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Message-Id: <c23a5b2ad7c756c05d8a19af6033462ddbd948a6.1687957589.git.falcon@tinylab.org>
Date: Wed, 28 Jun 2023 21:08:32 +0800
From: Zhangjin Wu <falcon@...ylab.org>
To: thomas@...ch.de, w@....eu
Cc: falcon@...ylab.org, arnd@...db.de, david.laight@...lab.com,
linux-kernel@...r.kernel.org, linux-kselftest@...r.kernel.org,
linux-riscv@...ts.infradead.org,
Thomas Weißschuh <linux@...ssschuh.net>
Subject: [PATCH v5 01/14] tools/nolibc: sys.h: add a syscall return helper
Most of the library routines share the same syscall return logic:
In general, a 0 return value indicates success. A -1 return value
indicates an error, and an error number is stored in errno. [1]
Let's add a __sysret() helper for the above logic to simplify the coding
and shrink the code lines too.
Thomas suggested to use inline function instead of macro for __sysret().
Willy suggested to make __sysret() be always inline.
[1]: https://man7.org/linux/man-pages/man2/syscall.2.html
Suggested-by: Willy Tarreau <w@....eu>
Link: https://lore.kernel.org/linux-riscv/ZH1+hkhiA2+ItSvX@1wt.eu/
Suggested-by: Thomas Weißschuh <linux@...ssschuh.net>
Link: https://lore.kernel.org/linux-riscv/ea4e7442-7223-4211-ba29-70821e907888@t-8ch.de/
Reviewed-by: Thomas Weißschuh <linux@...ssschuh.net>
Signed-off-by: Zhangjin Wu <falcon@...ylab.org>
---
tools/include/nolibc/sys.h | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index 5464f93e863e..097eef88cf7e 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -28,6 +28,16 @@
#include "errno.h"
#include "types.h"
+/* Syscall return helper, set errno as -ret when ret < 0 */
+static __inline__ __attribute__((unused, always_inline))
+long __sysret(long ret)
+{
+ if (ret < 0) {
+ SET_ERRNO(-ret);
+ ret = -1;
+ }
+ return ret;
+}
/* Functions in this file only describe syscalls. They're declared static so
* that the compiler usually decides to inline them while still being allowed
--
2.25.1
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