sh: Initial ELF FDPIC support.

This adds initial support for ELF FDPIC on MMU-less SH, as per version
0.2 of the ABI definition at:

	http://www.codesourcery.com/public/docs/sh-fdpic/sh-fdpic-abi.txt

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

diff --git a/arch/sh/kernel/ptrace_32.c b/arch/sh/kernel/ptrace_32.c
index fddb547..2bc72de 100644 (file)
--- a/arch/sh/kernel/ptrace_32.c
+++ b/arch/sh/kernel/ptrace_32.c
@@ -241,6 +241,29 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                break;
        }
 #endif
+#ifdef CONFIG_BINFMT_ELF_FDPIC
+       case PTRACE_GETFDPIC: {
+               unsigned long tmp = 0;
+
+               switch (addr) {
+               case PTRACE_GETFDPIC_EXEC:
+                       tmp = child->mm->context.exec_fdpic_loadmap;
+                       break;
+               case PTRACE_GETFDPIC_INTERP:
+                       tmp = child->mm->context.interp_fdpic_loadmap;
+                       break;
+               default:
+                       break;
+               }
+
+               ret = 0;
+               if (put_user(tmp, (unsigned long *) data)) {
+                       ret = -EFAULT;
+                       break;
+               }
+               break;
+       }
+#endif
        default:
                ret = ptrace_request(child, request, addr, data);
                break;

diff --git a/arch/sh/kernel/signal_32.c b/arch/sh/kernel/signal_32.c
index f311551..46170a9 100644 (file)
--- a/arch/sh/kernel/signal_32.c
+++ b/arch/sh/kernel/signal_32.c
@@ -33,6 +33,11 @@
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
+struct fdpic_func_descriptor {
+       unsigned long   text;
+       unsigned long   GOT;
+};
+
 /*
  * Atomically swap in the new signal mask, and wait for a signal.
  */
@@ -378,7 +383,15 @@ static int setup_frame(int sig, struct k_sigaction *ka,
        regs->regs[4] = signal; /* Arg for signal handler */
        regs->regs[5] = 0;
        regs->regs[6] = (unsigned long) &frame->sc;
-       regs->pc = (unsigned long) ka->sa.sa_handler;
+
+       if (current->personality & FDPIC_FUNCPTRS) {
+               struct fdpic_func_descriptor __user *funcptr =
+                       (struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
+
+               __get_user(regs->pc, &funcptr->text);
+               __get_user(regs->regs[12], &funcptr->GOT);
+       } else
+               regs->pc = (unsigned long)ka->sa.sa_handler;
 
        set_fs(USER_DS);
 
@@ -458,7 +471,15 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
        regs->regs[4] = signal; /* Arg for signal handler */
        regs->regs[5] = (unsigned long) &frame->info;
        regs->regs[6] = (unsigned long) &frame->uc;
-       regs->pc = (unsigned long) ka->sa.sa_handler;
+
+       if (current->personality & FDPIC_FUNCPTRS) {
+               struct fdpic_func_descriptor __user *funcptr =
+                       (struct fdpic_func_descriptor __user *)ka->sa.sa_handler;
+
+               __get_user(regs->pc, &funcptr->text);
+               __get_user(regs->regs[12], &funcptr->GOT);
+       } else
+               regs->pc = (unsigned long)ka->sa.sa_handler;
 
        set_fs(USER_DS);
 

diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt
index 3263084..4a551af 100644 (file)
--- a/fs/Kconfig.binfmt
+++ b/fs/Kconfig.binfmt
@@ -30,7 +30,7 @@ config COMPAT_BINFMT_ELF
 config BINFMT_ELF_FDPIC
        bool "Kernel support for FDPIC ELF binaries"
        default y
-       depends on (FRV || BLACKFIN)
+       depends on (FRV || BLACKFIN || (SUPERH32 && !MMU))
        help
          ELF FDPIC binaries are based on ELF, but allow the individual load
          segments of a binary to be located in memory independently of each

diff --git a/include/asm-sh/elf.h b/include/asm-sh/elf.h
index 05092da..f01449a 100644 (file)
--- a/include/asm-sh/elf.h
+++ b/include/asm-sh/elf.h
@@ -1,10 +1,15 @@
 #ifndef __ASM_SH_ELF_H
 #define __ASM_SH_ELF_H
 
+#include <linux/utsname.h>
 #include <asm/auxvec.h>
 #include <asm/ptrace.h>
 #include <asm/user.h>
 
