Messages in this thread | | | From | Khem Raj <> | Date | Tue, 29 Nov 2022 18:47:55 -0800 | Subject | Re: [PATCH 1/2] RISC-V: Align the shadow stack |
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Hi Palmer
On Tue, Nov 29, 2022 at 6:36 PM Palmer Dabbelt <palmer@rivosinc.com> wrote: > > The standard RISC-V ABIs all require 16-byte stack alignment. We're > only calling that one function on the shadow stack so I doubt it'd > result in a real issue, but might as well keep this lined up.
Is 16-byte alignment required on rv32 as well ?
> > Fixes: 31da94c25aea ("riscv: add VMAP_STACK overflow detection") > Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com> > --- > arch/riscv/kernel/traps.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c > index be54ccea8c47..acdfcacd7e57 100644 > --- a/arch/riscv/kernel/traps.c > +++ b/arch/riscv/kernel/traps.c > @@ -206,7 +206,7 @@ static DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], > * shadow stack, handled_ kernel_ stack_ overflow(in kernel/entry.S) is used > * to get per-cpu overflow stack(get_overflow_stack). > */ > -long shadow_stack[SHADOW_OVERFLOW_STACK_SIZE/sizeof(long)]; > +long shadow_stack[SHADOW_OVERFLOW_STACK_SIZE/sizeof(long)] __aligned(16); > asmlinkage unsigned long get_overflow_stack(void) > { > return (unsigned long)this_cpu_ptr(overflow_stack) + > -- > 2.38.1 > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv
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