Messages in this thread Patch in this message | | | From | Roland McGrath <> | Subject | [PATCH 2/4] x86: syscall_get_nr returns int | Date | Tue, 22 Sep 2009 23:20:15 -0700 (PDT) |
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Make syscall_get_nr() return int, so we always sign-extend the low 32 bits of orig_ax in checks.
Signed-off-by: Roland McGrath <roland@redhat.com> --- arch/x86/include/asm/syscall.h | 14 +++++++------- 1 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h index d82f39b..8d33bc5 100644 --- a/arch/x86/include/asm/syscall.h +++ b/arch/x86/include/asm/syscall.h @@ -1,7 +1,7 @@ /* * Access to user system call parameters and results * - * Copyright (C) 2008 Red Hat, Inc. All rights reserved. + * Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved. * * This copyrighted material is made available to anyone wishing to use, * modify, copy, or redistribute it subject to the terms and conditions @@ -16,13 +16,13 @@ #include <linux/sched.h> #include <linux/err.h> -static inline long syscall_get_nr(struct task_struct *task, - struct pt_regs *regs) +/* + * Only the low 32 bits of orig_ax are meaningful, so we return int. + * This importantly ignores the high bits on 64-bit, so comparisons + * sign-extend the low 32 bits. + */ +static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) { - /* - * We always sign-extend a -1 value being set here, - * so this is always either -1L or a syscall number. - */ return regs->orig_ax; }
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