From FEDORA_PATCHES Mon Sep 17 00:00:00 2001
From: Bruno Larsen <blarsen@redhat.com>
Date: Tue, 18 Oct 2022 11:10:41 +0200
Subject: gdb-backport-fix-break-main-file-remove-fail.patch
;; [gdb/testsuite] Use prototype to call libc functions
;; (Tom de Vries)
On openSUSE Tumbleweed (using glibc 2.36), I run into:
...
(gdb) print /d (int) munmap (4198400, 4096)^M
Invalid cast.^M
(gdb) FAIL: gdb.base/break-main-file-remove-fail.exp: cmdline: \
get integer valueof "(int) munmap (4198400, 4096)"
...
The problem is that after starting the executable, the symbol has type
"void (*) (void)":
...
(gdb) p munmap
$1 = {<text variable, no debug info>} 0x401030 <munmap@plt>
(gdb) start
...
(gdb) p munmap
$2 = {void (void)} 0x7ffff7feb9a0 <__GI_munmap>
...
which causes the "Invalid cast" error.
Looking at the debug info for glibc for symbol __GI_munmap:
...
<0><189683>: Abbrev Number: 1 (DW_TAG_compile_unit)
<189691> DW_AT_name : ../sysdeps/unix/syscall-template.S
<189699> DW_AT_producer : GNU AS 2.39.0
<1><1896ae>: Abbrev Number: 2 (DW_TAG_subprogram)
<1896af> DW_AT_name : __GI___munmap
<1896b3> DW_AT_external : 1
<1896b4> DW_AT_low_pc : 0x10cad0
<1896bc> DW_AT_high_pc : 37
...
that's probably caused by this bit (or similar bits for other munmap aliases).
This is fixed in gas on trunk by commit 5578fbf672e ("GAS: Add a return type
tag to DWARF DIEs generated for function symbols").
Work around this (for say gas 2.39) by explicitly specifying the prototype for
munmap.
Likewise for getpid in a couple of other test-cases.
Tested on x86_64-linux.
diff --git a/gdb/testsuite/gdb.base/break-main-file-remove-fail.exp b/gdb/testsuite/gdb.base/break-main-file-remove-fail.exp
--- a/gdb/testsuite/gdb.base/break-main-file-remove-fail.exp
+++ b/gdb/testsuite/gdb.base/break-main-file-remove-fail.exp
@@ -87,7 +87,9 @@ proc test_remove_bp { initial_load } {
# should warn the user about it.
set pagesize [get_integer_valueof "pg_size" 0]
set align_addr [expr $bp_addr - $bp_addr % $pagesize]
- set munmap [get_integer_valueof "(int) munmap ($align_addr, $pagesize)" -1]
+ set munmap_prototype "int (*) (void *, size_t)"
+ set munmap_expr "(($munmap_prototype) munmap) ($align_addr, $pagesize)"
+ set munmap [get_integer_valueof $munmap_expr -1]
if {$munmap != 0} {
unsupported "can't munmap foo's page"
diff --git a/gdb/testsuite/gdb.base/dprintf-detach.exp b/gdb/testsuite/gdb.base/dprintf-detach.exp
--- a/gdb/testsuite/gdb.base/dprintf-detach.exp
+++ b/gdb/testsuite/gdb.base/dprintf-detach.exp
@@ -52,7 +52,7 @@ proc dprintf_detach_test { breakpoint_always_inserted dprintf_style disconnected
# Get PID of test program.
set inferior_pid -1
set test "get inferior process ID"
- gdb_test_multiple "call (int) getpid ()" $test {
+ gdb_test_multiple "call ((int (*) (void)) getpid) ()" $test {
-re ".* = ($decimal).*$gdb_prompt $" {
set inferior_pid $expect_out(1,string)
pass $test
diff --git a/gdb/testsuite/gdb.base/info-os.exp b/gdb/testsuite/gdb.base/info-os.exp
--- a/gdb/testsuite/gdb.base/info-os.exp
+++ b/gdb/testsuite/gdb.base/info-os.exp
@@ -39,7 +39,7 @@ if ![runto_main] then {
# Get PID of test program.
set inferior_pid ""
set test "get inferior process ID"
-gdb_test_multiple "call (int) getpid()" $test {
+gdb_test_multiple "call ((int (*) (void)) getpid) ()" $test {
-re ".* = ($decimal).*$gdb_prompt $" {
set inferior_pid $expect_out(1,string)
pass $test
diff --git a/gdb/testsuite/gdb.threads/siginfo-threads.exp b/gdb/testsuite/gdb.threads/siginfo-threads.exp
--- a/gdb/testsuite/gdb.threads/siginfo-threads.exp
+++ b/gdb/testsuite/gdb.threads/siginfo-threads.exp
@@ -41,7 +41,7 @@ gdb_breakpoint [gdb_get_line_number "break-at-exit"]
set test "get pid"
set pid ""
-gdb_test_multiple "p (int) getpid ()" $test {
+gdb_test_multiple "p ((int (*) (void))getpid) ()" $test {
-re " = (\[0-9\]+)\r\n$gdb_prompt $" {
set pid $expect_out(1,string)
pass $test