sh: switch to generic kernel_thread()/kernel_execve()
authorAl Viro <viro@zeniv.linux.org.uk>
Sun, 14 Oct 2012 05:41:42 +0000 (01:41 -0400)
committerAl Viro <viro@zeniv.linux.org.uk>
Tue, 23 Oct 2012 02:31:01 +0000 (22:31 -0400)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
arch/sh/Kconfig
arch/sh/include/asm/processor_32.h
arch/sh/include/asm/processor_64.h
arch/sh/kernel/Makefile
arch/sh/kernel/cpu/sh5/entry.S
arch/sh/kernel/entry-common.S
arch/sh/kernel/process_32.c
arch/sh/kernel/process_64.c
arch/sh/kernel/sys_sh32.c
arch/sh/kernel/sys_sh64.c [deleted file]

index babc2b826c5caf5f26f9a029452e5067451190c1..8451317eed58d3b79bc7ec3df8df6eac0b20fd0d 100644 (file)
@@ -40,6 +40,8 @@ config SUPERH
        select GENERIC_STRNLEN_USER
        select HAVE_MOD_ARCH_SPECIFIC if DWARF_UNWINDER
        select MODULES_USE_ELF_RELA
+       select GENERIC_KERNEL_THREAD
+       select GENERIC_KERNEL_EXECVE
        help
          The SuperH is a RISC processor targeted for use in embedded systems
          and consumer electronics; it was also used in the Sega Dreamcast
index b6311fd2d066a1db774409f1dac29f2b856290e4..b1320d55ca305139f5087694a6c6b3c2db3a6990 100644 (file)
@@ -126,11 +126,6 @@ extern void start_thread(struct pt_regs *regs, unsigned long new_pc, unsigned lo
 /* Free all resources held by a thread. */
 extern void release_thread(struct task_struct *);
 
-/*
- * create a kernel thread without removing it from tasklists
- */
-extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
-
 /* Copy and release all segment info associated with a VM */
 #define copy_segments(p, mm)   do { } while(0)
 #define release_segments(mm)   do { } while(0)
index cd6029fb2c015f89742e3519b5b04172ef39ce5e..1ee8946f09520a987a19ae477cac15087f19bf4a 100644 (file)
@@ -159,11 +159,6 @@ struct mm_struct;
 
 /* Free all resources held by a thread. */
 extern void release_thread(struct task_struct *);
-/*
- * create a kernel thread without removing it from tasklists
- */
-extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
-
 
 /* Copy and release all segment info associated with a VM */
 #define copy_segments(p, mm)   do { } while (0)
index 88571ff8eeec463fd36d68dc67f7cf0a9cc1b8e1..f259b37874e907176dfe8ee3a50cde1cef9fdc72 100644 (file)
@@ -16,7 +16,7 @@ obj-y := debugtraps.o dma-nommu.o dumpstack.o                 \
           machvec.o nmi_debug.o process.o                              \
           process_$(BITS).o ptrace.o ptrace_$(BITS).o                  \
           reboot.o return_address.o                                    \
-          setup.o signal_$(BITS).o sys_sh.o sys_sh$(BITS).o            \
+          setup.o signal_$(BITS).o sys_sh.o                            \
           syscalls_$(BITS).o time.o topology.o traps.o                 \
           traps_$(BITS).o unwinder.o
 
@@ -25,6 +25,7 @@ obj-y                         += iomap.o
 obj-$(CONFIG_HAS_IOPORT)       += ioport.o
 endif
 
+obj-$(CONFIG_SUPERH32)         += sys_sh32.o
 obj-y                          += cpu/
 obj-$(CONFIG_VSYSCALL)         += vsyscall/
 obj-$(CONFIG_SMP)              += smp.o
index 7e605b95592aea7ac767b817df3a7a61af8d4f20..0c8d0377d40bdf005a1d90e9929b9fe26011b0a9 100644 (file)
@@ -1228,6 +1228,25 @@ ret_from_fork:
        pta     ret_from_syscall, tr0
        blink   tr0, ZERO
 
