From: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
To: Mark Brown <broonie@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Jonathan Corbet <corbet@lwn.net>,
Andrew Morton <akpm@linux-foundation.org>,
Marc Zyngier <maz@kernel.org>,
Oliver Upton <oliver.upton@linux.dev>,
James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Arnd Bergmann <arnd@arndb.de>, Oleg Nesterov <oleg@redhat.com>,
Eric Biederman <ebiederm@xmission.com>,
Kees Cook <keescook@chromium.org>, Shuah Khan <shuah@kernel.org>,
"Rick P. Edgecombe" <rick.p.edgecombe@intel.com>,
Deepak Gupta <debug@rivosinc.com>,
Ard Biesheuvel <ardb@kernel.org>,
Szabolcs Nagy <Szabolcs.Nagy@arm.com>,
"H.J. Lu" <hjl.tools@gmail.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Florian Weimer <fweimer@redhat.com>,
Christian Brauner <brauner@kernel.org>,
linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org,
kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org,
linux-arch@vger.kernel.org, linux-mm@kvack.org,
linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-riscv@lists.infradead.org
Subject: Re: [PATCH v8 33/38] kselftest/arm64: Add a GCS test program built with the system libc
Date: Mon, 19 Feb 2024 23:15:57 -0300 [thread overview]
Message-ID: <87sf1n7uea.fsf@linaro.org> (raw)
In-Reply-To: <20240203-arm64-gcs-v8-33-c9fec77673ef@kernel.org>
Mark Brown <broonie@kernel.org> writes:
> There are things like threads which nolibc struggles with which we want
> to add coverage for, and the ABI allows us to test most of these even if
> libc itself does not understand GCS so add a test application built
> using the system libc.
>
> Signed-off-by: Mark Brown <broonie@kernel.org>
> ---
> tools/testing/selftests/arm64/gcs/.gitignore | 1 +
> tools/testing/selftests/arm64/gcs/Makefile | 4 +-
> tools/testing/selftests/arm64/gcs/gcs-util.h | 10 +
> tools/testing/selftests/arm64/gcs/libc-gcs.c | 736 +++++++++++++++++++++++++++
> 4 files changed, 750 insertions(+), 1 deletion(-)
In v7, several tests weren't running in my FVT VM for some reason.
This time they do:
$ ./run_kselftest.sh -t arm64:libc-gcs
TAP version 13
1..1
# timeout set to 45
# selftests: arm64: libc-gcs
# TAP version 13
# 1..118
# # Starting 118 tests from 32 test cases.
# # RUN global.can_call_function ...
# # can_call_function: Test terminated unexpectedly by signal 11
# # FAIL global.can_call_function
# not ok 1 global.can_call_function
# # RUN global.gcs_enabled_thread ...
# # OK global.gcs_enabled_thread
# ok 2 global.gcs_enabled_thread
⋮
# # RUN invalid_mprotect.exec_bti.do_map_read ...
# # Allocated stack from 0xffffb3aa9000-0xffffb3aaa000
# # OK invalid_mprotect.exec_bti.do_map_read
# ok 118 invalid_mprotect.exec_bti.do_map_read
# # FAILED: 117 / 118 tests passed.
# # Totals: pass:117 fail:1 xfail:0 xpass:0 skip:0 error:0
not ok 1 selftests: arm64: libc-gcs # exit=1
The only issue as can be seen above is that the can_call_function test
is failing. The child is getting a GCS Segmentation fault when returning
from fork().
I tried debugging it with GDB, but I don't see what's wrong since the
address in LR matches the first entry in GCSPR. Here is the
debug session:
(gdb) break libc-gcs.c:58
Breakpoint 1 at 0x3894: file libc-gcs.c, line 58.
(gdb) set follow-fork-mode child
(gdb) r
Starting program: /var/tmp/selftests/arm64/libc-gcs
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/aarch64-linux-gnu/libthread_db.so.1".
TAP version 13
1..118
# Starting 118 tests from 32 test cases.
# RUN global.can_call_function ...
[Attaching after Thread 0xfffff7ff7e80 (LWP 9164) fork to child process 9168]
[New inferior 2 (process 9168)]
[Detaching after fork from parent process 9164]
[Inferior 1 (process 9164) detached]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/aarch64-linux-gnu/libthread_db.so.1".
