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author | Andrew Burgess <aburgess@redhat.com> | 2023-01-03 10:18:48 +0100 |
---|---|---|
committer | Tom de Vries <tdevries@suse.de> | 2023-01-03 10:18:48 +0100 |
commit | 08fd407675396cf9500519f02033e6cec270a4a6 (patch) | |
tree | 040fc440e58e090766cfd8c697fc87fe726054da /gdb | |
parent | fdbd297027e61f03192f73a4d888f91b3d0dfbbb (diff) | |
download | gdb-08fd407675396cf9500519f02033e6cec270a4a6.zip gdb-08fd407675396cf9500519f02033e6cec270a4a6.tar.gz gdb-08fd407675396cf9500519f02033e6cec270a4a6.tar.bz2 |
[gdb] Fix segfault during inferior call to ifunc
With a simple test-case:
...
$ cat test.c
char *p = "a";
int main (void) {
return strlen (p);
}
$ gcc -g test.c
...
we run into this segfault:
...
$ gdb -q -batch a.out -ex start -ex "p strlen (p)"
Temporary breakpoint 1 at 0x1151: file test.c, line 4.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Temporary breakpoint 1, main () at test.c:4
4 return strlen (p);
Fatal signal: Segmentation fault
...
The strlen is an ifunc, and consequently during the call to
call_function_by_hand_dummy for "p strlen (p)" another call
to call_function_by_hand_dummy is used to resolve the ifunc.
This invalidates the get_current_frame () result in the outer call.
Fix this by using prepare_reinflate and reinflate.
Note that this series (
https://inbox.sourceware.org/gdb-patches/20221214033441.499512-1-simon.marchi@polymtl.ca/ )
should address this problem, but this patch is a simpler fix which is easy to
backport.
Tested on x86_64-linux.
Co-Authored-By: Tom de Vries <tdevries@suse.de>
PR gdb/29941
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29941
Diffstat (limited to 'gdb')
-rw-r--r-- | gdb/infcall.c | 3 | ||||
-rw-r--r-- | gdb/testsuite/gdb.base/gnu-ifunc.exp | 9 |
2 files changed, 10 insertions, 2 deletions
diff --git a/gdb/infcall.c b/gdb/infcall.c index 4d5780b..ec2aa18 100644 --- a/gdb/infcall.c +++ b/gdb/infcall.c @@ -848,6 +848,7 @@ call_function_by_hand_dummy (struct value *function, bool stack_temporaries = thread_stack_temporaries_enabled_p (call_thread.get ()); frame = get_current_frame (); + frame.prepare_reinflate (); gdbarch = get_frame_arch (frame); if (!gdbarch_push_dummy_call_p (gdbarch)) @@ -863,6 +864,8 @@ call_function_by_hand_dummy (struct value *function, "target calling convention."), get_function_name (funaddr, name_buf, sizeof (name_buf))); + frame.reinflate (); + if (values_type == NULL || values_type->is_stub ()) values_type = default_return_type; if (values_type == NULL) diff --git a/gdb/testsuite/gdb.base/gnu-ifunc.exp b/gdb/testsuite/gdb.base/gnu-ifunc.exp index 9a5052e..783b123 100644 --- a/gdb/testsuite/gdb.base/gnu-ifunc.exp +++ b/gdb/testsuite/gdb.base/gnu-ifunc.exp @@ -240,14 +240,19 @@ proc misc_tests {resolver_attr resolver_debug final_debug} { # Test GDB will automatically indirect the call. if {!$resolver_debug && !$final_debug} { + # Do the test that is supposed to succeed first, to make sure + # elf_gnu_ifunc_record_cache is empty. This excercises PR28224. + gdb_test "p (int) gnu_ifunc (3)" " = 4" + gdb_test "p gnu_ifunc()" \ "'${dot}final' has unknown return type; cast the call to its declared return type" gdb_test "p gnu_ifunc (3)" \ "'${dot}final' has unknown return type; cast the call to its declared return type" - gdb_test "p (int) gnu_ifunc (3)" " = 4" } else { - gdb_test "p gnu_ifunc()" "Too few arguments in function call\\." + # Do the test that is supposed to succeed first, see above. gdb_test "p gnu_ifunc (3)" " = 4" + + gdb_test "p gnu_ifunc()" "Too few arguments in function call\\." } # Test that the resolver received its argument. |