arch/parisc/kernel/unwind.c b/arch/parisc/kernel/unwind.c
index cad9d78..3221677 100644
--- a/arch/parisc/kernel/unwind.c
+++ b/arch/parisc/kernel/unwind.c
@@ -16,6 +16,8 @@
#include <asm/uaccess.h>
#include <asm/assembly.h>
+#include <asm/asm-offsets.h>
+#include <asm/ptrace.h>
#include <asm/unwind.h>
@@ -199,6 +201,29 @@
return 0;
}
+#ifdef CONFIG_64BIT
+#define get_func_addr(fptr) fptr[2]
+#else
+#define get_func_addr(fptr) fptr[0]
+#endif
+
+static int unwind_special(struct unwind_frame_info *info, unsigned long pc, int frame_size)
+{
+ void handle_interruption(int, struct pt_regs *);
+ static unsigned long *hi = (unsigned long)&handle_interruption;
+
+ if (pc == get_func_addr(hi)) {
+ struct pt_regs *regs = (struct pt_regs *)(info->sp - frame_size - PT_SZ_ALGN);
+ dbg("Unwinding through handle_interruption()\n");
+ info->prev_sp = regs->gr[30];
+ info->prev_ip = regs->iaoq[0];
+
+ return 1;
+ }
+
+ return 0;
+}
+
static void unwind_frame_regs(struct unwind_frame_info *info)
{
const struct unwind_table_entry *e;
@@ -312,13 +337,15 @@
}
}
- info->prev_sp = info->sp - frame_size;
- if (e->Millicode)
- info->rp = info->r31;
- else if (rpoffset)
- info->rp = *(unsigned long *)(info->prev_sp - rpoffset);
- info->prev_ip = info->rp;
- info->rp = 0;
+ if (!unwind_special(info, e->region_start, frame_size)) {
+ info->prev_sp = info->sp - frame_size;
+ if (e->Millicode)
+ info->rp = info->r31;
+ else if (rpoffset)
+ info->rp = *(unsigned long *)(info->prev_sp - rpoffset);
+ info->prev_ip = info->rp;
+ info->rp = 0;
+ }
dbg("analyzing func @ %lx, setting prev_sp=%lx "
"prev_ip=%lx npc=%lx\n", info->ip, info->prev_sp,