ptrace_bps is already an array of size HBP_NUM_MAX. But we use
hardcoded index 0 while fetching/updating it. Convert such code
to loop over array.
ptrace interface to use multiple watchpoint remains same. eg:
two PPC_PTRACE_SETHWDEBUG calls will create two watchpoint if
underneath hw supports it.
Signed-off-by: Ravi Bangoria <ravi.bango...@linux.ibm.com>
Reviewed-by: Michael Neuling <mi...@neuling.org>
---
arch/powerpc/kernel/hw_breakpoint.c | 7 ++++--
arch/powerpc/kernel/process.c | 6 ++++-
arch/powerpc/kernel/ptrace/ptrace-noadv.c | 28 +++++++++++++++++------
3 files changed, 31 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/kernel/hw_breakpoint.c
b/arch/powerpc/kernel/hw_breakpoint.c
index 5826f1f2cab9..772b2c953220 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -419,10 +419,13 @@ NOKPROBE_SYMBOL(hw_breakpoint_exceptions_notify);
*/
void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
{
+ int i;
struct thread_struct *t = &tsk->thread;
- unregister_hw_breakpoint(t->ptrace_bps[0]);
- t->ptrace_bps[0] = NULL;
+ for (i = 0; i < nr_wp_slots(); i++) {
+ unregister_hw_breakpoint(t->ptrace_bps[i]);
+ t->ptrace_bps[i] = NULL;
+ }
}
void hw_breakpoint_pmu_read(struct perf_event *bp)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 6d1b7cede900..41a59a37383b 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1604,6 +1604,9 @@ int copy_thread_tls(unsigned long clone_flags, unsigned
long usp,
void (*f)(void);
unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
struct thread_info *ti = task_thread_info(p);
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ int i;
+#endif
klp_init_thread_info(p);
@@ -1663,7 +1666,8 @@ int copy_thread_tls(unsigned long clone_flags, unsigned
long usp,
p->thread.ksp_limit = (unsigned long)end_of_stack(p);
#endif
#ifdef CONFIG_HAVE_HW_BREAKPOINT
- p->thread.ptrace_bps[0] = NULL;
+ for (i = 0; i < nr_wp_slots(); i++)
+ p->thread.ptrace_bps[i] = NULL;
#endif
p->thread.fp_save_area = NULL;
diff --git a/arch/powerpc/kernel/ptrace/ptrace-noadv.c
b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
index 0dbb35392dd2..08cb8c1b504c 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-noadv.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-noadv.c
@@ -168,6 +168,19 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned
long addr, unsigned l
return 0;
}
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+static int find_empty_ptrace_bp(struct thread_struct *thread)
+{
+ int i;
+
+ for (i = 0; i < nr_wp_slots(); i++) {
+ if (!thread->ptrace_bps[i])
+ return i;
+ }
+ return -1;
+}
+#endif
+
static int find_empty_hw_brk(struct thread_struct *thread)
{
int i;
@@ -217,8 +230,9 @@ long ppc_set_hwdebug(struct task_struct *child, struct
ppc_hw_breakpoint *bp_inf
len = 1;
else
return -EINVAL;
- bp = thread->ptrace_bps[0];
- if (bp)
+
+ i = find_empty_ptrace_bp(thread);
+ if (i < 0)
return -ENOSPC;
/* Create a new breakpoint request if one doesn't exist already */
@@ -228,13 +242,13 @@ long ppc_set_hwdebug(struct task_struct *child, struct
ppc_hw_breakpoint *bp_inf
arch_bp_generic_fields(brk.type, &attr.bp_type);
bp = register_user_hw_breakpoint(&attr, ptrace_triggered, NULL, child);
- thread->ptrace_bps[0] = bp;
+ thread->ptrace_bps[i] = bp;
if (IS_ERR(bp)) {
- thread->ptrace_bps[0] = NULL;
+ thread->ptrace_bps[i] = NULL;
return PTR_ERR(bp);
}
- return 1;
+ return i + 1;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT)
@@ -263,10 +277,10 @@ long ppc_del_hwdebug(struct task_struct *child, long data)
return -EINVAL;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
- bp = thread->ptrace_bps[0];
+ bp = thread->ptrace_bps[data - 1];
if (bp) {
unregister_hw_breakpoint(bp);
- thread->ptrace_bps[0] = NULL;
+ thread->ptrace_bps[data - 1] = NULL;
} else {
ret = -ENOENT;
}
--
2.21.1
