From fa9cfbfcb70bd3736ec54eeeb4d0796aa4b9521f Mon Sep 17 00:00:00 2001 From: Volodymyr Boyko Date: Fri, 23 Nov 2018 02:19:55 +0200 Subject: Defined INLINE_SYSCALL_NOERR_NCS in mips/bits/syscalls.h On Linux/MIPS (O32 ABI) for system call we have two result registers - v0 and a3. v0 contains actual syscall result on success or error number on fail, a3 set to 0/1 for indicating syscall success/fail. (if a3 == 1, v0 contains errno). Now as we can see from definition of handle_sys (arch/mips/kernel/scall32-o32.S), handler treats returned by syscall function (let's call "original") values in range [-EMAXERRNO; 0[ as -errno, a3 is set to 1 and final returned (to userspace) value is (-original). INLINE_SYSCALL_NOERR_NCS defined in mips/bits/syscalls.h will handle this behaviour. Signed-off-by: Volodymyr Boyko --- libc/sysdeps/linux/mips/bits/syscalls.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'libc/sysdeps/linux') diff --git a/libc/sysdeps/linux/mips/bits/syscalls.h b/libc/sysdeps/linux/mips/bits/syscalls.h index 787bb7d55..b8f80597e 100644 --- a/libc/sysdeps/linux/mips/bits/syscalls.h +++ b/libc/sysdeps/linux/mips/bits/syscalls.h @@ -29,6 +29,16 @@ } \ result_var; }) +#define INLINE_SYSCALL_NOERR_NCS(name, nr, args...) \ +({ \ + INTERNAL_SYSCALL_DECL(err); \ + long res = INTERNAL_SYSCALL_NCS(name, err, nr, args); \ + if (unlikely(INTERNAL_SYSCALL_ERROR_P(res, err))) { \ + res = -res; \ + } \ + res; \ +}) + #define INTERNAL_SYSCALL_DECL(err) long err attribute_unused #define INTERNAL_SYSCALL_ERROR_P(val, err) ((long) (err)) -- cgit v1.2.3