From: Tom de Vries <tdevries@suse.de>
To: gdb-patches@sourceware.org
Cc: Bruno Larsen <blarsen@redhat.com>,
Andrew Burgess <aburgess@redhat.com>,
Luis Machado <luis.machado@arm.com>
Subject: [PATCH 2/4] [gdb/testsuite] Improve gdb.base/unwind-on-each-insn.exp
Date: Thu, 19 Jan 2023 11:46:16 +0100 [thread overview]
Message-ID: <20230119104618.15503-3-tdevries@suse.de> (raw)
In-Reply-To: <20230119104618.15503-1-tdevries@suse.de>
In test-case gdb.base/unwind-on-each-insn.exp, we stepi through function foo
to check various invariants at each insn, in particular hoping to excercise
insns that modify stack and frame pointers.
For x86_64-linux, we have a reasonably complex foo (and similar for -m32):
...
4004bc: 55 push %rbp
4004bd: 48 89 e5 mov %rsp,%rbp
4004c0: 90 nop
4004c1: 5d pop %rbp
4004c2: c3 ret
...
Both stack pointer (%rsp) and frame pointer (%rbp) are modified.
Also for s390x-linux (and similar for -m31):
...
0000000001000668 <foo>:
1000668: e3 b0 f0 58 00 24 stg %r11,88(%r15)
100066e: b9 04 00 bf lgr %r11,%r15
1000672: e3 b0 b0 58 00 04 lg %r11,88(%r11)
1000678: 07 fe br %r14
...
Frame pointer (%r11) is modified.
Likewise for powerpc64le-linux:
...
00000000100006c8 <foo>:
100006c8: f8 ff e1 fb std r31,-8(r1)
100006cc: d1 ff 21 f8 stdu r1,-48(r1)
100006d0: 78 0b 3f 7c mr r31,r1
100006d4: 00 00 00 60 nop
100006d8: 30 00 3f 38 addi r1,r31,48
100006dc: f8 ff e1 eb ld r31,-8(r1)
100006e0: 20 00 80 4e blr
...
Both stack pointer (r1) and frame pointer (r31) are modified.
But for aarch64-linux, we have:
...
00000000004005fc <foo>:
4005fc: d503201f nop
400600: d65f03c0 ret
...
There's no insn that modifies stack or frame pointer.
Fix this by making foo more complex, adding an (unused) argument:
...
0000000000400604 <foo>:
400604: d10043ff sub sp, sp, #0x10
400608: f90007e0 str x0, [sp, #8]
40060c: d503201f nop
400610: 910043ff add sp, sp, #0x10
400614: d65f03c0 ret
...
such that the stack pointer (sp) is modified.
[ Note btw that we're seeing the effects of -momit-leaf-frame-pointer, with
-mno-omit-leaf-frame-pointer we have instead:
...
0000000000400604 <foo>:
400604: a9be7bfd stp x29, x30, [sp, #-32]!
400608: 910003fd mov x29, sp
40060c: f9000fa0 str x0, [x29, #24]
400610: d503201f nop
400614: a8c27bfd ldp x29, x30, [sp], #32
400618: d65f03c0 ret
...
such that also the frame pointer (x29) is modified. ]
Having made foo more complex, we now run into the following fail on
x86_64/-m32:
...
FAIL: gdb.base/unwind-on-each-insn.exp: instruction 1: $sp_value == $main_sp
....
The problem is that the stack pointer has changed inbetween the sampling of
main_sp and *foo, in particular by the push insn:
...
804841a: 68 c0 84 04 08 push $0x80484c0
804841f: e8 10 00 00 00 call 8048434 <foo>
...
Fix this by updating main_sp.
On aarch64-linux, we run into PR tdep/30011:
...
FAIL: gdb.base/unwind-on-each-insn.exp: insn 5: $fba_value == $foo_fba
FAIL: gdb.base/unwind-on-each-insn.exp: insn 5: check frame-id matches
FAIL: gdb.base/unwind-on-each-insn.exp: insn 5: $sp_value == $main_sp
...
On powerpc64le-line, we run into PR tdep/30021:
...
