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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 /mm/maccess.c
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 'mm/maccess.c')
-rw-r--r--mm/maccess.c119
1 files changed, 0 insertions, 119 deletions
diff --git a/mm/maccess.c b/mm/maccess.c
index 3fed2b876539..5f4d240f67ec 100644
--- a/mm/maccess.c
+++ b/mm/maccess.c
@@ -12,8 +12,6 @@ bool __weak copy_from_kernel_nofault_allowed(const void *unsafe_src,
return true;
}
-#ifdef HAVE_GET_KERNEL_NOFAULT
-
#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \
while (len >= sizeof(type)) { \
__get_kernel_nofault(dst, src, type, err_label); \
@@ -102,112 +100,6 @@ Efault:
dst[-1] = '\0';
return -EFAULT;
}
-#else /* HAVE_GET_KERNEL_NOFAULT */
-/**
- * copy_from_kernel_nofault(): safely attempt to read from kernel-space
- * @dst: pointer to the buffer that shall take the data
- * @src: address to read from
- * @size: size of the data chunk
- *
- * Safely read from kernel address @src to the buffer at @dst. If a kernel
- * fault happens, handle that and return -EFAULT. If @src is not a valid kernel
- * address, return -ERANGE.
- *
- * We ensure that the copy_from_user is executed in atomic context so that
- * do_page_fault() doesn't attempt to take mmap_lock. This makes
- * copy_from_kernel_nofault() suitable for use within regions where the caller
- * already holds mmap_lock, or other locks which nest inside mmap_lock.
- */
-long copy_from_kernel_nofault(void *dst, const void *src, size_t size)
-{
- long ret;
- mm_segment_t old_fs = get_fs();
-
- if (!copy_from_kernel_nofault_allowed(src, size))
- return -ERANGE;
-
- set_fs(KERNEL_DS);
- pagefault_disable();
- ret = __copy_from_user_inatomic(dst, (__force const void __user *)src,
- size);
- pagefault_enable();
- set_fs(old_fs);
-
- if (ret)
- return -EFAULT;
- return 0;
-}
-EXPORT_SYMBOL_GPL(copy_from_kernel_nofault);
-
-/**
- * copy_to_kernel_nofault(): safely attempt to write to a location
- * @dst: address to write to
- * @src: pointer to the data that shall be written
- * @size: size of the data chunk
- *
- * Safely write to address @dst from the buffer at @src. If a kernel fault
- * happens, handle that and return -EFAULT.
- */
-long copy_to_kernel_nofault(void *dst, const void *src, size_t size)
-{
- long ret;
- mm_segment_t old_fs = get_fs();
-
- set_fs(KERNEL_DS);
- pagefault_disable();
- ret = __copy_to_user_inatomic((__force void __user *)dst, src, size);
- pagefault_enable();
- set_fs(old_fs);
-
- if (ret)
- return -EFAULT;
- return 0;
-}
-
-/**
- * strncpy_from_kernel_nofault: - Copy a NUL terminated string from unsafe
- * address.
- * @dst: Destination address, in kernel space. This buffer must be at
- * least @count bytes long.
- * @unsafe_addr: Unsafe address.
- * @count: Maximum number of bytes to copy, including the trailing NUL.
- *
- * Copies a NUL-terminated string from unsafe address to kernel buffer.
- *
- * On success, returns the length of the string INCLUDING the trailing NUL.
- *
- * If access fails, returns -EFAULT (some data may have been copied and the
- * trailing NUL added). If @unsafe_addr is not a valid kernel address, return
- * -ERANGE.
- *
- * If @count is smaller than the length of the string, copies @count-1 bytes,
- * sets the last byte of @dst buffer to NUL and returns @count.
- */
-long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count)
-{
- mm_segment_t old_fs = get_fs();
- const void *src = unsafe_addr;
- long ret;
-
- if (unlikely(count <= 0))
- return 0;
- if (!copy_from_kernel_nofault_allowed(unsafe_addr, count))
- return -ERANGE;
-
- set_fs(KERNEL_DS);
- pagefault_disable();
-
- do {
- ret = __get_user(*dst++, (const char __user __force *)src++);
- } while (dst[-1] && ret == 0 && src - unsafe_addr < count);
-
- dst[-1] = '\0';
- pagefault_enable();
- set_fs(old_fs);
-
- return ret ? -EFAULT : src - unsafe_addr;
-}
-#endif /* HAVE_GET_KERNEL_NOFAULT */
/**
* copy_from_user_nofault(): safely attempt to read from a user-space location
@@ -221,14 +113,11 @@ long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count)
long copy_from_user_nofault(void *dst, const void __user *src, size_t size)
{
long ret = -EFAULT;
- mm_segment_t old_fs = force_uaccess_begin();
-
if (access_ok(src, size)) {
pagefault_disable();
ret = __copy_from_user_inatomic(dst, src, size);
pagefault_enable();
}
- force_uaccess_end(old_fs);
if (ret)
return -EFAULT;
@@ -248,14 +137,12 @@ EXPORT_SYMBOL_GPL(copy_from_user_nofault);
long copy_to_user_nofault(void __user *dst, const void *src, size_t size)
{
long ret = -EFAULT;
- mm_segment_t old_fs = force_uaccess_begin();
if (access_ok(dst, size)) {
pagefault_disable();
ret = __copy_to_user_inatomic(dst, src, size);
pagefault_enable();
}
- force_uaccess_end(old_fs);
if (ret)
return -EFAULT;
@@ -284,17 +171,14 @@ EXPORT_SYMBOL_GPL(copy_to_user_nofault);
long strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr,
long count)
{
- mm_segment_t old_fs;
long ret;
if (unlikely(count <= 0))
return 0;
- old_fs = force_uaccess_begin();
pagefault_disable();
ret = strncpy_from_user(dst, unsafe_addr, count);
pagefault_enable();
- force_uaccess_end(old_fs);
if (ret >= count) {
ret = count;
@@ -324,14 +208,11 @@ long strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr,
*/
long strnlen_user_nofault(const void __user *unsafe_addr, long count)
{
- mm_segment_t old_fs;
int ret;
- old_fs = force_uaccess_begin();
pagefault_disable();
ret = strnlen_user(unsafe_addr, count);
pagefault_enable();
- force_uaccess_end(old_fs);
return ret;
}