Re: [PATCH v23 06/28] riscv/mm : ensure PROT_WRITE leads to VM_READ | VM_WRITE
From: Andreas Schwab
Date: Mon Jun 01 2026 - 17:00:16 EST
On Jun 01 2026, Deepak Gupta wrote:
> riscv uses `VM_SHADOW_STACK`. It's just very simple to use `protection_map`
> with just `VM_WRITE`. On RISC-V, `-W-` is a shadow stack mapping. It's not same
> on x86 or arm64. So `protection_map[VM_WRITE]` simply picks shadow stack
> encoding. We just ensure that PROT_WRITE is converted to
> "VM_READ | VM_WRITE" at vma level.
That does not explain _why_ you need to make that user visible change,
when others can get away without it.
--
Andreas Schwab, schwab@xxxxxxxxxxxxxx
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
"And now for something completely different."