ARM: add ELF_FDPIC support

This includes the necessary code to recognise the FDPIC format on ARM
and the ptrace command definitions used by the common ptrace code.

Based on patches originally from Mickael Guene <mickael.guene@st.com>.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Mickael GUENE <mickael.guene@st.com>
Tested-by: Vincent Abriou <vincent.abriou@st.com>
Tested-by: Andras Szemzo <szemzo.andras@gmail.com>

diff --git a/arch/arm/include/asm/elf.h b/arch/arm/include/asm/elf.h
index e2786acf8202e92b5c57233e3ff975473669e280..ad0ca4f2ba13091d1e61e75951ce180177b8c56e 100644 (file)
--- a/arch/arm/include/asm/elf.h
+++ b/arch/arm/include/asm/elf.h
@@ -100,6 +100,11 @@ struct elf32_hdr;
 extern int elf_check_arch(const struct elf32_hdr *);
 #define elf_check_arch elf_check_arch
 
+#define ELFOSABI_ARM_FDPIC  65 /* ARM FDPIC platform */
+#define elf_check_fdpic(x)  ((x)->e_ident[EI_OSABI] == ELFOSABI_ARM_FDPIC)
+#define elf_check_const_displacement(x)  ((x)->e_flags & EF_ARM_PIC)
+#define ELF_FDPIC_CORE_EFLAGS  0
+
 #define vmcore_elf64_check_arch(x) (0)
 
 extern int arm_elf_read_implies_exec(int);
@@ -120,6 +125,13 @@ int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs);
    have no such handler.  */
 #define ELF_PLAT_INIT(_r, load_addr)   (_r)->ARM_r0 = 0
 
+#define ELF_FDPIC_PLAT_INIT(_r, _exec_map_addr, _interp_map_addr, dynamic_addr) \
+       do { \
+               (_r)->ARM_r7 = _exec_map_addr; \
+               (_r)->ARM_r8 = _interp_map_addr; \
+               (_r)->ARM_r9 = dynamic_addr; \
+       } while(0)
+
 extern void elf_set_personality(const struct elf32_hdr *);
 #define SET_PERSONALITY(ex)    elf_set_personality(&(ex))
 

diff --git a/arch/arm/include/asm/mmu.h b/arch/arm/include/asm/mmu.h
index a5b47421059dc34153f7450a1cc7d2baf21200b5..e0eb16680a5bd448cc1bc2e53bfcd7b24fae71fc 100644 (file)
--- a/arch/arm/include/asm/mmu.h
+++ b/arch/arm/include/asm/mmu.h
@@ -33,6 +33,10 @@ typedef struct {
  */
 typedef struct {
        unsigned long   end_brk;
+#ifdef CONFIG_BINFMT_ELF_FDPIC
+       unsigned long   exec_fdpic_loadmap;
+       unsigned long   interp_fdpic_loadmap;
+#endif
 } mm_context_t;
 
 #endif

diff --git a/arch/arm/include/uapi/asm/ptrace.h b/arch/arm/include/uapi/asm/ptrace.h
index 5af0ed1b825a2aa95dc0626c9e1a685924979e24..3173eb9751fd27b0291ec5bcaa7567f9a2ca62c0 100644 (file)
--- a/arch/arm/include/uapi/asm/ptrace.h
+++ b/arch/arm/include/uapi/asm/ptrace.h
@@ -31,6 +31,10 @@
 #define PTRACE_SETVFPREGS      28
 #define PTRACE_GETHBPREGS      29
 #define PTRACE_SETHBPREGS      30
+#define PTRACE_GETFDPIC                31
+
+#define PTRACE_GETFDPIC_EXEC   0
+#define PTRACE_GETFDPIC_INTERP 1
 
 /*
  * PSR bits

diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt
index b2f82cf6bf86826050038af029e8bd311f6555a7..6ef70ce8e976de99979ed96c70ea9e54d0fbd820 100644 (file)
--- a/fs/Kconfig.binfmt
+++ b/fs/Kconfig.binfmt
@@ -35,7 +35,7 @@ config ARCH_BINFMT_ELF_STATE
 config BINFMT_ELF_FDPIC
        bool "Kernel support for FDPIC ELF binaries"
        default y
-       depends on (FRV || BLACKFIN || (SUPERH32 && !MMU) || C6X)
+       depends on ((ARM && !MMU) || FRV || BLACKFIN || (SUPERH32 && !MMU) || C6X)
        select ELFCORE
        help
          ELF FDPIC binaries are based on ELF, but allow the individual load