path: root/include
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authorLinus Torvalds <torvalds@linux-foundation.org>2020-06-18 12:35:51 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-18 12:35:51 -0700
commit5e857ce6eae7ca21b2055cca4885545e29228fe2 (patch)
treeb3b5b9a88222fe189ba44989a84932c7258c64c4 /include
parentsparse: use identifiers to define address spaces (diff)
parentmaccess: make get_kernel_nofault() check for minimal type compatibility (diff)
Merge branch 'hch' (maccess patches from Christoph Hellwig)
Merge non-faulting memory access cleanups from Christoph Hellwig: "Andrew and I decided to drop the patches implementing your suggested rename of the probe_kernel_* and probe_user_* helpers from -mm as there were way to many conflicts. After -rc1 might be a good time for this as all the conflicts are resolved now" This also adds a type safety checking patch on top of the renaming series to make the subtle behavioral difference between 'get_user()' and 'get_kernel_nofault()' less potentially dangerous and surprising. * emailed patches from Christoph Hellwig <hch@lst.de>: maccess: make get_kernel_nofault() check for minimal type compatibility maccess: rename probe_kernel_address to get_kernel_nofault maccess: rename probe_user_{read,write} to copy_{from,to}_user_nofault maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault
Diffstat (limited to 'include')
1 files changed, 13 insertions, 10 deletions
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 7bcadca22100..0a76ddc07d59 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -301,13 +301,14 @@ copy_struct_from_user(void *dst, size_t ksize, const void __user *src,
return 0;
-bool probe_kernel_read_allowed(const void *unsafe_src, size_t size);
+bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size);
-extern long probe_kernel_read(void *dst, const void *src, size_t size);
-extern long probe_user_read(void *dst, const void __user *src, size_t size);
+long copy_from_kernel_nofault(void *dst, const void *src, size_t size);
+long notrace copy_to_kernel_nofault(void *dst, const void *src, size_t size);
-extern long notrace probe_kernel_write(void *dst, const void *src, size_t size);
-extern long notrace probe_user_write(void __user *dst, const void *src, size_t size);
+long copy_from_user_nofault(void *dst, const void __user *src, size_t size);
+long notrace copy_to_user_nofault(void __user *dst, const void *src,
+ size_t size);
long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr,
long count);
@@ -317,14 +318,16 @@ long strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr,
long strnlen_user_nofault(const void __user *unsafe_addr, long count);
- * probe_kernel_address(): safely attempt to read from a location
- * @addr: address to read from
- * @retval: read into this variable
+ * get_kernel_nofault(): safely attempt to read from a location
+ * @val: read into this variable
+ * @ptr: address to read from
* Returns 0 on success, or -EFAULT.
-#define probe_kernel_address(addr, retval) \
- probe_kernel_read(&retval, addr, sizeof(retval))
+#define get_kernel_nofault(val, ptr) ({ \
+ const typeof(val) *__gk_ptr = (ptr); \
+ copy_from_kernel_nofault(&(val), __gk_ptr, sizeof(val));\
#ifndef user_access_begin
#define user_access_begin(ptr,len) access_ok(ptr, len)