• Amit Daniel Kachhap's avatar
    arm64/crash_core: Export KERNELPACMASK in vmcoreinfo · 203b1152
    Amit Daniel Kachhap authored
    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 ec6e822d ("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: default avatarAmit Daniel Kachhap <amit.kachhap@arm.com>
    Cc: Catalin Marinas <catalin.marinas@arm.com>
    Cc: Will Deacon <will@kernel.org>
    Cc: Mark Rutland <mark.rutland@arm.com>
    Link: https://lore.kernel.org/r/1589202116-18265-1-git-send-email-amit.kachhap@arm.comSigned-off-by: default avatarWill Deacon <will@kernel.org>
    203b1152
compiler.h 731 Bytes