module: Sort exported symbols

This patch places every exported symbol in its own section
(i.e. "___ksymtab+printk").  Thus the linker will use its SORT() directive
to sort and finally merge all symbol in the right and final section
(i.e. "__ksymtab").

The symbol prefixed archs use an underscore as prefix for symbols.
To avoid collision we use a different character to create the temporary
section names.

This work was supported by a hardware donation from the CE Linux Forum.

Signed-off-by: Alessio Igor Bogani <abogani@kernel.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (folded in '+' fixup)
Tested-by: Dirk Behme <dirk.behme@googlemail.com>

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index bd297a2..b27445e 100644 (file)
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -274,70 +274,70 @@
        /* Kernel symbol table: Normal symbols */                       \
        __ksymtab         : AT(ADDR(__ksymtab) - LOAD_OFFSET) {         \
                VMLINUX_SYMBOL(__start___ksymtab) = .;                  \
-               *(__ksymtab)                                            \
+               *(SORT(___ksymtab+*))                                   \
                VMLINUX_SYMBOL(__stop___ksymtab) = .;                   \
        }                                                               \
                                                                        \
        /* Kernel symbol table: GPL-only symbols */                     \
        __ksymtab_gpl     : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) {     \
                VMLINUX_SYMBOL(__start___ksymtab_gpl) = .;              \
-               *(__ksymtab_gpl)                                        \
+               *(SORT(___ksymtab_gpl+*))                               \
                VMLINUX_SYMBOL(__stop___ksymtab_gpl) = .;               \
        }                                                               \
                                                                        \
        /* Kernel symbol table: Normal unused symbols */                \
        __ksymtab_unused  : AT(ADDR(__ksymtab_unused) - LOAD_OFFSET) {  \
                VMLINUX_SYMBOL(__start___ksymtab_unused) = .;           \
-               *(__ksymtab_unused)                                     \
+               *(SORT(___ksymtab_unused+*))                            \
                VMLINUX_SYMBOL(__stop___ksymtab_unused) = .;            \
        }                                                               \
                                                                        \
        /* Kernel symbol table: GPL-only unused symbols */              \
        __ksymtab_unused_gpl : AT(ADDR(__ksymtab_unused_gpl) - LOAD_OFFSET) { \
                VMLINUX_SYMBOL(__start___ksymtab_unused_gpl) = .;       \
-               *(__ksymtab_unused_gpl)                                 \
+               *(SORT(___ksymtab_unused_gpl+*))                        \
                VMLINUX_SYMBOL(__stop___ksymtab_unused_gpl) = .;        \
        }                                                               \
                                                                        \
        /* Kernel symbol table: GPL-future-only symbols */              \
        __ksymtab_gpl_future : AT(ADDR(__ksymtab_gpl_future) - LOAD_OFFSET) { \
                VMLINUX_SYMBOL(__start___ksymtab_gpl_future) = .;       \
-               *(__ksymtab_gpl_future)                                 \
+               *(SORT(___ksymtab_gpl_future+*))                        \
                VMLINUX_SYMBOL(__stop___ksymtab_gpl_future) = .;        \
        }                                                               \
                                                                        \
        /* Kernel symbol table: Normal symbols */                       \
        __kcrctab         : AT(ADDR(__kcrctab) - LOAD_OFFSET) {         \
                VMLINUX_SYMBOL(__start___kcrctab) = .;                  \
-               *(__kcrctab)                                            \
+               *(SORT(___kcrctab+*))                                   \
                VMLINUX_SYMBOL(__stop___kcrctab) = .;                   \
        }                                                               \
                                                                        \
        /* Kernel symbol table: GPL-only symbols */                     \
        __kcrctab_gpl     : AT(ADDR(__kcrctab_gpl) - LOAD_OFFSET) {     \
                VMLINUX_SYMBOL(__start___kcrctab_gpl) = .;              \
-               *(__kcrctab_gpl)                                        \
+               *(SORT(___kcrctab_gpl+*))                               \
                VMLINUX_SYMBOL(__stop___kcrctab_gpl) = .;               \
        }                                                               \
                                                                        \
        /* Kernel symbol table: Normal unused symbols */                \
        __kcrctab_unused  : AT(ADDR(__kcrctab_unused) - LOAD_OFFSET) {  \
                VMLINUX_SYMBOL(__start___kcrctab_unused) = .;           \
-               *(__kcrctab_unused)                                     \
+               *(SORT(___kcrctab_unused+*))                            \
                VMLINUX_SYMBOL(__stop___kcrctab_unused) = .;            \
        }                                                               \
                                                                        \
        /* Kernel symbol table: GPL-only unused symbols */              \
        __kcrctab_unused_gpl : AT(ADDR(__kcrctab_unused_gpl) - LOAD_OFFSET) { \
                VMLINUX_SYMBOL(__start___kcrctab_unused_gpl) = .;       \
-               *(__kcrctab_unused_gpl)                                 \
+               *(SORT(___kcrctab_unused_gpl+*))                        \
                VMLINUX_SYMBOL(__stop___kcrctab_unused_gpl) = .;        \
        }                                                               \
                                                                        \
        /* Kernel symbol table: GPL-future-only symbols */              \
        __kcrctab_gpl_future : AT(ADDR(__kcrctab_gpl_future) - LOAD_OFFSET) { \
                VMLINUX_SYMBOL(__start___kcrctab_gpl_future) = .;       \
-               *(__kcrctab_gpl_future)                                 \
+               *(SORT(___kcrctab_gpl_future+*))                        \
                VMLINUX_SYMBOL(__stop___kcrctab_gpl_future) = .;        \
        }                                                               \
                                                                        \