Thread 2.1 "libc-gcs" received signal SIGSEGV, Segmentation fault
Guarded Control Stack error.
[Switching to Thread 0xfffff7ff7e80 (LWP 9168)]
0x0000fffff7ec6fc0 [GCS error] in __GI__Fork () at ../sysdeps/nptl/_Fork.c:50
warning: 50 ../sysdeps/nptl/_Fork.c: No such file or directory
(gdb) bt
#0 0x0000fffff7ec6fc0 [GCS error] in __GI__Fork () at ../sysdeps/nptl/_Fork.c:50
#1 0x0000fffff7ec6be0 in __libc_fork () at ./posix/fork.c:73
#2 0x0000aaaaaaaa49b8 in __run_test (f=f@entry=0xaaaaaaab98c8 <_fixture_global>,
variant=variant@entry=0xffffffffefb8, t=t@entry=0xaaaaaaab81b0 <_can_call_function_object>)
at /home/thiago.bauermann/src/linux/tools/testing/selftests/kselftest_harness.h:1128
#3 0x0000aaaaaaaa2ac4 in test_harness_run (argv=0xfffffffff158, argc=1)
at /home/thiago.bauermann/src/linux/tools/testing/selftests/kselftest_harness.h:1199
#4 main (argc=1, argv=0xfffffffff158) at libc-gcs.c:735
(gdb) p $gcspr
$1 = (void *) 0xfffff7dfffe0
(gdb) p/x $lr
$3 = 0xfffff7ec6be0
(gdb) p/x *(unsigned long *)$gcspr
$5 = 0xfffff7ec6be0
(gdb) disassemble
Dump of assembler code for function __GI__Fork:
0x0000fffff7ec6f70 <+0>: mrs x5, tpidr_el0
0x0000fffff7ec6f74 <+4>: mov x0, #0x11 // #17
0x0000fffff7ec6f78 <+8>: sub x6, x5, #0x7c0
0x0000fffff7ec6f7c <+12>: sub x4, x5, #0x6f0
0x0000fffff7ec6f80 <+16>: movk x0, #0x120, lsl #16
0x0000fffff7ec6f84 <+20>: mov x1, #0x0 // #0
0x0000fffff7ec6f88 <+24>: mov x2, #0x0 // #0
0x0000fffff7ec6f8c <+28>: mov x3, #0x0 // #0
0x0000fffff7ec6f90 <+32>: mov x8, #0xdc // #220
0x0000fffff7ec6f94 <+36>: svc #0x0
0x0000fffff7ec6f98 <+40>: cmn x0, #0x1, lsl #12
0x0000fffff7ec6f9c <+44>: b.hi 0xfffff7ec6fc4 <__GI__Fork+84> // b.pmore
0x0000fffff7ec6fa0 <+48>: mov w2, w0
0x0000fffff7ec6fa4 <+52>: cbnz w0, 0xfffff7ec6fbc <__GI__Fork+76>
0x0000fffff7ec6fa8 <+56>: sub x0, x5, #0x6e0
0x0000fffff7ec6fac <+60>: mov x1, #0x18 // #24
0x0000fffff7ec6fb0 <+64>: mov x8, #0x63 // #99
0x0000fffff7ec6fb4 <+68>: stp x0, x0, [x6, #216]
0x0000fffff7ec6fb8 <+72>: svc #0x0
0x0000fffff7ec6fbc <+76>: mov w0, w2
=> 0x0000fffff7ec6fc0 <+80>: ret
0x0000fffff7ec6fc4 <+84>: adrp x1, 0xfffff7faa000 <sys_siglist+424>
0x0000fffff7ec6fc8 <+88>: ldr x1, [x1, #3528]
0x0000fffff7ec6fcc <+92>: neg w0, w0
0x0000fffff7ec6fd0 <+96>: mov w2, #0xffffffff // #-1
0x0000fffff7ec6fd4 <+100>: str w0, [x5, x1]
0x0000fffff7ec6fd8 <+104>: mov w0, w2
0x0000fffff7ec6fdc <+108>: ret
End of assembler dump.
