Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

42859eea · Linus Torvalds <[email protected]> · 2012-10-10 12:02:25 +09:00

Pull generic execve() changes from Al Viro:
 "This introduces the generic kernel_thread() and kernel_execve()
  functions, and switches x86, arm, alpha, um and s390 over to them."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits)
  s390: convert to generic kernel_execve()
  s390: switch to generic kernel_thread()
  s390: fold kernel_thread_helper() into ret_from_fork()
  s390: fold execve_tail() into start_thread(), convert to generic sys_execve()
  um: switch to generic kernel_thread()
  x86, um/x86: switch to generic sys_execve and kernel_execve
  x86: split ret_from_fork
  alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
  alpha: switch to generic kernel_thread()
  alpha: switch to generic sys_execve()
  arm: get rid of execve wrapper, switch to generic execve() implementation
  arm: optimized current_pt_regs()
  arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
  arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk]
  generic sys_execve()
  generic kernel_execve()
  new helper: current_pt_regs()
  preparation for generic kernel_thread()
  um: kill thread->forking
  um: let signal_delivered() do SIGTRAP on singlestepping into handler
  ...

Commit: 42859eea96ba6beabfb0369a1eeffa3c7d2bd9cb
Parents: f59b51fe · f322220d

Merge commit. Changes below are compared with the first parent: f59b51fe.

