kernel/linux.git/include/asm-generic/uaccess.h, branch v5.15.208

asm-generic: uaccess: remove inline strncpy_from_user/strnlen_user

2021-07-27T21:01:13+00:00

The inline version is used on three NOMMU architectures and is particularly inefficient when it scans the string one byte at a time twice. It also lacks a check for user_addr_max(), but this is probably ok on NOMMU targets. Consolidate the asm-generic implementation with the library version that is used everywhere else. This version is generalized enough to work efficiently on both MMU and NOMMU targets, and using the same code everywhere reduces the potential for subtle bugs. Mark the prototypes as __must_check in the process. Reviewed-by: Geert Uytterhoeven Acked-by: Geert Uytterhoeven Reviewed-by: Christoph Hellwig Signed-off-by: Arnd Bergmann

asm-generic/uaccess.h: remove __strncpy_from_user/__strnlen_user

2021-07-23T12:39:56+00:00

This is a preparation for changing over architectures to the generic implementation one at a time. As there are no callers of either __strncpy_from_user() or __strnlen_user(), fold these into the strncpy_from_user() and strnlen_user() functions to make each implementation independent of the others. Many of these implementations have known bugs, but the intention here is to not change behavior at all and stay compatible with those bugs for the moment. Reviewed-by: Christoph Hellwig Signed-off-by: Arnd Bergmann

asm-generic: uaccess: 1-byte access is always aligned

2021-05-17T11:30:29+00:00

With the cleaned up version of asm-generic/unaligned.h, there is a warning about the get_user/put_user helpers using unaligned access for single-byte variables: include/asm-generic/uaccess.h: In function ‘__get_user_fn’: include/asm-generic/unaligned.h:13:15: warning: ‘packed’ attribute ignored for field of type ‘u8’ {aka ‘unsigned char’} [-Wattributes] const struct { type x __packed; } *__pptr = (typeof(__pptr))(ptr); \ Change these to use a direct pointer dereference to avoid the warnings. Signed-off-by: Arnd Bergmann

asm-generic: mark __{get,put}_user_fn as __always_inline

2020-10-27T15:13:09+00:00

Without the explicit __always_inline, some RISC-V configs place the functions out of line, triggering the BUILD_BUG_ON checks in the function. Fixes: 11129e8ed4d9 ("riscv: use memcpy based uaccess for nommu again") Reported-by: kernel test robot Signed-off-by: Christoph Hellwig Signed-off-by: Arnd Bergmann

asm-generic: make the set_fs implementation optional

2020-10-04T17:27:02+00:00

Put all the set_fs related code under CONFIG_SET_FS so that asm-generic/uaccess.h can be used for set_fs-less builds. Signed-off-by: Christoph Hellwig Acked-by: Arnd Bergmann Signed-off-by: Palmer Dabbelt

asm-generic: add nommu implementations of __{get,put}_kernel_nofault

2020-10-04T17:26:57+00:00

Add native implementations of __{get,put}_kernel_nofault using {get,put}_unaligned, just like the {get,put}_user implementations. Signed-off-by: Christoph Hellwig Acked-by: Arnd Bergmann Signed-off-by: Palmer Dabbelt

asm-generic: improve the nommu {get,put}_user handling

2020-10-04T17:26:43+00:00

Instead of reusing raw_{copy,to}_from_user implement separate handlers using {get,put}_unaligned. This ensures unaligned access is handled correctly, and avoid the need for the small constant size optimization in raw_{copy,to}_from_user. Signed-off-by: Christoph Hellwig Acked-by: Arnd Bergmann Signed-off-by: Palmer Dabbelt

uaccess: remove segment_eq

2020-08-12T17:57:58+00:00

segment_eq is only used to implement uaccess_kernel. Just open code uaccess_kernel in the arch uaccess headers and remove one layer of indirection. Signed-off-by: Christoph Hellwig Signed-off-by: Andrew Morton Acked-by: Linus Torvalds Acked-by: Greentime Hu Acked-by: Geert Uytterhoeven Cc: Nick Hu Cc: Vincent Chen Cc: Paul Walmsley Cc: Palmer Dabbelt Link: http://lkml.kernel.org/r/20200710135706.537715-5-hch@lst.de Signed-off-by: Linus Torvalds

asm-generic: optimize generic uaccess for 8-byte loads and stores

2019-04-23T19:51:41+00:00

On 64-bit architectures we can also use the direct load/store trick for 8-byte values. Signed-off-by: Christoph Hellwig Signed-off-by: Arnd Bergmann

asm-generic: provide entirely generic nommu uaccess

2019-04-23T19:51:40+00:00

Move the code to implement uaccess using memcpy or direct loads and stores to asm-generic/uaccess.h and make it selectable kconfig option. Signed-off-by: Christoph Hellwig Signed-off-by: Arnd Bergmann