+.global        ret_from_kernel_thread
+ret_from_kernel_thread:
+
+       movi    schedule_tail,r5
+       ori     r5, 1, r5
+       ptabs   r5, tr0
+       blink   tr0, LINK
+
+       ld.q    SP, FRAME_R(2), r2
+       ld.q    SP, FRAME_R(3), r3
+       ptabs   r3, tr0
+       blink   tr0, LINK
+
+       ld.q    SP, FRAME_S(FSPC), r2
+       addi    r2, 4, r2               /* Move PC, being pre-execution event */
+       st.q    SP, FRAME_S(FSPC), r2
+       pta     ret_from_syscall, tr0
+       blink   tr0, ZERO
+
 syscall_allowed:
        /* Use LINK to deflect the exit point, default is syscall_ret */
        pta     syscall_ret, tr0
index b96489d8b27dde9e38630d51de4e9d7f04115c08..9b6e4beeb296261c2fb5b315377822e236c587cf 100644 (file)
@@ -297,6 +297,19 @@ ret_from_fork:
         mov    r0, r4
        bra     syscall_exit
         nop
+
+       .align  2
+       .globl  ret_from_kernel_thread
+ret_from_kernel_thread:
+       mov.l   1f, r8
+       jsr     @r8
+        mov    r0, r4
+       mov.l   @(OFF_R5,r15), r5   ! fn
+       jsr     @r5
+        mov.l  @(OFF_R4,r15), r4   ! arg
+       bra     syscall_exit
+        nop
+
        .align  2
 1:     .long   schedule_tail
 
index ba7345f37bc9d0c6a1e4cc62760ca5e34fe65342..b55070b9a634ab91adf6661223b812e8c0dfef99 100644 (file)
@@ -68,38 +68,6 @@ void show_regs(struct pt_regs * regs)
        show_code(regs);
 }
 
-/*
- * Create a kernel thread
- */
-__noreturn void kernel_thread_helper(void *arg, int (*fn)(void *))
-{
-       do_exit(fn(arg));
-}
-
-/* Don't use this in BL=1(cli).  Or else, CPU resets! */
-int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
-{
-       struct pt_regs regs;
-       int pid;
-
-       memset(&regs, 0, sizeof(regs));
-       regs.regs[4] = (unsigned long)arg;
-       regs.regs[5] = (unsigned long)fn;
-
-       regs.pc = (unsigned long)kernel_thread_helper;
-       regs.sr = SR_MD;
-#if defined(CONFIG_SH_FPU)
-       regs.sr |= SR_FD;
-#endif
-
-       /* Ok, create the new process.. */
-       pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
-                     &regs, 0, NULL, NULL);
-
-       return pid;
-}
-EXPORT_SYMBOL(kernel_thread);
-
 void start_thread(struct pt_regs *regs, unsigned long new_pc,
                  unsigned long new_sp)
 {
@@ -157,9 +125,10 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 EXPORT_SYMBOL(dump_fpu);
 
 asmlinkage void ret_from_fork(void);
+asmlinkage void ret_from_kernel_thread(void);
 
 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);
@@ -177,29 +146,34 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
        }
 #endif
 
-       childregs = task_pt_regs(p);
-       *childregs = *regs;
+       memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
 
