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Revert "riscv: misaligned: fix sleeping function called during misaligned access handling" 

This reverts commit 61a74ad254 ("riscv: misaligned: fix sleeping function
called during misaligned access handling"). The commit addresses a sleeping
in atomic context problem, but it is not the correct fix as explained by
Clément:

"Using nofault would lead to failure to read from user memory that is paged
out for instance. This is not really acceptable, we should handle user
misaligned access even at an address that would generate a page fault."

This bug has been properly fixed by commit 453805f0a2 ("riscv:
misaligned: enable IRQs while handling misaligned accesses").

Revert this improper fix.

Link: https://lore.kernel.org/linux-riscv/b779beed-e44e-4a5e-9551-4647682b0d21@rivosinc.com/
Signed-off-by: Nam Cao <namcao@linutronix.de>
Cc: stable@vger.kernel.org
Reviewed-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Fixes: 61a74ad254 ("riscv: misaligned: fix sleeping function called during misaligned access handling")
Link: https://lore.kernel.org/r/20250620110939.1642735-1-namcao@linutronix.de
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
pull/1280/head
Nam Cao 2025-06-20 13:09:39 +02:00 committed by Palmer Dabbelt
parent 850f0e2433
commit 2f73c62d4e
No known key found for this signature in database
GPG Key ID: 2E1319F35FBB1889
1 changed files with 2 additions and 2 deletions
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4
arch/riscv/kernel/traps_misaligned.c
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@ -454,7 +454,7 @@ static int handle_scalar_misaligned_load(struct pt_regs *regs)
val.data_u64 = 0;
if (user_mode(regs)) {
if (copy_from_user_nofault(&val, (u8 __user *)addr, len))
if (copy_from_user(&val, (u8 __user *)addr, len))
return -1;
} else {
memcpy(&val, (u8 *)addr, len);
@ -555,7 +555,7 @@ static int handle_scalar_misaligned_store(struct pt_regs *regs)
return -EOPNOTSUPP;
if (user_mode(regs)) {
if (copy_to_user_nofault((u8 __user *)addr, &val, len))
if (copy_to_user((u8 __user *)addr, &val, len))
return -1;
} else {
memcpy((u8 *)addr, &val, len);