linux/tools/include
Willy Tarreau 556fb7131e tools/nolibc: avoid undesired casts in the __sysret() macro
Having __sysret() as an inline function has the unfortunate effect of
adding casts and large constants comparisons after the syscall returns
that significantly inflate some light code that's otherwise syscall-
heavy. Even nolibc-test grew by ~1%.

Let's switch back to a macro for this, and use it only with signed
arguments. Note that it is also possible to design a slightly more
complex macro covering unsigned and pointers but we only have 3 such
syscalls so it is pointless, and these were just addressed not to use
this macro anymore. Now for the argument (the local variable containing
the syscall return value), any negative value is an error, that results
in -1 being returned and errno to be assigned the opposite value.

This may be revisited again in the future if really needed but for now
let's get back to something sane.

Fixes: 428905da6e ("tools/nolibc: sys.h: add a syscall return helper")
Link: https://lore.kernel.org/lkml/20230806095846.GB10627@1wt.eu/
Link: https://lore.kernel.org/lkml/ZNKOJY+g66nkIyvv@1wt.eu/
Cc: Zhangjin Wu <falcon@tinylab.org>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Thomas Weißschuh <thomas@t-8ch.de>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 05:17:07 +02:00
..
asm tools headers: Update the copy of x86's mem{cpy,set}_64.S used in 'perf bench' 2023-05-17 10:42:19 -03:00
asm-generic tools: KVM: selftests: Convert clear/set_bit() to actual atomics 2022-12-02 13:22:35 -05:00
linux perf cs-etm: Copy kernel coresight-pmu.h header 2023-05-26 16:03:27 -03:00
nolibc tools/nolibc: avoid undesired casts in the __sysret() macro 2023-08-23 05:17:07 +02:00
tools tools include: add dis-asm-compat.h to handle version differences 2022-08-01 15:29:49 -03:00
trace/events
uapi asm-generic updates for 6.5 2023-07-06 10:06:04 -07:00
vdso tools headers: Synchronize {linux,vdso}/bits.h with the kernel sources 2023-03-03 22:34:15 -03:00