| Message ID | 20210119160723.116983-1-vladimir.murzin@arm.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | arm64: Support Enhanced PAN | expand |
On Tue, Jan 19, 2021 at 04:07:21PM +0000, Vladimir Murzin wrote: > ARM architecture gains support of Enhanced Privileged Access Never > (EPAN) which allows Privileged Access Never to be used with > Execute-only mappings. > > As a consequence 24cecc377463 ("arm64: Revert support for execute-only > user mappings") can be revisited and re-enabled. Does ptdump.c need updating too? Will
On 1/26/21 11:09 AM, Will Deacon wrote: > On Tue, Jan 19, 2021 at 04:07:21PM +0000, Vladimir Murzin wrote: >> ARM architecture gains support of Enhanced Privileged Access Never >> (EPAN) which allows Privileged Access Never to be used with >> Execute-only mappings. >> >> As a consequence 24cecc377463 ("arm64: Revert support for execute-only >> user mappings") can be revisited and re-enabled. > > Does ptdump.c need updating too? I had a look at ptdump.c and IIUIC that supposed to pretty print bits for page table entry. Thus with EPAN supported we stop seeing "USR" for execute only mapping, but it correctly reflects state of pte. What I'm missing? Cheers Vladimir
Hi ARM architecture gains support of Enhanced Privileged Access Never (EPAN) which allows Privileged Access Never to be used with Execute-only mappings. As a consequence 24cecc377463 ("arm64: Revert support for execute-only user mappings") can be revisited and re-enabled. Changelog: RFC -> v1 - removed cap check in pte_valid_not_user (per Catalin) - local_flush_tlb_all() in cpu_enable_epan() (per Catalin) - reordered with CnP (per Catalin) - s/HWCAP2_EPAN/HWCAP2_EXECONLY/ (per Catalin) v1 -> v2 - rebased on for-next/uaccess (for INIT_SCTLR_EL1_MMU_ON) - moved EPAN enable to proc.S (via INIT_SCTLR_EL1_MMU_ON), so no need in enable method from cpufeature, no need to keep ordering relative to CnP (per Catalin) v2 -> v3 - rebased on 5.11-rc4 Thanks! Vladimir Murzin (2): arm64: Support execute-only permissions with Enhanced PAN arm64: Introduce HWCAPS2_EXECONLY arch/arm64/Kconfig | 17 +++++++++++++++++ arch/arm64/include/asm/cpucaps.h | 3 ++- arch/arm64/include/asm/hwcap.h | 1 + arch/arm64/include/asm/pgtable-prot.h | 5 +++-- arch/arm64/include/asm/pgtable.h | 14 +++++++++++++- arch/arm64/include/asm/sysreg.h | 4 +++- arch/arm64/include/uapi/asm/hwcap.h | 1 + arch/arm64/kernel/cpufeature.c | 15 +++++++++++++++ arch/arm64/kernel/cpuinfo.c | 1 + arch/arm64/mm/fault.c | 3 +++ 10 files changed, 59 insertions(+), 5 deletions(-)