Changes

96 files changed · +390 −899

File	Status	Add	Del	Content
arch/Kconfig	modified	+3	−0	View file
arch/alpha/Kconfig	modified	+1	−0	View file
arch/alpha/include/asm/Kbuild	modified	+1	−0	View file
arch/alpha/include/asm/exec.h	deleted	+0	−6	View before deletion
arch/alpha/include/asm/processor.h	modified	+0	−3	View file
arch/alpha/include/asm/unistd.h	modified	+2	−0	View file
arch/alpha/kernel/alpha_ksyms.c	modified	+0	−3	View file
arch/alpha/kernel/entry.S	modified	+18	−51	View file
arch/alpha/kernel/process.c	modified	+20	−59	View file
arch/arm/Kconfig	modified	+1	−0	View file
arch/arm/include/asm/processor.h	modified	+0	−5	View file
arch/arm/include/asm/ptrace.h	modified	+5	−0	View file
arch/arm/include/asm/system.h	modified	+0	−1	View file
arch/arm/include/asm/unistd.h	modified	+2	−0	View file
arch/arm/kernel/calls.S	modified	+1	−1	View file
arch/arm/kernel/entry-common.S	modified	+24	−5	View file
arch/arm/kernel/process.c	modified	+13	−62	View file
arch/arm/kernel/sys_arm.c	modified	+0	−63	View file
arch/avr32/include/asm/Kbuild	modified	+1	−0	View file
arch/avr32/include/asm/exec.h	deleted	+0	−13	View before deletion
arch/c6x/include/asm/Kbuild	modified	+1	−0	View file
arch/c6x/include/asm/exec.h	deleted	+0	−6	View before deletion
arch/cris/include/asm/Kbuild	modified	+1	−0	View file
arch/cris/include/asm/exec.h	deleted	+0	−6	View before deletion
arch/frv/include/asm/Kbuild	modified	+1	−0	View file
arch/frv/include/asm/exec.h	deleted	+0	−17	View before deletion
arch/h8300/include/asm/Kbuild	modified	+2	−1	View file
arch/h8300/include/asm/exec.h	deleted	+0	−6	View before deletion
arch/hexagon/kernel/syscall.c	modified	+0	−1	View file
arch/ia64/include/asm/Kbuild	modified	+1	−0	View file
arch/ia64/include/asm/exec.h	deleted	+0	−14	View before deletion
arch/m32r/include/asm/Kbuild	modified	+2	−1	View file
arch/m32r/include/asm/exec.h	deleted	+0	−14	View before deletion
arch/m68k/include/asm/Kbuild	modified	+1	−0	View file
arch/m68k/include/asm/exec.h	deleted	+0	−6	View before deletion
arch/microblaze/include/asm/Kbuild	modified	+1	−0	View file
arch/microblaze/include/asm/exec.h	deleted	+0	−14	View before deletion
arch/mn10300/include/asm/Kbuild	modified	+1	−0	View file
arch/mn10300/include/asm/exec.h	deleted	+0	−16	View before deletion
arch/parisc/include/asm/Kbuild	modified	+1	−0	View file
arch/parisc/include/asm/exec.h	deleted	+0	−6	View before deletion
arch/s390/Kconfig	modified	+1	−0	View file
arch/s390/include/asm/processor.h	modified	+3	−1	View file
arch/s390/include/asm/unistd.h	modified	+2	−0	View file
arch/s390/kernel/compat_linux.c	modified	+0	−26	View file
arch/s390/kernel/compat_linux.h	modified	+0	−2	View file
arch/s390/kernel/compat_wrapper.S	modified	+1	−1	View file
arch/s390/kernel/entry.S	modified	+21	−30	View file
arch/s390/kernel/entry.h	modified	+0	−3	View file
arch/s390/kernel/entry64.S	modified	+20	−30	View file
arch/s390/kernel/process.c	modified	+33	−74	View file
arch/sh/include/asm/Kbuild	modified	+1	−0	View file
arch/sh/include/asm/exec.h	deleted	+0	−10	View before deletion
arch/sparc/include/asm/Kbuild	modified	+1	−0	View file
arch/sparc/include/asm/exec.h	deleted	+0	−6	View before deletion
arch/tile/include/asm/Kbuild	modified	+1	−0	View file
arch/tile/include/asm/exec.h	deleted	+0	−20	View before deletion
arch/um/include/asm/processor-generic.h	modified	+0	−2	View file
arch/um/kernel/exec.c	modified	+2	−23	View file
arch/um/kernel/internal.h	deleted	+0	−1	View before deletion
arch/um/kernel/process.c	modified	+3	−14	View file
arch/um/kernel/syscall.c	modified	+0	−17	View file
arch/unicore32/include/asm/Kbuild	modified	+1	−0	View file
arch/unicore32/include/asm/exec.h	deleted	+0	−15	View before deletion
arch/unicore32/kernel/sys.c	modified	+0	−1	View file
arch/x86/Kconfig	modified	+1	−0	View file
arch/x86/ia32/ia32entry.S	modified	+1	−1	View file
arch/x86/ia32/sys_ia32.c	modified	+0	−15	View file
arch/x86/include/asm/processor.h	modified	+0	−5	View file
arch/x86/include/asm/sys_ia32.h	modified	+0	−2	View file
arch/x86/include/asm/syscalls.h	modified	+1	−1	View file
arch/x86/include/asm/thread_info.h	modified	+0	−2	View file
arch/x86/include/asm/unistd.h	modified	+2	−0	View file
arch/x86/kernel/Makefile	modified	+1	−1	View file
arch/x86/kernel/asm-offsets.c	modified	+3	−0	View file
arch/x86/kernel/entry_32.S	modified	+18	−8	View file
arch/x86/kernel/entry_64.S	modified	+25	−49	View file
arch/x86/kernel/process.c	modified	+0	−65	View file
arch/x86/kernel/process_32.c	modified	+30	−7	View file
arch/x86/kernel/process_64.c	modified	+21	−14	View file
arch/x86/kernel/signal.c	modified	+0	−4	View file
arch/x86/kernel/sys_i386_32.c	deleted	+0	−40	View before deletion
arch/x86/kernel/vm86_32.c	modified	+3	−3	View file
arch/x86/syscalls/syscall_32.tbl	modified	+1	−1	View file
arch/x86/um/Kconfig	modified	+1	−0	View file
arch/x86/um/sys_call_table_32.c	modified	+0	−1	View file
arch/xtensa/include/asm/Kbuild	modified	+1	−0	View file
arch/xtensa/include/asm/exec.h	deleted	+0	−14	View before deletion
fs/binfmt_elf.c	modified	+0	−1	View file
fs/binfmt_elf_fdpic.c	modified	+0	−1	View file
fs/exec.c	modified	+56	−5	View file
include/linux/binfmts.h	modified	+6	−0	View file
include/linux/compat.h	modified	+6	−2	View file
include/linux/ptrace.h	modified	+4	−0	View file
include/linux/sched.h	modified	+3	−0	View file
kernel/fork.c	modified	+12	−1	View file

