[PATCH v2 0/4] xtensa: conversion to generic kernel_thread and friends

[PATCH v2 0/4] xtensa: conversion to generic kernel_thread and friends

[Max Filippov]

Hi.

This is v2 of xtensa conversion to generic kernel_thread and friends series,
for inclusion into git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
tree.

Changes v1 -> v2:
- rebase on top of czankel/xtensa-linux dev branch; a fix to copy_thread from
  that branch on which kernel_thread conversion depends is also included;
- move pt_regs memset from copy_thread to start_thread;
- drop {set,clear}_child_tid manipulation;
- don't look at regs argument to copy_thread;
- move zero newsp logic from xtensa_clone to copy_thread.

Chris Zankel (1):
  xtensa: reset windowbase/windowstart when cloning the VM

Max Filippov (3):
  xtensa: switch to generic kernel_thread()
  xtensa: switch to generic kernel_execve()
  xtensa: switch to generic sys_execve()

 arch/xtensa/Kconfig                   |    2 +
 arch/xtensa/include/asm/processor.h   |    4 +-
 arch/xtensa/include/asm/syscall.h     |    2 +-
 arch/xtensa/include/asm/unistd.h      |    1 +
 arch/xtensa/include/uapi/asm/unistd.h |    2 +-
 arch/xtensa/kernel/entry.S            |   57 ++++-----------
 arch/xtensa/kernel/process.c          |  128 ++++++++++++++++++---------------
 arch/xtensa/kernel/xtensa_ksyms.c     |    1 -
 8 files changed, 90 insertions(+), 107 deletions(-)

-- 
1.7.7.6

[PATCH v2 1/4] xtensa: reset windowbase/windowstart when cloning the VM

[Max Filippov]

From: Chris Zankel <chris@zankel.net>

When we copy a user thread with CLONE_VM, we also have to reset
windowbase and windowstart to start a pristine stack frame. Otherwise,
overflows can happen using the address 0 as the stack pointer.
Also add a special case for vfork, which continues on the
parent stack until it calls execve. Because this could be a call8, we
need to spill the stack pointer of the previus frame (if still 'live' in
the register file).

Signed-off-by: Chris Zankel <chris@zankel.net>
---
 arch/xtensa/kernel/process.c |   26 +++++++++++++++++++++++++-
 1 files changed, 25 insertions(+), 1 deletions(-)

diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c
index 1908f66..341c151 100644
--- a/arch/xtensa/kernel/process.c
+++ b/arch/xtensa/kernel/process.c
@@ -220,8 +220,32 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	if (user_mode(regs)) {
 
 		childregs->areg[1] = usp;
+
+		/* 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],
-- 
1.7.7.6

RE: [PATCH v2 1/4] xtensa: reset windowbase/windowstart when cloning the VM

[Marc Gauthier]

Max Filippov wrote:
> From: Chris Zankel <chris@zankel.net>
>
> When we copy a user thread with CLONE_VM, we also have to reset
> windowbase and windowstart to start a pristine stack frame. Otherwise,
> overflows can happen using the address 0 as the stack pointer.
> Also add a special case for vfork, which continues on the
> parent stack until it calls execve. Because this could be a call8, we
> need to spill the stack pointer of the previus frame (if
> still 'live' in
> the register file).
>
> Signed-off-by: Chris Zankel <chris@zankel.net>
> ---
>  arch/xtensa/kernel/process.c |   26 +++++++++++++++++++++++++-
>  1 files changed, 25 insertions(+), 1 deletions(-)
>
> diff --git a/arch/xtensa/kernel/process.c
> b/arch/xtensa/kernel/process.c
> index 1908f66..341c151 100644
> --- a/arch/xtensa/kernel/process.c
> +++ b/arch/xtensa/kernel/process.c
> @@ -220,8 +220,32 @@ int copy_thread(unsigned long
> clone_flags, unsigned long usp,
>       if (user_mode(regs)) {
>
>               childregs->areg[1] = usp;
> +
> +             /* 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],


Acked-by: Marc Gauthier <marc@tensilica.com>

[PATCH v2 2/4] xtensa: switch to generic kernel_thread()

[Max Filippov]

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/Kconfig                 |    1 +
 arch/xtensa/include/asm/processor.h |    4 +-
 arch/xtensa/kernel/entry.S          |   41 ++++++-------------
 arch/xtensa/kernel/process.c        |   77 +++++++++++++++++++++--------------
 arch/xtensa/kernel/xtensa_ksyms.c   |    1 -
 5 files changed, 61 insertions(+), 63 deletions(-)

