Merge tag 'xtensa-next-20121101' of git://github.com/czankel/xtensa-linux
Pull Xtensa fixes from Chris Zankel:
"Some important bug fixes.
With the change to uapi, there was a bug introduced that results in an
empty syscall table (mult-inclusion bug). Switching to the generic
thread/execve allowed us to fix a bug we had in vfork()."
* tag 'xtensa-next-20121101' of git://github.com/czankel/xtensa-linux:
xtensa: switch to generic sys_execve()
xtensa: switch to generic kernel_execve()
xtensa: switch to generic kernel_thread()
xtensa: reset windowbase/windowstart when cloning the VM
xtensa: use physical addresses for bus addresses
xtensa: allow multi-inclusion for uapi/unistd.h
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index cdcb48a..0d1f36a 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -13,6 +13,8 @@
select GENERIC_CPU_DEVICES
select MODULES_USE_ELF_RELA
select GENERIC_PCI_IOMAP
+ select GENERIC_KERNEL_THREAD
+ select GENERIC_KERNEL_EXECVE
select ARCH_WANT_OPTIONAL_GPIOLIB
help
Xtensa processors are 32-bit RISC machines designed by Tensilica
diff --git a/arch/xtensa/include/asm/io.h b/arch/xtensa/include/asm/io.h
index e6be5b9..700c2e6 100644
--- a/arch/xtensa/include/asm/io.h
+++ b/arch/xtensa/include/asm/io.h
@@ -62,6 +62,10 @@
static inline void iounmap(volatile void __iomem *addr)
{
}
+
+#define virt_to_bus virt_to_phys
+#define bus_to_virt phys_to_virt
+
#endif /* CONFIG_MMU */
/*
diff --git a/arch/xtensa/include/asm/processor.h b/arch/xtensa/include/asm/processor.h
index 5c371d8..2d630e7 100644
--- a/arch/xtensa/include/asm/processor.h
+++ b/arch/xtensa/include/asm/processor.h
@@ -152,6 +152,7 @@
/* Clearing a0 terminates the backtrace. */
#define start_thread(regs, new_pc, new_sp) \
+ memset(regs, 0, sizeof(*regs)); \
regs->pc = new_pc; \
regs->ps = USER_PS_VALUE; \
regs->areg[1] = new_sp; \
@@ -168,9 +169,6 @@
/* Free all resources held by a thread. */
#define release_thread(thread) do { } while(0)
-/* 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)
diff --git a/arch/xtensa/include/asm/syscall.h b/arch/xtensa/include/asm/syscall.h
index c1dacca..124aeee 100644
--- a/arch/xtensa/include/asm/syscall.h
+++ b/arch/xtensa/include/asm/syscall.h
@@ -10,7 +10,7 @@
struct pt_regs;
struct sigaction;
-asmlinkage long xtensa_execve(char*, char**, char**, struct pt_regs*);
+asmlinkage long sys_execve(char*, char**, char**, struct pt_regs*);
asmlinkage long xtensa_clone(unsigned long, unsigned long, struct pt_regs*);
asmlinkage long xtensa_ptrace(long, long, long, long);
asmlinkage long xtensa_sigreturn(struct pt_regs*);
diff --git a/arch/xtensa/include/asm/unistd.h b/arch/xtensa/include/asm/unistd.h
index 9ef1c31..f4e6eaa 100644
--- a/arch/xtensa/include/asm/unistd.h
+++ b/arch/xtensa/include/asm/unistd.h
@@ -1,16 +1,9 @@
-/*
- * include/asm-xtensa/unistd.h
- *
- * 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.
- *
- * Copyright (C) 2001 - 2005 Tensilica Inc.
