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Ard Biesheuvel authored
We will be enabling THREAD_INFO_IN_TASK support for ARM, which means that we can no longer load the stack canary value by masking the stack pointer and taking the copy that lives in thread_info. Instead, we will be able to load it from the task_struct directly, by using the TPIDRURO register which will hold the current task pointer when THREAD_INFO_IN_TASK is in effect. This is much more straight-forward, and allows us to declutter this code a bit while at it. Note that this means that ARMv6 (non-v6K) SMP systems can no longer use this feature, but those are quite rare to begin with, so this is a reasonable trade off. Reviewed-by:
Kees Cook <keescook@chromium.org> Signed-off-by:
Ard Biesheuvel <ardb@kernel.org> Reviewed-by:
Linus Walleij <linus.walleij@linaro.org> Tested-by:
Amit Daniel Kachhap <amit.kachhap@arm.com>
Ard Biesheuvel authoredWe will be enabling THREAD_INFO_IN_TASK support for ARM, which means that we can no longer load the stack canary value by masking the stack pointer and taking the copy that lives in thread_info. Instead, we will be able to load it from the task_struct directly, by using the TPIDRURO register which will hold the current task pointer when THREAD_INFO_IN_TASK is in effect. This is much more straight-forward, and allows us to declutter this code a bit while at it. Note that this means that ARMv6 (non-v6K) SMP systems can no longer use this feature, but those are quite rare to begin with, so this is a reasonable trade off. Reviewed-by:
arm_ssp_per_task_plugin.c 2.45 KiB