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Commit 583d632f authored by Al Viro's avatar Al Viro
Browse files

arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve() 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 9e14f828

arch/arm/include/asm/unistd.h

+1 −0
Original line number Diff line number Diff line
@@ -469,6 +469,7 @@ 
#define __ARCH_WANT_OLD_READDIR

#define __ARCH_WANT_SYS_SOCKETCALL

#endif

#define __ARCH_WANT_KERNEL_EXECVE



/*

 * "Conditional" syscalls

arch/arm/kernel/entry-common.S

+12 −0
Original line number Diff line number Diff line
@@ -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"

arch/arm/kernel/sys_arm.c

+0 −42
Original line number Diff line number Diff line
@@ -79,48 +79,6 @@ asmlinkage int sys_execve(const char __user *filenamei, 
	return error;

}



int kernel_execve(const char *filename,

		  const char *const argv[],

		  const char *const envp[])

{

	struct pt_regs regs;

	int ret;



	memset(&regs, 0, sizeof(struct pt_regs));

	ret = do_execve(filename,

			(const char __user *const __user *)argv,

			(const char __user *const __user *)envp, &regs);

	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" (&regs),

		  "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.