Only the first 600 diff lines are shown. Download the complete patch.

arch/Kconfig

View file

diff --git a/arch/Kconfig b/arch/Kconfig
index 550cce4..26a2841 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -271,6 +271,9 @@ config ARCH_WANT_OLD_COMPAT_IPC
 	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
 	bool
 
+config GENERIC_KERNEL_THREAD
+	bool
+
 config HAVE_ARCH_SECCOMP_FILTER
 	bool
 	help

arch/alpha/Kconfig

View file

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 9944ded..7da9124 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -20,6 +20,7 @@ config ALPHA
 	select GENERIC_CMOS_UPDATE
 	select GENERIC_STRNCPY_FROM_USER
 	select GENERIC_STRNLEN_USER
+	select GENERIC_KERNEL_THREAD
 	help
 	  The Alpha is a 64-bit general-purpose processor designed and
 	  marketed by the Digital Equipment Corporation of blessed memory,

arch/alpha/include/asm/Kbuild

View file

diff --git a/arch/alpha/include/asm/Kbuild b/arch/alpha/include/asm/Kbuild
index d97d663..64ffc9e 100644
--- a/arch/alpha/include/asm/Kbuild
+++ b/arch/alpha/include/asm/Kbuild
@@ -10,3 +10,4 @@ header-y += pal.h
 header-y += reg.h
 header-y += regdef.h
 header-y += sysinfo.h
+generic-y += exec.h

arch/alpha/include/asm/exec.h

View before deletion

diff --git a/arch/alpha/include/asm/exec.h b/arch/alpha/include/asm/exec.h
deleted file mode 100644
index 4a5a41f..0000000
--- a/arch/alpha/include/asm/exec.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef __ALPHA_EXEC_H
-#define __ALPHA_EXEC_H
-
-#define arch_align_stack(x) (x)
-
-#endif /* __ALPHA_EXEC_H */

arch/alpha/include/asm/processor.h

View file

diff --git a/arch/alpha/include/asm/processor.h b/arch/alpha/include/asm/processor.h
index e37b887..6cb7fe8 100644
--- a/arch/alpha/include/asm/processor.h
+++ b/arch/alpha/include/asm/processor.h
@@ -49,9 +49,6 @@ extern void start_thread(struct pt_regs *, unsigned long, unsigned long);
 /* Free all resources held by a thread. */
 extern void release_thread(struct task_struct *);
 
-/* Create a kernel thread without removing it from tasklists.  */
-extern long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
-
 unsigned long get_wchan(struct task_struct *p);
 
 #define KSTK_EIP(tsk) (task_pt_regs(tsk)->pc)

arch/alpha/include/asm/unistd.h

View file

diff --git a/arch/alpha/include/asm/unistd.h b/arch/alpha/include/asm/unistd.h
index a31a78e..3cb6c11 100644
--- a/arch/alpha/include/asm/unistd.h
+++ b/arch/alpha/include/asm/unistd.h
@@ -481,6 +481,8 @@
 #define __ARCH_WANT_SYS_OLDUMOUNT
 #define __ARCH_WANT_SYS_SIGPENDING
 #define __ARCH_WANT_SYS_RT_SIGSUSPEND
+#define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_KERNEL_EXECVE
 
 /* "Conditional" syscalls.  What we want is
 

arch/alpha/kernel/alpha_ksyms.c

View file

diff --git a/arch/alpha/kernel/alpha_ksyms.c b/arch/alpha/kernel/alpha_ksyms.c
index 15fa821..89566b3 100644
--- a/arch/alpha/kernel/alpha_ksyms.c
+++ b/arch/alpha/kernel/alpha_ksyms.c
@@ -50,9 +50,6 @@ EXPORT_SYMBOL(alpha_read_fp_reg_s);
 EXPORT_SYMBOL(alpha_write_fp_reg);
 EXPORT_SYMBOL(alpha_write_fp_reg_s);
 
-/* entry.S */
-EXPORT_SYMBOL(kernel_thread);
-
 /* Networking helper routines. */
 EXPORT_SYMBOL(csum_tcpudp_magic);
 EXPORT_SYMBOL(ip_compute_csum);

arch/alpha/kernel/entry.S

View file

diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S
index ec0da05..7e43e11 100644
--- a/arch/alpha/kernel/entry.S
+++ b/arch/alpha/kernel/entry.S
@@ -609,59 +609,35 @@ ret_from_fork:
 .end ret_from_fork
 
