diff mbox series

[gdb/testsuite] Make gdb.base/solib-search.exp more robust

Message ID 20240101074941.18426-1-tdevries@suse.de
State Committed
Headers
Series [gdb/testsuite] Make gdb.base/solib-search.exp more robust |

Checks

Context Check Description
linaro-tcwg-bot/tcwg_gdb_build--master-aarch64 success Testing passed
linaro-tcwg-bot/tcwg_gdb_build--master-arm success Testing passed
linaro-tcwg-bot/tcwg_gdb_check--master-aarch64 success Testing passed
linaro-tcwg-bot/tcwg_gdb_check--master-arm fail Testing failed

Commit Message

Tom de Vries Jan. 1, 2024, 7:49 a.m. UTC 
  On aarch64-linux, with gcc 13.2.1, I run into:
...
 (gdb) backtrace^M
 #0  break_here () at solib-search.c:30^M
 #1  0x0000fffff7f20194 in lib2_func4 () at solib-search-lib2.c:50^M
 #2  0x0000fffff7f70194 in lib1_func3 () at solib-search-lib1.c:50^M
 #3  0x0000fffff7f20174 in lib2_func2 () at solib-search-lib2.c:30^M
 #4  0x0000fffff7f70174 in lib1_func1 () at solib-search-lib1.c:30^M
 #5  0x00000000004101b4 in main () at solib-search.c:23^M
 (gdb) PASS: gdb.base/solib-search.exp: \
   backtrace (with wrong libs) (data collection)
 FAIL: gdb.base/solib-search.exp: backtrace (with wrong libs)
...

The FAIL is generated by this code in the test-case:
...
    if { $expect_fail } {
	# If the backtrace output is correct the test isn't sufficiently
	# testing what it should.
	if { $count == $total_expected } {
	    set fail 1
	}
...

The test-case:
- builds two versions of two shared libs, a "right" and "wrong" version, the
  difference being an additional dummy function (called spacer function),
- uses the "right" version to generate a core file,
- uses the "wrong" version to interpret the core file, and
- generates a backtrace.

The intent is that the backtrace is incorrect due to using the "wrong"
version, but actually it's correct.  This is because the spacer functions
aren't large enough.

Fix this by increasing the size of the spacer functions by adding a dummy
loop, after which we have, as expected, an incorrect backtrace:
...
 (gdb) backtrace^M
 #0  break_here () at solib-search.c:30^M
 #1  0x0000fffff7f201c0 in ?? ()^M
 #2  0x0000fffff7f20174 in lib2_func2 () at solib-search-lib2.c:30^M
 #3  0x0000fffff7f20174 in lib2_func2 () at solib-search-lib2.c:30^M
 #4  0x0000fffff7f70174 in lib1_func1 () at solib-search-lib1.c:30^M
 #5  0x00000000004101b4 in main () at solib-search.c:23^M
 (gdb) PASS: gdb.base/solib-search.exp: \
   backtrace (with wrong libs) (data collection)
 PASS: gdb.base/solib-search.exp: backtrace (with wrong libs)
...

Tested on aarch64-linux.
---
 gdb/testsuite/gdb.base/solib-search-lib1.c | 3 +++
 gdb/testsuite/gdb.base/solib-search-lib2.c | 3 +++
 2 files changed, 6 insertions(+)


