sugar/linux
1
0
Fork 0
Code Activity

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

Browse Source 
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
  ...
This commit is contained in:
Linus Torvalds
2012-10-10 12:02:25 +09:00
parent f59b51fe3d f322220d61
commit 42859eea96
96 changed files with 391 additions and 900 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
arch/arm/Kconfig
View File

@@ -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

5
arch/arm/include/asm/processor.h
View File

@@ -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)

5
arch/arm/include/asm/ptrace.h
View File

@@ -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__ */

1
arch/arm/include/asm/system.h
View File

@@ -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>

2
arch/arm/include/asm/unistd.h
View File

@@ -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

2
arch/arm/kernel/calls.S
View File

@@ -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)

29
arch/arm/kernel/entry-common.S
View File

@@ -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]

75
arch/arm/kernel/process.c
View File

@@ -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;

63
arch/arm/kernel/sys_arm.c
View File

@@ -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.