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Subject[PATCH V2 1/4] perf: Add hardware breakpoint address mask
Date
Some architectures (for us, AMD Family 16h) allow for "don't care" bit
mask to further qualify a hardware breakpoint address, in order to
trap on range of addresses. Update perf uapi to add bp_addr_mask field.

Signed-off-by: Jacob Shin <jacob.shin@amd.com>
---
include/uapi/linux/perf_event.h | 5 ++++-
kernel/events/hw_breakpoint.c | 9 +++++++++
2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index fb104e5..e22e1d1 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -286,7 +286,10 @@ struct perf_event_attr {
__u64 config1; /* extension of config */
};
union {
- __u64 bp_len;
+ struct {
+ __u32 bp_len;
+ __u32 bp_addr_mask;
+ };
__u64 config2; /* extension of config1 */
};
__u64 branch_sample_type; /* enum perf_branch_sample_type */
diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index a64f8ae..c454880 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -385,6 +385,11 @@ int dbg_release_bp_slot(struct perf_event *bp)
return 0;
}

+__weak int arch_validate_hwbkpt_addr_mask(struct perf_event *bp)
+{
+ return bp->attr.bp_addr_mask == 0;
+}
+
static int validate_hw_breakpoint(struct perf_event *bp)
{
int ret;
@@ -393,6 +398,10 @@ static int validate_hw_breakpoint(struct perf_event *bp)
if (ret)
return ret;

+ ret = arch_validate_hwbkpt_addr_mask(bp);
+ if (ret)
+ return ret;
+
if (arch_check_bp_in_kernelspace(bp)) {
if (bp->attr.exclude_kernel)
return -EINVAL;
--
1.7.9.5



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