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-rw-r--r--tools/perf/util/arm64-frame-pointer-unwind-support.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/tools/perf/util/arm64-frame-pointer-unwind-support.c b/tools/perf/util/arm64-frame-pointer-unwind-support.c
new file mode 100644
index 000000000..4940be4a0
--- /dev/null
+++ b/tools/perf/util/arm64-frame-pointer-unwind-support.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "arm64-frame-pointer-unwind-support.h"
+#include "callchain.h"
+#include "event.h"
+#include "perf_regs.h" // SMPL_REG_MASK
+#include "unwind.h"
+
+#define perf_event_arm_regs perf_event_arm64_regs
+#include "../../arch/arm64/include/uapi/asm/perf_regs.h"
+#undef perf_event_arm_regs
+
+struct entries {
+ u64 stack[2];
+ size_t length;
+};
+
+static bool get_leaf_frame_caller_enabled(struct perf_sample *sample)
+{
+ return callchain_param.record_mode == CALLCHAIN_FP && sample->user_regs.regs
+ && sample->user_regs.mask & SMPL_REG_MASK(PERF_REG_ARM64_LR);
+}
+
+static int add_entry(struct unwind_entry *entry, void *arg)
+{
+ struct entries *entries = arg;
+
+ entries->stack[entries->length++] = entry->ip;
+ return 0;
+}
+
+u64 get_leaf_frame_caller_aarch64(struct perf_sample *sample, struct thread *thread, int usr_idx)
+{
+ int ret;
+ struct entries entries = {};
+ struct regs_dump old_regs = sample->user_regs;
+
+ if (!get_leaf_frame_caller_enabled(sample))
+ return 0;
+
+ /*
+ * If PC and SP are not recorded, get the value of PC from the stack
+ * and set its mask. SP is not used when doing the unwinding but it
+ * still needs to be set to prevent failures.
+ */
+
+ if (!(sample->user_regs.mask & SMPL_REG_MASK(PERF_REG_ARM64_PC))) {
+ sample->user_regs.cache_mask |= SMPL_REG_MASK(PERF_REG_ARM64_PC);
+ sample->user_regs.cache_regs[PERF_REG_ARM64_PC] = sample->callchain->ips[usr_idx+1];
+ }
+
+ if (!(sample->user_regs.mask & SMPL_REG_MASK(PERF_REG_ARM64_SP))) {
+ sample->user_regs.cache_mask |= SMPL_REG_MASK(PERF_REG_ARM64_SP);
+ sample->user_regs.cache_regs[PERF_REG_ARM64_SP] = 0;
+ }
+
+ ret = unwind__get_entries(add_entry, &entries, thread, sample, 2, true);
+ sample->user_regs = old_regs;
+
+ if (ret || entries.length != 2)
+ return ret;
+
+ return callchain_param.order == ORDER_CALLER ? entries.stack[0] : entries.stack[1];
+}