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 75bb9a5..1033a1a 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -13,6 +13,7 @@ config XTENSA
 	select GENERIC_CPU_DEVICES
 	select MODULES_USE_ELF_RELA
 	select GENERIC_PCI_IOMAP
+	select GENERIC_KERNEL_THREAD
 	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select OF
 	select OF_EARLY_FLATTREE
diff --git a/arch/xtensa/include/asm/processor.h b/arch/xtensa/include/asm/processor.h
index 5d6c536..c1fc2d4 100644
--- a/arch/xtensa/include/asm/processor.h
+++ b/arch/xtensa/include/asm/processor.h
@@ -152,6 +152,7 @@ struct thread_struct {
 
 /* 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 @@ struct mm_struct;
 /* 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/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 0dead62..0fc994f 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -1833,34 +1833,6 @@ ENTRY(system_call)
 
 
 /*
- * 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.
  *
@@ -1958,3 +1930,16 @@ ENTRY(ret_from_fork)
 
 	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
+	call4	do_exit
+
+ENDPROC(ret_from_kernel_thread)
diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c
index 341c151..be52fe4 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 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 /*
  * 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.
@@ -185,41 +198,37 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
  * 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
@@ -254,11 +263,19 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 // 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)
@@ -354,8 +371,6 @@ long xtensa_clone(unsigned long clone_flags, unsigned long newsp,
                   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);
 }
 
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(__strncpy_user);
 EXPORT_SYMBOL(clear_page);
 EXPORT_SYMBOL(copy_page);
 
-EXPORT_SYMBOL(kernel_thread);
 EXPORT_SYMBOL(empty_zero_page);
 
 /*
-- 
1.7.7.6

[PATCH v2 3/4] xtensa: switch to generic kernel_execve()

[Max Filippov]

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/Kconfig        |    1 +
 arch/xtensa/kernel/entry.S |   18 +-----------------
 2 files changed, 2 insertions(+), 17 deletions(-)

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 1033a1a..e957454 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -14,6 +14,7 @@ config XTENSA
 	select MODULES_USE_ELF_RELA
 	select GENERIC_PCI_IOMAP
 	select GENERIC_KERNEL_THREAD
+	select GENERIC_KERNEL_EXECVE
 	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select OF
 	select OF_EARLY_FLATTREE
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 0fc994f..7da2c02 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -1833,22 +1833,6 @@ ENTRY(system_call)
 
 
 /*
- * 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)
@@ -1940,6 +1924,6 @@ ENTRY(ret_from_kernel_thread)
 	call4	schedule_tail
 	mov	a6, a3
 	callx4	a2
-	call4	do_exit
+	j	common_exception_return
 
 ENDPROC(ret_from_kernel_thread)
-- 
1.7.7.6

[PATCH v2 4/4] xtensa: switch to generic sys_execve()

[Max Filippov]

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/include/asm/syscall.h     |    2 +-
 arch/xtensa/include/asm/unistd.h      |    1 +
 arch/xtensa/include/uapi/asm/unistd.h |    2 +-
 arch/xtensa/kernel/process.c          |   25 -------------------------
 4 files changed, 3 insertions(+), 27 deletions(-)

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 d9fa52d..f4e6eaa 100644
--- a/arch/xtensa/include/asm/unistd.h
+++ b/arch/xtensa/include/asm/unistd.h
@@ -1,6 +1,7 @@
 #ifndef _XTENSA_UNISTD_H
 #define _XTENSA_UNISTD_H
 
+#define __ARCH_WANT_SYS_EXECVE
 #include <uapi/asm/unistd.h>
 
 /*
diff --git a/arch/xtensa/include/uapi/asm/unistd.h b/arch/xtensa/include/uapi/asm/unistd.h
index 1fd157f..9f36d0e 100644
--- a/arch/xtensa/include/uapi/asm/unistd.h
+++ b/arch/xtensa/include/uapi/asm/unistd.h
@@ -262,7 +262,7 @@ __SYSCALL(115, sys_sendmmsg, 4)
 #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
diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c
index be52fe4..09ae7bf 100644
--- a/arch/xtensa/kernel/process.c
+++ b/arch/xtensa/kernel/process.c
@@ -373,28 +373,3 @@ long xtensa_clone(unsigned long clone_flags, unsigned long newsp,
 {
         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;
-}
-
-- 
1.7.7.6

Re: [PATCH v2 0/4] xtensa: conversion to generic kernel_thread and friends

[czankel]

Hi Max,

Has anything changed from the version that's already in linux-next? I 
wanted to push that version upstream today.

