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authorVolodymyr Boyko <boyko.cxx@gmail.com>2018-11-23 02:19:55 +0200
committerWaldemar Brodkorb <wbx@openadk.org>2018-11-23 14:24:29 +0100
commitfa9cfbfcb70bd3736ec54eeeb4d0796aa4b9521f (patch)
treed1c5c7599703f7024acf6769cdd378e1c0a58b77 /libc
parentcbfdb7abf4790bac4da52b2161a12bf8abd9f174 (diff)
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 <boyko.cxx@gmail.com>
Diffstat (limited to 'libc')
-rw-r--r--libc/sysdeps/linux/mips/bits/syscalls.h10
1 files changed, 10 insertions, 0 deletions
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))