-       if (user_mode(regs)) {
-               childregs->regs[15] = usp;
-               ti->addr_limit = USER_DS;
-       } else {
-               childregs->regs[15] = (unsigned long)childregs;
+       childregs = task_pt_regs(p);
+       p->thread.sp = (unsigned long) childregs;
+       if (unlikely(p->flags & PF_KTHREAD)) {
+               memset(childregs, 0, sizeof(struct pt_regs));
+               p->thread.pc = (unsigned long) ret_from_kernel_thread;
+               childregs->regs[4] = arg;
+               childregs->regs[5] = usp;
+               childregs->sr = SR_MD;
+#if defined(CONFIG_SH_FPU)
+               childregs->sr |= SR_FD;
+#endif
                ti->addr_limit = KERNEL_DS;
                ti->status &= ~TS_USEDFPU;
                p->fpu_counter = 0;
+               return 0;
        }
+       *childregs = *regs;
+
+       childregs->regs[15] = usp;
+       ti->addr_limit = USER_DS;
 
        if (clone_flags & CLONE_SETTLS)
                childregs->gbr = childregs->regs[0];
 
        childregs->regs[0] = 0; /* Set return value for child */
-
-       p->thread.sp = (unsigned long) childregs;
        p->thread.pc = (unsigned long) ret_from_fork;
-
-       memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
-
        return 0;
 }
 
index 98a709f0c3c45c1f6ece40d34b79a69cd4de4e2c..fd338b030fd97f791f39d4c87b2a5ccdffe72bbc 100644 (file)
@@ -284,39 +284,6 @@ void show_regs(struct pt_regs *regs)
        }
 }
 
-/*
- * Create a kernel thread
- */
-__noreturn void kernel_thread_helper(void *arg, int (*fn)(void *))
-{
-       do_exit(fn(arg));
-}
-
-/*
- * This is the mechanism for creating a new kernel thread.
- *
- * NOTE! Only a kernel-only process(ie the swapper or direct descendants
- * who haven't done an "execve()") should use this: it will work within
- * a system call from a "real" process, but the process memory space will
- * not be freed until both the parent and the child have exited.
- */
-int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
-{
-       struct pt_regs regs;
-
-       memset(&regs, 0, sizeof(regs));
-       regs.regs[2] = (unsigned long)arg;
-       regs.regs[3] = (unsigned long)fn;
-
-       regs.pc = (unsigned long)kernel_thread_helper;
-       regs.sr = (1 << 30);
-
-       /* Ok, create the new process.. */
-       return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
-                     &regs, 0, NULL, NULL);
-}
-EXPORT_SYMBOL(kernel_thread);
-
 /*
  * Free current thread data structures etc..
  */
@@ -401,15 +368,17 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 EXPORT_SYMBOL(dump_fpu);
 
 asmlinkage void ret_from_fork(void);
+asmlinkage void ret_from_kernel_thread(void);
 
 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 pt_regs *childregs;
 
 #ifdef CONFIG_SH_FPU
-       if(last_task_used_math == current) {
+       /* can't happen for a kernel thread */
+       if (last_task_used_math == current) {
                enable_fpu();
                save_fpu(current);
                disable_fpu();
@@ -419,7 +388,17 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 #endif
        /* Copy from sh version */
        childregs = (struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1;
+       p->thread.sp = (unsigned long) childregs;
 
+       if (unlikely(p->flags & PF_KTHREAD)) {
+               memset(childregs, 0, sizeof(struct pt_regs));
+               childregs->regs[2] = (unsigned long)arg;
+               childregs->regs[3] = (unsigned long)fn;
+               childregs->sr = (1 << 30); /* not user_mode */
+               childregs->sr |= SR_FD; /* Invalidate FPU flag */
+               p->thread.pc = (unsigned long) ret_from_kernel_thread;
+               return 0;
+       }
        *childregs = *regs;
 
        /*
@@ -428,19 +407,12 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
         * 32-bit wide and context switch must take care
         * of NEFF sign extension.
         */
-       if (user_mode(regs)) {
-               childregs->regs[15] = neff_sign_extend(usp);
-               p->thread.uregs = childregs;
-       } else {
-               childregs->regs[15] =
-                       neff_sign_extend((unsigned long)task_stack_page(p) +
-                                        THREAD_SIZE);
-       }
+       childregs->regs[15] = neff_sign_extend(usp);
+       p->thread.uregs = childregs;
 
        childregs->regs[9] = 0; /* Set return value for child */
        childregs->sr |= SR_FD; /* Invalidate FPU flag */
 