- */
+#ifndef _XTENSA_UNISTD_H
+#define _XTENSA_UNISTD_H
+#define __ARCH_WANT_SYS_EXECVE
#include <uapi/asm/unistd.h>
-
/*
* "Conditional" syscalls
*
@@ -37,3 +30,5 @@
#define __IGNORE_mmap /* use mmap2 */
#define __IGNORE_vfork /* use clone */
#define __IGNORE_fadvise64 /* use fadvise64_64 */
+
+#endif /* _XTENSA_UNISTD_H */
diff --git a/arch/xtensa/include/uapi/asm/unistd.h b/arch/xtensa/include/uapi/asm/unistd.h
index 479abae..9f36d0e 100644
--- a/arch/xtensa/include/uapi/asm/unistd.h
+++ b/arch/xtensa/include/uapi/asm/unistd.h
@@ -1,14 +1,4 @@
-/*
- * include/asm-xtensa/unistd.h
- *
- * 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.
- *
- * Copyright (C) 2001 - 2012 Tensilica Inc.
- */
-
-#ifndef _UAPI_XTENSA_UNISTD_H
+#if !defined(_UAPI_XTENSA_UNISTD_H) || defined(__SYSCALL)
#define _UAPI_XTENSA_UNISTD_H
#ifndef __SYSCALL
@@ -272,7 +262,7 @@
#define __NR_clone 116
__SYSCALL(116, xtensa_clone, 5)
#define __NR_execve 117
-__SYSCALL(117, xtensa_execve, 3)
+__SYSCALL(117, sys_execve, 3)
#define __NR_exit 118
__SYSCALL(118, sys_exit, 1)
#define __NR_exit_group 119
@@ -759,4 +749,6 @@
#define SYS_XTENSA_COUNT 5 /* count */
+#undef __SYSCALL
+
#endif /* _UAPI_XTENSA_UNISTD_H */
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 18453067..90bfc1d 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -1833,50 +1833,6 @@
/*
- * Create a kernel thread
- *
- * int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
- * a2 a2 a3 a4
- */
-
-ENTRY(kernel_thread)
- entry a1, 16
-
- mov a5, a2 # preserve fn over syscall
- mov a7, a3 # preserve args over syscall
-
- movi a3, _CLONE_VM | _CLONE_UNTRACED
- movi a2, __NR_clone
- or a6, a4, a3 # arg0: flags
- mov a3, a1 # arg1: sp
- syscall
-
- beq a3, a1, 1f # branch if parent
- mov a6, a7 # args
- callx4 a5 # fn(args)
-
- movi a2, __NR_exit
- syscall # return value of fn(args) still in a6
-
-1: retw
-
-/*
- * Do a system call from kernel instead of calling sys_execve, so we end up
- * with proper pt_regs.
- *
- * int kernel_execve(const char *fname, char *const argv[], charg *const envp[])
- * a2 a2 a3 a4
- */
-
-ENTRY(kernel_execve)
- entry a1, 16
- mov a6, a2 # arg0 is in a6
- movi a2, __NR_execve
- syscall
-
- retw
-
-/*
* Task switch.
*
* struct task* _switch_to (struct task* prev, struct task* next)
@@ -1958,3 +1914,16 @@
j common_exception_return
+/*
+ * Kernel thread creation helper
+ * On entry, set up by copy_thread: a2 = thread_fn, a3 = thread_fn arg
+ * left from _switch_to: a6 = prev
+ */
+ENTRY(ret_from_kernel_thread)
+
+ call4 schedule_tail
+ mov a6, a3
+ callx4 a2
+ j common_exception_return
+
+ENDPROC(ret_from_kernel_thread)
diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c
index 1908f66..09ae7bf 100644
--- a/arch/xtensa/kernel/process.c
+++ b/arch/xtensa/kernel/process.c
@@ -45,6 +45,7 @@
#include <asm/regs.h>
extern void ret_from_fork(void);
+extern void ret_from_kernel_thread(void);
struct task_struct *current_set[NR_CPUS] = {&init_task, };
@@ -158,18 +159,30 @@
/*
* Copy thread.
*
+ * There are two modes in which this function is called:
+ * 1) Userspace thread creation,
+ * regs != NULL, usp_thread_fn is userspace stack pointer.
+ * It is expected to copy parent regs (in case CLONE_VM is not set
+ * in the clone_flags) and set up passed usp in the childregs.
