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glibc/sysdeps
Adhemerval Zanella 7cbeabac0f x86: Remove vsyscall usage
This patch removes the vsyscall usage for x86_64 port.  As indicated
by kernel code comments [1], vsyscalls are a legacy ABI and its concept
is problematic:

- It interferes with ASLR.
- It's awkward to write code that lives in kernel addresses but is
  callable by userspace at fixed addresses.
- The whole concept is impossible for 32-bit compat userspace.
- UML cannot easily virtualize a vsyscall.

The VDSO is a better approach for such functionality.  Tested on i686,
x86_64, and x32.

	* sysdeps/unix/sysv/linux/i386/gettimeofday.c
	(__gettimeofday_syscall): Remove vsyscall fallback.
	* sysdeps/unix/sysv/linux/i386/time.c (__time_syscall): Likewise.
	* sysdeps/unix/sysv/linux/x86/gettimeofday.c (__gettimeofday_syscall):
	Add syscall fallback function.
	(gettimeofday_ifunc): Use __gettimeofday_syscall as fallback mechanism
	if vDSO is not present.
	* sysdeps/unix/sysv/linux/x86/time.c (__time_syscall): Add syscall
	fallback function.
	(time_ifunc): Use __time_syscall as fallback mechanism if vDSO is not
	present.
	* sysdeps/unix/sysv/linux/x86_64/gettimeofday.c: Remove file.
	* sysdeps/unix/sysv/linux/x86_64/time.c: Likewise.

[1] arch/x86/kernel/vsyscall_64.c
2015-06-09 18:10:19 -03:00
..
2015-05-19 09:43:54 -07:00
2015-02-08 18:46:00 +01:00
2015-06-03 16:35:44 +01:00
2015-03-21 04:49:44 +01:00
2015-03-06 11:32:24 +01:00
2015-04-24 13:37:48 +02:00
2015-06-09 18:10:19 -03:00
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