@samitouri / QOSamiQemu / commits / 1be42dc241

linux-user: add MTE_STORE_ONLY to prctl

Linux-user processes can now control whether MTE_STORE_ONLY is enabled using the prctl syscall. Signed-off-by: Gabriel Brookman <brookmangabriel@gmail.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20260529-feat-mte4-v7-4-ccbd3c14eb3c@gmail.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Gabriel Brookman committed May 29, 2026 at 12:52 UTC 1be42dc241322571ca5d6a54be068962d38d7dae
5 files changed +28 -8
linux-user/aarch64/mte_user_helper.c
+10 -1
@@ -10,7 +10,7 @@
10 #include "qemu.h"
11 #include "mte_user_helper.h"
12
13 -void arm_set_mte_tcf0(CPUArchState *env, abi_long value)
13 +void arm_set_tagged_addr_ctrl(CPUArchState *env, abi_long value)
14 {
15 /*
16 * Write PR_MTE_TCF to SCTLR_EL1[TCF0].
@@ -32,4 +32,13 @@ void arm_set_mte_tcf0(CPUArchState *env, abi_long value)
32 tcf = 2;
33 }
34 env->cp15.sctlr_el[1] = deposit64(env->cp15.sctlr_el[1], 38, 2, tcf);
35 +
36 + /*
37 + * If MTE_STORE_ONLY is enabled, set the corresponding sctlr_el1 bit
38 + */
39 + if (value & PR_MTE_STORE_ONLY) {
40 + env->cp15.sctlr_el[1] |= SCTLR_TCSO0;
41 + } else {
42 + env->cp15.sctlr_el[1] &= ~SCTLR_TCSO0;
43 + }
44 }
linux-user/aarch64/mte_user_helper.h
+9 -5
@@ -20,15 +20,19 @@
20 # define PR_MTE_TAG_SHIFT 3
21 # define PR_MTE_TAG_MASK (0xffffUL << PR_MTE_TAG_SHIFT)
22 #endif
23 +#ifndef PR_MTE_STORE_ONLY
24 +# define PR_MTE_STORE_ONLY (1UL << 19)
25 +#endif
26
27 /**
25 - * arm_set_mte_tcf0 - Set TCF0 field in SCTLR_EL1 register
28 + * arm_set_tagged_addr_ctrl - Set TCF0 and TCSO0 fields in SCTLR_EL1 register
29 * @env: The CPU environment
27 - * @value: The value to be set for the Tag Check Fault in EL0 field.
30 + * @value: The value to be set for the Tag Check Fault and Tag Check Store Only
31 + * in EL0 field.
32 *
29 - * Only SYNC and ASYNC modes can be selected. If ASYMM mode is given, the SYNC
30 - * mode is selected instead. So, there is no way to set the ASYMM mode.
33 + * Only SYNC and ASYNC modes can be selected for TCF0. If ASYMM mode is given,
34 + * the SYNC mode is selected instead. So, there is no way to set the ASYMM mode.
35 */
32 -void arm_set_mte_tcf0(CPUArchState *env, abi_long value);
36 +void arm_set_tagged_addr_ctrl(CPUArchState *env, abi_long value);
37
38 #endif /* AARCH64_MTE_USER_HELPER_H */
linux-user/aarch64/target_prctl.h
+5 -1
@@ -168,6 +168,9 @@ static abi_long do_prctl_set_tagged_addr_ctrl(CPUArchState *env, abi_long arg2)
168 if (cpu_isar_feature(aa64_mte, cpu)) {
169 valid_mask |= PR_MTE_TCF_MASK;
170 valid_mask |= PR_MTE_TAG_MASK;
171 + if (cpu_isar_feature(aa64_mte_store_only, cpu)) {
172 + valid_mask |= PR_MTE_STORE_ONLY;
173 + }
174 }
175
176 if (arg2 & ~valid_mask) {
@@ -176,7 +179,7 @@ static abi_long do_prctl_set_tagged_addr_ctrl(CPUArchState *env, abi_long arg2)
179 env->tagged_addr_enable = arg2 & PR_TAGGED_ADDR_ENABLE;
180
181 if (cpu_isar_feature(aa64_mte, cpu)) {
179 - arm_set_mte_tcf0(env, arg2);
182 + arm_set_tagged_addr_ctrl(env, arg2);
183
184 /*
185 * Write PR_MTE_TAG to GCR_EL1[Exclude].
@@ -185,6 +188,7 @@ static abi_long do_prctl_set_tagged_addr_ctrl(CPUArchState *env, abi_long arg2)
188 */
189 env->cp15.gcr_el1 =
190 deposit64(env->cp15.gcr_el1, 0, 16, ~arg2 >> PR_MTE_TAG_SHIFT);
191 +
192 arm_rebuild_hflags(env);
193 }
194 return 0;
target/arm/gdbstub64.c
+1 -1
@@ -684,7 +684,7 @@ int aarch64_gdb_set_tag_ctl_reg(CPUState *cs, uint8_t *buf, int reg)
684 * expose options regarding the type of MTE fault that can be controlled at
685 * runtime.
686 */
687 - arm_set_mte_tcf0(env, tcf);
687 + arm_set_tagged_addr_ctrl(env, tcf);
688
689 return 1;
690 #else
tests/tcg/aarch64/mte.h
+3
@@ -20,6 +20,9 @@
20 #ifndef PR_TAGGED_ADDR_ENABLE
21 # define PR_TAGGED_ADDR_ENABLE (1UL << 0)
22 #endif
23 +#ifndef PR_MTE_STORE_ONLY
24 +# define PR_MTE_STORE_ONLY (1UL << 19)
25 +#endif
26 #ifndef PR_MTE_TCF_SHIFT
27 # define PR_MTE_TCF_SHIFT 1
28 # define PR_MTE_TCF_NONE (0UL << PR_MTE_TCF_SHIFT)