ARM: 7568/1: Sort exception table at compile time

Add the ARM machine identifier to sortextable and select the
config option so that we can sort the exception table at compile
time. sortextable relies on a section named __ex_table existing
in the vmlinux, but ARM's linker script places the exception
table in the data section. Give the exception table its own
section so that sortextable can find it.

This allows us to skip the sorting step during boot.

Cc: David Daney <david.daney@cavium.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 73067efd484530d4021a220fecce329b4752b3c0..208414c0506a863a42d5b467ec60f613db1aec07 100644 (file)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -5,6 +5,7 @@ config ARM
        select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
        select ARCH_HAVE_CUSTOM_GPIO_H
        select ARCH_WANT_IPC_PARSE_VERSION
+       select BUILDTIME_EXTABLE_SORT if MMU
        select CPU_PM if (SUSPEND || CPU_IDLE)
        select DCACHE_WORD_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && !CPU_BIG_ENDIAN
        select GENERIC_ATOMIC64 if (CPU_V6 || !CPU_32v6K || !AEABI)

diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index 36ff15bbfdd4961afecfef9ea292c6445e9b3836..b9f38e388b43ed968cda7b16d2efe081faefc0c0 100644 (file)
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -114,6 +114,15 @@ SECTIONS
 
        RO_DATA(PAGE_SIZE)
 
+       . = ALIGN(4);
+       __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
+               __start___ex_table = .;
+#ifdef CONFIG_MMU
+               *(__ex_table)
+#endif
+               __stop___ex_table = .;
+       }
+
 #ifdef CONFIG_ARM_UNWIND
        /*
         * Stack unwinding tables
@@ -219,16 +228,6 @@ SECTIONS
                CACHELINE_ALIGNED_DATA(L1_CACHE_BYTES)
                READ_MOSTLY_DATA(L1_CACHE_BYTES)
 
-               /*
-                * The exception fixup table (might need resorting at runtime)
-                */
-               . = ALIGN(4);
-               __start___ex_table = .;
-#ifdef CONFIG_MMU
-               *(__ex_table)
-#endif
-               __stop___ex_table = .;
-
                /*
                 * and the usual data section
                 */

diff --git a/scripts/sortextable.c b/scripts/sortextable.c
index f19ddc47304c8f1e2a52a4acff95697fa9b3c902..1f10e89d15b4d03a07523e6c89482b5b0edfdc3d 100644 (file)
--- a/scripts/sortextable.c
+++ b/scripts/sortextable.c
@@ -248,6 +248,7 @@ do_file(char const *const fname)
        case EM_S390:
                custom_sort = sort_relative_table;
                break;
+       case EM_ARM:
        case EM_MIPS:
                break;
        }  /* end switch */