[v4,08/21] nptl: aarch64: Fix Race conditions in pthread cancellation [BZ#12683]
Commit Message
This patch adds the aarch64 modifications required for the BZ#12683 fix
by adding the arch-specific cancellation syscall bridge.
Checked on aarch64-linux-gnu.
---
sysdeps/aarch64/nptl/tcb-offsets.sym | 3 +
.../unix/sysv/linux/aarch64/syscall_cancel.S | 59 +++++++++++++++++++
2 files changed, 62 insertions(+)
create mode 100644 sysdeps/unix/sysv/linux/aarch64/syscall_cancel.S
Comments
03.04.2020 в 17:31:48 -0300 Adhemerval Zanella написал:
> This patch adds the aarch64 modifications required for the BZ#12683 fix
> by adding the arch-specific cancellation syscall bridge.
>
> Checked on aarch64-linux-gnu.
> ---
> sysdeps/aarch64/nptl/tcb-offsets.sym | 3 +
> .../unix/sysv/linux/aarch64/syscall_cancel.S | 59 +++++++++++++++++++
> 2 files changed, 62 insertions(+)
> create mode 100644 sysdeps/unix/sysv/linux/aarch64/syscall_cancel.S
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/syscall_cancel.S
> @@ -0,0 +1,59 @@
> +/* Cancellable syscall wrapper. Linux/AArch64 version.
> + Copyright (C) 2020 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library 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
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library; if not, see
> + <http://www.gnu.org/licenses/>. */
> +
> +#include <sysdep.h>
> +
> +/* long int [r0] __syscall_cancel_arch (int *cancelhandling [r0],
> + long int nr [r1],
> + long int arg1 [r2],
> + long int arg2 [r3],
> + long int arg3 [SP],
> + long int arg4 [SP+4],
> + long int arg5 [SP+8],
> + long int arg6 [SP+12]) */
Looks like this comment was copypasted from 32-bit arm. Texts in
square brackets obviously do not correspond to reality. Starting
from the fact that they imply that sizeof (long int) == 4.
> +
> +ENTRY (__syscall_cancel_arch)
> +
> + .globl __syscall_cancel_arch_start
> +__syscall_cancel_arch_start:
> +
> + /* if (*cancelhandling & CANCELED_BITMASK)
> + __syscall_do_cancel() */
> + ldr w0, [x0]
> + tbnz w0, TCB_CANCELED_BIT, 1f
> +
> + /* Issue a 6 argument syscall, the nr [x1] being the syscall
> + number. */
> + mov x8, x1
> + mov x0, x2
> + mov x1, x3
> + mov x2, x4
> + mov x3, x5
> + mov x4, x6
> + mov x5, x7
> + svc 0x0
> +
> + .globl __syscall_cancel_arch_end
> +__syscall_cancel_arch_end:
> + ret
> +
> +1:
> + b __syscall_do_cancel
> +
> +END (__syscall_cancel_arch)
> +libc_hidden_def (__syscall_cancel_arch)
> --
> 2.17.1
>
On 12/04/2020 12:29, Stepan Golosunov wrote:
> 03.04.2020 в 17:31:48 -0300 Adhemerval Zanella написал:
>> This patch adds the aarch64 modifications required for the BZ#12683 fix
>> by adding the arch-specific cancellation syscall bridge.
>>
>> Checked on aarch64-linux-gnu.
>> ---
>> sysdeps/aarch64/nptl/tcb-offsets.sym | 3 +
>> .../unix/sysv/linux/aarch64/syscall_cancel.S | 59 +++++++++++++++++++
>> 2 files changed, 62 insertions(+)
>> create mode 100644 sysdeps/unix/sysv/linux/aarch64/syscall_cancel.S
>
>> --- /dev/null
>> +++ b/sysdeps/unix/sysv/linux/aarch64/syscall_cancel.S
>> @@ -0,0 +1,59 @@
>> +/* Cancellable syscall wrapper. Linux/AArch64 version.
>> + Copyright (C) 2020 Free Software Foundation, Inc.
>> + This file is part of the GNU C Library.
