qemu/linux-user/aarch64/target_prctl.h
Richard Henderson 681dfc0d55 linux-user/aarch64: Choose SYNC as the preferred MTE mode
The API does not generate an error for setting ASYNC | SYNC; that merely
constrains the selection vs the per-cpu default.  For qemu linux-user,
choose SYNC as the default.

Cc: qemu-stable@nongnu.org
Reported-by: Gustavo Romero <gustavo.romero@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Gustavo Romero <gustavo.romero@linaro.org>
Message-id: 20240207025210.8837-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2024-02-15 11:30:44 +00:00

228 lines
7.3 KiB
C

/*
* AArch64 specific prctl functions for linux-user
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#ifndef AARCH64_TARGET_PRCTL_H
#define AARCH64_TARGET_PRCTL_H
#include "target/arm/cpu-features.h"
static abi_long do_prctl_sve_get_vl(CPUArchState *env)
{
ARMCPU *cpu = env_archcpu(env);
if (cpu_isar_feature(aa64_sve, cpu)) {
/* PSTATE.SM is always unset on syscall entry. */
return sve_vq(env) * 16;
}
return -TARGET_EINVAL;
}
#define do_prctl_sve_get_vl do_prctl_sve_get_vl
static abi_long do_prctl_sve_set_vl(CPUArchState *env, abi_long arg2)
{
/*
* We cannot support either PR_SVE_SET_VL_ONEXEC or PR_SVE_VL_INHERIT.
* Note the kernel definition of sve_vl_valid allows for VQ=512,
* i.e. VL=8192, even though the current architectural maximum is VQ=16.
*/
if (cpu_isar_feature(aa64_sve, env_archcpu(env))
&& arg2 >= 0 && arg2 <= 512 * 16 && !(arg2 & 15)) {
uint32_t vq, old_vq;
/* PSTATE.SM is always unset on syscall entry. */
old_vq = sve_vq(env);
/*
* Bound the value of arg2, so that we know that it fits into
* the 4-bit field in ZCR_EL1. Rely on the hflags rebuild to
* sort out the length supported by the cpu.
*/
vq = MAX(arg2 / 16, 1);
vq = MIN(vq, ARM_MAX_VQ);
env->vfp.zcr_el[1] = vq - 1;
arm_rebuild_hflags(env);
vq = sve_vq(env);
if (vq < old_vq) {
aarch64_sve_narrow_vq(env, vq);
}
return vq * 16;
}
return -TARGET_EINVAL;
}
#define do_prctl_sve_set_vl do_prctl_sve_set_vl
static abi_long do_prctl_sme_get_vl(CPUArchState *env)
{
ARMCPU *cpu = env_archcpu(env);
if (cpu_isar_feature(aa64_sme, cpu)) {
return sme_vq(env) * 16;
}
return -TARGET_EINVAL;
}
#define do_prctl_sme_get_vl do_prctl_sme_get_vl
static abi_long do_prctl_sme_set_vl(CPUArchState *env, abi_long arg2)
{
/*
* We cannot support either PR_SME_SET_VL_ONEXEC or PR_SME_VL_INHERIT.
* Note the kernel definition of sve_vl_valid allows for VQ=512,
* i.e. VL=8192, even though the architectural maximum is VQ=16.
*/
if (cpu_isar_feature(aa64_sme, env_archcpu(env))
&& arg2 >= 0 && arg2 <= 512 * 16 && !(arg2 & 15)) {
int vq, old_vq;
old_vq = sme_vq(env);
/*
* Bound the value of vq, so that we know that it fits into
* the 4-bit field in SMCR_EL1. Because PSTATE.SM is cleared
* on syscall entry, we are not modifying the current SVE
* vector length.
*/
vq = MAX(arg2 / 16, 1);
vq = MIN(vq, 16);
env->vfp.smcr_el[1] =
FIELD_DP64(env->vfp.smcr_el[1], SMCR, LEN, vq - 1);
/* Delay rebuilding hflags until we know if ZA must change. */
vq = sve_vqm1_for_el_sm(env, 0, true) + 1;
if (vq != old_vq) {
/*
* PSTATE.ZA state is cleared on any change to SVL.
* We need not call arm_rebuild_hflags because PSTATE.SM was
* cleared on syscall entry, so this hasn't changed VL.
*/
