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authorAl Viro <viro@zeniv.linux.org.uk>2012-10-03 23:28:08 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-10-14 19:36:30 -0400
commita44e060fc523c379341e35a981c09c3953cf4ba4 (patch)
treef32db182b2f746acd95cd7dbb8794352a8f98eb4
parentddffeb8c4d0331609ef2581d84de4d763607bd37 (diff)
downloadlinux-a44e060fc523c379341e35a981c09c3953cf4ba4.tar.bz2
parisc: switch to generic kernel_thread()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--arch/parisc/Kconfig1
-rw-r--r--arch/parisc/kernel/entry.S53
-rw-r--r--arch/parisc/kernel/process.c53
3 files changed, 18 insertions, 89 deletions
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 11def45b98c5..c779da7cd96b 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -22,6 +22,7 @@ config PARISC
select GENERIC_STRNCPY_FROM_USER
select HAVE_MOD_ARCH_SPECIFIC
select MODULES_USE_ELF_RELA
+ select GENERIC_KERNEL_THREAD
help
The PA-RISC microprocessor is designed by Hewlett-Packard and used
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
index 18670a078849..18d05e7373b5 100644
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -708,59 +708,9 @@ ENTRY(end_fault_vector)
.import do_cpu_irq_mask,code
/*
- * r26 = function to be called
- * r25 = argument to pass in
- * r24 = flags for do_fork()
- *
- * Kernel threads don't ever return, so they don't need
- * a true register context. We just save away the arguments
- * for copy_thread/ret_ to properly set up the child.
- */
-
-#define CLONE_VM 0x100 /* Must agree with <linux/sched.h> */
-#define CLONE_UNTRACED 0x00800000
-
- .import do_fork
-ENTRY(__kernel_thread)
- STREG %r2, -RP_OFFSET(%r30)
-
- copy %r30, %r1
- ldo PT_SZ_ALGN(%r30),%r30
-#ifdef CONFIG_64BIT
- /* Yo, function pointers in wide mode are little structs... -PB */
- ldd 24(%r26), %r2
- STREG %r2, PT_GR27(%r1) /* Store childs %dp */
- ldd 16(%r26), %r26
-
- STREG %r22, PT_GR22(%r1) /* save r22 (arg5) */
- copy %r0, %r22 /* user_tid */
-#endif
- STREG %r26, PT_GR26(%r1) /* Store function & argument for child */
- STREG %r25, PT_GR25(%r1)
- ldil L%CLONE_UNTRACED, %r26
- ldo CLONE_VM(%r26), %r26 /* Force CLONE_VM since only init_mm */
- or %r26, %r24, %r26 /* will have kernel mappings. */
- ldi 1, %r25 /* stack_start, signals kernel thread */
- stw %r0, -52(%r30) /* user_tid */
-#ifdef CONFIG_64BIT
- ldo -16(%r30),%r29 /* Reference param save area */
-#endif
- BL do_fork, %r2
- copy %r1, %r24 /* pt_regs */
-
- /* Parent Returns here */
-
- LDREG -PT_SZ_ALGN-RP_OFFSET(%r30), %r2
- ldo -PT_SZ_ALGN(%r30), %r30
- bv %r0(%r2)
- nop
-ENDPROC(__kernel_thread)
-
- /*
* Child Returns here
*
- * copy_thread moved args from temp save area set up above
- * into task save area.
+ * copy_thread moved args into task save area.
*/
ENTRY(ret_from_kernel_thread)
@@ -773,7 +723,6 @@ ENTRY(ret_from_kernel_thread)
LDREG TASK_PT_GR25(%r1), %r26
#ifdef CONFIG_64BIT
LDREG TASK_PT_GR27(%r1), %r27
- LDREG TASK_PT_GR22(%r1), %r22
#endif
LDREG TASK_PT_GR26(%r1), %r1
ble 0(%sr7, %r1)
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index cbc37216bf90..b7b4126774e0 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -165,23 +165,6 @@ void (*pm_power_off)(void) = machine_power_off;
EXPORT_SYMBOL(pm_power_off);
/*
- * Create a kernel thread
- */
-
-extern pid_t __kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
-pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
-{
-
- /*
- * FIXME: Once we are sure we don't need any debug here,
- * kernel_thread can become a #define.
- */
-
- return __kernel_thread(fn, arg, flags);
-}
-EXPORT_SYMBOL(kernel_thread);
-
-/*
* Free current thread data structures etc..
*/
void exit_thread(void)
@@ -256,8 +239,8 @@ sys_vfork(struct pt_regs *regs)
int
copy_thread(unsigned long clone_flags, unsigned long usp,
- unsigned long unused, /* in ia64 this is "user_stack_size" */
- struct task_struct * p, struct pt_regs * pregs)
+ unsigned long arg,
+ struct task_struct *p, struct pt_regs *pregs)
{
struct pt_regs * cregs = &(p->thread.regs);
void *stack = task_stack_page(p);
@@ -271,21 +254,8 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
extern void * const hpux_child_return;
#endif
- *cregs = *pregs;
-
- /* Set the return value for the child. Note that this is not
- actually restored by the syscall exit path, but we put it
- here for consistency in case of signals. */
- cregs->gr[28] = 0; /* child */
-
- /*
- * We need to differentiate between a user fork and a
- * kernel fork. We can't use user_mode, because the
- * the syscall path doesn't save iaoq. Right now
- * We rely on the fact that kernel_thread passes
- * in zero for usp.
- */
- if (usp == 1) {
+ if (unlikely((p->flags & PF_KTHREAD) && usp != 0)) {
+ memset(cregs, 0, sizeof(struct pt_regs));
/* kernel thread */
cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN;
/* Must exit via ret_from_kernel_thread in order
@@ -297,10 +267,12 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
* ret_from_kernel_thread.
*/
#ifdef CONFIG_64BIT
- cregs->gr[27] = pregs->gr[27];
+ cregs->gr[27] = ((unsigned long *)usp)[3];
+ cregs->gr[26] = ((unsigned long *)usp)[2];
+#else
+ cregs->gr[26] = usp;
#endif
- cregs->gr[26] = pregs->gr[26];
- cregs->gr[25] = pregs->gr[25];
+ cregs->gr[25] = arg;
} else {
/* user thread */
/*
@@ -308,6 +280,13 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
* for setting gr[21].
*/
+ *cregs = *pregs;
+
+ /* Set the return value for the child. Note that this is not
+ actually restored by the syscall exit path, but we put it
+ here for consistency in case of signals. */
+ cregs->gr[28] = 0; /* child */
+
/* Use same stack depth as parent */
cregs->ksp = (unsigned long)stack
+ (pregs->gr[21] & (THREAD_SIZE - 1));