linux-user/arm: Select vdso for be8 and be32 modes

In be8 mode, instructions are little-endian.
In be32 mode, instructions are big-endian.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2333
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

linux-user/arm/Makefile.vdso

@@ -3,15 +3,18 @@ include $(BUILD_DIR)/tests/tcg/arm-linux-user/config-target.mak
 SUBDIR = $(SRC_PATH)/linux-user/arm
 VPATH += $(SUBDIR)
 
-all: $(SUBDIR)/vdso-be.so $(SUBDIR)/vdso-le.so
+all: $(SUBDIR)/vdso-be8.so $(SUBDIR)/vdso-be32.so $(SUBDIR)/vdso-le.so
 
 # Adding -use-blx disables unneeded interworking without actually using blx.
 LDFLAGS = -nostdlib -shared -Wl,-use-blx -Wl,-z,max-page-size=4096 \
 	  -Wl,-h,linux-vdso.so.1 -Wl,--build-id=sha1 \
 	  -Wl,--hash-style=both -Wl,-T,$(SUBDIR)/vdso.ld
 
-$(SUBDIR)/vdso-be.so: vdso.S vdso.ld vdso-asmoffset.h
-	$(CC) -o $@ $(LDFLAGS) -mbig-endian $<
+$(SUBDIR)/vdso-be8.so: vdso.S vdso.ld vdso-asmoffset.h
+	$(CC) -o $@ $(LDFLAGS) -mbig-endian -mbe8 $<
+
+$(SUBDIR)/vdso-be32.so: vdso.S vdso.ld vdso-asmoffset.h
+	$(CC) -o $@ $(LDFLAGS) -mbig-endian -mbe32 $<
 
 $(SUBDIR)/vdso-le.so: vdso.S vdso.ld vdso-asmoffset.h
 	$(CC) -o $@ $(LDFLAGS) -mlittle-endian $<

linux-user/arm/meson.build

@@ -10,10 +10,17 @@ syscall_nr_generators += {
 # is always true as far as source_set.apply() is concerned.  Always build
 # both header files and include the right one via #if.
 
-vdso_be_inc = gen_vdso.process('vdso-be.so',
-                               extra_args: ['-s', 'sigreturn_codes'])
+vdso_be8_inc = gen_vdso.process('vdso-be8.so',
+                               extra_args: ['-s', 'sigreturn_codes',
+                                            '-p', 'vdso_be8'])
+
+vdso_be32_inc = gen_vdso.process('vdso-be32.so',
+                               extra_args: ['-s', 'sigreturn_codes',
+                                            '-p', 'vdso_be32'])
 
 vdso_le_inc = gen_vdso.process('vdso-le.so',
                                extra_args: ['-s', 'sigreturn_codes'])
 
-linux_user_ss.add(when: 'TARGET_ARM', if_true: [vdso_be_inc, vdso_le_inc])
+linux_user_ss.add(when: 'TARGET_ARM', if_true: [
+    vdso_be8_inc, vdso_be32_inc, vdso_le_inc
+])

linux-user/elfload.c

@@ -659,6 +659,23 @@ static const char *get_elf_platform(void)
 #undef END
 }
 
+#if TARGET_BIG_ENDIAN
+#include "elf.h"
+#include "vdso-be8.c.inc"
+#include "vdso-be32.c.inc"
+
+static const VdsoImageInfo *vdso_image_info(uint32_t elf_flags)
+{
+    return (EF_ARM_EABI_VERSION(elf_flags) >= EF_ARM_EABI_VER4
+            && (elf_flags & EF_ARM_BE8)
+            ? &vdso_be8_image_info
+            : &vdso_be32_image_info);
+}
+#define vdso_image_info vdso_image_info
+#else
+# define VDSO_HEADER  "vdso-le.c.inc"
+#endif
+
 #else
 /* 64 bit ARM definitions */
 
@@ -958,14 +975,14 @@ const char *elf_hwcap2_str(uint32_t bit)
 
 #undef GET_FEATURE_ID
 
-#endif /* not TARGET_AARCH64 */
-
 #if TARGET_BIG_ENDIAN
 # define VDSO_HEADER  "vdso-be.c.inc"
 #else
 # define VDSO_HEADER  "vdso-le.c.inc"
 #endif
 
+#endif /* not TARGET_AARCH64 */
+
 #endif /* TARGET_ARM */
 
 #ifdef TARGET_SPARC
@@ -3524,12 +3541,14 @@ static void load_elf_interp(const char *filename, struct image_info *info,
     load_elf_image(filename, &src, info, &ehdr, NULL);
 }
 
+#ifndef vdso_image_info
 #ifdef VDSO_HEADER
 #include VDSO_HEADER
-#define  vdso_image_info()  &vdso_image_info
+#define  vdso_image_info(flags)  &vdso_image_info
 #else
-#define  vdso_image_info()  NULL
-#endif
+#define  vdso_image_info(flags)  NULL
+#endif /* VDSO_HEADER */
+#endif /* vdso_image_info */
 
 static void load_elf_vdso(struct image_info *info, const VdsoImageInfo *vdso)
 {
@@ -3860,7 +3879,7 @@ int load_elf_binary(struct linux_binprm *bprm, struct image_info *info)
      * Load a vdso if available, which will amongst other things contain the
      * signal trampolines.  Otherwise, allocate a separate page for them.
      */
-    const VdsoImageInfo *vdso = vdso_image_info();
+    const VdsoImageInfo *vdso = vdso_image_info(info->elf_flags);
     if (vdso) {
         load_elf_vdso(&vdso_info, vdso);
         info->vdso = vdso_info.load_bias;