From 18107f8a2df6bf1c6cac8d0713f757f866d5af51 Mon Sep 17 00:00:00 2001 From: Vladimir Murzin Date: Fri, 12 Mar 2021 17:38:10 +0000 Subject: arm64: Support execute-only permissions with Enhanced PAN Enhanced Privileged Access Never (EPAN) allows Privileged Access Never to be used with Execute-only mappings. Absence of such support was a reason for 24cecc377463 ("arm64: Revert support for execute-only user mappings"). Thus now it can be revisited and re-enabled. Cc: Kees Cook Signed-off-by: Vladimir Murzin Acked-by: Will Deacon Link: https://lore.kernel.org/r/20210312173811.58284-2-vladimir.murzin@arm.com Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/sysreg.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/arm64/include/asm/sysreg.h') diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index d4a5fca984c3..94291c7c6443 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -597,6 +597,7 @@ (SCTLR_EL2_RES1 | ENDIAN_SET_EL2) /* SCTLR_EL1 specific flags. */ +#define SCTLR_EL1_EPAN (BIT(57)) #define SCTLR_EL1_ATA0 (BIT(42)) #define SCTLR_EL1_TCF0_SHIFT 38 @@ -637,7 +638,7 @@ SCTLR_EL1_SED | SCTLR_ELx_I | SCTLR_EL1_DZE | SCTLR_EL1_UCT | \ SCTLR_EL1_NTWE | SCTLR_ELx_IESB | SCTLR_EL1_SPAN | SCTLR_ELx_ITFSB | \ SCTLR_ELx_ATA | SCTLR_EL1_ATA0 | ENDIAN_SET_EL1 | SCTLR_EL1_UCI | \ - SCTLR_EL1_RES1) + SCTLR_EL1_EPAN | SCTLR_EL1_RES1) /* MAIR_ELx memory attributes (used by Linux) */ #define MAIR_ATTR_DEVICE_nGnRnE UL(0x00) -- cgit From 31c00d2aeaa2da89361f5b64a64ca831433be5fc Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Thu, 1 Apr 2021 19:09:40 +0100 Subject: arm64: Disable fine grained traps on boot The arm64 FEAT_FGT extension introduces a set of traps to EL2 for accesses to small sets of registers and instructions from EL1 and EL0. Currently Linux makes no use of this feature, ensure that it is not active at boot by disabling the traps during EL2 setup. Signed-off-by: Mark Brown Reviewed-by: Marc Zyngier Link: https://lore.kernel.org/r/20210401180942.35815-3-broonie@kernel.org Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/sysreg.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/arm64/include/asm/sysreg.h') diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index d4a5fca984c3..b35468927363 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -475,9 +475,15 @@ #define SYS_PMCCFILTR_EL0 sys_reg(3, 3, 14, 15, 7) #define SYS_SCTLR_EL2 sys_reg(3, 4, 1, 0, 0) +#define SYS_HFGRTR_EL2 sys_reg(3, 4, 1, 1, 4) +#define SYS_HFGWTR_EL2 sys_reg(3, 4, 1, 1, 5) +#define SYS_HFGITR_EL2 sys_reg(3, 4, 1, 1, 6) #define SYS_ZCR_EL2 sys_reg(3, 4, 1, 2, 0) #define SYS_TRFCR_EL2 sys_reg(3, 4, 1, 2, 1) #define SYS_DACR32_EL2 sys_reg(3, 4, 3, 0, 0) +#define SYS_HDFGRTR_EL2 sys_reg(3, 4, 3, 1, 4) +#define SYS_HDFGWTR_EL2 sys_reg(3, 4, 3, 1, 5) +#define SYS_HAFGRTR_EL2 sys_reg(3, 4, 3, 1, 6) #define SYS_SPSR_EL2 sys_reg(3, 4, 4, 0, 0) #define SYS_ELR_EL2 sys_reg(3, 4, 4, 0, 1) #define SYS_IFSR32_EL2 sys_reg(3, 4, 5, 0, 1) -- cgit From 201698626fbca1cf1a3b686ba14cf2a056500716 Mon Sep 17 00:00:00 2001 From: Peter Collingbourne Date: Thu, 18 Mar 2021 20:10:53 -0700 Subject: arm64: Introduce prctl(PR_PAC_{SET,GET}_ENABLED_KEYS) This change introduces a prctl that allows the user program to control which PAC keys are enabled in a particular task. The main reason why this is useful is to enable a userspace ABI that uses PAC to sign and authenticate function pointers and other pointers exposed outside of the function, while still allowing binaries conforming to the ABI to interoperate with legacy binaries that do not sign or authenticate pointers. The idea is that a dynamic loader or early startup code would issue this prctl very early after establishing that a process may load legacy binaries, but before executing any PAC instructions. This change adds a small amount of overhead to kernel entry and exit due to additional required instruction sequences. On a DragonBoard 845c (Cortex-A75) with the powersave governor, the overhead of similar instruction sequences was measured as 4.9ns when simulating the common case where IA is left enabled, or 43.7ns when simulating the uncommon case where IA is disabled. These numbers can be seen as the worst case scenario, since in more realistic scenarios a better performing governor would be used and a newer chip would be used that would support PAC unlike Cortex-A75 and would be expected to be faster than Cortex-A75. On an Apple M1 under a hypervisor, the overhead of the entry/exit instruction sequences introduced by this patch was measured as 0.3ns in the case where IA is left enabled, and 33.0ns in the case where IA is disabled. Signed-off-by: Peter Collingbourne Reviewed-by: Dave Martin Link: https://linux-review.googlesource.com/id/Ibc41a5e6a76b275efbaa126b31119dc197b927a5 Link: https://lore.kernel.org/r/d6609065f8f40397a4124654eb68c9f490b4d477.1616123271.git.pcc@google.com Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/sysreg.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/arm64/include/asm/sysreg.h') diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index d4a5fca984c3..9dc2e88b10c6 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -565,8 +565,10 @@ #define SCTLR_ELx_TCF_ASYNC (UL(0x2) << SCTLR_ELx_TCF_SHIFT) #define SCTLR_ELx_TCF_MASK (UL(0x3) << SCTLR_ELx_TCF_SHIFT) +#define SCTLR_ELx_ENIA_SHIFT 31 + #define SCTLR_ELx_ITFSB (BIT(37)) -#define SCTLR_ELx_ENIA (BIT(31)) +#define SCTLR_ELx_ENIA (BIT(SCTLR_ELx_ENIA_SHIFT)) #define SCTLR_ELx_ENIB (BIT(30)) #define SCTLR_ELx_ENDA (BIT(27)) #define SCTLR_ELx_EE (BIT(25)) -- cgit