+/* ELF header e_flags defines */
+#define EF_SH_PIC              0x100   /* -fpic */
+#define EF_SH_FDPIC            0x8000  /* -mfdpic */
+
 /* SH (particularly SHcompact) relocation types  */
 #define        R_SH_NONE               0
 #define        R_SH_DIR32              1
@@ -43,6 +48,28 @@
 #define        R_SH_RELATIVE           165
 #define        R_SH_GOTOFF             166
 #define        R_SH_GOTPC              167
+
+/* FDPIC relocs */
+#define R_SH_GOT20             70
+#define R_SH_GOTOFF20          71
+#define R_SH_GOTFUNCDESC       72
+#define R_SH_GOTFUNCDESC20     73
+#define R_SH_GOTOFFFUNCDESC    74
+#define R_SH_GOTOFFFUNCDESC20  75
+#define R_SH_FUNCDESC          76
+#define R_SH_FUNCDESC_VALUE    77
+
+#if 0 /* XXX - later .. */
+#define R_SH_GOT20             198
+#define R_SH_GOTOFF20          199
+#define R_SH_GOTFUNCDESC       200
+#define R_SH_GOTFUNCDESC20     201
+#define R_SH_GOTOFFFUNCDESC    202
+#define R_SH_GOTOFFFUNCDESC20  203
+#define R_SH_FUNCDESC          204
+#define R_SH_FUNCDESC_VALUE    205
+#endif
+
 /* SHmedia relocs */
 #define R_SH_IMM_LOW16         246
 #define R_SH_IMM_LOW16_PCREL   247
@@ -77,9 +104,12 @@ typedef struct user_fpu_struct elf_fpregset_t;
 /*
  * This is used to ensure we don't load something for the wrong architecture.
  */
-#define elf_check_arch(x) ( (x)->e_machine == EM_SH )
+#define elf_check_arch(x)              ((x)->e_machine == EM_SH)
+#define elf_check_fdpic(x)             ((x)->e_flags & EF_SH_FDPIC)
+#define elf_check_const_displacement(x)        ((x)->e_flags & EF_SH_PIC)
 
 #define USE_ELF_CORE_DUMP
+#define ELF_FDPIC_CORE_EFLAGS  EF_SH_FDPIC
 #define ELF_EXEC_PAGESIZE      PAGE_SIZE
 
 /* This is the location that an ET_DYN program is loaded if exec'ed.  Typical
@@ -136,6 +166,27 @@ typedef struct user_fpu_struct elf_fpregset_t;
        _r->regs[8]=0; _r->regs[9]=0; _r->regs[10]=0; _r->regs[11]=0; \
        _r->regs[12]=0; _r->regs[13]=0; _r->regs[14]=0; \
        _r->sr = SR_FD; } while (0)
+
+#define ELF_FDPIC_PLAT_INIT(_r, _exec_map_addr, _interp_map_addr,      \
+                           _dynamic_addr)                              \
+do {                                                                   \
+       _r->regs[0]     = 0;                                            \
+       _r->regs[1]     = 0;                                            \
+       _r->regs[2]     = 0;                                            \
+       _r->regs[3]     = 0;                                            \
+       _r->regs[4]     = 0;                                            \
+       _r->regs[5]     = 0;                                            \
+       _r->regs[6]     = 0;                                            \
+       _r->regs[7]     = 0;                                            \
+       _r->regs[8]     = _exec_map_addr;                               \
+       _r->regs[9]     = _interp_map_addr;                             \
+       _r->regs[10]    = _dynamic_addr;                                \
+       _r->regs[11]    = 0;                                            \
+       _r->regs[12]    = 0;                                            \
+       _r->regs[13]    = 0;                                            \
+       _r->regs[14]    = 0;                                            \
+       _r->sr          = SR_FD;                                        \
+} while (0)
 #endif
 
 #define SET_PERSONALITY(ex, ibcs2) set_personality(PER_LINUX_32BIT)

diff --git a/include/asm-sh/mmu.h b/include/asm-sh/mmu.h
index eb0358c..fdcb93b 100644 (file)
--- a/include/asm-sh/mmu.h
+++ b/include/asm-sh/mmu.h
@@ -12,6 +12,10 @@ typedef struct {
        struct vm_list_struct   *vmlist;
        unsigned long           end_brk;
 #endif
+#ifdef CONFIG_BINFMT_ELF_FDPIC
+       unsigned long           exec_fdpic_loadmap;
+       unsigned long           interp_fdpic_loadmap;
+#endif
 } mm_context_t;
 
 /*

diff --git a/include/asm-sh/ptrace.h b/include/asm-sh/ptrace.h
index 7d36dc3..643ab5a 100644 (file)
--- a/include/asm-sh/ptrace.h
+++ b/include/asm-sh/ptrace.h
@@ -87,6 +87,11 @@ struct pt_dspregs {
        unsigned long   mod;
 };
 
+#define PTRACE_GETFDPIC                31      /* get the ELF fdpic loadmap address */
+
+#define PTRACE_GETFDPIC_EXEC   0       /* [addr] request the executable loadmap */
+#define PTRACE_GETFDPIC_INTERP 1       /* [addr] request the interpreter loadmap */
+
 #define        PTRACE_GETDSPREGS       55
 #define        PTRACE_SETDSPREGS       56
 #endif