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be12984256
As we're going to enable pointer auth within the kernel and use a different APIAKey for the kernel itself, so move the user APIAKey switch to EL0 exception return. The other 4 keys could remain switched during task switch, but are also moved to keep things consistent. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: James Morse <james.morse@arm.com> Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> [Amit: commit msg, re-positioned the patch, comments] Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
44 lines
1.2 KiB
C
44 lines
1.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/errno.h>
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#include <linux/prctl.h>
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#include <linux/random.h>
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#include <linux/sched.h>
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#include <asm/cpufeature.h>
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#include <asm/pointer_auth.h>
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int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg)
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{
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struct ptrauth_keys_user *keys = &tsk->thread.keys_user;
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unsigned long addr_key_mask = PR_PAC_APIAKEY | PR_PAC_APIBKEY |
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PR_PAC_APDAKEY | PR_PAC_APDBKEY;
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unsigned long key_mask = addr_key_mask | PR_PAC_APGAKEY;
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if (!system_supports_address_auth() && !system_supports_generic_auth())
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return -EINVAL;
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if (!arg) {
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ptrauth_keys_init_user(keys);
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return 0;
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}
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if (arg & ~key_mask)
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return -EINVAL;
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if (((arg & addr_key_mask) && !system_supports_address_auth()) ||
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((arg & PR_PAC_APGAKEY) && !system_supports_generic_auth()))
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return -EINVAL;
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if (arg & PR_PAC_APIAKEY)
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get_random_bytes(&keys->apia, sizeof(keys->apia));
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if (arg & PR_PAC_APIBKEY)
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get_random_bytes(&keys->apib, sizeof(keys->apib));
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if (arg & PR_PAC_APDAKEY)
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get_random_bytes(&keys->apda, sizeof(keys->apda));
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if (arg & PR_PAC_APDBKEY)
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get_random_bytes(&keys->apdb, sizeof(keys->apdb));
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if (arg & PR_PAC_APGAKEY)
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get_random_bytes(&keys->apga, sizeof(keys->apga));
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return 0;
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}
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