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authorAdhemerval Zanella <adhemerval.zanella@linaro.com>2015-10-21 10:04:07 -0200
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2016-04-11 10:07:53 -0300
commiteeddfa91cbb1a619af135c7a9ac14251ec094b7a (patch)
tree29e923a48e615c43a4fcaf45bdde3a50a0a5c51a /sysdeps/unix/sysv/linux/generic/sysdep.h
parent482b2f87a88d30fd5bc0277e6a3f75efeb1aff7f (diff)
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Consolidate off_t/off64_t syscall argument passing
This patch add three new macros (SYSCALL_LL, SYSCALL_LL64, and
__ASSUME_WORDSIZE64_ILP32) to use along with off_t and off64_t argument
syscalls.  The rationale for this change is:

1. Remove multiple implementations for the same syscall for different
   architectures (for instance, pread have 6 different implementations).

2. Also remove the requirement to use syscall wrappers for cancellable
   entrypoints.

The macro usage should be used along __ALIGNMENT_ARG to follow ABI constrains
for architecture where it applies.  For instance, pread can be rewritten as:

  return SYSCALL_CANCEL (pread, fd, buf, count,
                         __ALIGNMENT_ARG SYSCALL_LL (offset));

Another macro, SYSCALL_LL64, is provided for off64_t.  The macro
__ASSUME_WORDSIZE64_ILP32 is used by the ABI to define is uses 64-bit register
even if ABI is ILP32 (for instance x32 and mips64-n32).

The changes itself are not currently used in any implementation, so no
code change is expected.

	* sysdeps/unix/sysv/linux/generic/sysdep.h (__ALIGNMENT_ARG): Move
	definition.
	(__ALIGNMENT_COUNT): Likewise.
	* sysdeps/unix/sysv/linux/sysdep.h (__ALIGNMENT_ARG): To here.
	(__ALIGNMENT_COUNT): Likewise.
	(SYSCALL_LL): New define.
	(SYSCALL_LL64): Likewise.
	* sysdeps/unix/sysv/linux/mips/kernel-features.h:
	[_MIPS_SIM == _ABIO32] (__ASSUME_WORDSIZE64_ILP32): Define.
	* sysdeps/unix/sysv/linux/x86_64/kernel-features.h:
	[ILP32] (__ASUME_WORDSIZE64_ILP32): Likewise.
Diffstat (limited to 'sysdeps/unix/sysv/linux/generic/sysdep.h')
-rw-r--r--sysdeps/unix/sysv/linux/generic/sysdep.h10
1 files changed, 0 insertions, 10 deletions
diff --git a/sysdeps/unix/sysv/linux/generic/sysdep.h b/sysdeps/unix/sysv/linux/generic/sysdep.h
index 4f2c65d074..b0422ff5b0 100644
--- a/sysdeps/unix/sysv/linux/generic/sysdep.h
+++ b/sysdeps/unix/sysv/linux/generic/sysdep.h
@@ -31,13 +31,3 @@
 #define __NR_pread __NR_pread64
 #define __NR_pwrite __NR_pwrite64
 #endif
-
-/* Provide a dummy argument that can be used to force register
-   alignment for register pairs if required by the syscall ABI.  */
-#ifdef __ASSUME_ALIGNED_REGISTER_PAIRS
-#define __ALIGNMENT_ARG 0,
-#define __ALIGNMENT_COUNT(a,b) b
-#else
-#define __ALIGNMENT_ARG
-#define __ALIGNMENT_COUNT(a,b) a
-#endif