From 583d632fb3f6d7e9d133a7260829dd7565f8cc99 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 2 Aug 2012 11:46:39 +0400 Subject: [PATCH] arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve() Signed-off-by: Al Viro --- arch/arm/include/asm/unistd.h | 1 + arch/arm/kernel/entry-common.S | 12 ++++++++++ arch/arm/kernel/sys_arm.c | 42 ---------------------------------- 3 files changed, 13 insertions(+), 42 deletions(-) diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h index 0cab47d4a83f..2c9b7a87e64b 100644 --- a/arch/arm/include/asm/unistd.h +++ b/arch/arm/include/asm/unistd.h @@ -469,6 +469,7 @@ #define __ARCH_WANT_OLD_READDIR #define __ARCH_WANT_SYS_SOCKETCALL #endif +#define __ARCH_WANT_KERNEL_EXECVE /* * "Conditional" syscalls diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 9a48b7a577e7..4a6e46a9a3d7 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -103,6 +103,18 @@ ENTRY(ret_from_kernel_thread) UNWIND(.fnend) ENDPROC(ret_from_kernel_thread) +/* + * turn a kernel thread into userland process + * use: ret_from_kernel_execve(struct pt_regs *normal) + */ +ENTRY(ret_from_kernel_execve) + mov why, #0 @ not a syscall + str why, [r0, #S_R0] @ ... and we want 0 in ->ARM_r0 as well + get_thread_info tsk @ thread structure + mov sp, r0 @ stack pointer just under pt_regs + b ret_slow_syscall +ENDPROC(ret_from_kernel_execve) + .equ NR_syscalls,0 #define CALL(x) .equ NR_syscalls,NR_syscalls+1 #include "calls.S" diff --git a/arch/arm/kernel/sys_arm.c b/arch/arm/kernel/sys_arm.c index 3ba62e3cd1a2..c8e729efc187 100644 --- a/arch/arm/kernel/sys_arm.c +++ b/arch/arm/kernel/sys_arm.c @@ -79,48 +79,6 @@ out: return error; } -int kernel_execve(const char *filename, - const char *const argv[], - const char *const envp[]) -{ - struct pt_regs regs; - int ret; - - memset(®s, 0, sizeof(struct pt_regs)); - ret = do_execve(filename, - (const char __user *const __user *)argv, - (const char __user *const __user *)envp, ®s); - if (ret < 0) - goto out; - - /* - * Save argc to the register structure for userspace. - */ - regs.ARM_r0 = ret; - - /* - * We were successful. We won't be returning to our caller, but - * instead to user space by manipulating the kernel stack. - */ - asm( "add r0, %0, %1\n\t" - "mov r1, %2\n\t" - "mov r2, %3\n\t" - "bl memmove\n\t" /* copy regs to top of stack */ - "mov r8, #0\n\t" /* not a syscall */ - "mov r9, %0\n\t" /* thread structure */ - "mov sp, r0\n\t" /* reposition stack pointer */ - "b ret_to_user" - : - : "r" (current_thread_info()), - "Ir" (THREAD_START_SP - sizeof(regs)), - "r" (®s), - "Ir" (sizeof(regs)) - : "r0", "r1", "r2", "r3", "r8", "r9", "ip", "lr", "memory"); - - out: - return ret; -} - /* * Since loff_t is a 64 bit type we avoid a lot of ABI hassle * with a different argument ordering. -- 2.39.5