 /*
- * kernel_thread(fn, arg, clone_flags)
+ * ... and new kernel threads - here
  */
 	.align 4
-	.globl	kernel_thread
-	.ent	kernel_thread
-kernel_thread:
-	/* We can be called from a module.  */
-	ldgp	$gp, 0($27)
-	.prologue 1
-	subq	$sp, SP_OFF+6*8, $sp
-	br	$1, 2f		/* load start address */
-
-	/* We've now "returned" from a fake system call.  */
-	unop
-	blt	$0, 1f		/* error?  */
-	ldi	$1, 0x3fff
-	beq	$20, 1f		/* parent or child?  */
-
-	bic	$sp, $1, $8	/* in child.  */
-	jsr	$26, ($27)
+	.globl	ret_from_kernel_thread
+	.ent	ret_from_kernel_thread
+ret_from_kernel_thread:
+	mov	$17, $16
+	jsr	$26, schedule_tail
+	mov	$9, $27
+	mov	$10, $16
+	jsr	$26, ($9)
 	ldgp	$gp, 0($26)
 	mov	$0, $16
 	mov	$31, $26
 	jmp	$31, sys_exit
+.end ret_from_kernel_thread
 
-1:	ret			/* in parent.  */
-
-	.align 4
-2:	/* Fake a system call stack frame, as we can't do system calls
-	   from kernel space.  Note that we store FN and ARG as they
-	   need to be set up in the child for the call.  Also store $8
-	   and $26 for use in the parent.  */
-	stq	$31, SP_OFF($sp)	/* ps */
-	stq	$1, SP_OFF+8($sp)	/* pc */
-	stq	$gp, SP_OFF+16($sp)	/* gp */
-	stq	$16, 136($sp)		/* $27; FN for child */
-	stq	$17, SP_OFF+24($sp)	/* $16; ARG for child */
-	stq	$8, 64($sp)		/* $8 */
-	stq	$26, 128($sp)		/* $26 */
+	.globl	ret_from_kernel_execve
+	.align	4
+	.ent	ret_from_kernel_execve
+ret_from_kernel_execve:
+	mov	$16, $sp
 	/* Avoid the HAE being gratuitously wrong, to avoid restoring it.  */
 	ldq	$2, alpha_mv+HAE_CACHE
 	stq	$2, 152($sp)		/* HAE */
+	mov	$31, $19		/* to disable syscall restarts */
+	br	$31, ret_to_user
 
-	/* Shuffle FLAGS to the front; add CLONE_VM.  */
-	ldi	$1, CLONE_VM|CLONE_UNTRACED
-	or	$18, $1, $16
-	bsr	$26, sys_clone
-
-	/* We don't actually care for a3 success widgetry in the kernel.
-	   Not for positive errno values.  */
-	stq	$0, 0($sp)		/* $0 */
-	br	ret_to_kernel
-.end kernel_thread
+.end	ret_from_kernel_execve
 
 
 /*
@@ -745,15 +721,6 @@ sys_rt_sigreturn:
 .end sys_rt_sigreturn
 
 	.align	4
-	.globl	sys_execve
-	.ent	sys_execve
-sys_execve:
-	.prologue 0
-	mov	$sp, $19
-	jmp	$31, do_sys_execve
-.end sys_execve
-
-	.align	4
 	.globl	alpha_ni_syscall
 	.ent	alpha_ni_syscall
 alpha_ni_syscall:

arch/alpha/kernel/process.c

View file

diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index 83638aa..4054e0f 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -263,33 +263,35 @@ alpha_vfork(struct pt_regs *regs)
 
