aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorH.J. Lu <hjl.tools@gmail.com>2017-10-12 03:45:55 -0700
committerH.J. Lu <hjl.tools@gmail.com>2017-10-12 15:56:40 -0700
commit5a951cc33ccec638bcd2a2ed44db34f2610dacd3 (patch)
tree45a17845a04432e24949a85dcc873a19aa4fbbdd
parentf725563967c1f277e0f02bb1516fe9ebfa4737bf (diff)
downloadtermbaud-hjl/pr22284/2.26.tar.gz
termbaud-hjl/pr22284/2.26.tar.xz
termbaud-hjl/pr22284/2.26.zip
Support profiling PIE [BZ #22284]hjl/pr22284/2.26
Since PIE can be loaded at any address, we need to subtract load address from PCs. [BZ #22284] * 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> (cherry picked from commit d165ca64980f90ccace088670652cc203d1b5411)
-rw-r--r--gmon/gmon.c47
1 files changed, 37 insertions, 10 deletions
diff --git a/gmon/gmon.c b/gmon/gmon.c
index f394a7870e7..4d97ba16f29 100644
--- a/gmon/gmon.c
+++ b/gmon/gmon.c
@@ -46,6 +46,26 @@
#include <libc-internal.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. */
struct __bb *__bb_head attribute_hidden;
@@ -62,8 +82,8 @@ static int s_scale;
void moncontrol (int mode);
void __moncontrol (int mode);
-static void write_hist (int fd) internal_function;
-static void write_call_graph (int fd) internal_function;
+static void write_hist (int fd, u_long load_address) internal_function;
+static void write_call_graph (int fd, u_long load_address) internal_function;
static void write_bb_counts (int fd) internal_function;
/*
@@ -172,7 +192,7 @@ weak_alias (__monstartup, monstartup)
static void
internal_function
-write_hist (int fd)
+write_hist (int fd, u_long load_address)
{
u_char tag = GMON_TAG_TIME_HIST;
@@ -209,8 +229,8 @@ 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
internal_function
-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]));
@@ -377,11 +398,17 @@ write_gmon (void)
memset (ghdr.spare, '\0', sizeof (ghdr.spare));
write_not_cancel (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);