linux_dsm_epyc7002/arch/arm64/kernel/pointer_auth.c
Will Deacon 84931327a8 arm64: ptr auth: Move per-thread keys from thread_info to thread_struct
We don't need to get at the per-thread keys from assembly at all, so
they can live alongside the rest of the per-thread register state in
thread_struct instead of thread_info.

This will also allow straighforward whitelisting of the keys for
hardened usercopy should we expose them via a ptrace request later on.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-13 16:42:47 +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 *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(keys);
ptrauth_keys_switch(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(keys);
return 0;
}