 /*
  * Copy an alpha thread..
- *
- * Note the "stack_offset" stuff: when returning to kernel mode, we need
- * to have some extra stack-space for the kernel stack that still exists
- * after the "ret_from_fork".  When returning to user mode, we only want
- * the space needed by the syscall stack frame (ie "struct pt_regs").
- * Use the passed "regs" pointer to determine how much space we need
- * for a kernel fork().
  */
 
 int
 copy_thread(unsigned long clone_flags, unsigned long usp,
-	    unsigned long unused,
+	    unsigned long arg,
 	    struct task_struct * p, struct pt_regs * regs)
 {
 	extern void ret_from_fork(void);
+	extern void ret_from_kernel_thread(void);
 
 	struct thread_info *childti = task_thread_info(p);
-	struct pt_regs * childregs;
-	struct switch_stack * childstack, *stack;
-	unsigned long stack_offset, settls;
-
-	stack_offset = PAGE_SIZE - sizeof(struct pt_regs);
-	if (!(regs->ps & 8))
-		stack_offset = (PAGE_SIZE-1) & (unsigned long) regs;
-	childregs = (struct pt_regs *)
-	  (stack_offset + PAGE_SIZE + task_stack_page(p));
-		
+	struct pt_regs *childregs = task_pt_regs(p);
+	struct switch_stack *childstack, *stack;
+	unsigned long settls;
+
+	childstack = ((struct switch_stack *) childregs) - 1;
+	if (unlikely(!regs)) {
+		/* kernel thread */
+		memset(childstack, 0,
+			sizeof(struct switch_stack) + sizeof(struct pt_regs));
+		childstack->r26 = (unsigned long) ret_from_kernel_thread;
+		childstack->r9 = usp;	/* function */
+		childstack->r10 = arg;
+		childregs->hae = alpha_mv.hae_cache,
+		childti->pcb.usp = 0;
+		childti->pcb.ksp = (unsigned long) childstack;
+		childti->pcb.flags = 1;	/* set FEN, clear everything else */
+		return 0;
+	}
 	*childregs = *regs;
 	settls = regs->r20;
 	childregs->r0 = 0;
@@ -297,7 +299,6 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
 	childregs->r20 = 1;	/* OSF/1 has some strange fork() semantics.  */
 	regs->r20 = 0;
 	stack = ((struct switch_stack *) regs) - 1;
-	childstack = ((struct switch_stack *) childregs) - 1;
 	*childstack = *stack;
 	childstack->r26 = (unsigned long) ret_from_fork;
 	childti->pcb.usp = usp;
@@ -386,27 +387,6 @@ dump_elf_task_fp(elf_fpreg_t *dest, struct task_struct *task)
 EXPORT_SYMBOL(dump_elf_task_fp);
 
 /*
- * sys_execve() executes a new program.
- */
-asmlinkage int
-do_sys_execve(const char __user *ufilename,
-	      const char __user *const __user *argv,
-	      const char __user *const __user *envp, struct pt_regs *regs)
-{
-	int error;
-	char *filename;
-
-	filename = getname(ufilename);
-	error = PTR_ERR(filename);
-	if (IS_ERR(filename))
-		goto out;
-	error = do_execve(filename, argv, envp, regs);
-	putname(filename);
-out:
-	return error;
-}
-
-/*
  * Return saved PC of a blocked thread.  This assumes the frame
  * pointer is the 6th saved long on the kernel stack and that the
  * saved return address is the first long in the frame.  This all
@@ -459,22 +439,3 @@ get_wchan(struct task_struct *p)
 	}
 	return pc;
 }
-
-int kernel_execve(const char *path, const char *const argv[], const char *const envp[])
-{
-	/* Avoid the HAE being gratuitously wrong, which would cause us
-	   to do the whole turn off interrupts thing and restore it.  */
-	struct pt_regs regs = {.hae = alpha_mv.hae_cache};
-	int err = do_execve(path, argv, envp, &regs);
-	if (!err) {
-		struct pt_regs *p = current_pt_regs();
-		/* copy regs to normal position and off to userland we go... */
-		*p = regs;
-		__asm__ __volatile__ (
-			"mov	%0, $sp;"
-			"br	$31, ret_from_sys_call"
-			: : "r"(p));
-	}
-	return err;
-}
-EXPORT_SYMBOL(kernel_execve);

arch/arm/Kconfig

View file

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 2867a77..e40eefb 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -52,6 +52,7 @@ config ARM
 	select GENERIC_STRNCPY_FROM_USER
 	select GENERIC_STRNLEN_USER
 	select DCACHE_WORD_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && !CPU_BIG_ENDIAN
+	select GENERIC_KERNEL_THREAD
 	help
 	  The ARM series is a line of low-power-consumption RISC chip designs
 	  licensed by ARM Ltd and targeted at embedded applications and

arch/arm/include/asm/processor.h

View file

diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h
index 99afa74..06e7d50 100644
--- a/arch/arm/include/asm/processor.h
+++ b/arch/arm/include/asm/processor.h
@@ -85,11 +85,6 @@ unsigned long get_wchan(struct task_struct *p);
 #define cpu_relax()			barrier()
 #endif
 
