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riscv: misaligned: enable IRQs while handling misaligned accesses

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[ Upstream commit 453805f0a28fc5091e46145e6560c776f7c7a611 ]

We can safely reenable IRQs if coming from userspace. This allows to
access user memory that could potentially trigger a page fault.

Fixes: b686ecdeac ("riscv: misaligned: Restrict user access to kernel memory")
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20250422162324.956065-3-cleger@rivosinc.com
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Clément Léger
2025-04-22 18:23:09 +02:00
committed by Greg Kroah-Hartman
parent 45a0697cee
commit d6b013b44e
1 changed files with 8 additions and 4 deletions
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12
arch/riscv/kernel/traps.c
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@@ -220,19 +220,23 @@ static void do_trap_misaligned(struct pt_regs *regs, enum misaligned_access_type
{
irqentry_state_t state;
if (user_mode(regs))
if (user_mode(regs)) {
irqentry_enter_from_user_mode(regs);
else
local_irq_enable();
} else {
state = irqentry_nmi_enter(regs);
}
if (misaligned_handler[type].handler(regs))
do_trap_error(regs, SIGBUS, BUS_ADRALN, regs->epc,
misaligned_handler[type].type_str);
if (user_mode(regs))
if (user_mode(regs)) {
local_irq_disable();
irqentry_exit_to_user_mode(regs);
else
} else {
irqentry_nmi_exit(regs, state);
}
}
asmlinkage __visible __trap_section void do_trap_load_misaligned(struct pt_regs *regs)