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From: Florian Weimer <fweimer@redhat.com>
To: Joe Simmons-Talbott via Libc-alpha <libc-alpha@sourceware.org>
Cc: Joe Simmons-Talbott <josimmon@redhat.com>
Subject: Re: [PATCH 2/2] aarch64: Set the syscall register right before doing the syscall.
Date: Tue, 11 Apr 2023 15:50:04 +0200	[thread overview]
Message-ID: <87h6tmil4j.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <20230411133004.2268170-3-josimmon@redhat.com> (Joe Simmons-Talbott via Libc-alpha's message of "Tue, 11 Apr 2023 09:30:04 -0400")

* Joe Simmons-Talbott via Libc-alpha:

>    ({ long _sys_result;						\
>       {								\
>         LOAD_ARGS_##nr (args)					\
>         register long _x8 asm ("x8") = (name);			\
> +       if (__builtin_constant_p(name))				\
> +         asm volatile ("mov	x8, " MSTR(name) ";"		\
> +                       : /* no output */ : "i" (name) : "x8");	\
>         asm volatile ("svc	0	// syscall " # name     \
>  		     : "=r" (_x0) : "r"(_x8) ASM_ARGS_##nr : "memory");	\
>         _sys_result = _x0;					\

I think you should do this in a single assembler statement, load the
constant only once.

Thanks,
Florian


  reply	other threads:[~2023-04-11 13:50 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-11 13:30 [PATCH 0/2] x86_64: aarch64: Set call number just before syscall Joe Simmons-Talbott
2023-04-11 13:30 ` [PATCH 1/2] x86_64: Set the syscall register right before doing the syscall Joe Simmons-Talbott
2023-04-17 22:35   ` Noah Goldstein
2023-04-17 22:36     ` Noah Goldstein
2023-04-11 13:30 ` [PATCH 2/2] aarch64: " Joe Simmons-Talbott
2023-04-11 13:50   ` Florian Weimer [this message]
2023-04-11 14:15     ` Adhemerval Zanella Netto
2023-04-11 15:43       ` Szabolcs Nagy
2023-04-11 16:03       ` Florian Weimer
2023-04-11 16:39         ` Adhemerval Zanella Netto
2023-04-12 15:27           ` Joe Simmons-Talbott
2023-04-12 21:11 ` [PATCH v2 0/2] x86_64: aarch64: Set call number just before syscall Joe Simmons-Talbott
2023-04-12 21:11   ` [PATCH v2 1/2] x86_64: Set the syscall register right before doing the syscall Joe Simmons-Talbott
2023-04-12 21:11   ` [PATCH v2 2/2] aarch64: " Joe Simmons-Talbott
2023-04-17 15:34 ` [PATCH v3 0/2] x86_64: aarch64: Set call number just before syscall Joe Simmons-Talbott
2023-04-17 15:34   ` [PATCH v3 1/2] x86_64: Set the syscall register right before doing the syscall Joe Simmons-Talbott
2023-04-17 15:54     ` H.J. Lu
2023-04-17 16:00       ` Joe Simmons-Talbott
2023-04-17 18:38         ` H.J. Lu
2023-04-17 15:34   ` [PATCH v3 2/2] aarch64: " Joe Simmons-Talbott
2023-04-17 21:20 ` [PATCH v4 0/2] x86_64: aarch64: Set call number just before syscall Joe Simmons-Talbott
2023-04-17 21:20   ` [PATCH v4 1/2] x86_64: Set the syscall register right before doing the syscall Joe Simmons-Talbott
2023-04-17 21:20   ` [PATCH v4 2/2] aarch64: " Joe Simmons-Talbott
2023-04-18 12:57     ` Szabolcs Nagy
2023-04-18 19:33       ` Joe Simmons-Talbott
2023-04-19 13:58 ` [PATCH v5 0/3] x86_64: aarch64: Set call number just before syscall Joe Simmons-Talbott
2023-04-19 13:58   ` [PATCH v5 1/3] x86_64: Set the syscall register right before doing the syscall Joe Simmons-Talbott
2023-04-19 15:35     ` H.J. Lu
2023-04-19 15:48       ` Joe Simmons-Talbott
2023-04-19 13:58   ` [PATCH v5 2/3] aarch64: " Joe Simmons-Talbott
2023-04-19 14:56     ` Szabolcs Nagy
2023-04-19 15:21       ` Joe Simmons-Talbott
2023-04-19 13:58   ` [PATCH v5 3/3] nptl: Use direct syscall numbers in setxid Joe Simmons-Talbott

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