[PATCH v2 11/17] linux-user/aarch64: Implement PROT_MTE

[Richard Henderson]

Remember the PROT_MTE bit as PAGE_TARGET_2.
Otherwise this does not yet have effect.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/exec/cpu-all.h    |  1 +
 linux-user/syscall_defs.h |  1 +
 linux-user/mmap.c         | 20 ++++++++++++--------
 3 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
index 3cac7750e4..7ff10a8b08 100644
--- a/include/exec/cpu-all.h
+++ b/include/exec/cpu-all.h
@@ -286,6 +286,7 @@ extern intptr_t qemu_host_page_mask;
 #endif
 /* Target-specific bits that will be used via page_get_flags().  */
 #define PAGE_TARGET_1  0x0080
+#define PAGE_TARGET_2  0x0100
 
 #if defined(CONFIG_USER_ONLY)
 void page_dump(FILE *f);
diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
index 36bdafb3f1..f2bfa3b17f 100644
--- a/linux-user/syscall_defs.h
+++ b/linux-user/syscall_defs.h
@@ -1196,6 +1196,7 @@ struct target_winsize {
 
 #ifdef TARGET_AARCH64
 #define TARGET_PROT_BTI         0x10
+#define TARGET_PROT_MTE         0x20
 #endif
 
 /* Common */
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index fdd55986a1..b5618c40bd 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -84,18 +84,22 @@ static int validate_prot_to_pageflags(int *host_prot, int 
prot)
                | (prot & PROT_EXEC ? PROT_READ : 0);
 
 #ifdef TARGET_AARCH64
-    /*
-     * The PROT_BTI bit is only accepted if the cpu supports the feature.
-     * Since this is the unusual case, don't bother checking unless
-     * the bit has been requested.  If set and valid, record the bit
-     * within QEMU's page_flags as PAGE_TARGET_1.
-     */
-    if (prot & TARGET_PROT_BTI) {
+    {
         ARMCPU *cpu = ARM_CPU(thread_cpu);
-        if (cpu_isar_feature(aa64_bti, cpu)) {
+        /*
+         * The PROT_BTI bit is only accepted if the cpu supports the feature.
+         * If set and valid, record the bit within QEMU's page_flags
+         * as PAGE_TARGET_1.
+         */
+        if ((prot & TARGET_PROT_BTI) && cpu_isar_feature(aa64_bti, cpu)) {
             valid |= TARGET_PROT_BTI;
             page_flags |= PAGE_TARGET_1;
         }
+        /* Similarly for the PROT_MTE bit; set PAGE_TARGET_2. */
+        if ((prot & TARGET_PROT_MTE) && cpu_isar_feature(aa64_mte, cpu)) {
+            valid |= TARGET_PROT_MTE;
+            page_flags |= PAGE_TARGET_2;
+        }
     }
 #endif
 
-- 
2.25.1