We're about to start validating PAGE_EXEC, which means that we've
got to the vsyscall page executable. We had been special casing
this entirely within translate.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
linux-user/elfload.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 29d910c4cc..d783240a36 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -195,6 +195,28 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs,
const CPUX86State *en
(*regs)[26] = tswapreg(env->segs[R_GS].selector & 0xffff);
}
+#if ULONG_MAX >= TARGET_VSYSCALL_PAGE
+#define HI_COMMPAGE TARGET_VSYSCALL_PAGE
+
+static bool init_guest_commpage(void)
+{
+ /*
+ * The vsyscall page is at a high negative address aka kernel space,
+ * which means that we cannot actually allocate it with target_mmap.
+ * We still should be able to use page_set_flags, unless the user
+ * has specified -R reserved_va, which would trigger an assert().
+ */
+ if (reserved_va != 0 &&
+ TARGET_VSYSCALL_PAGE + TARGET_PAGE_SIZE >= reserved_va) {
+ error_report("Cannot allocate vsyscall page");
+ exit(EXIT_FAILURE);
+ }
+ page_set_flags(TARGET_VSYSCALL_PAGE,
+ TARGET_VSYSCALL_PAGE + TARGET_PAGE_SIZE,
+ PAGE_EXEC | PAGE_VALID);
+ return true;
+}
+#endif
#else
#define ELF_START_MMAP 0x80000000
--
2.34.1