FAIL: gdb.base/unwind-on-each-insn.exp: insn 7: $fba_value == $main_fba
FAIL: gdb.base/unwind-on-each-insn.exp: insn 7: [string equal $fid $main_fid]
...
Tested on:
- x86_64-linux (-m64 and -m32)
- s390x-linux (-m64 and -m31)
- powerpc64le-linux
- aarch64-linux
Also I've checked that the test-case still functions as regression test for PR
record/16678 on x86_64/-m32.
---
gdb/testsuite/gdb.base/unwind-on-each-insn-foo.c | 2 +-
gdb/testsuite/gdb.base/unwind-on-each-insn.c | 4 ++--
gdb/testsuite/gdb.base/unwind-on-each-insn.exp | 7 ++++++-
3 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/gdb/testsuite/gdb.base/unwind-on-each-insn-foo.c b/gdb/testsuite/gdb.base/unwind-on-each-insn-foo.c
index af9fc11ddab..635aa44135e 100644
--- a/gdb/testsuite/gdb.base/unwind-on-each-insn-foo.c
+++ b/gdb/testsuite/gdb.base/unwind-on-each-insn-foo.c
@@ -16,7 +16,7 @@
along with this program. If not, see <http://www.gnu.org/licenses/>. */
void
-foo ()
+foo (const char *s)
{
/* Nothing. */
}
diff --git a/gdb/testsuite/gdb.base/unwind-on-each-insn.c b/gdb/testsuite/gdb.base/unwind-on-each-insn.c
index 60bc83a6d4f..821df375115 100644
--- a/gdb/testsuite/gdb.base/unwind-on-each-insn.c
+++ b/gdb/testsuite/gdb.base/unwind-on-each-insn.c
@@ -15,11 +15,11 @@
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
-extern void foo ();
+extern void foo (const char *);
int
main ()
{
- foo ();
+ foo ("foo");
return 0;
}
diff --git a/gdb/testsuite/gdb.base/unwind-on-each-insn.exp b/gdb/testsuite/gdb.base/unwind-on-each-insn.exp
index 5e822effaf1..c61ffe5d174 100644
--- a/gdb/testsuite/gdb.base/unwind-on-each-insn.exp
+++ b/gdb/testsuite/gdb.base/unwind-on-each-insn.exp
@@ -103,7 +103,12 @@ for { set i_count 1 } { true } { incr i_count } {
# Check we can unwind the stack-pointer and the frame base
# address correctly.
lassign [get_sp_and_fba "for main"] sp_value fba_value
- gdb_assert { $sp_value == $main_sp }
+ if { $i_count == 1 } {
+ # The stack-pointer may have changed while running to *foo.
+ set main_sp $sp_value
+ } else {
+ gdb_assert { $sp_value == $main_sp }
+ }
gdb_assert { $fba_value == $main_fba }
# Check we have a consistent value for main's frame-id.
--
2.35.3
next prev parent reply other threads:[~2023-01-19 10:46 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-19 10:46 [PATCH 0/4] [gdb] Test-case gdb.base/unwind-on-each-insn.exp improvements Tom de Vries
2023-01-19 10:46 ` [PATCH 1/4] [gdb/testsuite] Simplify gdb.base/unwind-on-each-insn.exp Tom de Vries
2023-01-23 9:36 ` Tom de Vries
2023-01-19 10:46 ` Tom de Vries [this message]
2023-01-23 9:55 ` [PATCH 2/4] [gdb/testsuite] Improve gdb.base/unwind-on-each-insn.exp Luis Machado
2023-01-19 10:46 ` [PATCH 3/4] [gdb/tdep, aarch64] Fix frame address of last insn in leaf function Tom de Vries
2023-01-20 10:25 ` Tom de Vries
2023-01-23 10:07 ` Luis Machado
2023-01-23 11:59 ` Tom de Vries
2023-01-23 12:09 ` Luis Machado
2023-01-19 10:46 ` [PATCH 4/4] [gdb/testsuite] Analyze non-leaf fn in gdb.base/unwind-on-each-insn.exp Tom de Vries
2023-01-23 10:18 ` Luis Machado
2023-01-25 12:32 ` [PATCH 0/4] [gdb] Test-case gdb.base/unwind-on-each-insn.exp improvements Tom de Vries
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