[PATCH v4 1/2] perf tools arm64: Add support for generating bpf prologue

He Kuang
2017-02-07T07:34:42Z

Since HAVE_KPROBES can be enabled in arm64, this patch introduces
regs_query_register_offset() to convert register name to offset for
arm64, so the BPF prologue feature is ready to use.

Signed-off-by: He Kuang <hekuang@huawei.com>
---
tools/perf/arch/arm64/Makefile | 1 +
tools/perf/arch/arm64/util/dwarf-regs.c | 15 ++++++++++++++-
2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/tools/perf/arch/arm64/Makefile b/tools/perf/arch/arm64/Makefile
index 18b1351..eebe1ec 100644
--- a/tools/perf/arch/arm64/Makefile
+++ b/tools/perf/arch/arm64/Makefile
@@ -2,3 +2,4 @@ ifndef NO_DWARF
PERF_HAVE_DWARF_REGS := 1
endif
PERF_HAVE_JITDUMP := 1
+PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET := 1
diff --git a/tools/perf/arch/arm64/util/dwarf-regs.c b/tools/perf/arch/arm64/util/dwarf-regs.c
index d49efeb..068b618 100644
--- a/tools/perf/arch/arm64/util/dwarf-regs.c
+++ b/tools/perf/arch/arm64/util/dwarf-regs.c
@@ -10,17 +10,20 @@

#include <stddef.h>
#include <dwarf-regs.h>
+#include <linux/ptrace.h> /* for struct user_pt_regs */
+#include "util.h"

struct pt_regs_dwarfnum {
const char *name;
unsigned int dwarfnum;
};

-#define STR(s) #s
#define REG_DWARFNUM_NAME(r, num) {.name = r, .dwarfnum = num}
#define GPR_DWARFNUM_NAME(num) \
{.name = STR(%x##num), .dwarfnum = num}
#define REG_DWARFNUM_END {.name = NULL, .dwarfnum = 0}
+#define DWARFNUM2OFFSET(index) \
+ (index * sizeof((struct user_pt_regs *)0)->regs[0])

/*
* Reference:
@@ -78,3 +81,13 @@ const char *get_arch_regstr(unsigned int n)
return roff->name;
return NULL;
}
+
+int regs_query_register_offset(const char *name)
+{
+ const struct pt_regs_dwarfnum *roff;
+
+ for (roff = regdwarfnum_table; roff->name != NULL; roff++)
+ if (!strcmp(roff->name, name))
+ return DWARFNUM2OFFSET(roff->dwarfnum);
+ return -EINVAL;
+}
--
1.8.5.2