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authorLinus Torvalds <torvalds@linux-foundation.org>2012-10-10 12:02:25 +0900
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-10 12:02:25 +0900
commit42859eea96ba6beabfb0369a1eeffa3c7d2bd9cb (patch)
treefa38aeda0d6e7a4c48a882b166b8643594a1ad50 /arch/arm/kernel
parentf59b51fe3d3092c08d7d554ecb40db24011b2ebc (diff)
parentf322220d6159455da2b5a8a596d802c8695fed30 (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
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 ...
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/calls.S2
-rw-r--r--arch/arm/kernel/entry-common.S29
-rw-r--r--arch/arm/kernel/process.c75
-rw-r--r--arch/arm/kernel/sys_arm.c63
4 files changed, 38 insertions, 131 deletions
diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S
index e337879595e5..831cd38c8d99 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)
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index f45987037bf1..e340fa1db203 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]
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 04eea22d7958..f98c17ff1957 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;
diff --git a/arch/arm/kernel/sys_arm.c b/arch/arm/kernel/sys_arm.c
index 76cbb055dd05..c2a898aa57aa 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");
-
- out:
- return ret;
-}
-EXPORT_SYMBOL(kernel_execve);
-
/*
* Since loff_t is a 64 bit type we avoid a lot of ABI hassle
* with a different argument ordering.