--- /dev/null
+/* This test program is part of GDB, the GNU debugger.
+
+ Copyright 2025 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/auxv.h>
+#include <linux/prctl.h>
+#include <sys/syscall.h>
+
+/* Feature check for Guarded Control Stack. */
+#ifndef HWCAP_GCS
+#define HWCAP_GCS (1UL << 32)
+#endif
+
+#ifndef PR_GET_SHADOW_STACK_STATUS
+#define PR_GET_SHADOW_STACK_STATUS 74
+#define PR_SET_SHADOW_STACK_STATUS 75
+#define PR_SHADOW_STACK_ENABLE (1UL << 0)
+#endif
+
+/* We need to use a macro to call prctl because after GCS is enabled, it's not
+ possible to return from the function which enabled it. This is because the
+ return address of the calling function isn't on the GCS. */
+#define my_syscall2(num, arg1, arg2) \
+ ({ \
+ register long _num __asm__("x8") = (num); \
+ register long _arg1 __asm__("x0") = (long)(arg1); \
+ register long _arg2 __asm__("x1") = (long)(arg2); \
+ register long _arg3 __asm__("x2") = 0; \
+ register long _arg4 __asm__("x3") = 0; \
+ register long _arg5 __asm__("x4") = 0; \
+ \
+ __asm__ volatile("svc #0\n" \
+ : "=r"(_arg1) \
+ : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \
+ "r"(_arg5), "r"(_num) \
+ : "memory", "cc"); \
+ _arg1; \
+ })
+
+#define get_gcspr(void) \
+ ({ \
+ unsigned long *gcspr; \
+ \
+ /* Get GCSPR_EL0. */ \
+ asm volatile("mrs %0, S3_3_C2_C5_1" : "=r"(gcspr) : : "cc"); \
+ \
+ gcspr; \
+ })
+
+/* Corrupt the return address to see if GDB will report a SIGSEGV with the
+ expected
+ $_siginfo.si_code. */
+static void __attribute__ ((noinline))
+function (unsigned long *gcspr)
+{
+ /* x30 holds the return address. */
+ register long x30 __asm__("x30") __attribute__ ((unused));
+
+ /* Print GCSPR to stdout so that the testcase can capture it. */
+ printf ("%p\n", get_gcspr ());
+ fflush (stdout);
+
+ /* Cause a GCS exception. */
+ x30 = 0xbadc0ffee;
+ __asm__ volatile("ret\n");
+}
+
+int
+main (void)
+{
+ if (!(getauxval (AT_HWCAP) & HWCAP_GCS))
+ {
+ fprintf (stderr, "GCS support not found in AT_HWCAP\n");
+ return EXIT_FAILURE;
+ }
+
+ /* Force shadow stacks on, our tests *should* be fine with or
+ without libc support and with or without this having ended
+ up tagged for GCS and enabled by the dynamic linker. We
+ can't use the libc prctl() function since we can't return
+ from enabling the stack. Also lock GCS if not already
+ locked so we can test behaviour when it's locked. */
+ unsigned long gcs_mode;
+ int ret = my_syscall2 (__NR_prctl, PR_GET_SHADOW_STACK_STATUS, &gcs_mode);
+ if (ret)
+ {
+ fprintf (stderr, "Failed to read GCS state: %d\n", ret);
+ return EXIT_FAILURE;
+ }
+
+ if (!(gcs_mode & PR_SHADOW_STACK_ENABLE))
+ {
+ gcs_mode = PR_SHADOW_STACK_ENABLE;
+ ret = my_syscall2 (__NR_prctl, PR_SET_SHADOW_STACK_STATUS, gcs_mode);
+ if (ret)
+ {
+ fprintf (stderr, "Failed to configure GCS: %d\n", ret);
+ return EXIT_FAILURE;
+ }
+ }
+
+ unsigned long *gcspr = get_gcspr ();
+
+ /* Pass gscpr to function just so it's used for something. */
+ function (gcspr); /* Break here. */
+
+ /* Avoid returning, in case libc doesn't understand GCS. */
+ exit (EXIT_SUCCESS);
+}
--- /dev/null
+# Copyright 2025 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# Test reading and writing the core dump of a binary that uses a Guarded
+# Control Stack.
+
+require allow_aarch64_gcs_tests
+
+standard_testfile
+
+if { [prepare_for_testing "failed to prepare" $testfile $srcfile] } {
+ return
+}
+
+set linespec ${srcfile}:[gdb_get_line_number "Break here"]
+
+if ![runto $linespec] {
+ return
+}
+
+# Continue until a crash. The line with the hex number is optional because
+# it's printed by the test program, and doesn't appear in the Expect buffer
+# when testing a remote target.
+gdb_test "continue" \
+ [multi_line \
+ "Continuing\\." \
+ "($hex\r\n)?" \
+ "Program received signal SIGSEGV, Segmentation fault" \
+ "Guarded Control Stack error\\." \
+ "function \\(gcspr=$hex\\) at .*aarch64-gcs-core.c:$decimal" \
+ {.*__asm__ volatile\("ret\\n"\);}] \
+ "continue to SIGSEGV"
+
+set gcspr_in_gcore [get_valueof "/x" "\$gcspr" "*unknown*"]
+
+# Generate the gcore core file.
+set gcore_filename [standard_output_file "${testfile}.gcore"]
+set gcore_generated [gdb_gcore_cmd "$gcore_filename" "generate gcore file"]
+
+# Obtain an OS-generated core file.
+set core_filename [core_find $binfile {} {} "${binfile}.out"]
+set core_generated [expr {$core_filename != ""}]
+set os_core_name "${binfile}.core"
+remote_exec build "mv $core_filename $os_core_name"
+set core_filename $os_core_name
+
+# At this point we have a couple of core files, the gcore one generated by
+# GDB and the one generated by the operating system. Make sure GDB can
+# read both correctly.
+
+proc check_core_file {core_filename saved_gcspr} {
+ global decimal hex
+
+ # Load the core file.
+ if [gdb_test "core $core_filename" \
+ [multi_line \
+ "Core was generated by .*\\." \
+ "Program terminated with signal SIGSEGV, Segmentation fault" \
+ "Guarded Control Stack error\\." \
+ "#0 function \\(gcspr=$hex\\) at .*aarch64-gcs-core.c:$decimal" \
+ "$decimal.*__asm__ volatile\\(\"ret\\\\n\"\\);"] \
+ "load core file"] {
+ return -1
+ }
+
+ # Check the value of GCSPR in the core file.
+ gdb_test "print/x \$gcspr" "\\$\[0-9\]+ = $saved_gcspr" \
+ "gcspr contents from core file"
+}
+
+if {$gcore_generated} {
+ clean_restart $binfile
+
+ with_test_prefix "gcore corefile" {
+ check_core_file $gcore_filename $gcspr_in_gcore
+ }
+} else {
+ fail "gcore corefile not generated"
+}
+
+if {$core_generated} {
+ clean_restart $binfile
+
+ with_test_prefix "OS corefile" {
+ set out_id [open ${binfile}.out "r"]
+ set gcspr_in_core [gets $out_id]
+
+ close $out_id
+ check_core_file $core_filename $gcspr_in_core
+ }
+} else {
+ untested "OS corefile not generated"
+}
projects / thirdparty / binutils-gdb.git / commitdiff
