[PATCH 12/20] arm64: ilp32: introduce binfmt_ilp32.c

Yury Norov
2017-06-19T15:49:55Z

Like binfmt_elf32.c, binfmt_ilp32.c is needed to handle ILP32 binaries.

Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
---
arch/arm64/kernel/Makefile | 1 +
arch/arm64/kernel/binfmt_ilp32.c | 85 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 86 insertions(+)
create mode 100644 arch/arm64/kernel/binfmt_ilp32.c

diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index de6c84702d83..41d9a3ab07a7 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -29,6 +29,7 @@ $(obj)/%.stub.o: $(obj)/%.o FORCE

arm64-obj-$(CONFIG_AARCH32_EL0) += sys32.o kuser32.o signal32.o \
sys_compat.o entry32.o binfmt_elf32.o
+arm64-obj-$(CONFIG_ARM64_ILP32) += binfmt_ilp32.o
arm64-obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o entry-ftrace.o
arm64-obj-$(CONFIG_MODULES) += arm64ksyms.o module.o
arm64-obj-$(CONFIG_ARM64_MODULE_PLTS) += module-plts.o
diff --git a/arch/arm64/kernel/binfmt_ilp32.c b/arch/arm64/kernel/binfmt_ilp32.c
new file mode 100644
index 000000000000..bb31325e6f80
--- /dev/null
+++ b/arch/arm64/kernel/binfmt_ilp32.c
@@ -0,0 +1,85 @@
+/*
+ * Support for ILP32 Linux/aarch64 ELF binaries.
+ */
+#undef CONFIG_AARCH32_EL0
+#define compat_elf_gregset_t elf_gregset_t
+
+#include <linux/elfcore-compat.h>
+#include <linux/time.h>
+
+#undef ELF_CLASS
+#define ELF_CLASS ELFCLASS32
+
+#undef elfhdr
+#undef elf_phdr
+#undef elf_shdr
+#undef elf_note
+#undef elf_addr_t
+#define elfhdr elf32_hdr
+#define elf_phdr elf32_phdr
+#define elf_shdr elf32_shdr
+#define elf_note elf32_note
+#define elf_addr_t Elf32_Addr
+
+/*
+ * Some data types as stored in coredump.
+ */
+#define user_long_t compat_long_t
+#define user_siginfo_t compat_siginfo_t
+#define copy_siginfo_to_user copy_siginfo_to_user32
+
+/*
+ * The machine-dependent core note format types are defined in elfcore-compat.h,
+ * which requires asm/elf.h to define compat_elf_gregset_t et al.
+ */
+#define elf_prstatus compat_elf_prstatus
+#define elf_prpsinfo compat_elf_prpsinfo
+
+/* AARCH64 ILP32 EABI. */
+#undef elf_check_arch
+#define elf_check_arch(x) (((x)->e_machine == EM_AARCH64) \
+ && (x)->e_ident[EI_CLASS] == ELFCLASS32)
+
+#undef SET_PERSONALITY
+#define SET_PERSONALITY(ex) \
+do { \
+ set_bit(TIF_32BIT, &current->mm->context.flags); \
+ set_thread_flag(TIF_32BIT_AARCH64); \
+ clear_thread_flag(TIF_32BIT); \
+} while (0)
+
+#undef ARCH_DLINFO
+#define ARCH_DLINFO \
+do { \
+ NEW_AUX_ENT(AT_SYSINFO_EHDR, \
+ (elf_addr_t)(long)current->mm->context.vdso); \
+} while (0)
+
+#undef ELF_PLATFORM
+#ifdef __AARCH64EB__
+#define ELF_PLATFORM ("aarch64_be:ilp32")
+#else
+#define ELF_PLATFORM ("aarch64:ilp32")
+#endif
+
+#undef ELF_ET_DYN_BASE
+#define ELF_ET_DYN_BASE COMPAT_ELF_ET_DYN_BASE
+
+#undef ELF_HWCAP
+#undef ELF_HWCAP2
+#define ELF_HWCAP ((u32) elf_hwcap)
+#define ELF_HWCAP2 ((u32) (elf_hwcap >> 32))
+
+/*
+ * Rename a few of the symbols that binfmt_elf.c will define.
+ * These are all local so the names don't really matter, but it
+ * might make some debugging less confusing not to duplicate them.
+ */
+#define elf_format compat_elf_format
+#define init_elf_binfmt init_compat_elf_binfmt
+#define exit_elf_binfmt exit_compat_elf_binfmt
+
+#undef ns_to_timeval
+#define ns_to_timeval ns_to_compat_timeval
+
+#include "../../../fs/binfmt_elf.c"
--
2.11.0