4 files changed, 110 insertions, 8 deletions
diff --git a/linux-user/arm/elfload.c b/linux-user/arm/elfload.c
index 7de1f13f4b..308ed23fcb 100644
--- a/linux-user/arm/elfload.c
+++ b/linux-user/arm/elfload.c
@@ -3,7 +3,11 @@
 #include "qemu/osdep.h"
 #include "qemu.h"
 #include "loader.h"
+#include "user-internals.h"
+#include "target_elf.h"
 #include "target/arm/cpu-features.h"
+#include "target_elf.h"
+#include "elf.h"
 
 
 const char *get_elf_cpu_model(uint32_t eflags)
@@ -199,3 +203,75 @@ const char *get_elf_platform(CPUState *cs)
 
 #undef END
 }
+
+bool init_guest_commpage(void)
+{
+    ARMCPU *cpu = ARM_CPU(thread_cpu);
+    int host_page_size = qemu_real_host_page_size();
+    abi_ptr commpage;
+    void *want;
+    void *addr;
+
+    /*
+     * M-profile allocates maximum of 2GB address space, so can never
+     * allocate the commpage.  Skip it.
+     */
+    if (arm_feature(&cpu->env, ARM_FEATURE_M)) {
+        return true;
+    }
+
+    commpage = HI_COMMPAGE & -host_page_size;
+    want = g2h_untagged(commpage);
+    addr = mmap(want, host_page_size, PROT_READ | PROT_WRITE,
+                MAP_ANONYMOUS | MAP_PRIVATE |
+                (commpage < reserved_va ? MAP_FIXED : MAP_FIXED_NOREPLACE),
+                -1, 0);
+
+    if (addr == MAP_FAILED) {
+        perror("Allocating guest commpage");
+        exit(EXIT_FAILURE);
+    }
+    if (addr != want) {
+        return false;
+    }
+
+    /* Set kernel helper versions; rest of page is 0.  */
+    __put_user(5, (uint32_t *)g2h_untagged(0xffff0ffcu));
+
+    if (mprotect(addr, host_page_size, PROT_READ)) {
+        perror("Protecting guest commpage");
+        exit(EXIT_FAILURE);
+    }
+
+    page_set_flags(commpage, commpage | (host_page_size - 1),
+                   PAGE_READ | PAGE_EXEC | PAGE_VALID);
+    return true;
+}
+
+void elf_core_copy_regs(target_elf_gregset_t *r, const CPUARMState *env)
+{
+    for (int i = 0; i < 16; ++i) {
+        r->pt.regs[i] = tswapal(env->regs[i]);
+    }
+    r->pt.cpsr = tswapal(cpsr_read((CPUARMState *)env));
+    r->pt.orig_r0 = tswapal(env->regs[0]); /* FIXME */
+}
+
+#if TARGET_BIG_ENDIAN
+# include "vdso-be8.c.inc"
+# include "vdso-be32.c.inc"
+#else
+# include "vdso-le.c.inc"
+#endif
+
+const VdsoImageInfo *get_vdso_image_info(uint32_t elf_flags)
+{
+#if TARGET_BIG_ENDIAN
+    return (EF_ARM_EABI_VERSION(elf_flags) >= EF_ARM_EABI_VER4
+            && (elf_flags & EF_ARM_BE8)
+            ? &vdso_be8_image_info
+            : &vdso_be32_image_info);
+#else
+    return &vdso_image_info;
+#endif
+}
diff --git a/linux-user/arm/target_elf.h b/linux-user/arm/target_elf.h
index 856ca41b16..12cdc8e5a7 100644
--- a/linux-user/arm/target_elf.h
+++ b/linux-user/arm/target_elf.h
@@ -8,8 +8,26 @@
 #ifndef ARM_TARGET_ELF_H
 #define ARM_TARGET_ELF_H
 
+#include "target_ptrace.h"
+
+#define ELF_MACHINE             EM_ARM
+#define ELF_CLASS               ELFCLASS32
+#define EXSTACK_DEFAULT         true
+
 #define HAVE_ELF_HWCAP          1
 #define HAVE_ELF_HWCAP2         1
 #define HAVE_ELF_PLATFORM       1
+#define HAVE_ELF_CORE_DUMP      1
+#define HAVE_VDSO_IMAGE_INFO    1
+
+#define HI_COMMPAGE             ((intptr_t)0xffff0f00u)
+
+/*
+ * See linux kernel: arch/arm/include/asm/elf.h, where
+ * elf_gregset_t is mapped to struct pt_regs via sizeof.
+ */
+typedef struct target_elf_gregset_t {
+    struct target_pt_regs pt;
+} target_elf_gregset_t;
 
 #endif
diff --git a/linux-user/arm/target_ptrace.h b/linux-user/arm/target_ptrace.h
new file mode 100644
index 0000000000..1610b8e03c
--- /dev/null
+++ b/linux-user/arm/target_ptrace.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef ARM_TARGET_PTRACE_H
+#define ARM_TARGET_PTRACE_H
+
+/*
+ * See arch/arm/include/uapi/asm/ptrace.h.
+ * Instead of an array and ARM_xx defines, use proper fields.
+ */
+struct target_pt_regs {
+    abi_ulong regs[16];
+    abi_ulong cpsr;
+    abi_ulong orig_r0;
+};
+
+#endif /* ARM_TARGET_PTRACE_H */
diff --git a/linux-user/arm/target_syscall.h b/linux-user/arm/target_syscall.h
index 412ad434cf..8c4ddba717 100644
--- a/linux-user/arm/target_syscall.h
+++ b/linux-user/arm/target_syscall.h
@@ -1,14 +1,6 @@
 #ifndef ARM_TARGET_SYSCALL_H
 #define ARM_TARGET_SYSCALL_H
 
-/* this struct defines the way the registers are stored on the
-   stack during a system call. */
-
-/* uregs[0..15] are r0 to r15; uregs[16] is CPSR; uregs[17] is ORIG_r0 */
-struct target_pt_regs {
-    abi_long uregs[18];
-};
-
 #define ARM_SYSCALL_BASE	0x900000
 #define ARM_THUMB_SYSCALL	0