diff mbox series

[v4,08/21] nptl: aarch64: Fix Race conditions in pthread cancellation [BZ#12683]

Message ID 20200403203201.7494-9-adhemerval.zanella@linaro.org
State New
Headers show
Series nptl: Fix Race conditions in pthread cancellation [BZ#12683] | expand

Commit Message

Michael Kerrisk \(man-pages\) via Libc-alpha April 3, 2020, 8:31 p.m. UTC
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

Stepan Golosunov April 12, 2020, 3:29 p.m. UTC | #1
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
>
Adhemerval Zanella April 15, 2020, 2:30 p.m. UTC | #2
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
>>
diff mbox series

Patch

diff --git a/sysdeps/aarch64/nptl/tcb-offsets.sym b/sysdeps/aarch64/nptl/tcb-offsets.sym
index 238647dd47..614ea23034 100644
--- a/sysdeps/aarch64/nptl/tcb-offsets.sym
+++ b/sysdeps/aarch64/nptl/tcb-offsets.sym
@@ -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
diff --git a/sysdeps/unix/sysv/linux/aarch64/syscall_cancel.S b/sysdeps/unix/sysv/linux/aarch64/syscall_cancel.S
new file mode 100644
index 0000000000..fcb7cf66bf
--- /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])  */
+
+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)