-/*
- * Create a new kernel thread
- */
-extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
-
 #define task_pt_regs(p) \
 	((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)
 

arch/arm/include/asm/ptrace.h

View file

diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h
index 355ece5..44fe998 100644
--- a/arch/arm/include/asm/ptrace.h
+++ b/arch/arm/include/asm/ptrace.h
@@ -254,6 +254,11 @@ static inline unsigned long user_stack_pointer(struct pt_regs *regs)
 	return regs->ARM_sp;
 }
 
+#define current_pt_regs(void) ({				\
+	register unsigned long sp asm ("sp");			\
+	(struct pt_regs *)((sp | (THREAD_SIZE - 1)) - 7) - 1;	\
+})
+
 #endif /* __KERNEL__ */
 
 #endif /* __ASSEMBLY__ */

arch/arm/include/asm/system.h

View file

diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 74542c5..368165e 100644
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -2,7 +2,6 @@
 #include <asm/barrier.h>
 #include <asm/compiler.h>
 #include <asm/cmpxchg.h>
-#include <asm/exec.h>
 #include <asm/switch_to.h>
 #include <asm/system_info.h>
 #include <asm/system_misc.h>

arch/arm/include/asm/unistd.h

View file

diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h
index d9ff5cc..f259921 100644
--- a/arch/arm/include/asm/unistd.h
+++ b/arch/arm/include/asm/unistd.h
@@ -478,6 +478,8 @@
 #define __ARCH_WANT_OLD_READDIR
 #define __ARCH_WANT_SYS_SOCKETCALL
 #endif
+#define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_KERNEL_EXECVE
 
 /*
  * "Conditional" syscalls

arch/arm/kernel/calls.S

View file

diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S
index e337879..831cd38 100644
--- a/arch/arm/kernel/calls.S
+++ b/arch/arm/kernel/calls.S
@@ -20,7 +20,7 @@
 		CALL(sys_creat)
 		CALL(sys_link)
 /* 10 */	CALL(sys_unlink)
-		CALL(sys_execve_wrapper)
+		CALL(sys_execve)
 		CALL(sys_chdir)
 		CALL(OBSOLETE(sys_time))	/* used by libc4 */
 		CALL(sys_mknod)

arch/arm/kernel/entry-common.S

View file

diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index f459870..e340fa1 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -91,6 +91,30 @@ ENTRY(ret_from_fork)
 	b	ret_slow_syscall
 ENDPROC(ret_from_fork)
 
+ENTRY(ret_from_kernel_thread)
+ UNWIND(.fnstart)
+ UNWIND(.cantunwind)
+	bl	schedule_tail
+	mov	r0, r4
+	adr	lr, BSYM(1f)	@ kernel threads should not exit
+	mov	pc, r5
+1:	bl	do_exit
+	nop
+ 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"
@@ -517,11 +541,6 @@ sys_vfork_wrapper:
 		b	sys_vfork
 ENDPROC(sys_vfork_wrapper)
 
-sys_execve_wrapper:
-		add	r3, sp, #S_OFF
-		b	sys_execve
-ENDPROC(sys_execve_wrapper)
-
 sys_clone_wrapper:
 		add	ip, sp, #S_OFF
 		str	ip, [sp, #4]

arch/arm/kernel/process.c

View file

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 04eea22..f98c17f 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -373,6 +373,7 @@ void release_thread(struct task_struct *dead_task)
 }
 
 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
+asmlinkage void ret_from_kernel_thread(void) __asm__("ret_from_kernel_thread");
 
 int
 copy_thread(unsigned long clone_flags, unsigned long stack_start,
@@ -381,13 +382,20 @@ copy_thread(unsigned long clone_flags, unsigned long stack_start,
 	struct thread_info *thread = task_thread_info(p);
 	struct pt_regs *childregs = task_pt_regs(p);
 
