@@ -127,6 +127,22 @@ Some examples of using the structure to:
p.addr2 = (uint64_t) end_range;
p.condition_value = 0;
+- set a watchpoint in server processors (BookS)
+
+ p.version = 1;
+ p.trigger_type = PPC_BREAKPOINT_TRIGGER_RW;
+ p.addr_mode = PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE;
+ or
+ p.addr_mode = PPC_BREAKPOINT_MODE_EXACT;
+
+ p.condition_mode = PPC_BREAKPOINT_CONDITION_NONE;
+ p.addr = (uint64_t) begin_range;
+ /* For PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE addr2 needs to be specified, where
+ * addr2 - addr <= 8 Bytes.
+ */
+ p.addr2 = (uint64_t) end_range;
+ p.condition_value = 0;
+
3. PTRACE_DELHWDEBUG
Takes an integer which identifies an existing breakpoint or watchpoint
@@ -1339,6 +1339,12 @@ static int set_dac_range(struct task_struct *child,
static long ppc_set_hwdebug(struct task_struct *child,
struct ppc_hw_breakpoint *bp_info)
{
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ int ret, len = 0;
+ struct thread_struct *thread = &(child->thread);
+ struct perf_event *bp;
+ struct perf_event_attr attr;
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#ifndef CONFIG_PPC_ADV_DEBUG_REGS
unsigned long dabr;
#endif
@@ -1382,13 +1388,9 @@ static long ppc_set_hwdebug(struct task_struct *child,
*/
if ((bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_RW) == 0 ||
(bp_info->trigger_type & ~PPC_BREAKPOINT_TRIGGER_RW) != 0 ||
- bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT ||
bp_info->condition_mode != PPC_BREAKPOINT_CONDITION_NONE)
return -EINVAL;
- if (child->thread.dabr)
- return -ENOSPC;
-
if ((unsigned long)bp_info->addr >= TASK_SIZE)
return -EIO;
@@ -1398,15 +1400,63 @@ static long ppc_set_hwdebug(struct task_struct *child,
dabr |= DABR_DATA_READ;
if (bp_info->trigger_type & PPC_BREAKPOINT_TRIGGER_WRITE)
dabr |= DABR_DATA_WRITE;
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ if (ptrace_get_breakpoints(child) < 0)
+ return -ESRCH;
- child->thread.dabr = dabr;
+ /*
+ * Check if the request is for 'range' breakpoints. We can
+ * support it if range < 8 bytes.
+ */
+ if (bp_info->addr_mode == PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE) {
+ len = bp_info->addr2 - bp_info->addr;
+ } else if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT) {
+ ptrace_put_breakpoints(child);
+ return -EINVAL;
+ }
+ bp = thread->ptrace_bps[0];
+ if (bp) {
+ ptrace_put_breakpoints(child);
+ return -ENOSPC;
+ }
+
+ /* Create a new breakpoint request if one doesn't exist already */
+ hw_breakpoint_init(&attr);
+ attr.bp_addr = (unsigned long)bp_info->addr & ~HW_BREAKPOINT_ALIGN;
+ attr.bp_len = len;
+ arch_bp_generic_fields(dabr & (DABR_DATA_WRITE | DABR_DATA_READ),
+ &attr.bp_type);
+
+ thread->ptrace_bps[0] = bp = register_user_hw_breakpoint(&attr,
+ ptrace_triggered, NULL, child);
+ if (IS_ERR(bp)) {
+ thread->ptrace_bps[0] = NULL;
+ ptrace_put_breakpoints(child);
+ return PTR_ERR(bp);
+ }
+ ptrace_put_breakpoints(child);
+ return 1;
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
+
+ if (bp_info->addr_mode != PPC_BREAKPOINT_MODE_EXACT)
+ return -EINVAL;
+
+ if (child->thread.dabr)
+ return -ENOSPC;
+
+ child->thread.dabr = dabr;
return 1;
#endif /* !CONFIG_PPC_ADV_DEBUG_DVCS */
}
static long ppc_del_hwdebug(struct task_struct *child, long addr, long data)
{
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ int ret = 0;
+ struct thread_struct *thread = &(child->thread);
+ struct perf_event *bp;
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
int rc;
@@ -1426,10 +1476,25 @@ static long ppc_del_hwdebug(struct task_struct *child, long addr, long data)
#else
if (data != 1)
return -EINVAL;
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+ if (ptrace_get_breakpoints(child) < 0)
+ return -ESRCH;
+
+ bp = thread->ptrace_bps[0];
+ if (bp) {
+ unregister_hw_breakpoint(bp);
+ thread->ptrace_bps[0] = NULL;
+ } else
+ ret = -ENOENT;
+ ptrace_put_breakpoints(child);
+ return ret;
+#else /* CONFIG_HAVE_HW_BREAKPOINT */
if (child->thread.dabr == 0)
return -ENOENT;
child->thread.dabr = 0;
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
return 0;
#endif
@@ -1560,7 +1625,7 @@ long arch_ptrace(struct task_struct *child, long request,
dbginfo.data_bp_alignment = 4;
#endif
dbginfo.sizeof_condition = 0;
- dbginfo.features = 0;
+ dbginfo.features = PPC_DEBUG_FEATURE_DATA_BP_RANGE;
#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
if (!access_ok(VERIFY_WRITE, datavp,
PPC_PTRACE_GETHWDBGINFO, PPC_PTRACE_SETHWDEBUG and PPC_PTRACE_DELHWDEBUG are PowerPC specific ptrace flags that use the watchpoint register. While they are targeted primarily towards BookE users, user-space applications such as GDB have started using them for BookS too. This patch enables the use of generic hardware breakpoint interfaces for these new flags. Apart from the usual benefits of using generic hw-breakpoint interfaces, these changes allow debuggers (such as GDB) to use a common set of ptrace flags for their watchpoint needs and allow more precise breakpoint specification (length of the variable can be specified). Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com> --- Documentation/powerpc/ptrace.txt | 16 ++++++++ arch/powerpc/kernel/ptrace.c | 77 +++++++++++++++++++++++++++++++++++--- 2 files changed, 87 insertions(+), 6 deletions(-)