Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=5afe27...
Commit: 5afe27380bc42454254c9c83c045240249c15e35
Parent: c9b23e0c302377ccff700bee663b878d04e4ef3a
Author: David S. Miller <davem@davemloft.net>
AuthorDate: Wed Jul 30 21:57:59 2008 -0700
Committer: David S. Miller <davem@davemloft.net>
CommitDate: Wed Jul 30 21:57:59 2008 -0700
sparc64: Make global reg dumping even more useful.
Record one more level of stack frame program counter.
Particularly when lockdep and all sorts of spinlock debugging is
enabled, figuring out the caller of spin_lock() is difficult when the
cpu is stuck on the lock.
Signed-off-by: David S. Miller <davem@davemloft.net>
---
arch/sparc/include/asm/ptrace_64.h | 8 ++++----
arch/sparc64/kernel/process.c | 36 +++++++++++++++++++++++++++++-------
arch/sparc64/mm/ultra.S | 7 +++++++
3 files changed, 40 insertions(+), 11 deletions(-)
diff --git a/arch/sparc/include/asm/ptrace_64.h b/arch/sparc/include/asm/ptrace_64.h
index ec6d45c..390d92a 100644
--- a/arch/sparc/include/asm/ptrace_64.h
+++ b/arch/sparc/include/asm/ptrace_64.h
@@ -134,9 +134,9 @@ struct global_reg_snapshot {
unsigned long tnpc;
unsigned long o7;
unsigned long i7;
+ unsigned long rpc;
struct thread_info *thread;
unsigned long pad1;
- unsigned long pad2;
};
#define __ARCH_WANT_COMPAT_SYS_PTRACE
@@ -315,9 +315,9 @@ extern void __show_regs(struct pt_regs *);
#define GR_SNAP_TNPC 0x10
#define GR_SNAP_O7 0x18
#define GR_SNAP_I7 0x20
-#define GR_SNAP_THREAD 0x28
-#define GR_SNAP_PAD1 0x30
-#define GR_SNAP_PAD2 0x38
+#define GR_SNAP_RPC 0x28
+#define GR_SNAP_THREAD 0x30
+#define GR_SNAP_PAD1 0x38
#endif /* __KERNEL__ */
diff --git a/arch/sparc64/kernel/process.c b/arch/sparc64/kernel/process.c
index 0f60547..fc8137a 100644
--- a/arch/sparc64/kernel/process.c
+++ b/arch/sparc64/kernel/process.c
@@ -304,6 +304,19 @@ void show_regs(struct pt_regs *regs)
struct global_reg_snapshot global_reg_snapshot[NR_CPUS];
static DEFINE_SPINLOCK(global_reg_snapshot_lock);
+static bool kstack_valid(struct thread_info *tp, struct reg_window *rw)
+{
+ unsigned long thread_base, fp;
+
+ thread_base = (unsigned long) tp;
+ fp = (unsigned long) rw;
+
+ if (fp < (thread_base + sizeof(struct thread_info)) ||
+ fp >= (thread_base + THREAD_SIZE))
+ return false;
+ return true;
+}
+
static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
int this_cpu)
{
@@ -315,14 +328,22 @@ static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
global_reg_snapshot[this_cpu].o7 = regs->u_regs[UREG_I7];
if (regs->tstate & TSTATE_PRIV) {
+ struct thread_info *tp = current_thread_info();
struct reg_window *rw;
rw = (struct reg_window *)
(regs->u_regs[UREG_FP] + STACK_BIAS);
- global_reg_snapshot[this_cpu].i7 = rw->ins[7];
- } else
+ if (kstack_valid(tp, rw)) {
+ global_reg_snapshot[this_cpu].i7 = rw->ins[7];
+ rw = (struct reg_window *)
+ (rw->ins[6] + STACK_BIAS);
+ if (kstack_valid(tp, rw))
+ global_reg_snapshot[this_cpu].rpc = rw->ins[7];
+ }
+ } else {
global_reg_snapshot[this_cpu].i7 = 0;
-
+ global_reg_snapshot[this_cpu].rpc = 0;
+ }
global_reg_snapshot[this_cpu].thread = tp;
}
@@ -375,13 +396,14 @@ static void sysrq_handle_globreg(int key, struct tty_struct *tty)
((tp && tp->task) ? tp->task->pid : -1));
if (gp->tstate & TSTATE_PRIV) {
- printk(" TPC[%pS] O7[%pS] I7[%pS]\n",
+ printk(" TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
(void *) gp->tpc,
(void *) gp->o7,
- (void *) gp->i7);
+ (void *) gp->i7,
+ (void *) gp->rpc);
} else {
- printk(" TPC[%lx] O7[%lx] I7[%lx]\n",
- gp->tpc, gp->o7, gp->i7);
+ printk(" TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
+ gp->tpc, gp->o7, gp->i7, gp->rpc);
}
}
diff --git a/arch/sparc64/mm/ultra.S b/arch/sparc64/mm/ultra.S
index 4c8ca13..77ba885 100644
--- a/arch/sparc64/mm/ultra.S
+++ b/arch/sparc64/mm/ultra.S
@@ -531,6 +531,13 @@ xcall_fetch_glob_regs:
stx %g7, [%g1 + GR_SNAP_TNPC]
stx %o7, [%g1 + GR_SNAP_O7]
stx %i7, [%g1 + GR_SNAP_I7]
+ /* Don't try this at home kids... */
+ rdpr %cwp, %g2
+ sub %g2, 1, %g7
+ wrpr %g7, %cwp
+ mov %i7, %g7
+ wrpr %g2, %cwp
+ stx %g7, [%g1 + GR_SNAP_RPC]
sethi %hi(trap_block), %g7
or %g7, %lo(trap_block), %g7
sllx %g2, TRAP_BLOCK_SZ_SHIFT, %g2
--
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