* [PATCH] [gdb/testsuite] Drop -nostdlib in gdb.dwarf2/typeddwarf.exp
@ 2023-07-13 14:15 Tom de Vries
2023-07-24 16:21 ` Simon Marchi
0 siblings, 1 reply; 3+ messages in thread
From: Tom de Vries @ 2023-07-13 14:15 UTC (permalink / raw)
To: gdb-patches; +Cc: Tom Tromey
As reported in PR testsuite/30633, when running test-case
gdb.dwarf2/typeddwarf.exp with target board native-gdbserver on Ubuntu
22.04.2, we run into:
...
(gdb) continue^M
Continuing.^M
^M
Program received signal SIGSEGV, Segmentation fault.^M
0x0000000000000001 in ?? ()^M
(gdb) FAIL: gdb.dwarf2/typeddwarf.exp: runto: run to main
...
We run into the FAIL as follows:
- due to using gdbserver, we attach at the point of the first instruction, in
_start
- we then set a breakpoint at main
- the test-case is a .s file, that has main renamed to _start in the assembly,
but not in the debuginfo
- setting a breakpoint at main sets the breakpoint at the same instruction
we're currently stopped at
- continue doesn't hit the breakpoint, and we return out of _start, which
causes a sigsegv
Note that this is for the amd64 case (using gdb.dwarf2/typeddwarf-amd64.S).
For the i386 case (using gdb.dwarf2/typeddwarf.S), setting a breakpoint in
main sets it one insn after function entry, and consequently the problem does
not occur.
The FAIL is a regression since commit 90cce6c0551 ("[gdb/testsuite] Add nopie
in a few test-cases").
Without nopie the executable is PIE, with nopie it's static instead.
In the PIE case, we attach at the point of _start in the dynamic linker, and
consequently we do not skip the breakpoint in main, and also don't run into
the FAIL.
Fix this by:
- removing the -nostdlib setting, and
- renaming _start to main in both .S files.
The change to use -nostdlib and rename main to _start was originally added
in commit 6edba76fe8b (submitted here:
https://sourceware.org/pipermail/gdb-patches/2011-May/082657.html ) , I assume
to fix the problem now fixed by using nopie.
Tested on x86_64-linux.
Reported-By: Simon Marchi <simon.marchi@efficios.com>
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30633
---
gdb/testsuite/gdb.dwarf2/typeddwarf-amd64.S | 8 ++++----
gdb/testsuite/gdb.dwarf2/typeddwarf.S | 8 ++++----
gdb/testsuite/gdb.dwarf2/typeddwarf.exp | 1 -
3 files changed, 8 insertions(+), 9 deletions(-)
diff --git a/gdb/testsuite/gdb.dwarf2/typeddwarf-amd64.S b/gdb/testsuite/gdb.dwarf2/typeddwarf-amd64.S
index eecad231aa1..ac84f4c593f 100644
--- a/gdb/testsuite/gdb.dwarf2/typeddwarf-amd64.S
+++ b/gdb/testsuite/gdb.dwarf2/typeddwarf-amd64.S
@@ -116,9 +116,9 @@ f4:
.cfi_endproc
.LFE3:
.size f4, .-f4
- .globl _start
- .type _start, @function
-_start:
+ .globl main
+ .type main, @function
+main:
.LFB4:
.loc 1 87 0
.cfi_startproc
@@ -170,7 +170,7 @@ _start:
ret
.cfi_endproc
.LFE4:
- .size _start, .-_start
+ .size main, .-main
.comm vv,4,4
.section .rodata.cst8,"aM",@progbits,8
.align 8
diff --git a/gdb/testsuite/gdb.dwarf2/typeddwarf.S b/gdb/testsuite/gdb.dwarf2/typeddwarf.S
index f9e8e5c1c1e..654372c5dc0 100644
--- a/gdb/testsuite/gdb.dwarf2/typeddwarf.S
+++ b/gdb/testsuite/gdb.dwarf2/typeddwarf.S
@@ -212,9 +212,9 @@ f4:
.size f4, .-f4
.section .text.startup,"ax",@progbits
.p2align 4,,15
- .globl _start
- .type _start, @function
-_start:
+ .globl main
+ .type main, @function
+main:
.LFB4:
# typeddwarf.c:87
.LM37:
@@ -314,7 +314,7 @@ _start:
# SUCC: EXIT [100.0%]
ret
.LFE4:
- .size _start, .-_start
+ .size main, .-main
.comm vv,4,4
.section .rodata.cst4,"aM",@progbits,4
.align 4
diff --git a/gdb/testsuite/gdb.dwarf2/typeddwarf.exp b/gdb/testsuite/gdb.dwarf2/typeddwarf.exp
index 1e46cab03ef..3f96e9687c6 100644
--- a/gdb/testsuite/gdb.dwarf2/typeddwarf.exp
+++ b/gdb/testsuite/gdb.dwarf2/typeddwarf.exp
@@ -31,7 +31,6 @@ if { [is_x86_like_target] } {
set opts {}
lappend opts nodebug
-lappend opts additional_flags=-nostdlib
lappend opts nopie
if { [prepare_for_testing "failed to prepare" "${test}" ${sfile} $opts] } {
base-commit: 22e90ac5af46c01ee4972cf04e835266862bbb35
--
2.35.3
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] [gdb/testsuite] Drop -nostdlib in gdb.dwarf2/typeddwarf.exp
2023-07-13 14:15 [PATCH] [gdb/testsuite] Drop -nostdlib in gdb.dwarf2/typeddwarf.exp Tom de Vries
@ 2023-07-24 16:21 ` Simon Marchi
2023-07-26 11:47 ` Tom de Vries
0 siblings, 1 reply; 3+ messages in thread
From: Simon Marchi @ 2023-07-24 16:21 UTC (permalink / raw)
To: Tom de Vries, gdb-patches; +Cc: Tom Tromey
On 7/13/23 10:15, Tom de Vries via Gdb-patches wrote:
> As reported in PR testsuite/30633, when running test-case
> gdb.dwarf2/typeddwarf.exp with target board native-gdbserver on Ubuntu
> 22.04.2, we run into:
> ...
