From 203b1152d18c04823f73b843eb3b0ad646e4dbb2 Mon Sep 17 00:00:00 2001 From: Amit Daniel Kachhap Date: Mon, 11 May 2020 18:31:55 +0530 Subject: arm64/crash_core: Export KERNELPACMASK in vmcoreinfo Recently arm64 linux kernel added support for Armv8.3-A Pointer Authentication feature. If this feature is enabled in the kernel and the hardware supports address authentication then the return addresses are signed and stored in the stack to prevent ROP kind of attack. Kdump tool will now dump the kernel with signed lr values in the stack. Any user analysis tool for this kernel dump may need the kernel pac mask information in vmcoreinfo to generate the correct return address for stacktrace purpose as well as to resolve the symbol name. This patch is similar to commit ec6e822d1a22d0eef ("arm64: expose user PAC bit positions via ptrace") which exposes pac mask information via ptrace interfaces. The config gaurd ARM64_PTR_AUTH is removed form asm/compiler.h so macros like ptrauth_kernel_pac_mask can be used ungaurded. This config protection is confusing as the pointer authentication feature may be missing at runtime even though this config is present. Signed-off-by: Amit Daniel Kachhap Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Link: https://lore.kernel.org/r/1589202116-18265-1-git-send-email-amit.kachhap@arm.com Signed-off-by: Will Deacon --- arch/arm64/include/asm/compiler.h | 4 ---- 1 file changed, 4 deletions(-) (limited to 'arch/arm64/include/asm/compiler.h') diff --git a/arch/arm64/include/asm/compiler.h b/arch/arm64/include/asm/compiler.h index eece20d2c55f..51a7ce87cdfe 100644 --- a/arch/arm64/include/asm/compiler.h +++ b/arch/arm64/include/asm/compiler.h @@ -2,8 +2,6 @@ #ifndef __ASM_COMPILER_H #define __ASM_COMPILER_H -#if defined(CONFIG_ARM64_PTR_AUTH) - /* * The EL0/EL1 pointer bits used by a pointer authentication code. * This is dependent on TBI0/TBI1 being enabled, or bits 63:56 would also apply. @@ -19,6 +17,4 @@ #define __builtin_return_address(val) \ (void *)(ptrauth_clear_pac((unsigned long)__builtin_return_address(val))) -#endif /* CONFIG_ARM64_PTR_AUTH */ - #endif /* __ASM_COMPILER_H */ -- cgit v1.2.3