diff --git a/include/linux/module.h b/include/linux/module.h
index 49f4ad0..d9ca2d5 100644 (file)
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -224,7 +224,7 @@ struct module_use {
        extern void *__crc_##sym __attribute__((weak));         \
        static const unsigned long __kcrctab_##sym              \
        __used                                                  \
-       __attribute__((section("__kcrctab" sec), unused))       \
+       __attribute__((section("___kcrctab" sec "+" #sym), unused))     \
        = (unsigned long) &__crc_##sym;
 #else
 #define __CRC_SYMBOL(sym, sec)
@@ -239,7 +239,7 @@ struct module_use {
        = MODULE_SYMBOL_PREFIX #sym;                            \
        static const struct kernel_symbol __ksymtab_##sym       \
        __used                                                  \
-       __attribute__((section("__ksymtab" sec), unused))       \
+       __attribute__((section("___ksymtab" sec "+" #sym), unused))     \
        = { (unsigned long)&sym, __kstrtab_##sym }
 
 #define EXPORT_SYMBOL(sym)                                     \

diff --git a/scripts/module-common.lds b/scripts/module-common.lds
index 47a1f9a..0865b3e 100644 (file)
--- a/scripts/module-common.lds
+++ b/scripts/module-common.lds
@@ -5,4 +5,15 @@
  */
 SECTIONS {
        /DISCARD/ : { *(.discard) }
+
+       __ksymtab               : { *(SORT(___ksymtab+*)) }
+       __ksymtab_gpl           : { *(SORT(___ksymtab_gpl+*)) }
+       __ksymtab_unused        : { *(SORT(___ksymtab_unused+*)) }
+       __ksymtab_unused_gpl    : { *(SORT(___ksymtab_unused_gpl+*)) }
+       __ksymtab_gpl_future    : { *(SORT(___ksymtab_gpl_future+*)) }
+       __kcrctab               : { *(SORT(___kcrctab+*)) }
+       __kcrctab_gpl           : { *(SORT(___kcrctab_gpl+*)) }
+       __kcrctab_unused        : { *(SORT(___kcrctab_unused+*)) }
+       __kcrctab_unused_gpl    : { *(SORT(___kcrctab_unused_gpl+*)) }
+       __kcrctab_gpl_future    : { *(SORT(___kcrctab_gpl_future+*)) }
 }