@@ -, +, @@ --- --- --- linux-2.6.34.7.orig/arch/ia64/include/asm/compat.h 2010-05-16 22:17:36.000000000 +0100 +++ linux-2.6.34.7.orig/arch/ia64/include/asm/compat.h 2010-09-27 00:53:03.712604894 +0100 @@ -199,7 +199,7 @@ ptr_to_compat(void __user *uptr) } static __inline__ void __user * -compat_alloc_user_space (long len) +arch_compat_alloc_user_space (long len) { struct pt_regs *regs = task_pt_regs(current); return (void __user *) (((regs->r12 & 0xffffffff) & -16) - len); --- linux-2.6.34.7.orig/arch/mips/include/asm/compat.h 2010-05-16 22:17:36.000000000 +0100 +++ linux-2.6.34.7.orig/arch/mips/include/asm/compat.h 2010-09-27 00:53:03.712604894 +0100 @@ -145,7 +145,7 @@ static inline compat_uptr_t ptr_to_compa return (u32)(unsigned long)uptr; } -static inline void __user *compat_alloc_user_space(long len) +static inline void __user *arch_compat_alloc_user_space(long len) { struct pt_regs *regs = (struct pt_regs *) ((unsigned long) current_thread_info() + THREAD_SIZE - 32) - 1; --- linux-2.6.34.7.orig/arch/parisc/include/asm/compat.h 2010-05-16 22:17:36.000000000 +0100 +++ linux-2.6.34.7.orig/arch/parisc/include/asm/compat.h 2010-09-27 00:53:03.712604894 +0100 @@ -147,7 +147,7 @@ static inline compat_uptr_t ptr_to_compa return (u32)(unsigned long)uptr; } -static __inline__ void __user *compat_alloc_user_space(long len) +static __inline__ void __user *arch_compat_alloc_user_space(long len) { struct pt_regs *regs = ¤t->thread.regs; return (void __user *)regs->gr[30]; --- linux-2.6.34.7.orig/arch/powerpc/include/asm/compat.h 2010-05-16 22:17:36.000000000 +0100 +++ linux-2.6.34.7.orig/arch/powerpc/include/asm/compat.h 2010-09-27 00:53:03.712604894 +0100 @@ -134,7 +134,7 @@ static inline compat_uptr_t ptr_to_compa return (u32)(unsigned long)uptr; } -static inline void __user *compat_alloc_user_space(long len) +static inline void __user *arch_compat_alloc_user_space(long len) { struct pt_regs *regs = current->thread.regs; unsigned long usp = regs->gpr[1]; --- linux-2.6.34.7.orig/arch/s390/include/asm/compat.h 2010-05-16 22:17:36.000000000 +0100 +++ linux-2.6.34.7.orig/arch/s390/include/asm/compat.h 2010-09-27 00:53:03.712604894 +0100 @@ -181,7 +181,7 @@ static inline int is_compat_task(void) #endif -static inline void __user *compat_alloc_user_space(long len) +static inline void __user *arch_compat_alloc_user_space(long len) { unsigned long stack; --- linux-2.6.34.7.orig/arch/sparc/include/asm/compat.h 2010-05-16 22:17:36.000000000 +0100 +++ linux-2.6.34.7.orig/arch/sparc/include/asm/compat.h 2010-09-27 00:53:03.712604894 +0100 @@ -167,7 +167,7 @@ static inline compat_uptr_t ptr_to_compa return (u32)(unsigned long)uptr; } -static inline void __user *compat_alloc_user_space(long len) +static inline void __user *arch_compat_alloc_user_space(long len) { struct pt_regs *regs = current_thread_info()->kregs; unsigned long usp = regs->u_regs[UREG_I6]; --- linux-2.6.34.7.orig/arch/x86/include/asm/compat.h 2010-05-16 22:17:36.000000000 +0100 +++ linux-2.6.34.7.orig/arch/x86/include/asm/compat.h 2010-09-27 00:53:03.712604894 +0100 @@ -205,7 +205,7 @@ static inline compat_uptr_t ptr_to_compa return (u32)(unsigned long)uptr; } -static inline void __user *compat_alloc_user_space(long len) +static inline void __user *arch_compat_alloc_user_space(long len) { struct pt_regs *regs = task_pt_regs(current); return (void __user *)regs->sp - len; --- linux-2.6.34.7.orig/include/linux/compat.h 2010-09-26 23:12:10.377096155 +0100 +++ linux-2.6.34.7.orig/include/linux/compat.h 2010-09-27 00:54:31.405104526 +0100 @@ -360,5 +360,8 @@ extern ssize_t compat_rw_copy_check_uvec const struct compat_iovec __user *uvector, unsigned long nr_segs, unsigned long fast_segs, struct iovec *fast_pointer, struct iovec **ret_pointer); + +extern void __user *compat_alloc_user_space(unsigned long len); + #endif /* CONFIG_COMPAT */ #endif /* _LINUX_COMPAT_H */ --- linux-2.6.34.7.orig/kernel/compat.c 2010-09-26 23:12:10.381096260 +0100 +++ linux-2.6.34.7.orig/kernel/compat.c 2010-09-27 00:55:28.401102437 +0100 @@ -25,6 +25,7 @@ #include #include #include +#include #include #include @@ -1137,3 +1138,24 @@ compat_sys_sysinfo(struct compat_sysinfo return 0; } + +/* + * Allocate user-space memory for the duration of a single system call, + * in order to marshall parameters inside a compat thunk. + */ +void __user *compat_alloc_user_space(unsigned long len) +{ + void __user *ptr; + + /* If len would occupy more than half of the entire compat space... */ + if (unlikely(len > (((compat_uptr_t)~0) >> 1))) + return NULL; + + ptr = arch_compat_alloc_user_space(len); + + if (unlikely(!access_ok(VERIFY_WRITE, ptr, len))) + return NULL; + + return ptr; +} +EXPORT_SYMBOL_GPL(compat_alloc_user_space);