6.12-stable review patch. If anyone has any objections, please let me know.
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From: Nam Cao namcao@linutronix.de
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@riv... 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 --- arch/riscv/kernel/traps_misaligned.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/riscv/kernel/traps_misaligned.c +++ b/arch/riscv/kernel/traps_misaligned.c @@ -429,7 +429,7 @@ int handle_misaligned_load(struct pt_reg
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_re 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);