split sanitize_mpol_flags into sanitize and validate. Sanitize is used by set_mempolicy to split (int mode) into mode and mode_flags, and then validates them. Validate validates already split flags. Validate will be reused for new syscalls that accept already split mode and mode_flags. Signed-off-by: Gregory Price <gregory.price@xxxxxxxxxxxx> --- mm/mempolicy.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 46e6b6f36a10..6e2ea94c0f31 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1478,24 +1478,35 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode, return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0; } -/* Basic parameter sanity check used by both mbind() and set_mempolicy() */ -static inline int sanitize_mpol_flags(int *mode, unsigned short *flags) +/* + * Basic parameter sanity check used by mbind/set_mempolicy + * May modify flags to include internal flags (e.g. MPOL_F_MOF/F_MORON) + */ +static inline int validate_mpol_flags(unsigned short mode, unsigned short *flags) { - *flags = *mode & MPOL_MODE_FLAGS; - *mode &= ~MPOL_MODE_FLAGS; - - if ((unsigned int)(*mode) >= MPOL_MAX) + if ((unsigned int)(mode) >= MPOL_MAX) return -EINVAL; if ((*flags & MPOL_F_STATIC_NODES) && (*flags & MPOL_F_RELATIVE_NODES)) return -EINVAL; if (*flags & MPOL_F_NUMA_BALANCING) { - if (*mode != MPOL_BIND) + if (mode != MPOL_BIND) return -EINVAL; *flags |= (MPOL_F_MOF | MPOL_F_MORON); } return 0; } +/* + * Used by mbind/set_memplicy to split and validate mode/flags + */ +static inline int sanitize_mpol_flags(int *mode, unsigned short *flags) +{ + *flags = *mode & MPOL_MODE_FLAGS; + *mode = *mode & ~MPOL_MODE_FLAGS; + + return validate_mpol_flags(*mode, flags); +} + static long kernel_mbind(unsigned long start, unsigned long len, unsigned long mode, const unsigned long __user *nmask, unsigned long maxnode, unsigned int flags) -- 2.39.1