>> +
>> + The GNU C Library is free software; you can redistribute it and/or
>> + modify it under the terms of the GNU Lesser General Public
>> + License as published by the Free Software Foundation; either
>> + version 2.1 of the License, or (at your option) any later version.
>> +
>> + The GNU C Library 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
>> + Lesser General Public License for more details.
>> +
>> + You should have received a copy of the GNU Lesser General Public
>> + License along with the GNU C Library; if not, see
>> + <http://www.gnu.org/licenses/>. */
>> +
>> +#include <sysdep.h>
>> +
>> +/* long int [r0] __syscall_cancel_arch (int *cancelhandling [r0],
>> + long int nr [r1],
>> + long int arg1 [r2],
>> + long int arg2 [r3],
>> + long int arg3 [SP],
>> + long int arg4 [SP+4],
>> + long int arg5 [SP+8],
>> + long int arg6 [SP+12]) */
>
> Looks like this comment was copypasted from 32-bit arm. Texts in
> square brackets obviously do not correspond to reality. Starting
> from the fact that they imply that sizeof (long int) == 4.
Ack, I have fixed the comment to the expected aarch64 ABI. Thanks
for spotting it.
>
>> +
>> +ENTRY (__syscall_cancel_arch)
>> +
>> + .globl __syscall_cancel_arch_start
>> +__syscall_cancel_arch_start:
>> +
>> + /* if (*cancelhandling & CANCELED_BITMASK)
>> + __syscall_do_cancel() */
>> + ldr w0, [x0]
>> + tbnz w0, TCB_CANCELED_BIT, 1f
>> +
>> + /* Issue a 6 argument syscall, the nr [x1] being the syscall
>> + number. */
>> + mov x8, x1
>> + mov x0, x2
>> + mov x1, x3
>> + mov x2, x4
>> + mov x3, x5
>> + mov x4, x6
>> + mov x5, x7
>> + svc 0x0
>> +
>> + .globl __syscall_cancel_arch_end
>> +__syscall_cancel_arch_end:
>> + ret
>> +
>> +1:
>> + b __syscall_do_cancel
>> +
>> +END (__syscall_cancel_arch)
>> +libc_hidden_def (__syscall_cancel_arch)
>> --
>> 2.17.1
>>
@@ -4,3 +4,6 @@
PTHREAD_MULTIPLE_THREADS_OFFSET offsetof (struct pthread, header.multiple_threads)
PTHREAD_TID_OFFSET offsetof (struct pthread, tid)
PTHREAD_SIZEOF sizeof (struct pthread)
+
+-- Not strictly offsets, used on syscall_cancel.S
+TCB_CANCELED_BIT CANCELED_BIT
new file mode 100644
@@ -0,0 +1,59 @@
+/* Cancellable syscall wrapper. Linux/AArch64 version.
+ Copyright (C) 2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+
+/* long int [r0] __syscall_cancel_arch (int *cancelhandling [r0],
+ long int nr [r1],
+ long int arg1 [r2],
+ long int arg2 [r3],
+ long int arg3 [SP],
+ long int arg4 [SP+4],
+ long int arg5 [SP+8],
+ long int arg6 [SP+12]) */
+
+ENTRY (__syscall_cancel_arch)
+
+ .globl __syscall_cancel_arch_start
+__syscall_cancel_arch_start:
+
+ /* if (*cancelhandling & CANCELED_BITMASK)
+ __syscall_do_cancel() */
+ ldr w0, [x0]
+ tbnz w0, TCB_CANCELED_BIT, 1f
+
+ /* Issue a 6 argument syscall, the nr [x1] being the syscall
+ number. */
+ mov x8, x1
+ mov x0, x2
+ mov x1, x3
+ mov x2, x4
+ mov x3, x5
+ mov x4, x6
+ mov x5, x7
+ svc 0x0
+
+ .globl __syscall_cancel_arch_end
+__syscall_cancel_arch_end:
+ ret
+
+1:
+ b __syscall_do_cancel
+
+END (__syscall_cancel_arch)
+libc_hidden_def (__syscall_cancel_arch)