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authorAl Viro <viro@zeniv.linux.org.uk>2012-10-15 15:26:11 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-10-15 16:12:06 -0400
commit1856ab6db1296c9c31ad58263d49ee9b75568ddb (patch)
tree7e41497f50a2951381c9931da8c9c187f2acea57
parentddffeb8c4d0331609ef2581d84de4d763607bd37 (diff)
downloadop-kernel-dev-1856ab6db1296c9c31ad58263d49ee9b75568ddb.zip
op-kernel-dev-1856ab6db1296c9c31ad58263d49ee9b75568ddb.tar.gz
score: switch to generic kernel_thread()/kernel_execve()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--arch/score/Kconfig2
-rw-r--r--arch/score/include/asm/processor.h1
-rw-r--r--arch/score/kernel/entry.S7
-rw-r--r--arch/score/kernel/process.c55
-rw-r--r--arch/score/kernel/sys_score.c30
5 files changed, 23 insertions, 72 deletions
diff --git a/arch/score/Kconfig b/arch/score/Kconfig
index 4f93a43..a285e78 100644
--- a/arch/score/Kconfig
+++ b/arch/score/Kconfig
@@ -13,6 +13,8 @@ config SCORE
select GENERIC_CLOCKEVENTS
select HAVE_MOD_ARCH_SPECIFIC
select MODULES_USE_ELF_REL
+ select GENERIC_KERNEL_THREAD
+ select GENERIC_KERNEL_EXECVE
choice
prompt "System type"
diff --git a/arch/score/include/asm/processor.h b/arch/score/include/asm/processor.h
index ab3aceb..d9a922d 100644
--- a/arch/score/include/asm/processor.h
+++ b/arch/score/include/asm/processor.h
@@ -13,7 +13,6 @@ struct task_struct;
*/
extern void (*cpu_wait)(void);
-extern long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
extern unsigned long thread_saved_pc(struct task_struct *tsk);
extern void start_thread(struct pt_regs *regs,
unsigned long pc, unsigned long sp);
diff --git a/arch/score/kernel/entry.S b/arch/score/kernel/entry.S
index 83bb960..74a5cc7 100644
--- a/arch/score/kernel/entry.S
+++ b/arch/score/kernel/entry.S
@@ -278,6 +278,13 @@ need_resched:
nop
#endif
+ENTRY(ret_from_kernel_thread)
+ bl schedule_tail # r4=struct task_struct *prev
+ nop
+ mv r4, r13
+ brl r12
+ j syscall_exit
+
ENTRY(ret_from_fork)
bl schedule_tail # r4=struct task_struct *prev
diff --git a/arch/score/kernel/process.c b/arch/score/kernel/process.c
index 637970c..6f311cf 100644
--- a/arch/score/kernel/process.c
+++ b/arch/score/kernel/process.c
@@ -60,6 +60,7 @@ void __noreturn cpu_idle(void)
}
void ret_from_fork(void);
+void ret_from_kernel_thread(void);
void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
{
@@ -86,29 +87,27 @@ void flush_thread(void) {}
* set up the kernel stack and exception frames for a new process
*/
int copy_thread(unsigned long clone_flags, unsigned long usp,
- unsigned long unused,
+ unsigned long arg,
struct task_struct *p, struct pt_regs *regs)
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs = task_pt_regs(p);
- p->set_child_tid = NULL;
- p->clear_child_tid = NULL;
-
- *childregs = *regs;
- childregs->regs[7] = 0; /* Clear error flag */
- childregs->regs[4] = 0; /* Child gets zero as return value */
- regs->regs[4] = p->pid;
-
- if (childregs->cp0_psr & 0x8) { /* test kernel fork or user fork */
- childregs->regs[0] = usp; /* user fork */
+ p->thread.reg0 = (unsigned long) childregs;
+ if (unlikely(!regs)) {
+ memset(childregs, 0, sizeof(struct pt_regs));
+ p->thread->reg12 = usp;
+ p->thread->reg13 = arg;
+ p->thread.reg3 = (unsigned long) ret_from_kernel_thread;
} else {
- childregs->regs[28] = (unsigned long) ti; /* kernel fork */
- childregs->regs[0] = (unsigned long) childregs;
+ *childregs = *regs;
+ childregs->regs[7] = 0; /* Clear error flag */
+ childregs->regs[4] = 0; /* Child gets zero as return value */
+ childregs->regs[0] = usp; /* user fork */
+ regs->regs[4] = p->pid; /* WTF? */
+ p->thread.reg3 = (unsigned long) ret_from_fork;
}
- p->thread.reg0 = (unsigned long) childregs;
- p->thread.reg3 = (unsigned long) ret_from_fork;
p->thread.cp0_psr = 0;
return 0;
@@ -120,32 +119,6 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r)
return 1;
}
-static void __noreturn
-kernel_thread_helper(void *unused0, int (*fn)(void *),
- void *arg, void *unused1)
-{
- do_exit(fn(arg));
-}
-
-/*
- * Create a kernel thread.
- */
-long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
-{
- struct pt_regs regs;
-
- memset(&regs, 0, sizeof(regs));
-
- regs.regs[6] = (unsigned long) arg;
- regs.regs[5] = (unsigned long) fn;
- regs.cp0_epc = (unsigned long) kernel_thread_helper;
- regs.cp0_psr = (regs.cp0_psr & ~(0x1|0x4|0x8)) | \
- ((regs.cp0_psr & 0x3) << 2);
-
- return do_fork(flags | CLONE_VM | CLONE_UNTRACED, \
- 0, &regs, 0, NULL, NULL);
-}
-
unsigned long thread_saved_pc(struct task_struct *tsk)
{
return task_pt_regs(tsk)->cp0_epc;
diff --git a/arch/score/kernel/sys_score.c b/arch/score/kernel/sys_score.c
index d45cf00..5a682fc 100644
--- a/arch/score/kernel/sys_score.c
+++ b/arch/score/kernel/sys_score.c
@@ -107,33 +107,3 @@ score_execve(struct pt_regs *regs)
putname(filename);
return error;
}
-
-/*
- * Do a system call from kernel instead of calling sys_execve so we
- * end up with proper pt_regs.
- */
-asmlinkage
-int kernel_execve(const char *filename,
- const char *const argv[],
- const char *const envp[])
-{
- register unsigned long __r4 asm("r4") = (unsigned long) filename;
- register unsigned long __r5 asm("r5") = (unsigned long) argv;
- register unsigned long __r6 asm("r6") = (unsigned long) envp;
- register unsigned long __r7 asm("r7");
-
- __asm__ __volatile__ (" \n"
- "ldi r27, %5 \n"
- "syscall \n"
- "mv %0, r4 \n"
- "mv %1, r7 \n"
- : "=&r" (__r4), "=r" (__r7)
- : "r" (__r4), "r" (__r5), "r" (__r6), "i" (__NR_execve)
- : "r8", "r9", "r10", "r11", "r22", "r23", "r24", "r25",
- "r26", "r27", "memory");
-
- if (__r7 == 0)
- return __r4;
-
- return -__r4;
-}
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