[PATCH v4 03/21] nptl: x86_64: Fix Race conditions in pthread cancellation [BZ#12683]
Adhemerval Zanella
adhemerval.zanella@linaro.org
Fri Apr 3 20:31:43 GMT 2020
This patches adds the x86_64 modification required for the BZ#12683.
Checked on x86_64-linux-gnu.
---
.../unix/sysv/linux/x86_64/syscall_cancel.S | 59 +++++++++++++++++++
1 file changed, 59 insertions(+)
create mode 100644 sysdeps/unix/sysv/linux/x86_64/syscall_cancel.S
diff --git a/sysdeps/unix/sysv/linux/x86_64/syscall_cancel.S b/sysdeps/unix/sysv/linux/x86_64/syscall_cancel.S
new file mode 100644
index 0000000000..11c3eeb084
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86_64/syscall_cancel.S
@@ -0,0 +1,59 @@
+/* Cancellable syscall wrapper - x86_64 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 [rax] __syscall_cancel_arch (volatile int *cancelhandling [%rdi],
+ __syscall_arg_t nr [%rsi],
+ __syscall_arg_t arg1 [%rdx],
+ __syscall_arg_t arg2 [%rcx],
+ __syscall_arg_t arg3 [%r8],
+ __syscall_arg_t arg4 [%r9],
+ __syscall_arg_t arg5 [SP+8],
+ __syscall_arg_t arg6 [SP+16]) */
+
+ENTRY (__syscall_cancel_arch)
+
+ .globl __syscall_cancel_arch_start
+__syscall_cancel_arch_start:
+
+ /* if (*cancelhandling & CANCELED_BITMASK)
+ __syscall_do_cancel() */
+ mov (%rdi),%eax
+ testb $TCB_CANCELED_BITMASK, (%rdi)
+ jne __syscall_do_cancel
+
+ /* Issue a 6 argument syscall, the nr [%rax] being the syscall
+ number. */
+ mov %rdi,%r11
+ mov %rsi,%rax
+ mov %rdx,%rdi
+ mov %rcx,%rsi
+ mov %r8,%rdx
+ mov %r9,%r10
+ mov 8(%rsp),%r8
+ mov 16(%rsp),%r9
+ mov %r11,8(%rsp)
+ syscall
+
+ .globl __syscall_cancel_arch_end
+__syscall_cancel_arch_end:
+ ret
+
+END (__syscall_cancel_arch)
+libc_hidden_def (__syscall_cancel_arch)
--
2.17.1
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