> (gdb) continue^M
> Continuing.^M
> ^M
> Program received signal SIGSEGV, Segmentation fault.^M
> 0x0000000000000001 in ?? ()^M
> (gdb) FAIL: gdb.dwarf2/typeddwarf.exp: runto: run to main
> ...
>
> We run into the FAIL as follows:
> - due to using gdbserver, we attach at the point of the first instruction, in
> _start
> - we then set a breakpoint at main
> - the test-case is a .s file, that has main renamed to _start in the assembly,
> but not in the debuginfo
> - setting a breakpoint at main sets the breakpoint at the same instruction
> we're currently stopped at
> - continue doesn't hit the breakpoint, and we return out of _start, which
> causes a sigsegv
>
> Note that this is for the amd64 case (using gdb.dwarf2/typeddwarf-amd64.S).
> For the i386 case (using gdb.dwarf2/typeddwarf.S), setting a breakpoint in
> main sets it one insn after function entry, and consequently the problem does
> not occur.
>
> The FAIL is a regression since commit 90cce6c0551 ("[gdb/testsuite] Add nopie
> in a few test-cases").
>
> Without nopie the executable is PIE, with nopie it's static instead.
>
> In the PIE case, we attach at the point of _start in the dynamic linker, and
> consequently we do not skip the breakpoint in main, and also don't run into
> the FAIL.
>
> Fix this by:
> - removing the -nostdlib setting, and
> - renaming _start to main in both .S files.
>
> The change to use -nostdlib and rename main to _start was originally added
> in commit 6edba76fe8b (submitted here:
> https://sourceware.org/pipermail/gdb-patches/2011-May/082657.html ) , I assume
> to fix the problem now fixed by using nopie.
>
> Tested on x86_64-linux.
>
> Reported-By: Simon Marchi <simon.marchi@efficios.com>
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30633
I have not dug in the code at all, but I confirm that the patch fixes
the test. Therefore:
Tested-By: Simon Marchi <simon.marchi@efficios.com>
Thanks,
Simon
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] [gdb/testsuite] Drop -nostdlib in gdb.dwarf2/typeddwarf.exp
2023-07-24 16:21 ` Simon Marchi
@ 2023-07-26 11:47 ` Tom de Vries
0 siblings, 0 replies; 3+ messages in thread
From: Tom de Vries @ 2023-07-26 11:47 UTC (permalink / raw)
To: Simon Marchi, gdb-patches; +Cc: Tom Tromey
On 7/24/23 18:21, Simon Marchi wrote:
> On 7/13/23 10:15, Tom de Vries via Gdb-patches wrote:
>> As reported in PR testsuite/30633, when running test-case
>> gdb.dwarf2/typeddwarf.exp with target board native-gdbserver on Ubuntu
>> 22.04.2, we run into:
>> ...
>> (gdb) continue^M
>> Continuing.^M
>> ^M
>> Program received signal SIGSEGV, Segmentation fault.^M
>> 0x0000000000000001 in ?? ()^M
>> (gdb) FAIL: gdb.dwarf2/typeddwarf.exp: runto: run to main
>> ...
>>
>> We run into the FAIL as follows:
>> - due to using gdbserver, we attach at the point of the first instruction, in
>> _start
>> - we then set a breakpoint at main
>> - the test-case is a .s file, that has main renamed to _start in the assembly,
>> but not in the debuginfo
>> - setting a breakpoint at main sets the breakpoint at the same instruction
>> we're currently stopped at
>> - continue doesn't hit the breakpoint, and we return out of _start, which
>> causes a sigsegv
>>
>> Note that this is for the amd64 case (using gdb.dwarf2/typeddwarf-amd64.S).
>> For the i386 case (using gdb.dwarf2/typeddwarf.S), setting a breakpoint in
>> main sets it one insn after function entry, and consequently the problem does
>> not occur.
>>
>> The FAIL is a regression since commit 90cce6c0551 ("[gdb/testsuite] Add nopie
>> in a few test-cases").
>>
>> Without nopie the executable is PIE, with nopie it's static instead.
>>
>> In the PIE case, we attach at the point of _start in the dynamic linker, and
>> consequently we do not skip the breakpoint in main, and also don't run into
>> the FAIL.
>>
>> Fix this by:
>> - removing the -nostdlib setting, and
>> - renaming _start to main in both .S files.
>>
>> The change to use -nostdlib and rename main to _start was originally added
>> in commit 6edba76fe8b (submitted here:
>> https://sourceware.org/pipermail/gdb-patches/2011-May/082657.html ) , I assume
>> to fix the problem now fixed by using nopie.
>>
>> Tested on x86_64-linux.
>>
>> Reported-By: Simon Marchi <simon.marchi@efficios.com>
>> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30633
>
> I have not dug in the code at all, but I confirm that the patch fixes
> the test. Therefore:
>
> Tested-By: Simon Marchi <simon.marchi@efficios.com>
Thanks for testing, committed.
- Tom
^ permalink raw reply [flat|nested] 3+ messages in thread
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2023-07-13 14:15 [PATCH] [gdb/testsuite] Drop -nostdlib in gdb.dwarf2/typeddwarf.exp Tom de Vries
2023-07-24 16:21 ` Simon Marchi
2023-07-26 11:47 ` Tom de Vries
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