+ * 2) Kernel thread creation,
+ * regs == NULL, usp_thread_fn is the function to run in the new thread
+ * and thread_fn_arg is its parameter.
+ * childregs are not used for the kernel threads.
+ *
* The stack layout for the new thread looks like this:
*
- * +------------------------+ <- sp in childregs (= tos)
+ * +------------------------+
* | childregs |
* +------------------------+ <- thread.sp = sp in dummy-frame
* | dummy-frame | (saved in dummy-frame spill-area)
* +------------------------+
*
- * We create a dummy frame to return to ret_from_fork:
- * a0 points to ret_from_fork (simulating a call4)
+ * We create a dummy frame to return to either ret_from_fork or
+ * ret_from_kernel_thread:
+ * a0 points to ret_from_fork/ret_from_kernel_thread (simulating a call4)
* sp points to itself (thread.sp)
- * a2, a3 are unused.
+ * a2, a3 are unused for userspace threads,
+ * a2 points to thread_fn, a3 holds thread_fn arg for kernel threads.
*
* Note: This is a pristine frame, so we don't need any spill region on top of
* childregs.
@@ -185,43 +198,63 @@
* involved. Much simpler to just not copy those live frames across.
*/
-int copy_thread(unsigned long clone_flags, unsigned long usp,
- unsigned long unused,
- struct task_struct * p, struct pt_regs * regs)
+int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
+ unsigned long thread_fn_arg,
+ struct task_struct *p, struct pt_regs *unused)
{
- struct pt_regs *childregs;
- unsigned long tos;
- int user_mode = user_mode(regs);
+ struct pt_regs *childregs = task_pt_regs(p);
#if (XTENSA_HAVE_COPROCESSORS || XTENSA_HAVE_IO_PORTS)
struct thread_info *ti;
#endif
- /* Set up new TSS. */
- tos = (unsigned long)task_stack_page(p) + THREAD_SIZE;
- if (user_mode)
- childregs = (struct pt_regs*)(tos - PT_USER_SIZE);
- else
- childregs = (struct pt_regs*)tos - 1;
-
- /* This does not copy all the regs. In a bout of brilliance or madness,
- ARs beyond a0-a15 exist past the end of the struct. */
- *childregs = *regs;
-
/* Create a call4 dummy-frame: a0 = 0, a1 = childregs. */
*((int*)childregs - 3) = (unsigned long)childregs;
*((int*)childregs - 4) = 0;
- childregs->areg[2] = 0;
- p->set_child_tid = p->clear_child_tid = NULL;
- p->thread.ra = MAKE_RA_FOR_CALL((unsigned long)ret_from_fork, 0x1);
p->thread.sp = (unsigned long)childregs;
- if (user_mode(regs)) {
+ if (!(p->flags & PF_KTHREAD)) {
+ struct pt_regs *regs = current_pt_regs();
+ unsigned long usp = usp_thread_fn ?
+ usp_thread_fn : regs->areg[1];
+ p->thread.ra = MAKE_RA_FOR_CALL(
+ (unsigned long)ret_from_fork, 0x1);
+
+ /* This does not copy all the regs.
+ * In a bout of brilliance or madness,
+ * ARs beyond a0-a15 exist past the end of the struct.
+ */
+ *childregs = *regs;
childregs->areg[1] = usp;
+ childregs->areg[2] = 0;
+
+ /* When sharing memory with the parent thread, the child
+ usually starts on a pristine stack, so we have to reset
+ windowbase, windowstart and wmask.
+ (Note that such a new thread is required to always create
+ an initial call4 frame)
+ The exception is vfork, where the new thread continues to
+ run on the parent's stack until it calls execve. This could
+ be a call8 or call12, which requires a legal stack frame
+ of the previous caller for the overflow handlers to work.
+ (Note that it's always legal to overflow live registers).
