| Message ID | 1456346889-9862-4-git-send-email-adhemerval.zanella@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 24 Feb 2016 17:48, Adhemerval Zanella wrote: > +#define SYSCALL_LL(__val) \ > + __LONG_LONG_PAIR (__val >> 31, __val) > +#define SYSCALL_LL64(__val) \ > + __LONG_LONG_PAIR ((long) (__val >> 32), (long) (__val & 0xffffffff)) shouldn't __val be parenthesized ? #define SYSCALL_LL(__val) __LONG_LONG_PAIR ((__val) >> 31, (__val)) also, does this really need to be __val ? it's a macro so it's not like someone using a var or define named __val would affect this. -mike
diff --git a/sysdeps/unix/sysv/linux/generic/sysdep.h b/sysdeps/unix/sysv/linux/generic/sysdep.h index 4f2c65d..22bfe59 100644 --- a/sysdeps/unix/sysv/linux/generic/sysdep.h +++ b/sysdeps/unix/sysv/linux/generic/sysdep.h @@ -22,7 +22,9 @@ #include <sysdeps/unix/sysv/linux/sysdep.h> /* Provide the common name to allow more code reuse. */ +#ifndef __NR__llseek #define __NR__llseek __NR_llseek +#endif #if __WORDSIZE == 64 /* By defining the older names, glibc will build syscall wrappers for @@ -41,3 +43,14 @@ #define __ALIGNMENT_ARG #define __ALIGNMENT_COUNT(a,b) a #endif + +/* Provide a common macro to pass 64-bit value on syscalls. */ +#if __WORDSIZE == 64 || defined __ASSUME_WORDSIZE64_ILP32 +# define SYSCALL_LL(__val) (__val) +# define SYSCALL_LL64(__val) (__val) +#else +#define SYSCALL_LL(__val) \ + __LONG_LONG_PAIR (__val >> 31, __val) +#define SYSCALL_LL64(__val) \ + __LONG_LONG_PAIR ((long) (__val >> 32), (long) (__val & 0xffffffff)) +#endif
From: Adhemerval Zanella <adhemerval.zanella@linaro.com> This patch add two new macros 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 changes itself are not currently used in any implementation, so no code change is expected. * sysdeps/unix/sysv/linux/generic/sysdep.h (__NR__llseek): Define only if it is not already defined. (SYSCALL_LL): Define. (SYSCALL_LL64): Likewise. --- sysdeps/unix/sysv/linux/generic/sysdep.h | 13 +++++++++++++ 2 files changed, 18 insertions(+)