-       p->thread.sp = (unsigned long) childregs;
        p->thread.pc = (unsigned long) ret_from_fork;
 
        return 0;
index f56b6fe5c5d02d7cdb5084bce5732cba7c32ec68..497bab3a04015ca08774aa1771d47f40418d0b10 100644 (file)
@@ -60,27 +60,3 @@ asmlinkage int sys_fadvise64_64_wrapper(int fd, u32 offset0, u32 offset1,
                                (u64)len0 << 32 | len1, advice);
 #endif
 }
-
-#if defined(CONFIG_CPU_SH2) || defined(CONFIG_CPU_SH2A)
-#define SYSCALL_ARG3   "trapa #0x23"
-#else
-#define SYSCALL_ARG3   "trapa #0x13"
-#endif
-
-/*
- * Do a system call from kernel instead of calling sys_execve so we
- * end up with proper pt_regs.
- */
-int kernel_execve(const char *filename,
-                 const char *const argv[],
-                 const char *const envp[])
-{
-       register long __sc0 __asm__ ("r3") = __NR_execve;
-       register long __sc4 __asm__ ("r4") = (long) filename;
-       register long __sc5 __asm__ ("r5") = (long) argv;
-       register long __sc6 __asm__ ("r6") = (long) envp;
-       __asm__ __volatile__ (SYSCALL_ARG3 : "=z" (__sc0)
-                       : "0" (__sc0), "r" (__sc4), "r" (__sc5), "r" (__sc6)
-                       : "memory");
-       return __sc0;
-}
diff --git a/arch/sh/kernel/sys_sh64.c b/arch/sh/kernel/sys_sh64.c
deleted file mode 100644 (file)
index c5a38c4..0000000
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * arch/sh/kernel/sys_sh64.c
- *
- * Copyright (C) 2000, 2001  Paolo Alberelli
- *
- * This file contains various random system calls that
- * have a non-standard calling sequence on the Linux/SH5
- * platform.
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file "COPYING" in the main directory of this archive
- * for more details.
- */
-#include <linux/errno.h>
-#include <linux/rwsem.h>
-#include <linux/sched.h>
-#include <linux/mm.h>
-#include <linux/fs.h>
-#include <linux/smp.h>
-#include <linux/sem.h>
-#include <linux/msg.h>
-#include <linux/shm.h>
-#include <linux/stat.h>
-#include <linux/mman.h>
-#include <linux/file.h>
-#include <linux/syscalls.h>
-#include <linux/ipc.h>
-#include <asm/uaccess.h>
-#include <asm/ptrace.h>
-#include <asm/unistd.h>
-
-/*
- * Do a system call from kernel instead of calling sys_execve so we
- * end up with proper pt_regs.
- */
-int kernel_execve(const char *filename,
-                 const char *const argv[],
-                 const char *const envp[])
-{
-       register unsigned long __sc0 __asm__ ("r9") = ((0x13 << 16) | __NR_execve);
-       register unsigned long __sc2 __asm__ ("r2") = (unsigned long) filename;
-       register unsigned long __sc3 __asm__ ("r3") = (unsigned long) argv;
-       register unsigned long __sc4 __asm__ ("r4") = (unsigned long) envp;
-       __asm__ __volatile__ ("trapa    %1 !\t\t\t execve(%2,%3,%4)"
-       : "=r" (__sc0)
-       : "r" (__sc0), "r" (__sc2), "r" (__sc3), "r" (__sc4) );
-       __asm__ __volatile__ ("!dummy   %0 %1 %2 %3"
-       : : "r" (__sc0), "r" (__sc2), "r" (__sc3), "r" (__sc4) : "memory");
-       return __sc0;
-}