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

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commit 2f73c62d4e13df67380ff6faca39eec2bf08dd93 upstream.

This reverts commit 61a74ad25462 ("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 453805f0a28f ("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: 61a74ad25462 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Nam Cao
2025-06-20 13:09:39 +02:00
committed by Greg Kroah-Hartman
parent fe30c30bf3
commit 874b5818ca
1 changed files with 2 additions and 2 deletions
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4
arch/riscv/kernel/traps_misaligned.c
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@@ -429,7 +429,7 @@ int handle_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);
@@ -530,7 +530,7 @@ int handle_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);