| Message ID | 20250422162324.956065-3-cleger@rivosinc.com |
|---|---|
| State | New |
| Headers | show |
| Series | riscv: misaligned: fix interruptible context and add tests | expand |
On 22/04/2025 18:23, Clément Léger wrote: > We can safely reenable IRQs if coming from userspace. This allows to > access user memory that could potentially trigger a page fault. > > Fixes: b686ecdeacf6 ("riscv: misaligned: Restrict user access to kernel memory") > Signed-off-by: Clément Léger <cleger@rivosinc.com> > --- > arch/riscv/kernel/traps.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c > index b1d991c78a23..9c83848797a7 100644 > --- a/arch/riscv/kernel/traps.c > +++ b/arch/riscv/kernel/traps.c > @@ -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) Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Thanks, Alex
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index b1d991c78a23..9c83848797a7 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -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)
We can safely reenable IRQs if coming from userspace. This allows to access user memory that could potentially trigger a page fault. Fixes: b686ecdeacf6 ("riscv: misaligned: Restrict user access to kernel memory") Signed-off-by: Clément Léger <cleger@rivosinc.com> --- arch/riscv/kernel/traps.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)