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 <link.h>.
	[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 <carlos@redhat.com>
This commit is contained in:
H.J. Lu 2017-10-12 03:45:55 -07:00
parent bc9620d040
commit d165ca6498
4 changed files with 79 additions and 10 deletions

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@ -1,3 +1,23 @@
2017-10-12 H.J. Lu <hongjiu.lu@intel.com>
[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 <link.h>.
[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.
2017-10-11 Joseph Myers <joseph@codesourcery.com> 2017-10-11 Joseph Myers <joseph@codesourcery.com>
* math/Makefile (test-types-basic): New variable. * math/Makefile (test-types-basic): New variable.

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@ -33,6 +33,11 @@ tests-static += tst-profile-static
LDFLAGS-tst-profile-static = -profile LDFLAGS-tst-profile-static = -profile
endif endif
ifeq (yesyes,$(have-fpie)$(build-shared))
tests += tst-gmon-pie
tests-pie += tst-gmon-pie
endif
# The mcount code won't work without a frame pointer. # The mcount code won't work without a frame pointer.
CFLAGS-mcount.c := -fno-omit-frame-pointer CFLAGS-mcount.c := -fno-omit-frame-pointer
@ -44,6 +49,14 @@ ifeq ($(run-built-tests),yes)
tests-special += $(objpfx)tst-gmon-gprof.out tests-special += $(objpfx)tst-gmon-gprof.out
endif endif
CFLAGS-tst-gmon-pie.c := $(PIE-ccflag) -fno-omit-frame-pointer -pg
CRT-tst-gmon-pie := $(csu-objpfx)gcrt1.o
tst-gmon-pie-ENV := GMON_OUT_PREFIX=$(objpfx)tst-gmon-pie.data
ifeq ($(run-built-tests),yes)
tests-special += $(objpfx)tst-gmon-pie-gprof.out
endif
include ../Rules include ../Rules
# We cannot compile mcount.c with -pg because that would # We cannot compile mcount.c with -pg because that would
@ -69,3 +82,11 @@ clean-tst-gmon-data:
$(objpfx)tst-gmon-gprof.out: tst-gmon-gprof.sh $(objpfx)tst-gmon.out $(objpfx)tst-gmon-gprof.out: tst-gmon-gprof.sh $(objpfx)tst-gmon.out
$(SHELL) $< $(GPROF) $(objpfx)tst-gmon $(objpfx)tst-gmon.data.* > $@; \ $(SHELL) $< $(GPROF) $(objpfx)tst-gmon $(objpfx)tst-gmon.data.* > $@; \
$(evaluate-test) $(evaluate-test)
$(objpfx)tst-gmon-pie.out: clean-tst-gmon-pie-data
clean-tst-gmon-pie-data:
rm -f $(objpfx)tst-gmon-pie.data.*
$(objpfx)tst-gmon-pie-gprof.out: tst-gmon-gprof.sh $(objpfx)tst-gmon-pie.out
$(SHELL) $< $(GPROF) $(objpfx)tst-gmon-pie $(objpfx)tst-gmon-pie.data.* > $@; \
$(evaluate-test)

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@ -46,6 +46,26 @@
#include <libc-internal.h> #include <libc-internal.h>
#include <not-cancel.h> #include <not-cancel.h>
#ifdef PIC
# include <link.h>
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. */ /* Head of basic-block list or NULL. */
struct __bb *__bb_head attribute_hidden; struct __bb *__bb_head attribute_hidden;
@ -63,8 +83,8 @@ static int s_scale;
void moncontrol (int mode); void moncontrol (int mode);
void __moncontrol (int mode); void __moncontrol (int mode);
libc_hidden_proto (__moncontrol) libc_hidden_proto (__moncontrol)
static void write_hist (int fd); static void write_hist (int fd, u_long load_address);
static void write_call_graph (int fd); static void write_call_graph (int fd, u_long load_address);
static void write_bb_counts (int fd); static void write_bb_counts (int fd);
/* /*
@ -173,7 +193,7 @@ weak_alias (__monstartup, monstartup)
static void static void
write_hist (int fd) write_hist (int fd, u_long load_address)
{ {
u_char tag = GMON_TAG_TIME_HIST; u_char tag = GMON_TAG_TIME_HIST;
@ -210,8 +230,8 @@ write_hist (int fd)
!= offsetof (struct gmon_hist_hdr, dimen_abbrev))) != offsetof (struct gmon_hist_hdr, dimen_abbrev)))
abort (); abort ();
thdr.low_pc = (char *) _gmonparam.lowpc; thdr.low_pc = (char *) _gmonparam.lowpc - load_address;
thdr.high_pc = (char *) _gmonparam.highpc; thdr.high_pc = (char *) _gmonparam.highpc - load_address;
thdr.hist_size = _gmonparam.kcountsize / sizeof (HISTCOUNTER); thdr.hist_size = _gmonparam.kcountsize / sizeof (HISTCOUNTER);
thdr.prof_rate = __profile_frequency (); thdr.prof_rate = __profile_frequency ();
strncpy (thdr.dimen, "seconds", sizeof (thdr.dimen)); strncpy (thdr.dimen, "seconds", sizeof (thdr.dimen));
@ -223,7 +243,7 @@ write_hist (int fd)
static void static void
write_call_graph (int fd) write_call_graph (int fd, u_long load_address)
{ {
#define NARCS_PER_WRITEV 32 #define NARCS_PER_WRITEV 32
u_char tag = GMON_TAG_CG_ARC; u_char tag = GMON_TAG_CG_ARC;
@ -266,8 +286,9 @@ write_call_graph (int fd)
} }
arc; arc;
arc.frompc = (char *) frompc; arc.frompc = (char *) frompc - load_address;
arc.selfpc = (char *) _gmonparam.tos[to_index].selfpc; arc.selfpc = ((char *) _gmonparam.tos[to_index].selfpc
- load_address);
arc.count = _gmonparam.tos[to_index].count; arc.count = _gmonparam.tos[to_index].count;
memcpy (raw_arc + nfilled, &arc, sizeof (raw_arc [0])); memcpy (raw_arc + nfilled, &arc, sizeof (raw_arc [0]));
@ -376,11 +397,17 @@ write_gmon (void)
memset (ghdr.spare, '\0', sizeof (ghdr.spare)); memset (ghdr.spare, '\0', sizeof (ghdr.spare));
__write_nocancel (fd, &ghdr, sizeof (struct gmon_hdr)); __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 PC histogram: */
write_hist (fd); write_hist (fd, load_address);
/* write call-graph: */ /* write call-graph: */
write_call_graph (fd); write_call_graph (fd, load_address);
/* write basic-block execution counts: */ /* write basic-block execution counts: */
write_bb_counts (fd); write_bb_counts (fd);

1
gmon/tst-gmon-pie.c Normal file
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@ -0,0 +1 @@
#include "tst-gmon.c"