[Crash-utility] [PATCH] arm64: support compat user mode prstatus
compat user mode prstatus already just works, almost. This missing
pieces are that pt_regs->sp and pt_regs->fp are not in their usual
locations. We need to pull them out of their architecturally mapped
general purpose registers.
---
arm64.c | 42 ++++++++++++++++++++++++++++++++++--------
1 file changed, 34 insertions(+), 8 deletions(-)
diff --git a/arm64.c b/arm64.c
index 183e768498fe8..3a82d20cdd465 100644
--- a/arm64.c
+++ b/arm64.c
@@ -993,6 +993,25 @@ arm64_stackframe_init(void)
#define PSR_MODE_EL3h 0x0000000d
#define PSR_MODE_MASK 0x0000000f
+/* Architecturally defined mapping between AArch32 and AArch64 registers */
+#define compat_usr(x) regs[(x)]
+#define compat_fp regs[11]
+#define compat_sp regs[13]
+#define compat_lr regs[14]
+
+#define user_mode(ptregs) \
+ (((ptregs)->pstate & PSR_MODE_MASK) == PSR_MODE_EL0t)
+
+#define compat_user_mode(ptregs) \
+ (((ptregs)->pstate & (PSR_MODE32_BIT | PSR_MODE_MASK)) == \
+ (PSR_MODE32_BIT | PSR_MODE_EL0t))
+
+#define user_stack_pointer(ptregs) \
+ (!compat_user_mode(ptregs) ? (ptregs)->sp : (ptregs)->compat_sp)
+
+#define user_frame_pointer(ptregs) \
+ (!compat_user_mode(ptregs) ? (ptregs)->regs[29] : (ptregs)->compat_fp)
+
static int
arm64_is_kernel_exception_frame(struct bt_info *bt, ulong stkptr)
{
@@ -1340,21 +1359,28 @@ arm64_get_dumpfile_stackframe(struct bt_info *bt, struct
arm64_stackframe *frame
struct machine_specific *ms = machdep->machspec;
struct arm64_pt_regs *ptregs;
- if (!ms->panic_task_regs ||
- (!ms->panic_task_regs[bt->tc->processor].sp &&
- !ms->panic_task_regs[bt->tc->processor].pc)) {
+ if (!ms->panic_task_regs || !ms->panic_task_regs[bt->tc->processor].pc) {
bt->flags |= BT_REGS_NOT_FOUND;
return FALSE;
}
ptregs = &ms->panic_task_regs[bt->tc->processor];
- frame->sp = ptregs->sp;
frame->pc = ptregs->pc;
- frame->fp = ptregs->regs[29];
-
- if (!is_kernel_text(frame->pc) &&
- in_user_stack(bt->tc->task, frame->sp))
+ if (user_mode(ptregs)) {
+ frame->sp = user_stack_pointer(ptregs);
+ frame->fp = user_frame_pointer(ptregs);
+ if (is_kernel_text(frame->pc) ||
+ !in_user_stack(bt->tc->task, frame->sp)) {
+ error(WARNING, "Corrupt prstatus? pstate=0x%lx, but no user frame found\n",
+ ptregs->pstate);
+ bt->flags |= BT_REGS_NOT_FOUND;
+ return FALSE;
+ }
bt->flags |= BT_USER_SPACE;
+ } else {
+ frame->sp = ptregs->sp;
+ frame->fp = ptregs->regs[29];
+ }
if (arm64_in_kdump_text(bt, frame))
bt->flags |= BT_KDUMP_ADJUST;
--
1.8.3.1