[PATCH v4 16/24] arm64: add support for starting ILP32 (ELFCLASS32) binaries

Philipp Tomsich
2015-04-13T20:14:34Z

From: Andrew Pinski <apinski@cavium.com>

Handle ILP32 (AArch64, but ELFCLASS32) binaries on ARM64.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
---
arch/arm64/include/asm/elf.h | 66 +++++++++++++++++++++++++++++++++++++-------
1 file changed, 56 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h
index 8218925..ff005d9 100644
--- a/arch/arm64/include/asm/elf.h
+++ b/arch/arm64/include/asm/elf.h
@@ -135,7 +135,11 @@ extern unsigned long randomize_et_dyn(unsigned long base);
*/
#define ELF_PLAT_INIT(_r, load_addr) (_r)->regs[0] = 0

-#define SET_PERSONALITY(ex) clear_thread_flag(TIF_32BIT);
+#define SET_PERSONALITY(ex) \
+do { \
+ clear_thread_flag(TIF_32BIT_AARCH64); \
+ clear_thread_flag(TIF_32BIT); \
+} while (0)

#define ARCH_DLINFO \
do { \
@@ -185,25 +189,28 @@ typedef compat_a32_elf_greg_t compat_a32_elf_gregset_t[COMPAT_A32_ELF_NGREG];
((x)->e_flags & EF_ARM_EABI_MASK))

#define compat_start_thread compat_start_thread
-#define COMPAT_SET_PERSONALITY(ex) set_thread_flag(TIF_32BIT);
-#define COMPAT_ARCH_DLINFO
+#define COMPAT_A32_SET_PERSONALITY(ex) \
+do { \
+ clear_thread_flag(TIF_32BIT_AARCH64); \
+ set_thread_flag(TIF_32BIT); \
+} while (0)
+#define COMPAT_A32_ARCH_DLINFO do {} while (0)

extern int aarch32_setup_vectors_page(struct linux_binprm *bprm,
int uses_interp);
-#define compat_arch_setup_additional_pages \
- aarch32_setup_vectors_page

#else
-
typedef elf_greg_t compat_elf_greg_t;
typedef elf_gregset_t compat_elf_gregset_t;
#define compat_a32_elf_check_arch(x) 0
-#define COMPAT_SET_PERSONALITY(ex)
-#define COMPAT_ARCH_DLINFO
-
+#define COMPAT_A32_SET_PERSONALITY(ex) do {} while (0)
+#define COMPAT_A32_ARCH_DLINFO do {} while (0)
+#define aarch32_setup_vectors_page(x, y) -EINVAL
#endif

+
+
/* If ILP32 is turned on, we want to define the compat_elf_greg_t to the non compat
one and define PR_REG_SIZE/PRSTATUS_SIZE/SET_PR_FPVALID so we pick up the correct
ones for AARCH32. Note also the definition of the macros have to be correct for
@@ -222,7 +229,46 @@ typedef compat_a32_elf_greg_t compat_elf_greg_t;
typedef compat_a32_elf_gregset_t compat_elf_gregset_t;
#endif

-#define compat_elf_check_arch(x) compat_a32_elf_check_arch(x)
+#ifdef CONFIG_ARM64_ILP32
+#define compat_ilp32_elf_check_arch(x) ((x)->e_machine == EM_AARCH64)
+#define COMPAT_ILP32_SET_PERSONALITY(ex) \
+do { \
+ set_thread_flag(TIF_32BIT_AARCH64); \
+ clear_thread_flag(TIF_32BIT); \
+} while (0)
+#define COMPAT_ILP32_ARCH_DLINFO \
+do { \
+ NEW_AUX_ENT(AT_SYSINFO_EHDR, \
+ (elf_addr_t)(long)current->mm->context.vdso); \
+} while (0)
+#else
+#define compat_ilp32_elf_check_arch(x) 0
+#define COMPAT_ILP32_SET_PERSONALITY(ex) do {} while (0)
+#define COMPAT_ILP32_ARCH_DLINFO do {} while (0)
+#endif
+
+#define compat_elf_check_arch(x) (compat_a32_elf_check_arch(x) || compat_ilp32_elf_check_arch(x))
+#define COMPAT_SET_PERSONALITY(ex) \
+do { \
+ if (compat_a32_elf_check_arch(&ex)) \
+ COMPAT_A32_SET_PERSONALITY(ex); \
+ else \
+ COMPAT_ILP32_SET_PERSONALITY(ex); \
+} while (0)
+
+/* ILP32 uses the "LP64-like" vdso pages */
+#define compat_arch_setup_additional_pages \
+ (is_a32_compat_task() \
+ ? &aarch32_setup_vectors_page \
+ : &(arch_setup_additional_pages))
+
+#define COMPAT_ARCH_DLINFO \
+do { \
+ if (is_a32_compat_task()) \
+ COMPAT_A32_ARCH_DLINFO; \
+ else \
+ COMPAT_ILP32_ARCH_DLINFO; \
+} while (0)

#endif /* CONFIG_COMPAT */

--
1.9.1