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-rw-r--r--arch/powerpc/include/asm/ptrace.h4
-rw-r--r--arch/powerpc/kernel/head_booke.h10
-rw-r--r--arch/powerpc/kernel/ptrace.c23
-rw-r--r--arch/powerpc/kernel/traps.c34
4 files changed, 60 insertions, 11 deletions
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index c9c678fb2538..8c341490cfc5 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -135,7 +135,9 @@ do { \
* These are defined as per linux/ptrace.h, which see.
*/
#define arch_has_single_step() (1)
+#define arch_has_block_step() (!cpu_has_feature(CPU_FTR_601))
extern void user_enable_single_step(struct task_struct *);
+extern void user_enable_block_step(struct task_struct *);
extern void user_disable_single_step(struct task_struct *);
#endif /* __ASSEMBLY__ */
@@ -288,4 +290,6 @@ extern void user_disable_single_step(struct task_struct *);
#define PPC_PTRACE_PEEKUSR_3264 0x91
#define PPC_PTRACE_POKEUSR_3264 0x90
+#define PTRACE_SINGLEBLOCK 0x100 /* resume execution until next branch */
+
#endif /* _ASM_POWERPC_PTRACE_H */
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 95f39f1e68d4..5f9febc8d143 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -256,7 +256,7 @@ label:
* off DE in the DSRR1 value and clearing the debug status. \
*/ \
mfspr r10,SPRN_DBSR; /* check single-step/branch taken */ \
- andis. r10,r10,DBSR_IC@h; \
+ andis. r10,r10,(DBSR_IC|DBSR_BT)@h; \
beq+ 2f; \
\
lis r10,KERNELBASE@h; /* check if exception in vectors */ \
@@ -271,7 +271,7 @@ label:
\
/* here it looks like we got an inappropriate debug exception. */ \
1: rlwinm r9,r9,0,~MSR_DE; /* clear DE in the CDRR1 value */ \
- lis r10,DBSR_IC@h; /* clear the IC event */ \
+ lis r10,(DBSR_IC|DBSR_BT)@h; /* clear the IC event */ \
mtspr SPRN_DBSR,r10; \
/* restore state and get out */ \
lwz r10,_CCR(r11); \
@@ -309,7 +309,7 @@ label:
* off DE in the CSRR1 value and clearing the debug status. \
*/ \
mfspr r10,SPRN_DBSR; /* check single-step/branch taken */ \
- andis. r10,r10,DBSR_IC@h; \
+ andis. r10,r10,(DBSR_IC|DBSR_BT)@h; \
beq+ 2f; \
\
lis r10,KERNELBASE@h; /* check if exception in vectors */ \
@@ -317,14 +317,14 @@ label:
cmplw r12,r10; \
blt+ 2f; /* addr below exception vectors */ \
\
- lis r10,DebugCrit@h; \
+ lis r10,DebugCrit@h; \
ori r10,r10,DebugCrit@l; \
cmplw r12,r10; \
bgt+ 2f; /* addr above exception vectors */ \
\
/* here it looks like we got an inappropriate debug exception. */ \
1: rlwinm r9,r9,0,~MSR_DE; /* clear DE in the CSRR1 value */ \
- lis r10,DBSR_IC@h; /* clear the IC event */ \
+ lis r10,(DBSR_IC|DBSR_BT)@h; /* clear the IC event */ \
mtspr SPRN_DBSR,r10; \
/* restore state and get out */ \
lwz r10,_CCR(r11); \
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 3635be61f899..9fa2c7dcd05a 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -704,15 +704,34 @@ void user_enable_single_step(struct task_struct *task)
if (regs != NULL) {
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
+ task->thread.dbcr0 &= ~DBCR0_BT;
task->thread.dbcr0 |= DBCR0_IDM | DBCR0_IC;
regs->msr |= MSR_DE;
#else
+ regs->msr &= ~MSR_BE;
regs->msr |= MSR_SE;
#endif
}
set_tsk_thread_flag(task, TIF_SINGLESTEP);
}
+void user_enable_block_step(struct task_struct *task)
+{
+ struct pt_regs *regs = task->thread.regs;
+
+ if (regs != NULL) {
+#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
+ task->thread.dbcr0 &= ~DBCR0_IC;
+ task->thread.dbcr0 = DBCR0_IDM | DBCR0_BT;
+ regs->msr |= MSR_DE;
+#else
+ regs->msr &= ~MSR_SE;
+ regs->msr |= MSR_BE;
+#endif
+ }
+ set_tsk_thread_flag(task, TIF_SINGLESTEP);
+}
+
void user_disable_single_step(struct task_struct *task)
{
struct pt_regs *regs = task->thread.regs;
@@ -726,10 +745,10 @@ void user_disable_single_step(struct task_struct *task)
if (regs != NULL) {
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
- task->thread.dbcr0 &= ~(DBCR0_IC | DBCR0_IDM);
+ task->thread.dbcr0 &= ~(DBCR0_IC | DBCR0_BT | DBCR0_IDM);
regs->msr &= ~MSR_DE;
#else
- regs->msr &= ~MSR_SE;
+ regs->msr &= ~(MSR_SE | MSR_BE);
#endif
}
clear_tsk_thread_flag(task, TIF_SINGLESTEP);
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 6a5b2b731f43..6f0ae1a9bfae 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1041,7 +1041,34 @@ void SoftwareEmulation(struct pt_regs *regs)
void __kprobes DebugException(struct pt_regs *regs, unsigned long debug_status)
{
- if (debug_status & DBSR_IC) { /* instruction completion */
+ /* Hack alert: On BookE, Branch Taken stops on the branch itself, while
+ * on server, it stops on the target of the branch. In order to simulate
+ * the server behaviour, we thus restart right away with a single step
+ * instead of stopping here when hitting a BT
+ */
+ if (debug_status & DBSR_BT) {
+ regs->msr &= ~MSR_DE;
+
+ /* Disable BT */
+ mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_BT);
+ /* Clear the BT event */
+ mtspr(SPRN_DBSR, DBSR_BT);
+
+ /* Do the single step trick only when coming from userspace */
+ if (user_mode(regs)) {
+ current->thread.dbcr0 &= ~DBCR0_BT;
+ current->thread.dbcr0 |= DBCR0_IDM | DBCR0_IC;
+ regs->msr |= MSR_DE;
+ return;
+ }
+
+ if (notify_die(DIE_SSTEP, "block_step", regs, 5,
+ 5, SIGTRAP) == NOTIFY_STOP) {
+ return;
+ }
+ if (debugger_sstep(regs))
+ return;
+ } else if (debug_status & DBSR_IC) { /* Instruction complete */
regs->msr &= ~MSR_DE;
/* Disable instruction completion */
@@ -1057,9 +1084,8 @@ void __kprobes DebugException(struct pt_regs *regs, unsigned long debug_status)
if (debugger_sstep(regs))
return;
- if (user_mode(regs)) {
- current->thread.dbcr0 &= ~DBCR0_IC;
- }
+ if (user_mode(regs))
+ current->thread.dbcr0 &= ~(DBCR0_IC);
_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
} else if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) {
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