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()
  ...

arch/sparc/kernel/setup_32.c

@@ -86,7 +86,7 @@ static void prom_sync_me(void)
 	show_free_areas(0, NULL);
 	if (!is_idle_task(current)) {
 		local_irq_enable();
-		sys_sync();
+		ksys_sync();
 		local_irq_disable();
 	}
 	prom_printf("Returning to prom\n");

arch/sparc/kernel/sys_sparc32.c

@@ -57,7 +57,7 @@ asmlinkage long sys32_truncate64(const char __user * path, unsigned long high, u
 	if ((int)high < 0)
 		return -EINVAL;
 	else
-		return sys_truncate(path, (high << 32) | low);
+		return ksys_truncate(path, (high << 32) | low);
 }
 
 asmlinkage long sys32_ftruncate64(unsigned int fd, unsigned long high, unsigned long low)
@@ -65,7 +65,7 @@ asmlinkage long sys32_ftruncate64(unsigned int fd, unsigned long high, unsigned
 	if ((int)high < 0)
 		return -EINVAL;
 	else
-		return sys_ftruncate(fd, (high << 32) | low);
+		return ksys_ftruncate(fd, (high << 32) | low);
 }
 
 static int cp_compat_stat64(struct kstat *stat,
@@ -200,7 +200,7 @@ asmlinkage compat_ssize_t sys32_pread64(unsigned int fd,
 					unsigned long poshi,
 					unsigned long poslo)
 {
-	return sys_pread64(fd, ubuf, count, (poshi << 32) | poslo);
+	return ksys_pread64(fd, ubuf, count, (poshi << 32) | poslo);
 }
 
 asmlinkage compat_ssize_t sys32_pwrite64(unsigned int fd,
@@ -209,7 +209,7 @@ asmlinkage compat_ssize_t sys32_pwrite64(unsigned int fd,
 					 unsigned long poshi,
 					 unsigned long poslo)
 {
-	return sys_pwrite64(fd, ubuf, count, (poshi << 32) | poslo);
+	return ksys_pwrite64(fd, ubuf, count, (poshi << 32) | poslo);
 }
 
 asmlinkage long compat_sys_readahead(int fd,
@@ -217,7 +217,7 @@ asmlinkage long compat_sys_readahead(int fd,
 				     unsigned long offlo,
 				     compat_size_t count)
 {
-	return sys_readahead(fd, (offhi << 32) | offlo, count);
+	return ksys_readahead(fd, (offhi << 32) | offlo, count);
 }
 
 long compat_sys_fadvise64(int fd,
@@ -225,7 +225,7 @@ long compat_sys_fadvise64(int fd,
 			  unsigned long offlo,
 			  compat_size_t len, int advice)
 {
-	return sys_fadvise64_64(fd, (offhi << 32) | offlo, len, advice);
+	return ksys_fadvise64_64(fd, (offhi << 32) | offlo, len, advice);
 }
 
 long compat_sys_fadvise64_64(int fd,
@@ -233,15 +233,15 @@ long compat_sys_fadvise64_64(int fd,
 			     unsigned long lenhi, unsigned long lenlo,
 			     int advice)
 {
-	return sys_fadvise64_64(fd,
-				(offhi << 32) | offlo,
-				(lenhi << 32) | lenlo,
-				advice);
+	return ksys_fadvise64_64(fd,
+				 (offhi << 32) | offlo,
+				 (lenhi << 32) | lenlo,
+				 advice);
 }
 
 long sys32_sync_file_range(unsigned int fd, unsigned long off_high, unsigned long off_low, unsigned long nb_high, unsigned long nb_low, unsigned int flags)
 {
-	return sys_sync_file_range(fd,
+	return ksys_sync_file_range(fd,
 				   (off_high << 32) | off_low,
 				   (nb_high << 32) | nb_low,
 				   flags);
@@ -250,6 +250,6 @@ long sys32_sync_file_range(unsigned int fd, unsigned long off_high, unsigned lon
 asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
 				     u32 lenhi, u32 lenlo)
 {
-	return sys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
-			     ((loff_t)lenhi << 32) | lenlo);
+	return ksys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
+			      ((loff_t)lenhi << 32) | lenlo);
 }

arch/sparc/kernel/sys_sparc_32.c

@@ -104,8 +104,8 @@ asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
 {
 	/* Make sure the shift for mmap2 is constant (12), no matter what PAGE_SIZE
 	   we have. */
-	return sys_mmap_pgoff(addr, len, prot, flags, fd,
-			      pgoff >> (PAGE_SHIFT - 12));
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd,
+			       pgoff >> (PAGE_SHIFT - 12));
 }
 
 asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
@@ -113,7 +113,7 @@ asmlinkage long sys_mmap(unsigned long addr, unsigned long len,
 	unsigned long off)
 {
 	/* no alignment check? */
-	return sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
+	return ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
 }
 
 long sparc_remap_file_pages(unsigned long start, unsigned long size,

arch/sparc/kernel/sys_sparc_64.c

@@ -458,7 +458,7 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
 		goto out;
 	if (off & ~PAGE_MASK)
 		goto out;
-	retval = sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
+	retval = ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
 out:
 	return retval;
 }