-	*childregs = *regs;
-	childregs->ARM_r0 = 0;
-	childregs->ARM_sp = stack_start;
-
 	memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
+
+	if (likely(regs)) {
+		*childregs = *regs;
+		childregs->ARM_r0 = 0;
+		childregs->ARM_sp = stack_start;
+		thread->cpu_context.pc = (unsigned long)ret_from_fork;
+	} else {
+		thread->cpu_context.r4 = stk_sz;
+		thread->cpu_context.r5 = stack_start;
+		thread->cpu_context.pc = (unsigned long)ret_from_kernel_thread;
+		childregs->ARM_cpsr = SVC_MODE;
+	}
 	thread->cpu_context.sp = (unsigned long)childregs;
-	thread->cpu_context.pc = (unsigned long)ret_from_fork;
 
 	clear_ptrace_hw_breakpoint(p);
 
@@ -423,63 +431,6 @@ int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
 }
 EXPORT_SYMBOL(dump_fpu);
 
-/*
- * Shuffle the argument into the correct register before calling the
- * thread function.  r4 is the thread argument, r5 is the pointer to
- * the thread function, and r6 points to the exit function.
- */
-extern void kernel_thread_helper(void);
-asm(	".pushsection .text\n"
-"	.align\n"
-"	.type	kernel_thread_helper, #function\n"
-"kernel_thread_helper:\n"
-#ifdef CONFIG_TRACE_IRQFLAGS
-"	bl	trace_hardirqs_on\n"
-#endif
-"	msr	cpsr_c, r7\n"
-"	mov	r0, r4\n"
-"	mov	lr, r6\n"
-"	mov	pc, r5\n"
-"	.size	kernel_thread_helper, . - kernel_thread_helper\n"
-"	.popsection");
-
-#ifdef CONFIG_ARM_UNWIND
-extern void kernel_thread_exit(long code);
-asm(	".pushsection .text\n"
-"	.align\n"
-"	.type	kernel_thread_exit, #function\n"
-"kernel_thread_exit:\n"
-"	.fnstart\n"
-"	.cantunwind\n"
-"	bl	do_exit\n"
-"	nop\n"
-"	.fnend\n"
-"	.size	kernel_thread_exit, . - kernel_thread_exit\n"
-"	.popsection");
-#else
-#define kernel_thread_exit	do_exit
-#endif
-
-/*
- * Create a kernel thread.
- */
-pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
-{
-	struct pt_regs regs;
-
-	memset(&regs, 0, sizeof(regs));
-
-	regs.ARM_r4 = (unsigned long)arg;
-	regs.ARM_r5 = (unsigned long)fn;
-	regs.ARM_r6 = (unsigned long)kernel_thread_exit;
-	regs.ARM_r7 = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE;
-	regs.ARM_pc = (unsigned long)kernel_thread_helper;
-	regs.ARM_cpsr = regs.ARM_r7 | PSR_I_BIT;
-
-	return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
-}
-EXPORT_SYMBOL(kernel_thread);
-
 unsigned long get_wchan(struct task_struct *p)
 {
 	struct stackframe frame;

arch/arm/kernel/sys_arm.c

View file

diff --git a/arch/arm/kernel/sys_arm.c b/arch/arm/kernel/sys_arm.c
index 76cbb05..c2a898a 100644
--- a/arch/arm/kernel/sys_arm.c
+++ b/arch/arm/kernel/sys_arm.c
@@ -59,69 +59,6 @@ asmlinkage int sys_vfork(struct pt_regs *regs)
 	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
 }
 
-/* sys_execve() executes a new program.
- * This is called indirectly via a small wrapper
- */
-asmlinkage int sys_execve(const char __user *filenamei,
-			  const char __user *const __user *argv,
-			  const char __user *const __user *envp, struct pt_regs *regs)
-{
-	int error;
-	char * filename;
-
-	filename = getname(filenamei);
-	error = PTR_ERR(filename);
-	if (IS_ERR(filename))
-		goto out;
-	error = do_execve(filename, argv, envp, regs);
-	putname(filename);
-out:
-	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");
-