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authorRichard Henderson <richard.henderson@linaro.org>2020-10-21 10:37:39 -0700
committerPeter Maydell <peter.maydell@linaro.org>2020-10-27 10:44:02 +0000
commitbe5d6f4884021208ae0e73379c83e51500ad3a8d (patch)
tree900f37df4b572acc462d978b0653f29a8e60c029 /linux-user
parent0b6a03c044b6b0b09ad590c0d8b1bc60f12b9612 (diff)
linux-user: Set PAGE_TARGET_1 for TARGET_PROT_BTI
Transform the prot bit to a qemu internal page bit, and save it in the page tables. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20201021173749.111103-3-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'linux-user')
-rw-r--r--linux-user/mmap.c16
-rw-r--r--linux-user/syscall_defs.h4
2 files changed, 20 insertions, 0 deletions
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index f261563420..00c05e6a0f 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -83,6 +83,22 @@ static int validate_prot_to_pageflags(int *host_prot, int prot)
*host_prot = (prot & (PROT_READ | PROT_WRITE))
| (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.
+ */
+ if (prot & TARGET_PROT_BTI) {
+ ARMCPU *cpu = ARM_CPU(thread_cpu);
+ if (cpu_isar_feature(aa64_bti, cpu)) {
+ valid |= TARGET_PROT_BTI;
+ page_flags |= PAGE_BTI;
+ }
+ }
+#endif
+
return prot & ~valid ? 0 : page_flags;
}
diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
index 731c3d5341..cabbfb762d 100644
--- a/linux-user/syscall_defs.h
+++ b/linux-user/syscall_defs.h
@@ -1277,6 +1277,10 @@ struct target_winsize {
#define TARGET_PROT_SEM 0x08
#endif
+#ifdef TARGET_AARCH64
+#define TARGET_PROT_BTI 0x10
+#endif
+
/* Common */
#define TARGET_MAP_SHARED 0x01 /* Share changes */
#define TARGET_MAP_PRIVATE 0x02 /* Changes are private */