base-commit: ee0dbcf99efb17573724f1ede3a12491d7e81d19

Comments

Tom de Vries Jan. 8, 2024, 9:38 a.m. UTC | #1 
On 1/1/24 08:49, Tom de Vries wrote:
> On aarch64-linux, with gcc 13.2.1, I run into:
> ...
>   (gdb) backtrace^M
>   #0  break_here () at solib-search.c:30^M
>   #1  0x0000fffff7f20194 in lib2_func4 () at solib-search-lib2.c:50^M
>   #2  0x0000fffff7f70194 in lib1_func3 () at solib-search-lib1.c:50^M
>   #3  0x0000fffff7f20174 in lib2_func2 () at solib-search-lib2.c:30^M
>   #4  0x0000fffff7f70174 in lib1_func1 () at solib-search-lib1.c:30^M
>   #5  0x00000000004101b4 in main () at solib-search.c:23^M
>   (gdb) PASS: gdb.base/solib-search.exp: \
>     backtrace (with wrong libs) (data collection)
>   FAIL: gdb.base/solib-search.exp: backtrace (with wrong libs)
> ...
> 
> The FAIL is generated by this code in the test-case:
> ...
>      if { $expect_fail } {
> 	# If the backtrace output is correct the test isn't sufficiently
> 	# testing what it should.
> 	if { $count == $total_expected } {
> 	    set fail 1
> 	}
> ...
> 
> The test-case:
> - builds two versions of two shared libs, a "right" and "wrong" version, the
>    difference being an additional dummy function (called spacer function),
> - uses the "right" version to generate a core file,
> - uses the "wrong" version to interpret the core file, and
> - generates a backtrace.
> 
> The intent is that the backtrace is incorrect due to using the "wrong"
> version, but actually it's correct.  This is because the spacer functions
> aren't large enough.
> 
> Fix this by increasing the size of the spacer functions by adding a dummy
> loop, after which we have, as expected, an incorrect backtrace:
> ...
>   (gdb) backtrace^M
>   #0  break_here () at solib-search.c:30^M
>   #1  0x0000fffff7f201c0 in ?? ()^M
>   #2  0x0000fffff7f20174 in lib2_func2 () at solib-search-lib2.c:30^M
>   #3  0x0000fffff7f20174 in lib2_func2 () at solib-search-lib2.c:30^M
>   #4  0x0000fffff7f70174 in lib1_func1 () at solib-search-lib1.c:30^M
>   #5  0x00000000004101b4 in main () at solib-search.c:23^M
>   (gdb) PASS: gdb.base/solib-search.exp: \
>     backtrace (with wrong libs) (data collection)
>   PASS: gdb.base/solib-search.exp: backtrace (with wrong libs)
> ...
> 

Pushed.

Thanks,
- Tom

> Tested on aarch64-linux.
> ---
>   gdb/testsuite/gdb.base/solib-search-lib1.c | 3 +++
>   gdb/testsuite/gdb.base/solib-search-lib2.c | 3 +++
>   2 files changed, 6 insertions(+)
> 
> diff --git a/gdb/testsuite/gdb.base/solib-search-lib1.c b/gdb/testsuite/gdb.base/solib-search-lib1.c
> index 76338a8e216..6a4cc9aa1a7 100644
> --- a/gdb/testsuite/gdb.base/solib-search-lib1.c
> +++ b/gdb/testsuite/gdb.base/solib-search-lib1.c
> @@ -39,6 +39,9 @@ lib1_func1 (void)
>   void
>   lib1_spacer (void)
>   {
> +  int i;
> +  for (i = 0; i < 10; ++i)
> +    ;
>   }
>   
>   #endif
> diff --git a/gdb/testsuite/gdb.base/solib-search-lib2.c b/gdb/testsuite/gdb.base/solib-search-lib2.c
> index bf7c7bd071c..fb004d7377f 100644
> --- a/gdb/testsuite/gdb.base/solib-search-lib2.c
> +++ b/gdb/testsuite/gdb.base/solib-search-lib2.c
> @@ -39,6 +39,9 @@ lib2_func2 (void)
>   void
>   lib2_spacer (void)
>   {
> +  int i;
> +  for (i = 0; i < 10; ++i)
> +    ;
>   }
>   
>   #endif
> 
> base-commit: ee0dbcf99efb17573724f1ede3a12491d7e81d19
diff mbox series

Patch

diff --git a/gdb/testsuite/gdb.base/solib-search-lib1.c b/gdb/testsuite/gdb.base/solib-search-lib1.c
index 76338a8e216..6a4cc9aa1a7 100644
--- a/gdb/testsuite/gdb.base/solib-search-lib1.c
+++ b/gdb/testsuite/gdb.base/solib-search-lib1.c
@@ -39,6 +39,9 @@  lib1_func1 (void)
 void
 lib1_spacer (void)
 {
+  int i;
+  for (i = 0; i < 10; ++i)
+    ;
 }
 
 #endif
diff --git a/gdb/testsuite/gdb.base/solib-search-lib2.c b/gdb/testsuite/gdb.base/solib-search-lib2.c
index bf7c7bd071c..fb004d7377f 100644
--- a/gdb/testsuite/gdb.base/solib-search-lib2.c
+++ b/gdb/testsuite/gdb.base/solib-search-lib2.c
@@ -39,6 +39,9 @@  lib2_func2 (void)
 void
 lib2_spacer (void)
 {
+  int i;
+  for (i = 0; i < 10; ++i)
+    ;
 }
 
 #endif