(gdb) p $w0
$8 = 0
(gdb) p $_siginfo.si_signo
$12 = 11
(gdb) p $_siginfo.si_code
$13 = 10
(gdb) p $_siginfo._sifields._sigfault.si_addr
$14 = (void *) 0xfffff7ec6fc0 <__GI__Fork+80>
--
Thiago
next prev parent reply other threads:[~2024-02-20 2:16 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-03 12:25 [PATCH v8 00/38] arm64/gcs: Provide support for GCS in userspace Mark Brown
2024-02-03 12:25 ` [PATCH v8 01/38] arm64/mm: Restructure arch_validate_flags() for extensibility Mark Brown
2024-02-03 12:25 ` [PATCH v8 02/38] prctl: arch-agnostic prctl for shadow stack Mark Brown
2024-02-03 12:25 ` [PATCH v8 03/38] mman: Add map_shadow_stack() flags Mark Brown
2024-02-03 12:25 ` [PATCH v8 04/38] arm64: Document boot requirements for Guarded Control Stacks Mark Brown
2024-02-03 12:25 ` [PATCH v8 05/38] arm64/gcs: Document the ABI " Mark Brown
2024-02-03 12:25 ` [PATCH v8 06/38] arm64/sysreg: Add definitions for architected GCS caps Mark Brown
2024-02-03 12:25 ` [PATCH v8 07/38] arm64/gcs: Add manual encodings of GCS instructions Mark Brown
2024-02-03 12:25 ` [PATCH v8 08/38] arm64/gcs: Provide put_user_gcs() Mark Brown
2024-02-03 12:25 ` [PATCH v8 09/38] arm64/cpufeature: Runtime detection of Guarded Control Stack (GCS) Mark Brown
2024-02-03 12:25 ` [PATCH v8 10/38] arm64/mm: Allocate PIE slots for EL0 guarded control stack Mark Brown
2024-02-03 12:25 ` [PATCH v8 11/38] mm: Define VM_SHADOW_STACK for arm64 when we support GCS Mark Brown
2024-02-03 12:25 ` [PATCH v8 12/38] arm64/mm: Map pages for guarded control stack Mark Brown
2024-02-03 12:25 ` [PATCH v8 13/38] KVM: arm64: Manage GCS registers for guests Mark Brown
2024-02-05 9:46 ` Marc Zyngier
2024-02-05 12:35 ` Mark Brown
2024-02-05 15:34 ` Marc Zyngier
2024-02-05 16:58 ` Mark Brown
2024-02-03 12:25 ` [PATCH v8 14/38] arm64/gcs: Allow GCS usage at EL0 and EL1 Mark Brown
2024-02-03 12:25 ` [PATCH v8 15/38] arm64/idreg: Add overrride for GCS Mark Brown
2024-02-03 12:25 ` [PATCH v8 16/38] arm64/hwcap: Add hwcap " Mark Brown
2024-02-03 12:25 ` [PATCH v8 17/38] arm64/traps: Handle GCS exceptions Mark Brown
2024-02-03 12:25 ` [PATCH v8 18/38] arm64/mm: Handle GCS data aborts Mark Brown
2024-02-03 12:25 ` [PATCH v8 19/38] arm64/gcs: Context switch GCS state for EL0 Mark Brown
2024-02-03 12:25 ` [PATCH v8 20/38] arm64/gcs: Ensure that new threads have a GCS Mark Brown
2024-02-20 2:02 ` Thiago Jung Bauermann
2024-02-21 18:16 ` Mark Brown
2024-02-03 12:25 ` [PATCH v8 21/38] arm64/gcs: Implement shadow stack prctl() interface Mark Brown
2024-02-03 12:25 ` [PATCH v8 22/38] arm64/mm: Implement map_shadow_stack() Mark Brown
2024-02-03 12:25 ` [PATCH v8 23/38] arm64/signal: Set up and restore the GCS context for signal handlers Mark Brown
2024-02-20 2:03 ` Thiago Jung Bauermann
2024-02-03 12:25 ` [PATCH v8 24/38] arm64/signal: Expose GCS state in signal frames Mark Brown
2024-02-03 12:25 ` [PATCH v8 25/38] arm64/ptrace: Expose GCS via ptrace and core files Mark Brown
