From 76e22fdc2c2658ab595cdda7368d43d2dc16f3f4 Mon Sep 17 00:00:00 2001 From: Andy Chiu Date: Mon, 5 Jun 2023 11:07:13 +0000 Subject: riscv: signal: validate altstack to reflect Vector Some extensions, such as Vector, dynamically change footprint on a signal frame, so MINSIGSTKSZ is no longer accurate. For example, an RV64V implementation with vlen = 512 may occupy 2K + 40 + 12 Bytes of a signal frame with the upcoming support. And processes that do not execute any vector instructions do not need to reserve the extra sigframe. So we need a way to guard the allocation size of the sigframe at process runtime according to current status of V. Thus, provide the function sigaltstack_size_valid() to validate its size based on current allocation status of supported extensions. Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Reviewed-by: Heiko Stuebner Tested-by: Heiko Stuebner Link: https://lore.kernel.org/r/20230605110724.21391-17-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/signal.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/riscv/kernel/signal.c') diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c index f117641c1c49..180d951d3624 100644 --- a/arch/riscv/kernel/signal.c +++ b/arch/riscv/kernel/signal.c @@ -476,3 +476,10 @@ void __init init_rt_signal_env(void) */ signal_minsigstksz = get_rt_frame_size(true); } + +#ifdef CONFIG_DYNAMIC_SIGFRAME +bool sigaltstack_size_valid(size_t ss_size) +{ + return ss_size > get_rt_frame_size(false); +} +#endif /* CONFIG_DYNAMIC_SIGFRAME */ -- cgit