From b3c95109c131fcc959d2473e7c384d8cc62d23d0 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Mon, 18 Mar 2024 22:51:13 -0700 Subject: perf annotate-data: Add stack canary type When the stack protector is enabled, compiler would generate code to check stack overflow with a special value called 'stack carary' at runtime. On x86_64, GCC hard-codes the stack canary as %gs:40. While there's a definition of fixed_percpu_data in asm/processor.h, it seems that the header is not included everywhere and many places it cannot find the type info. As it's in the well-known location (at %gs:40), let's add a pseudo stack canary type to handle it specially. Signed-off-by: Namhyung Kim Cc: Adrian Hunter Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Linus Torvalds Cc: Masami Hiramatsu Cc: Peter Zijlstra Cc: Stephane Eranian Link: https://lore.kernel.org/r/20240319055115.4063940-22-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/annotate.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'tools/perf/util/annotate.c') diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c index e4121acb4f88..64e54ff1aa1d 100644 --- a/tools/perf/util/annotate.c +++ b/tools/perf/util/annotate.c @@ -118,6 +118,13 @@ struct annotated_data_type stackop_type = { }, }; +struct annotated_data_type canary_type = { + .self = { + .type_name = (char *)"(stack canary)", + .children = LIST_HEAD_INIT(canary_type.self.children), + }, +}; + static int arch__grow_instructions(struct arch *arch) { struct ins *new_instructions; @@ -3803,6 +3810,18 @@ static bool is_stack_operation(struct arch *arch, struct disasm_line *dl) return false; } +static bool is_stack_canary(struct arch *arch, struct annotated_op_loc *loc) +{ + /* On x86_64, %gs:40 is used for stack canary */ + if (arch__is(arch, "x86")) { + if (loc->segment == INSN_SEG_X86_GS && loc->imm && + loc->offset == 40) + return true; + } + + return false; +} + u64 annotate_calc_pcrel(struct map_symbol *ms, u64 ip, int offset, struct disasm_line *dl) { @@ -3929,6 +3948,12 @@ retry: } mem_type = find_data_type(&dloc); + + if (mem_type == NULL && is_stack_canary(arch, op_loc)) { + mem_type = &canary_type; + dloc.type_offset = 0; + } + if (mem_type) istat->good++; else -- cgit v1.2.3