Re: [PATCH 16/23] arm64: ilp32: introduce binfmt_ilp32.c

From: Zhangjian (Bamvor)
Date: Sun Jun 12 2016 - 23:06:22 EST


Hi, Yury

On 2016/5/24 8:04, Yury Norov wrote:
to handle ILP32 binaries

Signed-off-by: Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx>
---
arch/arm64/kernel/Makefile | 1 +
arch/arm64/kernel/binfmt_ilp32.c | 91 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 92 insertions(+)
create mode 100644 arch/arm64/kernel/binfmt_ilp32.c

diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 6bc9738..9dfdf86 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -28,6 +28,7 @@ $(obj)/%.stub.o: $(obj)/%.o FORCE
arm64-obj-$(CONFIG_AARCH32_EL0) += sys32.o kuser32.o signal32.o \
sys_compat.o entry32.o \
../../arm/kernel/opcodes.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 0000000..a934fd4
--- /dev/null
+++ b/arch/arm64/kernel/binfmt_ilp32.c
@@ -0,0 +1,91 @@
+/*
+ * Support for ILP32 Linux/aarch64 ELF binaries.
+ */
+
+#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
+
+/*
+ * Compat version of cputime_to_compat_timeval, perhaps this
+ * should be an inline in <linux/compat.h>.
+ */
+static void cputime_to_compat_timeval(const cputime_t cputime,
+ struct compat_timeval *value)
+{
+ struct timeval tv;
+ cputime_to_timeval(cputime, &tv);
+ value->tv_sec = tv.tv_sec;
+ value->tv_usec = tv.tv_usec;
+}
+
+#undef cputime_to_timeval
+#define cputime_to_timeval cputime_to_compat_timeval
+
+/* 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_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)
+
+#ifdef __AARCH64EB__
+#define COMPAT_ELF_PLATFORM ("aarch64_be:ilp32")
+#else
+#define COMPAT_ELF_PLATFORM ("aarch64:ilp32")
+#endif
fs/binfmt_elf.c use ELF_PLATFORM instead of the COMPAT one. Should we define
ELF_PLATFORM directly?
#undef ELF_PLATFORM
#ifdef __AARCH64EB__
#define ELF_PLATFORM ("aarch64_be:ilp32")
#else
#define ELF_PLATFORM ("aarch64:ilp32")
#endif

Regards

Bamvor
+
+#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
+
+#include "../../../fs/binfmt_elf.c"