diff options
| author | H.J. Lu <hjl.tools@gmail.com> | 2021-07-30 19:07:30 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2021-08-24 06:44:18 -0700 |
| commit | 84a7eb1f87c1d01b58ad887a0ab5d87abbc1c772 (patch) | |
| tree | 12496d55064d5d05d9aba22afa22a0312e341873 | |
| parent | 5eb3e2c794c3fdd553833af5342740051221479c (diff) | |
| download | glibc-84a7eb1f87c1d01b58ad887a0ab5d87abbc1c772.tar.gz | |
Use __executable_start as the lowest address for profiling [BZ #28153]
Glibc assumes that ENTRY_POINT is the lowest address for which we need
to keep profiling records and BFD linker uses a linker script to place
the input sections.
Starting from GCC 4.6, the main function is placed in .text.startup
section and starting from binutils 2.22, BFD linker with
commit add44f8d5c5c05e08b11e033127a744d61c26aee
Author: Alan Modra <amodra@gmail.com>
Date: Thu Nov 25 03:03:02 2010 +0000
* scripttempl/elf.sc: Group .text.exit, text.startup and .text.hot
sections.
places .text.startup section before .text section, which leave the main
function out of profiling records.
Starting from binutils 2.15, linker provides __executable_start to mark
the lowest address of the executable. Use __executable_start as the
lowest address to keep the main function in profiling records. This fixes
[BZ #28153].
Tested on Linux/x86-64, Linux/x32 and Linux/i686 as well as with
build-many-glibcs.py.
| -rw-r--r-- | csu/gmon-start.c | 10 | ||||
| -rw-r--r-- | gmon/tst-gmon-gprof.sh | 2 | ||||
| -rw-r--r-- | gmon/tst-gmon-static-gprof.sh | 2 |
3 files changed, 13 insertions, 1 deletions
diff --git a/csu/gmon-start.c b/csu/gmon-start.c index b3432885b3..344606a676 100644 --- a/csu/gmon-start.c +++ b/csu/gmon-start.c @@ -52,6 +52,11 @@ extern char ENTRY_POINT[]; #endif extern char etext[]; +/* Use __executable_start as the lowest address to keep profiling records + if it provided by the linker. */ +extern const char executable_start[] asm ("__executable_start") + __attribute__ ((weak, visibility ("hidden"))); + #ifndef TEXT_START # ifdef ENTRY_POINT_DECL # define TEXT_START ENTRY_POINT @@ -92,7 +97,10 @@ __gmon_start__ (void) called = 1; /* Start keeping profiling records. */ - __monstartup ((u_long) TEXT_START, (u_long) &etext); + if (&executable_start != NULL) + __monstartup ((u_long) &executable_start, (u_long) &etext); + else + __monstartup ((u_long) TEXT_START, (u_long) &etext); /* Call _mcleanup before exiting; it will write out gmon.out from the collected data. */ diff --git a/gmon/tst-gmon-gprof.sh b/gmon/tst-gmon-gprof.sh index 9d371582b9..dc0be02110 100644 --- a/gmon/tst-gmon-gprof.sh +++ b/gmon/tst-gmon-gprof.sh @@ -39,12 +39,14 @@ trap cleanup 0 cat > "$expected" <<EOF f1 2000 f2 1000 +f3 1 EOF # Special version for powerpc with function descriptors. cat > "$expected_dot" <<EOF .f1 2000 .f2 1000 +.f3 1 EOF "$GPROF" -C "$program" "$data" \ diff --git a/gmon/tst-gmon-static-gprof.sh b/gmon/tst-gmon-static-gprof.sh index 79218df967..4cc99c80d0 100644 --- a/gmon/tst-gmon-static-gprof.sh +++ b/gmon/tst-gmon-static-gprof.sh @@ -39,6 +39,7 @@ trap cleanup 0 cat > "$expected" <<EOF f1 2000 f2 1000 +f3 1 main 1 EOF @@ -46,6 +47,7 @@ EOF cat > "$expected_dot" <<EOF .f1 2000 .f2 1000 +.f3 1 .main 1 EOF |