[ARM] Improve non-executable support

Add support for detecting non-executable stack binaries, and adjust
permissions to prevent execution from data and stack areas.  Also,
ensure that READ_IMPLIES_EXEC is enabled for older CPUs where that
is true, and for any executable-stack binary.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 34 insertions, 34 deletions

diff --git a/arch/arm/include/asm/elf.h b/arch/arm/include/asm/elf.h
index 7ea302c14a59..5be016980c19 100644
--- a/arch/arm/include/asm/elf.h
+++ b/arch/arm/include/asm/elf.h
@@ -18,9 +18,32 @@ typedef elf_greg_t elf_gregset_t[ELF_NGREG];
 typedef struct user_fp elf_fpregset_t;
 
 #define EM_ARM  40
-#define EF_ARM_APCS26 0x08
-#define EF_ARM_SOFT_FLOAT 0x200
-#define EF_ARM_EABI_MASK 0xFF000000
+
+#define EF_ARM_EABI_MASK        0xff000000
+#define EF_ARM_EABI_UNKNOWN     0x00000000
+#define EF_ARM_EABI_VER1        0x01000000
+#define EF_ARM_EABI_VER2        0x02000000
+#define EF_ARM_EABI_VER3        0x03000000
+#define EF_ARM_EABI_VER4        0x04000000
+#define EF_ARM_EABI_VER5        0x05000000
+
+#define EF_ARM_BE8              0x00800000      /* ABI 4,5 */
+#define EF_ARM_LE8              0x00400000      /* ABI 4,5 */
+#define EF_ARM_MAVERICK_FLOAT   0x00000800      /* ABI 0 */
+#define EF_ARM_VFP_FLOAT        0x00000400      /* ABI 0 */
+#define EF_ARM_SOFT_FLOAT       0x00000200      /* ABI 0 */
+#define EF_ARM_OLD_ABI          0x00000100      /* ABI 0 */
+#define EF_ARM_NEW_ABI          0x00000080      /* ABI 0 */
+#define EF_ARM_ALIGN8           0x00000040      /* ABI 0 */
+#define EF_ARM_PIC              0x00000020      /* ABI 0 */
+#define EF_ARM_MAPSYMSFIRST     0x00000010      /* ABI 2 */
+#define EF_ARM_APCS_FLOAT       0x00000010      /* ABI 0, floats in fp regs */
+#define EF_ARM_DYNSYMSUSESEGIDX 0x00000008      /* ABI 2 */
+#define EF_ARM_APCS_26          0x00000008      /* ABI 0 */
+#define EF_ARM_SYMSARESORTED    0x00000004      /* ABI 1,2 */
+#define EF_ARM_INTERWORK        0x00000004      /* ABI 0 */
+#define EF_ARM_HASENTRY         0x00000002      /* All */
+#define EF_ARM_RELEXEC          0x00000001      /* All */
 
 #define R_ARM_NONE      0
 #define R_ARM_PC24      1
@@ -57,23 +80,16 @@ typedef struct user_fp elf_fpregset_t;
 
 extern char elf_platform[];
 
-/*
- * This is used to ensure we don't load something for the wrong architecture.
- */
-#define elf_check_arch(x) ((x)->e_machine == EM_ARM && ELF_PROC_OK(x))
+struct elf32_hdr;
 
 /*
- * 32-bit code is always OK.  Some cpus can do 26-bit, some can't.
+ * This is used to ensure we don't load something for the wrong architecture.
  */
-#define ELF_PROC_OK(x)  (ELF_THUMB_OK(x) && ELF_26BIT_OK(x))
-
-#define ELF_THUMB_OK(x) \
-        ((elf_hwcap & HWCAP_THUMB && ((x)->e_entry & 1) == 1) || \
-         ((x)->e_entry & 3) == 0)
+extern int elf_check_arch(const struct elf32_hdr *);
+#define elf_check_arch elf_check_arch
 
-#define ELF_26BIT_OK(x) \
-        ((elf_hwcap & HWCAP_26BIT && (x)->e_flags & EF_ARM_APCS26) || \
-          ((x)->e_flags & EF_ARM_APCS26) == 0)
+extern int arm_elf_read_implies_exec(const struct elf32_hdr *, int);
+#define elf_read_implies_exec(ex,stk) arm_elf_read_implies_exec(&(ex), stk)
 
 #define USE_ELF_CORE_DUMP
 #define ELF_EXEC_PAGESIZE       4096
@@ -90,23 +106,7 @@ extern char elf_platform[];
    have no such handler.  */
 #define ELF_PLAT_INIT(_r, load_addr)    (_r)->ARM_r0 = 0
 
-/*
- * Since the FPA coprocessor uses CP1 and CP2, and iWMMXt uses CP0
- * and CP1, we only enable access to the iWMMXt coprocessor if the
- * binary is EABI or softfloat (and thus, guaranteed not to use
- * FPA instructions.)
- */
-#define SET_PERSONALITY(ex, ibcs2)                                      \
-        do {                                                            \
-                if ((ex).e_flags & EF_ARM_APCS26) {                     \
-                        set_personality(PER_LINUX);                     \
-                } else {                                                \
-                        set_personality(PER_LINUX_32BIT);               \
-                        if (elf_hwcap & HWCAP_IWMMXT && (ex).e_flags & (EF_ARM_EABI_MASK | EF_ARM_SOFT_FLOAT)) \
-                                set_thread_flag(TIF_USING_IWMMXT);      \
-                        else                                            \
-                                clear_thread_flag(TIF_USING_IWMMXT);    \
-                }                                                       \
-        } while (0)
+extern void elf_set_personality(const struct elf32_hdr *);
+#define SET_PERSONALITY(ex, ibcs2)      elf_set_personality(&(ex))
 
 #endif