Once we make it to accept struct prctl_mm_map as an argument it will be possible to reuse this functionallity for the rest of PR_SET_MM_x operations. Here we simply allocate struct prctl_mm_map in a caller and provide it downstairs.
CC: Jonathan de Boyne Pollard <[email protected]> CC: Andrey Vagin <[email protected]> CC: Andrew Morton <[email protected]> CC: Michael Kerrisk <[email protected]> CC: Yang Shi <[email protected]> CC: Michal Hocko <[email protected]> Signed-off-by: Cyrill Gorcunov <[email protected]> --- kernel/sys.c | 59 +++++++++++++++++++++++++++++++---------------------------- 1 file changed, 31 insertions(+), 28 deletions(-) Index: linux-ml.git/kernel/sys.c =================================================================== --- linux-ml.git.orig/kernel/sys.c +++ linux-ml.git/kernel/sys.c @@ -1969,9 +1969,8 @@ exit_err: goto exit; } -static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size) +static int prctl_set_mm_map(struct prctl_mm_map *prctl_map) { - struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, }; unsigned long user_auxv[AT_VECTOR_SIZE]; struct mm_struct *mm = current->mm; int error; @@ -1979,21 +1978,15 @@ static int prctl_set_mm_map(int opt, con BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256); - if (data_size != sizeof(prctl_map)) - return -EINVAL; - - if (copy_from_user(&prctl_map, addr, sizeof(prctl_map))) - return -EFAULT; - - error = validate_prctl_map(&prctl_map); + error = validate_prctl_map(prctl_map); if (error) return error; - if (prctl_map.auxv_size) { + if (prctl_map->auxv_size) { memset(user_auxv, 0, sizeof(user_auxv)); if (copy_from_user(user_auxv, - (const void __user *)prctl_map.auxv, - prctl_map.auxv_size)) + (const void __user *)prctl_map->auxv, + prctl_map->auxv_size)) return -EFAULT; /* Last entry must be AT_NULL as specification requires */ @@ -2001,8 +1994,8 @@ static int prctl_set_mm_map(int opt, con user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL; } - if (prctl_map.exe_fd != (u32)-1) { - error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd); + if (prctl_map->exe_fd != (u32)-1) { + error = prctl_set_mm_exe_file(mm, prctl_map->exe_fd); if (error) return error; } @@ -2026,17 +2019,17 @@ static int prctl_set_mm_map(int opt, con */ spin_lock(&mm->arg_lock); - mm->start_code = prctl_map.start_code; - mm->end_code = prctl_map.end_code; - mm->start_data = prctl_map.start_data; - mm->end_data = prctl_map.end_data; - mm->start_brk = prctl_map.start_brk; - mm->brk = prctl_map.brk; - mm->start_stack = prctl_map.start_stack; - mm->arg_start = prctl_map.arg_start; - mm->arg_end = prctl_map.arg_end; - mm->env_start = prctl_map.env_start; - mm->env_end = prctl_map.env_end; + mm->start_code = prctl_map->start_code; + mm->end_code = prctl_map->end_code; + mm->start_data = prctl_map->start_data; + mm->end_data = prctl_map->end_data; + mm->start_brk = prctl_map->start_brk; + mm->brk = prctl_map->brk; + mm->start_stack = prctl_map->start_stack; + mm->arg_start = prctl_map->arg_start; + mm->arg_end = prctl_map->arg_end; + mm->env_start = prctl_map->env_start; + mm->env_end = prctl_map->env_end; spin_unlock(&mm->arg_lock); /* @@ -2047,7 +2040,7 @@ static int prctl_set_mm_map(int opt, con * not introduce additional locks here making the kernel * more complex. */ - if (prctl_map.auxv_size) + if (prctl_map->auxv_size) memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv)); up_read(&mm->mmap_sem); @@ -2063,8 +2056,18 @@ static int prctl_set_mm(int opt, unsigne return put_user((unsigned int)sizeof(struct prctl_mm_map), (unsigned int __user *)addr); - if (opt == PR_SET_MM_MAP) - return prctl_set_mm_map(opt, (const void __user *)addr, arg4); + if (opt == PR_SET_MM_MAP) { + struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, }; + + if (arg4 != sizeof(prctl_map)) + return -EINVAL; + + if (copy_from_user(&prctl_map, (const void __user *)addr, + sizeof(prctl_map))) + return -EFAULT; + + return prctl_set_mm_map(&prctl_map); + } #endif pr_warn_once("PR_SET_MM_* has been removed. Use PR_SET_MM_MAP instead\n");