2024-02-03 12:25 ` [PATCH v8 26/38] arm64: Add Kconfig for Guarded Control Stack (GCS) Mark Brown
2024-02-03 12:25 ` [PATCH v8 27/38] kselftest/arm64: Verify the GCS hwcap Mark Brown
2024-02-03 12:25 ` [PATCH v8 28/38] kselftest/arm64: Add GCS as a detected feature in the signal tests Mark Brown
2024-02-03 12:25 ` [PATCH v8 29/38] kselftest/arm64: Add framework support for GCS to signal handling tests Mark Brown
2024-02-03 12:25 ` [PATCH v8 30/38] kselftest/arm64: Allow signals tests to specify an expected si_code Mark Brown
2024-02-03 12:25 ` [PATCH v8 31/38] kselftest/arm64: Always run signals tests with GCS enabled Mark Brown
2024-02-03 12:25 ` [PATCH v8 32/38] kselftest/arm64: Add very basic GCS test program Mark Brown
2024-02-03 12:25 ` [PATCH v8 33/38] kselftest/arm64: Add a GCS test program built with the system libc Mark Brown
2024-02-20 2:15 ` Thiago Jung Bauermann [this message]
2024-02-21 19:20 ` Mark Brown
2024-02-22 19:11 ` Mark Brown
2024-02-23 2:24 ` Thiago Jung Bauermann
2024-02-27 16:14 ` Mark Brown
2024-02-27 19:08 ` Thiago Jung Bauermann
2024-02-29 21:45 ` Mark Brown
2024-02-29 22:13 ` Thiago Jung Bauermann
2024-02-03 12:26 ` [PATCH v8 34/38] kselftest/arm64: Add test coverage for GCS mode locking Mark Brown
2024-02-03 12:26 ` [PATCH v8 35/38] selftests/arm64: Add GCS signal tests Mark Brown
2024-02-20 2:17 ` Thiago Jung Bauermann
2024-02-03 12:26 ` [PATCH v8 36/38] kselftest/arm64: Add a GCS stress test Mark Brown
2024-02-03 12:26 ` [PATCH v8 37/38] kselftest/arm64: Enable GCS for the FP stress tests Mark Brown
2024-02-03 12:26 ` [PATCH v8 38/38] kselftest: Provide shadow stack enable helpers for arm64 Mark Brown
2024-02-20 2:00 ` [PATCH v8 00/38] arm64/gcs: Provide support for GCS in userspace Thiago Jung Bauermann
2024-02-20 16:36 ` Stefan O'Rear
2024-02-20 18:41 ` Edgecombe, Rick P
2024-02-20 18:57 ` [musl] " Rich Felker
2024-02-20 23:30 ` Edgecombe, Rick P
2024-02-20 23:54 ` dalias
2024-02-21 0:35 ` Edgecombe, Rick P
2024-02-21 0:44 ` Mark Brown
2024-02-21 1:27 ` dalias
2024-02-21 2:11 ` Edgecombe, Rick P
2024-02-21 4:18 ` Edgecombe, Rick P
2024-02-21 13:53 ` Mark Brown
2024-02-21 14:58 ` dalias
2024-02-21 17:36 ` Mark Brown
2024-02-21 17:57 ` dalias
2024-02-21 18:12 ` Edgecombe, Rick P
2024-02-21 18:30 ` dalias
2024-02-21 18:53 ` Edgecombe, Rick P
2024-02-21 19:06 ` dalias
2024-02-21 19:22 ` Edgecombe, Rick P
2024-02-21 20:18 ` H.J. Lu
2024-02-21 20:25 ` H.J. Lu
2024-02-21 21:12 ` H.J. Lu
2024-02-21 20:18 ` dalias
2024-02-22 13:57 ` Mark Brown
2024-02-21 18:32 ` Mark Brown
2024-02-21 19:10 ` dalias
2024-03-02 14:57 ` Szabolcs Nagy
2024-03-02 15:05 ` H.J. Lu
2024-03-14 14:03 ` Mark Brown
2024-02-20 23:59 ` Stefan O'Rear
2024-02-21 0:40 ` Mark Brown
2024-02-21 4:30 ` Edgecombe, Rick P
2024-02-20 20:14 ` Mark Brown
2024-02-20 23:30 ` Edgecombe, Rick P
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