Unverified Commit 22b5f16f authored by Akira Tsukamoto's avatar Akira Tsukamoto Committed by Palmer Dabbelt
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riscv: __asm_copy_to-from_user: Fix: fail on RV32 



Had a bug when converting bytes to bits when the cpu was rv32.

The a3 contains the number of bytes and multiple of 8
would be the bits. The LGREG is holding 2 for RV32 and 3 for
RV32, so to achieve multiple of 8 it must always be constant 3.
The 2 was mistakenly used for rv32.

Signed-off-by: default avatarAkira Tsukamoto <akira.tsukamoto@gmail.com>
Fixes: ca6eaaa2 ("riscv: __asm_copy_to-from_user: Optimize unaligned memory access and pipeline stall")
Signed-off-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
parent 6010d300

arch/riscv/lib/uaccess.S

+1 −1
Original line number Original line Diff line number Diff line
@@ -125,7 +125,7 @@ ENTRY(__asm_copy_from_user) 
	 * t3 - prev shift

	 * t3 - prev shift

	 * t4 - current shift

	 * t4 - current shift

	 */

	 */

	slli	t3, a3, LGREG

	slli	t3, a3, 3 /* converting bytes in a3 to bits */

	li	a5, SZREG*8

	li	a5, SZREG*8

	sub	t4, a5, t3

	sub	t4, a5, t3