+ In this case, ensure to spill at least the stack pointer
+ of that frame. */
+
if (clone_flags & CLONE_VM) {
- childregs->wmask = 1; /* can't share live windows */
+ /* check that caller window is live and same stack */
+ int len = childregs->wmask & ~0xf;
+ if (regs->areg[1] == usp && len != 0) {
+ int callinc = (regs->areg[0] >> 30) & 3;
+ int caller_ars = XCHAL_NUM_AREGS - callinc * 4;
+ put_user(regs->areg[caller_ars+1],
+ (unsigned __user*)(usp - 12));
+ }
+ childregs->wmask = 1;
+ childregs->windowstart = 1;
+ childregs->windowbase = 0;
} else {
int len = childregs->wmask & ~0xf;
memcpy(&childregs->areg[XCHAL_NUM_AREGS - len/4],
@@ -230,11 +263,19 @@
// FIXME: we need to set THREADPTR in thread_info...
if (clone_flags & CLONE_SETTLS)
childregs->areg[2] = childregs->areg[6];
-
} else {
- /* In kernel space, we start a new thread with a new stack. */
- childregs->wmask = 1;
- childregs->areg[1] = tos;
+ p->thread.ra = MAKE_RA_FOR_CALL(
+ (unsigned long)ret_from_kernel_thread, 1);
+
+ /* pass parameters to ret_from_kernel_thread:
+ * a2 = thread_fn, a3 = thread_fn arg
+ */
+ *((int *)childregs - 1) = thread_fn_arg;
+ *((int *)childregs - 2) = usp_thread_fn;
+
+ /* Childregs are only used when we're going to userspace
+ * in which case start_thread will set them up.
+ */
}
#if (XTENSA_HAVE_COPROCESSORS || XTENSA_HAVE_IO_PORTS)
@@ -330,32 +371,5 @@
void __user *child_tid, long a5,
struct pt_regs *regs)
{
- if (!newsp)
- newsp = regs->areg[1];
return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid);
}
-
-/*
- * xtensa_execve() executes a new program.
- */
-
-asmlinkage
-long xtensa_execve(const char __user *name,
- const char __user *const __user *argv,
- const char __user *const __user *envp,
- long a3, long a4, long a5,
- struct pt_regs *regs)
-{
- long error;
- struct filename *filename;
-
- filename = getname(name);
- error = PTR_ERR(filename);
- if (IS_ERR(filename))
- goto out;
- error = do_execve(filename->name, argv, envp, regs);
- putname(filename);
-out:
- return error;
-}
-
diff --git a/arch/xtensa/kernel/syscall.c b/arch/xtensa/kernel/syscall.c
index a5c01e7..5702065 100644
--- a/arch/xtensa/kernel/syscall.c
+++ b/arch/xtensa/kernel/syscall.c
@@ -32,10 +32,8 @@
syscall_t sys_call_table[__NR_syscall_count] /* FIXME __cacheline_aligned */= {
[0 ... __NR_syscall_count - 1] = (syscall_t)&sys_ni_syscall,
-#undef __SYSCALL
#define __SYSCALL(nr,symbol,nargs) [ nr ] = (syscall_t)symbol,
-#undef __KERNEL_SYSCALLS__
-#include <asm/unistd.h>
+#include <uapi/asm/unistd.h>
};
asmlinkage long xtensa_shmat(int shmid, char __user *shmaddr, int shmflg)
@@ -49,7 +47,8 @@
return (long)ret;
}
-asmlinkage long xtensa_fadvise64_64(int fd, int advice, unsigned long long offset, unsigned long long len)
+asmlinkage long xtensa_fadvise64_64(int fd, int advice,
+ unsigned long long offset, unsigned long long len)
{
return sys_fadvise64_64(fd, offset, len, advice);
}
diff --git a/arch/xtensa/kernel/xtensa_ksyms.c b/arch/xtensa/kernel/xtensa_ksyms.c
index a8b9f1f..afe058b 100644
--- a/arch/xtensa/kernel/xtensa_ksyms.c
+++ b/arch/xtensa/kernel/xtensa_ksyms.c
@@ -43,7 +43,6 @@
EXPORT_SYMBOL(clear_page);
EXPORT_SYMBOL(copy_page);
-EXPORT_SYMBOL(kernel_thread);
EXPORT_SYMBOL(empty_zero_page);
/*