Commit dfa9771a authored by Michal Simek's avatar Michal Simek Committed by Linus Torvalds
Browse files

microblaze: fix clone syscall 



Fix inadvertent breakage in the clone syscall ABI for Microblaze that
was introduced in commit f3268edb ("microblaze: switch to generic
fork/vfork/clone").

The Microblaze syscall ABI for clone takes the parent tid address in the
4th argument; the third argument slot is used for the stack size.  The
incorrectly-used CLONE_BACKWARDS type assigned parent tid to the 3rd
slot.

This commit restores the original ABI so that existing userspace libc
code will work correctly.

All kernel versions from v3.8-rc1 were affected.

Signed-off-by: default avatarMichal Simek <michal.simek@xilinx.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 41bb3476

arch/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -407,6 +407,12 @@ config CLONE_BACKWARDS2 
	help

	  Architecture has the first two arguments of clone(2) swapped.



config CLONE_BACKWARDS3

	bool

	help

	  Architecture has tls passed as the 3rd argument of clone(2),

	  not the 5th one.



config ODD_RT_SIGACTION

	bool

	help

arch/microblaze/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -28,7 +28,7 @@ config MICROBLAZE 
	select GENERIC_CLOCKEVENTS

	select GENERIC_IDLE_POLL_SETUP

	select MODULES_USE_ELF_RELA

	select CLONE_BACKWARDS

	select CLONE_BACKWARDS3



config SWAP

	def_bool n

include/linux/syscalls.h

+5 −0
Original line number Diff line number Diff line
@@ -802,9 +802,14 @@ asmlinkage long sys_vfork(void); 
asmlinkage long sys_clone(unsigned long, unsigned long, int __user *, int,

	       int __user *);

#else

#ifdef CONFIG_CLONE_BACKWARDS3

asmlinkage long sys_clone(unsigned long, unsigned long, int, int __user *,

			  int __user *, int);

#else

asmlinkage long sys_clone(unsigned long, unsigned long, int __user *,

	       int __user *, int);

#endif

#endif



asmlinkage long sys_execve(const char __user *filename,

		const char __user *const __user *argv,

kernel/fork.c

+6 −0
Original line number Diff line number Diff line
@@ -1679,6 +1679,12 @@ SYSCALL_DEFINE5(clone, unsigned long, newsp, unsigned long, clone_flags, 
		 int __user *, parent_tidptr,

		 int __user *, child_tidptr,

		 int, tls_val)

#elif defined(CONFIG_CLONE_BACKWARDS3)

SYSCALL_DEFINE6(clone, unsigned long, clone_flags, unsigned long, newsp,

		int, stack_size,

		int __user *, parent_tidptr,

		int __user *, child_tidptr,

		int, tls_val)

#else

SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,

		 int __user *, parent_tidptr,

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