Thanks,
-Chris


On 10/29/12 7:56 AM, Max Filippov wrote:
> Hi.
>
> This is v2 of xtensa conversion to generic kernel_thread and friends series,
> for inclusion into git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
> tree.
>
> Changes v1 ->  v2:
> - rebase on top of czankel/xtensa-linux dev branch; a fix to copy_thread from
>    that branch on which kernel_thread conversion depends is also included;
> - move pt_regs memset from copy_thread to start_thread;
> - drop {set,clear}_child_tid manipulation;
> - don't look at regs argument to copy_thread;
> - move zero newsp logic from xtensa_clone to copy_thread.
>
> Chris Zankel (1):
>    xtensa: reset windowbase/windowstart when cloning the VM
>
> Max Filippov (3):
>    xtensa: switch to generic kernel_thread()
>    xtensa: switch to generic kernel_execve()
>    xtensa: switch to generic sys_execve()
>
>   arch/xtensa/Kconfig                   |    2 +
>   arch/xtensa/include/asm/processor.h   |    4 +-
>   arch/xtensa/include/asm/syscall.h     |    2 +-
>   arch/xtensa/include/asm/unistd.h      |    1 +
>   arch/xtensa/include/uapi/asm/unistd.h |    2 +-
>   arch/xtensa/kernel/entry.S            |   57 ++++-----------
>   arch/xtensa/kernel/process.c          |  128 ++++++++++++++++++---------------
>   arch/xtensa/kernel/xtensa_ksyms.c     |    1 -
>   8 files changed, 90 insertions(+), 107 deletions(-)
>

Re: [PATCH v2 0/4] xtensa: conversion to generic kernel_thread and friends

[Max Filippov]

On Mon, Oct 29, 2012 at 8:23 PM, czankel <chris@zankel.net> wrote:
> Hi Max,
>
> Has anything changed from the version that's already in linux-next? I wanted
> to push that version upstream today.

It's the same. I sent self-contained series to Al in case it blocks whatever.

> On 10/29/12 7:56 AM, Max Filippov wrote:
>>
>> Hi.
>>
>> This is v2 of xtensa conversion to generic kernel_thread and friends
>> series,
>> for inclusion into
>> git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
>> tree.
>>
>> Changes v1 ->  v2:
>> - rebase on top of czankel/xtensa-linux dev branch; a fix to copy_thread
>> from
>>    that branch on which kernel_thread conversion depends is also included;
>> - move pt_regs memset from copy_thread to start_thread;
>> - drop {set,clear}_child_tid manipulation;
>> - don't look at regs argument to copy_thread;
>> - move zero newsp logic from xtensa_clone to copy_thread.
>>
>> Chris Zankel (1):
>>    xtensa: reset windowbase/windowstart when cloning the VM
>>
>> Max Filippov (3):
>>    xtensa: switch to generic kernel_thread()
>>    xtensa: switch to generic kernel_execve()
>>    xtensa: switch to generic sys_execve()
>>
>>   arch/xtensa/Kconfig                   |    2 +
>>   arch/xtensa/include/asm/processor.h   |    4 +-
>>   arch/xtensa/include/asm/syscall.h     |    2 +-
>>   arch/xtensa/include/asm/unistd.h      |    1 +
>>   arch/xtensa/include/uapi/asm/unistd.h |    2 +-
>>   arch/xtensa/kernel/entry.S            |   57 ++++-----------
>>   arch/xtensa/kernel/process.c          |  128
>> ++++++++++++++++++---------------
>>   arch/xtensa/kernel/xtensa_ksyms.c     |    1 -
>>   8 files changed, 90 insertions(+), 107 deletions(-)
>>

-- 
Thanks.
-- Max

Re: [PATCH v2 0/4] xtensa: conversion to generic kernel_thread and friends

[Al Viro]

On Mon, Oct 29, 2012 at 07:58:02PM +0300, Max Filippov wrote:
> On Mon, Oct 29, 2012 at 8:23 PM, czankel <chris@zankel.net> wrote:
> > Hi Max,
> >
> > Has anything changed from the version that's already in linux-next? I wanted
> > to push that version upstream today.
> 
> It's the same. I sent self-contained series to Al in case it blocks whatever.

I'd very much prefer to pull from xtensa tree, to avoid the PITA with
merge conflicts later.  It's your current #for_next, right?  And there's
not much besides those commits in there, so I'm grabbing that one...