Introducing perf_regs_load function, which is going to be used for dwarf unwind test in following patches.
It takes single argument as a pointer to the regs dump buffer and populates it with current registers values, as expected by the perf built-in unwinding test.
Signed-off-by: Jean Pihet jean.pihet@linaro.org Cc: Steve Capper steve.capper@linaro.org Cc: Corey Ashford cjashfor@linux.vnet.ibm.com Cc: Frederic Weisbecker fweisbec@gmail.com Cc: Ingo Molnar mingo@kernel.org Cc: Namhyung Kim namhyung@kernel.org Cc: Paul Mackerras paulus@samba.org Cc: Peter Zijlstra a.p.zijlstra@chello.nl Cc: Arnaldo Carvalho de Melo acme@ghostprotocols.net Cc: David Ahern dsahern@gmail.com Cc: Jiri Olsa jolsa@redhat.com --- tools/perf/arch/arm64/Makefile | 1 + tools/perf/arch/arm64/include/perf_regs.h | 2 ++ tools/perf/arch/arm64/tests/regs_load.S | 39 +++++++++++++++++++++++++++++++ 3 files changed, 42 insertions(+) create mode 100644 tools/perf/arch/arm64/tests/regs_load.S
diff --git a/tools/perf/arch/arm64/Makefile b/tools/perf/arch/arm64/Makefile index 67e9b3d..9b8f87e 100644 --- a/tools/perf/arch/arm64/Makefile +++ b/tools/perf/arch/arm64/Makefile @@ -4,4 +4,5 @@ LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o endif ifndef NO_LIBUNWIND LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/unwind-libunwind.o +LIB_OBJS += $(OUTPUT)arch/$(ARCH)/tests/regs_load.o endif diff --git a/tools/perf/arch/arm64/include/perf_regs.h b/tools/perf/arch/arm64/include/perf_regs.h index 2359546..1e052f1 100644 --- a/tools/perf/arch/arm64/include/perf_regs.h +++ b/tools/perf/arch/arm64/include/perf_regs.h @@ -9,6 +9,8 @@ #define PERF_REG_IP PERF_REG_ARM64_PC #define PERF_REG_SP PERF_REG_ARM64_SP
+void perf_regs_load(u64 *regs); + static inline const char *perf_reg_name(int id) { switch (id) { diff --git a/tools/perf/arch/arm64/tests/regs_load.S b/tools/perf/arch/arm64/tests/regs_load.S new file mode 100644 index 0000000..92ab968 --- /dev/null +++ b/tools/perf/arch/arm64/tests/regs_load.S @@ -0,0 +1,39 @@ +#include <linux/linkage.h> + +/* + * Implementation of void perf_regs_load(u64 *regs); + * + * This functions fills in the 'regs' buffer from the actual registers values, + * in the way the perf built-in unwinding test expects them: + * - the PC at the time at the call to this function. Since this function + * is called using a bl instruction, the PC value is taken from LR, + * - the current SP (not touched by this function), + * - the current value of LR is merely retrieved and stored because the + * value before the call to this function is unknown at this time; it will + * be unwound from the dwarf information in unwind__get_entries. + */ + +.text +.type perf_regs_load,%function +ENTRY(perf_regs_load) + stp x0, x1, [x0], #16 // store x0..x29 + stp x2, x3, [x0], #16 + stp x4, x5, [x0], #16 + stp x6, x7, [x0], #16 + stp x8, x9, [x0], #16 + stp x10, x11, [x0], #16 + stp x12, x13, [x0], #16 + stp x14, x15, [x0], #16 + stp x16, x17, [x0], #16 + stp x18, x19, [x0], #16 + stp x20, x21, [x0], #16 + stp x22, x23, [x0], #16 + stp x24, x25, [x0], #16 + stp x26, x27, [x0], #16 + stp x28, x29, [x0], #16 + mov x1, sp + stp x30, x1, [x0], #16 // store lr and sp + str x30, [x0] // store pc as lr in order to skip the call + // to this function + ret +ENDPROC(perf_regs_load)