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authorLinus Torvalds <torvalds@linux-foundation.org>2022-03-24 04:03:08 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-24 04:03:08 +0300
commit194dfe88d62ed12d0cf30f6f20734c2d0d111533 (patch)
treef057597d411df53a152ac41ae8bd900aabb94994 /include/asm-generic
parent9c0e6a89b592f4c4e4d769dbc22d399ab0685159 (diff)
parentaec499c75cf8e0b599be4d559e6922b613085f8f (diff)
downloadlinux-194dfe88d62ed12d0cf30f6f20734c2d0d111533.tar.xz
Merge tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull asm-generic updates from Arnd Bergmann: "There are three sets of updates for 5.18 in the asm-generic tree: - The set_fs()/get_fs() infrastructure gets removed for good. This was already gone from all major architectures, but now we can finally remove it everywhere, which loses some particularly tricky and error-prone code. There is a small merge conflict against a parisc cleanup, the solution is to use their new version. - The nds32 architecture ends its tenure in the Linux kernel. The hardware is still used and the code is in reasonable shape, but the mainline port is not actively maintained any more, as all remaining users are thought to run vendor kernels that would never be updated to a future release. - A series from Masahiro Yamada cleans up some of the uapi header files to pass the compile-time checks" * tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (27 commits) nds32: Remove the architecture uaccess: remove CONFIG_SET_FS ia64: remove CONFIG_SET_FS support sh: remove CONFIG_SET_FS support sparc64: remove CONFIG_SET_FS support lib/test_lockup: fix kernel pointer check for separate address spaces uaccess: generalize access_ok() uaccess: fix type mismatch warnings from access_ok() arm64: simplify access_ok() m68k: fix access_ok for coldfire MIPS: use simpler access_ok() MIPS: Handle address errors for accesses above CPU max virtual user address uaccess: add generic __{get,put}_kernel_nofault nios2: drop access_ok() check from __put_user() x86: use more conventional access_ok() definition x86: remove __range_not_ok() sparc64: add __{get,put}_kernel_nofault() nds32: fix access_ok() checks in get/put_user uaccess: fix nios2 and microblaze get_user_8() sparc64: fix building assembly files ...
Diffstat (limited to 'include/asm-generic')
-rw-r--r--include/asm-generic/access_ok.h48
-rw-r--r--include/asm-generic/uaccess.h46
2 files changed, 49 insertions, 45 deletions
diff --git a/include/asm-generic/access_ok.h b/include/asm-generic/access_ok.h
new file mode 100644
index 000000000000..2866ae61b1cd
--- /dev/null
+++ b/include/asm-generic/access_ok.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_GENERIC_ACCESS_OK_H__
+#define __ASM_GENERIC_ACCESS_OK_H__
+
+/*
+ * Checking whether a pointer is valid for user space access.
+ * These definitions work on most architectures, but overrides can
+ * be used where necessary.
+ */
+
+/*
+ * architectures with compat tasks have a variable TASK_SIZE and should
+ * override this to a constant.
+ */
+#ifndef TASK_SIZE_MAX
+#define TASK_SIZE_MAX TASK_SIZE
+#endif
+
+#ifndef __access_ok
+/*
+ * 'size' is a compile-time constant for most callers, so optimize for
+ * this case to turn the check into a single comparison against a constant
+ * limit and catch all possible overflows.
+ * On architectures with separate user address space (m68k, s390, parisc,
+ * sparc64) or those without an MMU, this should always return true.
+ *
+ * This version was originally contributed by Jonas Bonn for the
+ * OpenRISC architecture, and was found to be the most efficient
+ * for constant 'size' and 'limit' values.
+ */
+static inline int __access_ok(const void __user *ptr, unsigned long size)
+{
+ unsigned long limit = TASK_SIZE_MAX;
+ unsigned long addr = (unsigned long)ptr;
+
+ if (IS_ENABLED(CONFIG_ALTERNATE_USER_ADDRESS_SPACE) ||
+ !IS_ENABLED(CONFIG_MMU))
+ return true;
+
+ return (size <= limit) && (addr <= (limit - size));
+}
+#endif
+
+#ifndef access_ok
+#define access_ok(addr, size) likely(__access_ok(addr, size))
+#endif
+
+#endif
diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index 10ffa8b5c117..a5be9e61a2a2 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -8,6 +8,7 @@
* address space, e.g. all NOMMU machines.
*/
#include <linux/string.h>
+#include <asm-generic/access_ok.h>
#ifdef CONFIG_UACCESS_MEMCPY
#include <asm/unaligned.h>
@@ -77,8 +78,6 @@ do { \
goto err_label; \
} while (0)
-#define HAVE_GET_KERNEL_NOFAULT 1
-
static inline __must_check unsigned long
raw_copy_from_user(void *to, const void __user * from, unsigned long n)
{
@@ -96,49 +95,6 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n)
#define INLINE_COPY_TO_USER
#endif /* CONFIG_UACCESS_MEMCPY */
-#ifdef CONFIG_SET_FS
-#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
-
-#ifndef KERNEL_DS
-#define KERNEL_DS MAKE_MM_SEG(~0UL)
-#endif
-
-#ifndef USER_DS
-#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
-#endif
-
-#ifndef get_fs
-#define get_fs() (current_thread_info()->addr_limit)
-
-static inline void set_fs(mm_segment_t fs)
-{
- current_thread_info()->addr_limit = fs;
-}
-#endif
-
-#ifndef uaccess_kernel
-#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
-#endif
-
-#ifndef user_addr_max
-#define user_addr_max() (uaccess_kernel() ? ~0UL : TASK_SIZE)
-#endif
-
-#endif /* CONFIG_SET_FS */
-
-#define access_ok(addr, size) __access_ok((unsigned long)(addr),(size))
-
-/*
- * The architecture should really override this if possible, at least
- * doing a check on the get_fs()
- */
-#ifndef __access_ok
-static inline int __access_ok(unsigned long addr, unsigned long size)
-{
- return 1;
-}
-#endif
-
/*
* These are the main single-value transfer routines. They automatically
* use the right size if we just have the right pointer type.