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linux-next/arch/arm64/kernel/pointer_auth.c
Kristina Martsenko 91a1b6ccff arm64: rename ptrauth key structures to be user-specific
We currently enable ptrauth for userspace, but do not use it within the
kernel. We're going to enable it for the kernel, and will need to manage
a separate set of ptrauth keys for the kernel.

We currently keep all 5 keys in struct ptrauth_keys. However, as the
kernel will only need to use 1 key, it is a bit wasteful to allocate a
whole ptrauth_keys struct for every thread.

Therefore, a subsequent patch will define a separate struct, with only 1
key, for the kernel. In preparation for that, rename the existing struct
(and associated macros and functions) to reflect that they are specific
to userspace.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
[Amit: Re-positioned the patch to reduce the diff]
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-18 09:50:18 +00:00

48 lines
1.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/errno.h>
#include <linux/prctl.h>
#include <linux/random.h>
#include <linux/sched.h>
#include <asm/cpufeature.h>
#include <asm/pointer_auth.h>
int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg)
{
struct ptrauth_keys_user *keys = &tsk->thread.keys_user;
unsigned long addr_key_mask = PR_PAC_APIAKEY | PR_PAC_APIBKEY |
PR_PAC_APDAKEY | PR_PAC_APDBKEY;
unsigned long key_mask = addr_key_mask | PR_PAC_APGAKEY;
if (!system_supports_address_auth() && !system_supports_generic_auth())
return -EINVAL;
if (!arg) {
ptrauth_keys_init_user(keys);
ptrauth_keys_switch_user(keys);
return 0;
}
if (arg & ~key_mask)
return -EINVAL;
if (((arg & addr_key_mask) && !system_supports_address_auth()) ||
((arg & PR_PAC_APGAKEY) && !system_supports_generic_auth()))
return -EINVAL;
if (arg & PR_PAC_APIAKEY)
get_random_bytes(&keys->apia, sizeof(keys->apia));
if (arg & PR_PAC_APIBKEY)
get_random_bytes(&keys->apib, sizeof(keys->apib));
if (arg & PR_PAC_APDAKEY)
get_random_bytes(&keys->apda, sizeof(keys->apda));
if (arg & PR_PAC_APDBKEY)
get_random_bytes(&keys->apdb, sizeof(keys->apdb));
if (arg & PR_PAC_APGAKEY)
get_random_bytes(&keys->apga, sizeof(keys->apga));
ptrauth_keys_switch_user(keys);
return 0;
}