Re: [PATCH] Revert "riscv: Reset pmm when PR_TAGGED_ADDR_ENABLE is not set"
Paul Walmsley <[email protected]>
| Newsgroups | org.infradead.lists.linux-riscv,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
On Wed, 19 Aug 2026, Samuel Holland wrote: > This reverts commit 3033b2b1e3949274f33a140e2a97571b5a307298. > > The reverted patch is userspace-visible behavior change, not a bug fix. > The two variables here (pmm and pmlen) control two independent features: > pmm is the _hardware_ pointer masking mode that applies while executing > in userspace. pmlen is the shift amount that the _kernel_ uses when > untagging addresses; PMLEN_0 means no untagging occurs, so the kernel > does not accept tagged addresses in syscall arguments. > > It is valid (as documented and tested by the self test) to enable > pointer masking without enabling the tagged address ABI. This separation > is necessary to allow userspace to create an execution environment > similar to what the kernel supports on arm64 by default, where TBI is > enabled but the tagged address ABI is not. (On arm64, there is no > equivalent to PR_PMLEN_MASK because TBI is always enabled.) > > Signed-off-by: Samuel Holland <[email protected]> Thanks, queued for v7.3-rc with a Fixes: tag and cc: stable. - Paul _______________________________________________ linux-riscv mailing list [email protected] http://lists.infradead.org/mailman/listinfo/linux-riscv