From 6760856791c6e527da678021ee6a67896549d4da Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 2 Oct 2006 02:18:26 -0700 Subject: [PATCH] introduce kernel_execve The use of execve() in the kernel is dubious, since it relies on the __KERNEL_SYSCALLS__ mechanism that stores the result in a global errno variable. As a first step of getting rid of this, change all users to a global kernel_execve function that returns a proper error code. This function is a terrible hack, and a later patch removes it again after the kernel syscalls are gone. Signed-off-by: Arnd Bergmann Cc: Andi Kleen Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Russell King Cc: Ian Molton Cc: Mikael Starvik Cc: David Howells Cc: Yoshinori Sato Cc: Hirokazu Takata Cc: Ralf Baechle Cc: Kyle McMartin Cc: Heiko Carstens Cc: Martin Schwidefsky Cc: Paul Mundt Cc: Kazumoto Kojima Cc: Richard Curnow Cc: William Lee Irwin III Cc: "David S. Miller" Cc: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Cc: Miles Bader Cc: Chris Zankel Cc: "Luck, Tony" Cc: Geert Uytterhoeven Cc: Roman Zippel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/sparc64/kernel/power.c | 5 ++--- init/do_mounts_initrd.c | 3 +-- init/main.c | 4 +--- kernel/kmod.c | 5 ++--- lib/Makefile | 2 ++ lib/execve.c | 23 +++++++++++++++++++++++ 6 files changed, 31 insertions(+), 11 deletions(-) create mode 100644 lib/execve.c diff --git a/arch/sparc64/kernel/power.c b/arch/sparc64/kernel/power.c index e55466c77b6..0b9c70627ce 100644 --- a/arch/sparc64/kernel/power.c +++ b/arch/sparc64/kernel/power.c @@ -4,8 +4,6 @@ * Copyright (C) 1999 David S. Miller (davem@redhat.com) */ -#define __KERNEL_SYSCALLS__ - #include #include #include @@ -14,6 +12,7 @@ #include #include #include +#include #include #include @@ -98,7 +97,7 @@ again: /* Ok, down we go... */ button_pressed = 0; - if (execve("/sbin/shutdown", argv, envp) < 0) { + if (kernel_execve("/sbin/shutdown", argv, envp) < 0) { printk("powerd: shutdown execution failed\n"); add_wait_queue(&powerd_wait, &wait); goto again; diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c index a06f037fa00..919a80cb322 100644 --- a/init/do_mounts_initrd.c +++ b/init/do_mounts_initrd.c @@ -1,4 +1,3 @@ -#define __KERNEL_SYSCALLS__ #include #include #include @@ -35,7 +34,7 @@ static int __init do_linuxrc(void * shell) (void) sys_open("/dev/console",O_RDWR,0); (void) sys_dup(0); (void) sys_dup(0); - return execve(shell, argv, envp_init); + return kernel_execve(shell, argv, envp_init); } static void __init handle_initrd(void) diff --git a/init/main.c b/init/main.c index 0766e69712b..a49b00235bd 100644 --- a/init/main.c +++ b/init/main.c @@ -9,8 +9,6 @@ * Simplified starting of init: Michael A. Griffith */ -#define __KERNEL_SYSCALLS__ - #include #include #include @@ -703,7 +701,7 @@ static void do_pre_smp_initcalls(void) static void run_init_process(char *init_filename) { argv_init[0] = init_filename; - execve(init_filename, argv_init, envp_init); + kernel_execve(init_filename, argv_init, envp_init); } static int init(void * unused) diff --git a/kernel/kmod.c b/kernel/kmod.c index f8121b95183..bb4e29d924e 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -18,8 +18,6 @@ call_usermodehelper wait flag, and remove exec_usermodehelper. Rusty Russell Jan 2003 */ -#define __KERNEL_SYSCALLS__ - #include #include #include @@ -169,7 +167,8 @@ static int ____call_usermodehelper(void *data) retval = -EPERM; if (current->fs->root) - retval = execve(sub_info->path, sub_info->argv, sub_info->envp); + retval = kernel_execve(sub_info->path, + sub_info->argv, sub_info->envp); /* Exec failed? */ sub_info->retval = retval; diff --git a/lib/Makefile b/lib/Makefile index ddf3e676e1f..4d752be0edc 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -35,6 +35,8 @@ ifneq ($(CONFIG_HAVE_DEC_LOCK),y) lib-y += dec_and_lock.o endif +lib-y += execve.o + obj-$(CONFIG_CRC_CCITT) += crc-ccitt.o obj-$(CONFIG_CRC16) += crc16.o obj-$(CONFIG_CRC32) += crc32.o diff --git a/lib/execve.c b/lib/execve.c new file mode 100644 index 00000000000..2667ebc1504 --- /dev/null +++ b/lib/execve.c @@ -0,0 +1,23 @@ +#include +#include + +#define __KERNEL_SYSCALLS__ +static int errno __attribute__((unused)); +#include + +#ifdef _syscall3 +int kernel_execve (const char *filename, char *const argv[], char *const envp[]) + __attribute__((__weak__)); +int kernel_execve (const char *filename, char *const argv[], char *const envp[]) +{ + mm_segment_t fs = get_fs(); + int ret; + + WARN_ON(segment_eq(fs, USER_DS)); + ret = execve(filename, (char **)argv, (char **)envp); + if (ret) + ret = -errno; + + return ret; +} +#endif -- cgit v1.2.3-18-g5258