From d165ca64980f90ccace088670652cc203d1b5411 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Thu, 12 Oct 2017 03:45:55 -0700 Subject: Support profiling PIE [BZ #22284] Since PIE can be loaded at any address, we need to subtract load address from PCs. [BZ #22284] * gmon/Makefile [$(have-fpie)$(build-shared) == yesyes] (tests, tests-pie): Add tst-gmon-pie. (CFLAGS-tst-gmon-pie.c): New. (CRT-tst-gmon-pie): Likewise. (tst-gmon-pie-ENV): Likewise. [$(have-fpie)$(build-shared) == yesyes] (tests-special): Likewise. ($(objpfx)tst-gmon-pie.out): Likewise. (clean-tst-gmon-pie-data): Likewise. ($(objpfx)tst-gmon-pie-gprof.out): Likewise. * gmon/gmon.c [PIC]: Include . [PIC] (callback): New function. (write_hist): Add an argument for load address. Subtract load address from PCs. (write_call_graph): Likewise. (write_gmon): Call __dl_iterate_phdr to get load address, pass it to write_hist and write_call_graph. Reviewed-by: Carlos O'Donell --- gmon/gmon.c | 47 +++++++++++++++++++++++++++++++++++++---------- 1 file changed, 37 insertions(+), 10 deletions(-) (limited to 'gmon/gmon.c') diff --git a/gmon/gmon.c b/gmon/gmon.c index f1aa3b776c..dee64803ad 100644 --- a/gmon/gmon.c +++ b/gmon/gmon.c @@ -46,6 +46,26 @@ #include #include +#ifdef PIC +# include + +static int +callback (struct dl_phdr_info *info, size_t size, void *data) +{ + if (info->dlpi_name[0] == '\0') + { + /* The link map for the executable is created by calling + _dl_new_object with "" as filename. dl_iterate_phdr + calls the callback function with filename from the + link map as dlpi_name. */ + u_long *load_address = data; + *load_address = (u_long) info->dlpi_addr; + return 1; + } + + return 0; +} +#endif /* Head of basic-block list or NULL. */ struct __bb *__bb_head attribute_hidden; @@ -63,8 +83,8 @@ static int s_scale; void moncontrol (int mode); void __moncontrol (int mode); libc_hidden_proto (__moncontrol) -static void write_hist (int fd); -static void write_call_graph (int fd); +static void write_hist (int fd, u_long load_address); +static void write_call_graph (int fd, u_long load_address); static void write_bb_counts (int fd); /* @@ -173,7 +193,7 @@ weak_alias (__monstartup, monstartup) static void -write_hist (int fd) +write_hist (int fd, u_long load_address) { u_char tag = GMON_TAG_TIME_HIST; @@ -210,8 +230,8 @@ write_hist (int fd) != offsetof (struct gmon_hist_hdr, dimen_abbrev))) abort (); - thdr.low_pc = (char *) _gmonparam.lowpc; - thdr.high_pc = (char *) _gmonparam.highpc; + thdr.low_pc = (char *) _gmonparam.lowpc - load_address; + thdr.high_pc = (char *) _gmonparam.highpc - load_address; thdr.hist_size = _gmonparam.kcountsize / sizeof (HISTCOUNTER); thdr.prof_rate = __profile_frequency (); strncpy (thdr.dimen, "seconds", sizeof (thdr.dimen)); @@ -223,7 +243,7 @@ write_hist (int fd) static void -write_call_graph (int fd) +write_call_graph (int fd, u_long load_address) { #define NARCS_PER_WRITEV 32 u_char tag = GMON_TAG_CG_ARC; @@ -266,8 +286,9 @@ write_call_graph (int fd) } arc; - arc.frompc = (char *) frompc; - arc.selfpc = (char *) _gmonparam.tos[to_index].selfpc; + arc.frompc = (char *) frompc - load_address; + arc.selfpc = ((char *) _gmonparam.tos[to_index].selfpc + - load_address); arc.count = _gmonparam.tos[to_index].count; memcpy (raw_arc + nfilled, &arc, sizeof (raw_arc [0])); @@ -376,11 +397,17 @@ write_gmon (void) memset (ghdr.spare, '\0', sizeof (ghdr.spare)); __write_nocancel (fd, &ghdr, sizeof (struct gmon_hdr)); + /* Get load_address to profile PIE. */ + u_long load_address = 0; +#ifdef PIC + __dl_iterate_phdr (callback, &load_address); +#endif + /* write PC histogram: */ - write_hist (fd); + write_hist (fd, load_address); /* write call-graph: */ - write_call_graph (fd); + write_call_graph (fd, load_address); /* write basic-block execution counts: */ write_bb_counts (fd); -- cgit 1.4.1