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authorLinus Torvalds <torvalds@linux-foundation.org>2018-04-02 21:22:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-02 21:22:12 -0700
commit642e7fd23353e22290e3d51719fcb658dc252342 (patch)
tree93688d5ff15836d8e5b0e097748f7fabb13a303a /init/main.c
parent21035965f60b0502fc6537b232839389bb4ce664 (diff)
parentc9a211951c7c79cfb5de888d7d9550872868b086 (diff)
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Merge branch 'syscalls-next' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux
Pull removal of in-kernel calls to syscalls from Dominik Brodowski: "System calls are interaction points between userspace and the kernel. Therefore, system call functions such as sys_xyzzy() or compat_sys_xyzzy() should only be called from userspace via the syscall table, but not from elsewhere in the kernel. At least on 64-bit x86, it will likely be a hard requirement from v4.17 onwards to not call system call functions in the kernel: It is better to use use a different calling convention for system calls there, where struct pt_regs is decoded on-the-fly in a syscall wrapper which then hands processing over to the actual syscall function. This means that only those parameters which are actually needed for a specific syscall are passed on during syscall entry, instead of filling in six CPU registers with random user space content all the time (which may cause serious trouble down the call chain). Those x86-specific patches will be pushed through the x86 tree in the near future. Moreover, rules on how data may be accessed may differ between kernel data and user data. This is another reason why calling sys_xyzzy() is generally a bad idea, and -- at most -- acceptable in arch-specific code. This patchset removes all in-kernel calls to syscall functions in the kernel with the exception of arch/. On top of this, it cleans up the three places where many syscalls are referenced or prototyped, namely kernel/sys_ni.c, include/linux/syscalls.h and include/linux/compat.h" * 'syscalls-next' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux: (109 commits) bpf: whitelist all syscalls for error injection kernel/sys_ni: remove {sys_,sys_compat} from cond_syscall definitions kernel/sys_ni: sort cond_syscall() entries syscalls/x86: auto-create compat_sys_*() prototypes syscalls: sort syscall prototypes in include/linux/compat.h net: remove compat_sys_*() prototypes from net/compat.h syscalls: sort syscall prototypes in include/linux/syscalls.h kexec: move sys_kexec_load() prototype to syscalls.h x86/sigreturn: use SYSCALL_DEFINE0 x86: fix sys_sigreturn() return type to be long, not unsigned long x86/ioport: add ksys_ioperm() helper; remove in-kernel calls to sys_ioperm() mm: add ksys_readahead() helper; remove in-kernel calls to sys_readahead() mm: add ksys_mmap_pgoff() helper; remove in-kernel calls to sys_mmap_pgoff() mm: add ksys_fadvise64_64() helper; remove in-kernel call to sys_fadvise64_64() fs: add ksys_fallocate() wrapper; remove in-kernel calls to sys_fallocate() fs: add ksys_p{read,write}64() helpers; remove in-kernel calls to syscalls fs: add ksys_truncate() wrapper; remove in-kernel calls to sys_truncate() fs: add ksys_sync_file_range helper(); remove in-kernel calls to syscall kernel: add ksys_setsid() helper; remove in-kernel call to sys_setsid() kernel: add ksys_unshare() helper; remove in-kernel calls to sys_unshare() ...
Diffstat (limited to 'init/main.c')
-rw-r--r--init/main.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/init/main.c b/init/main.c
index 21efbf6ace93..e4a3160991ea 100644
--- a/init/main.c
+++ b/init/main.c
@@ -1074,11 +1074,11 @@ static noinline void __init kernel_init_freeable(void)
do_basic_setup();
/* Open the /dev/console on the rootfs, this should never fail */
- if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
+ if (ksys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
pr_err("Warning: unable to open an initial console.\n");
- (void) sys_dup(0);
- (void) sys_dup(0);
+ (void) ksys_dup(0);
+ (void) ksys_dup(0);
/*
* check if there is an early userspace init. If yes, let it do all
* the work
@@ -1087,7 +1087,8 @@ static noinline void __init kernel_init_freeable(void)
if (!ramdisk_execute_command)
ramdisk_execute_command = "/init";
- if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
+ if (ksys_access((const char __user *)
+ ramdisk_execute_command, 0) != 0) {
ramdisk_execute_command = NULL;
prepare_namespace();
}