env->svcr = FIELD_DP64(env->svcr, SVCR, ZA, 0);
arm_rebuild_hflags(env);
}
return vq * 16;
}
return -TARGET_EINVAL;
}
#define do_prctl_sme_set_vl do_prctl_sme_set_vl
static abi_long do_prctl_reset_keys(CPUArchState *env, abi_long arg2)
{
ARMCPU *cpu = env_archcpu(env);
if (cpu_isar_feature(aa64_pauth, cpu)) {
int all = (PR_PAC_APIAKEY | PR_PAC_APIBKEY |
PR_PAC_APDAKEY | PR_PAC_APDBKEY | PR_PAC_APGAKEY);
int ret = 0;
Error *err = NULL;
if (arg2 == 0) {
arg2 = all;
} else if (arg2 & ~all) {
return -TARGET_EINVAL;
}
if (arg2 & PR_PAC_APIAKEY) {
ret |= qemu_guest_getrandom(&env->keys.apia,
sizeof(ARMPACKey), &err);
}
if (arg2 & PR_PAC_APIBKEY) {
ret |= qemu_guest_getrandom(&env->keys.apib,
sizeof(ARMPACKey), &err);
}
if (arg2 & PR_PAC_APDAKEY) {
ret |= qemu_guest_getrandom(&env->keys.apda,
sizeof(ARMPACKey), &err);
}
if (arg2 & PR_PAC_APDBKEY) {
ret |= qemu_guest_getrandom(&env->keys.apdb,
sizeof(ARMPACKey), &err);
}
if (arg2 & PR_PAC_APGAKEY) {
ret |= qemu_guest_getrandom(&env->keys.apga,
sizeof(ARMPACKey), &err);
}
if (ret != 0) {
/*
* Some unknown failure in the crypto. The best
* we can do is log it and fail the syscall.
* The real syscall cannot fail this way.
*/
qemu_log_mask(LOG_UNIMP, "PR_PAC_RESET_KEYS: Crypto failure: %s",
error_get_pretty(err));
error_free(err);
return -TARGET_EIO;
}
return 0;
}
return -TARGET_EINVAL;
}
#define do_prctl_reset_keys do_prctl_reset_keys
static abi_long do_prctl_set_tagged_addr_ctrl(CPUArchState *env, abi_long arg2)
{
abi_ulong valid_mask = PR_TAGGED_ADDR_ENABLE;
ARMCPU *cpu = env_archcpu(env);
if (cpu_isar_feature(aa64_mte, cpu)) {
valid_mask |= PR_MTE_TCF_MASK;
valid_mask |= PR_MTE_TAG_MASK;
}
if (arg2 & ~valid_mask) {
return -TARGET_EINVAL;
}
env->tagged_addr_enable = arg2 & PR_TAGGED_ADDR_ENABLE;
if (cpu_isar_feature(aa64_mte, cpu)) {
/*
* Write PR_MTE_TCF to SCTLR_EL1[TCF0].
*
* The kernel has a per-cpu configuration for the sysadmin,
* /sys/devices/system/cpu/cpu<N>/mte_tcf_preferred,
* which qemu does not implement.
*
* Because there is no performance difference between the modes, and
* because SYNC is most useful for debugging MTE errors, choose SYNC
* as the preferred mode. With this preference, and the way the API
* uses only two bits, there is no way for the program to select
* ASYMM mode.
*/
unsigned tcf = 0;
if (arg2 & PR_MTE_TCF_SYNC) {
tcf = 1;
} else if (arg2 & PR_MTE_TCF_ASYNC) {
tcf = 2;
}
env->cp15.sctlr_el[1] = deposit64(env->cp15.sctlr_el[1], 38, 2, tcf);
/*
* Write PR_MTE_TAG to GCR_EL1[Exclude].
* Note that the syscall uses an include mask,
* and hardware uses an exclude mask -- invert.
*/
env->cp15.gcr_el1 =
deposit64(env->cp15.gcr_el1, 0, 16, ~arg2 >> PR_MTE_TAG_SHIFT);
arm_rebuild_hflags(env);
}
return 0;
}
#define do_prctl_set_tagged_addr_ctrl do_prctl_set_tagged_addr_ctrl
static abi_long do_prctl_get_tagged_addr_ctrl(CPUArchState *env)
{
ARMCPU *cpu = env_archcpu(env);
abi_long ret = 0;
if (env->tagged_addr_enable) {
ret |= PR_TAGGED_ADDR_ENABLE;
}
if (cpu_isar_feature(aa64_mte, cpu)) {
/* See do_prctl_set_tagged_addr_ctrl. */
ret |= extract64(env->cp15.sctlr_el[1], 38, 2) << PR_MTE_TCF_SHIFT;
ret = deposit64(ret, PR_MTE_TAG_SHIFT, 16, ~env->cp15.gcr_el1);
}
return ret;
}
#define do_prctl_get_tagged_addr_ctrl do_prctl_get_tagged_addr_ctrl
#endif /* AARCH64_TARGET_PRCTL_H */