3a52c12b3a
Defer enabling pointer authentication on boot core until after its required to be enabled by cpufeature framework. This will help in controlling the feature dynamically with a boot parameter. Signed-off-by: Ajay Patil <pajay@qti.qualcomm.com> Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org> Signed-off-by: Srinivas Ramana <sramana@codeaurora.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/1610152163-16554-2-git-send-email-sramana@codeaurora.org Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: David Brazdil <dbrazdil@google.com> Link: https://lore.kernel.org/r/20210208095732.3267263-22-maz@kernel.org Signed-off-by: Will Deacon <will@kernel.org> (cherry picked from commit 7f6240858cf3abb75237c9ba63ec70d232573ae8 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/cpufeature) Signed-off-by: Will Deacon <willdeacon@google.com> Bug: 175544340 Change-Id: I05c400e88abf15ab0348ce8ac2698c0ce800456a
48 lines
1.3 KiB
C
48 lines
1.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* GCC stack protector support.
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*
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* Stack protector works by putting predefined pattern at the start of
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* the stack frame and verifying that it hasn't been overwritten when
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* returning from the function. The pattern is called stack canary
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* and gcc expects it to be defined by a global variable called
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* "__stack_chk_guard" on ARM. This unfortunately means that on SMP
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* we cannot have a different canary value per task.
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*/
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#ifndef __ASM_STACKPROTECTOR_H
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#define __ASM_STACKPROTECTOR_H
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#include <linux/random.h>
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#include <linux/version.h>
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#include <asm/pointer_auth.h>
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extern unsigned long __stack_chk_guard;
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/*
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* Initialize the stackprotector canary value.
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*
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* NOTE: this must only be called from functions that never return,
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* and it must always be inlined.
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*/
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static __always_inline void boot_init_stack_canary(void)
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{
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#if defined(CONFIG_STACKPROTECTOR)
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unsigned long canary;
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/* Try to get a semi random initial value. */
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get_random_bytes(&canary, sizeof(canary));
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canary ^= LINUX_VERSION_CODE;
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canary &= CANARY_MASK;
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current->stack_canary = canary;
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if (!IS_ENABLED(CONFIG_STACKPROTECTOR_PER_TASK))
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__stack_chk_guard = current->stack_canary;
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#endif
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ptrauth_thread_init_kernel(current);
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ptrauth_thread_switch_kernel(current);
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ptrauth_enable();
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}
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#endif /* _ASM_STACKPROTECTOR_H */
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