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| author | H.J. Lu <hjl.tools@gmail.com> | 2018-09-12 08:40:59 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2018-09-12 08:41:26 -0700 |
| commit | 5a274db4ea363d6b0b92933f085a92daaf1be2f2 (patch) | |
| tree | fcf9a31bcdb057c13892ae72bdbe62d738ee00d8 /sysdeps/i386 | |
| parent | 4e7fbdd7c2884e8909ea8f2f59d52f7d0c699252 (diff) | |
| download | glibc-5a274db4ea363d6b0b92933f085a92daaf1be2f2.tar.gz glibc-5a274db4ea363d6b0b92933f085a92daaf1be2f2.tar.xz glibc-5a274db4ea363d6b0b92933f085a92daaf1be2f2.zip | |
i386: Use ENTRY and END in start.S [BZ #23606]
Wrapping the _start function with ENTRY and END to insert ENDBR32 at
function entry when CET is enabled. Since _start now includes CFI,
without "cfi_undefined (eip)", unwinder may not terminate at _start
and we will get
Program received signal SIGSEGV, Segmentation fault.
0xf7dc661e in ?? () from /lib/libgcc_s.so.1
Missing separate debuginfos, use: dnf debuginfo-install libgcc-8.2.1-3.0.fc28.i686
(gdb) bt
#0 0xf7dc661e in ?? () from /lib/libgcc_s.so.1
#1 0xf7dc7c18 in _Unwind_Backtrace () from /lib/libgcc_s.so.1
#2 0xf7f0d809 in __GI___backtrace (array=array@entry=0xffffc7d0,
size=size@entry=20) at ../sysdeps/i386/backtrace.c:127
#3 0x08049254 in compare (p1=p1@entry=0xffffcad0, p2=p2@entry=0xffffcad4)
at backtrace-tst.c:12
#4 0xf7e2a28c in msort_with_tmp (p=p@entry=0xffffca5c, b=b@entry=0xffffcad0,
n=n@entry=2) at msort.c:65
#5 0xf7e29f64 in msort_with_tmp (n=2, b=0xffffcad0, p=0xffffca5c)
at msort.c:53
#6 msort_with_tmp (p=p@entry=0xffffca5c, b=b@entry=0xffffcad0, n=n@entry=5)
at msort.c:53
#7 0xf7e29f64 in msort_with_tmp (n=5, b=0xffffcad0, p=0xffffca5c)
at msort.c:53
#8 msort_with_tmp (p=p@entry=0xffffca5c, b=b@entry=0xffffcad0, n=n@entry=10)
at msort.c:53
#9 0xf7e29f64 in msort_with_tmp (n=10, b=0xffffcad0, p=0xffffca5c)
at msort.c:53
#10 msort_with_tmp (p=p@entry=0xffffca5c, b=b@entry=0xffffcad0, n=n@entry=20)
at msort.c:53
#11 0xf7e2a5b6 in msort_with_tmp (n=20, b=0xffffcad0, p=0xffffca5c)
at msort.c:297
#12 __GI___qsort_r (b=b@entry=0xffffcad0, n=n@entry=20, s=s@entry=4,
cmp=cmp@entry=0x8049230 <compare>, arg=arg@entry=0x0) at msort.c:297
#13 0xf7e2a84d in __GI_qsort (b=b@entry=0xffffcad0, n=n@entry=20, s=s@entry=4,
cmp=cmp@entry=0x8049230 <compare>) at msort.c:308
#14 0x080490f6 in main (argc=2, argv=0xffffcbd4) at backtrace-tst.c:39
FAIL: debug/backtrace-tst
[BZ #23606]
* sysdeps/i386/start.S: Include <sysdep.h>
(_start): Use ENTRY/END to insert ENDBR32 at entry when CET is
enabled. Add cfi_undefined (eip).
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Diffstat (limited to 'sysdeps/i386')
| -rw-r--r-- | sysdeps/i386/start.S | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/sysdeps/i386/start.S b/sysdeps/i386/start.S index 91035fa83f..e35e9bd31b 100644 --- a/sysdeps/i386/start.S +++ b/sysdeps/i386/start.S @@ -52,10 +52,11 @@ NULL */ - .text - .globl _start - .type _start,@function -_start: +#include <sysdep.h> + +ENTRY (_start) + /* Clearing frame pointer is insufficient, use CFI. */ + cfi_undefined (eip) /* Clear the frame pointer. The ABI suggests this be done, to mark the outermost frame obviously. */ xorl %ebp, %ebp @@ -131,6 +132,7 @@ _start: 1: movl (%esp), %ebx ret #endif +END (_start) /* To fulfill the System V/i386 ABI we need this symbol. Yuck, it's so meaningless since we don't support machines < 80386. */ |