target/linux/generic/patches-4.0/220-gc_sections.patch

   1 From: Felix Fietkau <nbd@openwrt.org>
   2
   3 use -ffunction-sections, -fdata-sections and --gc-sections --sort-section=name
   4
   5 In combination with kernel symbol export stripping this significantly reduces
   6 the kernel image size. Used on both ARM and MIPS architectures.
   7
   8 Signed-off-by: Felix Fietkau <nbd@openwrt.org>
   9 Signed-off-by: Jonas Gorski <jogo@openwrt.org>
  10 Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
  11 ---
  12
  13 --- a/arch/mips/Makefile
  14 +++ b/arch/mips/Makefile
  15 @@ -89,10 +89,14 @@ all-$(CONFIG_SYS_SUPPORTS_ZBOOT)+= vmlin
  16  #
  17  cflags-y                       += -G 0 -mno-abicalls -fno-pic -pipe
  18  cflags-y                       += -msoft-float
  19 -LDFLAGS_vmlinux                        += -G 0 -static -n -nostdlib
  20 +LDFLAGS_vmlinux                        += -G 0 -static -n -nostdlib --gc-sections --sort-section=name
  21  KBUILD_AFLAGS_MODULE           += -mlong-calls
  22  KBUILD_CFLAGS_MODULE           += -mlong-calls
  23
  24 +ifndef CONFIG_FUNCTION_TRACER
  25 +KBUILD_CFLAGS_KERNEL           += -ffunction-sections -fdata-sections
  26 +endif
  27 +
  28  #
  29  # pass -msoft-float to GAS if it supports it.  However on newer binutils
  30  # (specifically newer than 2.24.51.20140728) we then also need to explicitly
  31 --- a/arch/mips/kernel/vmlinux.lds.S
  32 +++ b/arch/mips/kernel/vmlinux.lds.S
  33 @@ -67,7 +67,7 @@ SECTIONS
  34         /* Exception table for data bus errors */
  35         __dbe_table : {
  36                 __start___dbe_table = .;
  37 -               *(__dbe_table)
  38 +               KEEP(*(__dbe_table))
  39                 __stop___dbe_table = .;
  40         }
  41
  42 @@ -112,7 +112,7 @@ SECTIONS
  43         . = ALIGN(4);
  44         .mips.machines.init : AT(ADDR(.mips.machines.init) - LOAD_OFFSET) {
  45                 __mips_machines_start = .;
  46 -               *(.mips.machines.init)
  47 +               KEEP(*(.mips.machines.init))
  48                 __mips_machines_end = .;
  49         }
  50
  51 --- a/include/asm-generic/vmlinux.lds.h
  52 +++ b/include/asm-generic/vmlinux.lds.h
  53 @@ -89,7 +89,7 @@
  54  #ifdef CONFIG_FTRACE_MCOUNT_RECORD
  55  #define MCOUNT_REC()   . = ALIGN(8);                           \
  56                         VMLINUX_SYMBOL(__start_mcount_loc) = .; \
  57 -                       *(__mcount_loc)                         \
  58 +                       KEEP(*(__mcount_loc))                   \
  59                         VMLINUX_SYMBOL(__stop_mcount_loc) = .;
  60  #else
  61  #define MCOUNT_REC()
  62 @@ -97,7 +97,7 @@
  63
  64  #ifdef CONFIG_TRACE_BRANCH_PROFILING
  65  #define LIKELY_PROFILE()       VMLINUX_SYMBOL(__start_annotated_branch_profile) = .; \
  66 -                               *(_ftrace_annotated_branch)                           \
  67 +                               KEEP(*(_ftrace_annotated_branch))                     \
  68                                 VMLINUX_SYMBOL(__stop_annotated_branch_profile) = .;
  69  #else
  70  #define LIKELY_PROFILE()
  71 @@ -105,7 +105,7 @@
  72
  73  #ifdef CONFIG_PROFILE_ALL_BRANCHES
  74  #define BRANCH_PROFILE()       VMLINUX_SYMBOL(__start_branch_profile) = .;   \
  75 -                               *(_ftrace_branch)                             \
  76 +                               KEEP(*(_ftrace_branch))                       \
  77                                 VMLINUX_SYMBOL(__stop_branch_profile) = .;
  78  #else
  79  #define BRANCH_PROFILE()
  80 @@ -114,7 +114,7 @@
  81  #ifdef CONFIG_KPROBES
  82  #define KPROBE_BLACKLIST()     . = ALIGN(8);                                 \
  83                                 VMLINUX_SYMBOL(__start_kprobe_blacklist) = .; \
  84 -                               *(_kprobe_blacklist)                          \
  85 +                               KEEP(*(_kprobe_blacklist))                    \
  86                                 VMLINUX_SYMBOL(__stop_kprobe_blacklist) = .;
  87  #else
  88  #define KPROBE_BLACKLIST()
  89 @@ -123,7 +123,7 @@
  90  #ifdef CONFIG_EVENT_TRACING
  91  #define FTRACE_EVENTS()        . = ALIGN(8);                                   \
  92                         VMLINUX_SYMBOL(__start_ftrace_events) = .;      \
  93 -                       *(_ftrace_events)                               \
  94 +                       KEEP(*(_ftrace_events))                         \
  95                         VMLINUX_SYMBOL(__stop_ftrace_events) = .;
  96  #else
  97  #define FTRACE_EVENTS()
  98 @@ -131,7 +131,7 @@
  99
 100  #ifdef CONFIG_TRACING
 101  #define TRACE_PRINTKS() VMLINUX_SYMBOL(__start___trace_bprintk_fmt) = .;      \
 102 -                        *(__trace_printk_fmt) /* Trace_printk fmt' pointer */ \
 103 +                        KEEP(*(__trace_printk_fmt)) /* Trace_printk fmt' pointer */ \
 104                          VMLINUX_SYMBOL(__stop___trace_bprintk_fmt) = .;
 105  #define TRACEPOINT_STR() VMLINUX_SYMBOL(__start___tracepoint_str) = .; \
 106                          *(__tracepoint_str) /* Trace_printk fmt' pointer */ \
 107 @@ -144,7 +144,7 @@
 108  #ifdef CONFIG_FTRACE_SYSCALLS
 109  #define TRACE_SYSCALLS() . = ALIGN(8);                                 \
 110                          VMLINUX_SYMBOL(__start_syscalls_metadata) = .; \
 111 -                        *(__syscalls_metadata)                         \
 112 +                        KEEP(*(__syscalls_metadata))                   \
 113                          VMLINUX_SYMBOL(__stop_syscalls_metadata) = .;
 114  #else
 115  #define TRACE_SYSCALLS()
 116 @@ -158,8 +158,8 @@
 117  #define _OF_TABLE_1(name)                                              \
 118         . = ALIGN(8);                                                   \
 119         VMLINUX_SYMBOL(__##name##_of_table) = .;                        \
 120 -       *(__##name##_of_table)                                          \
 121 -       *(__##name##_of_table_end)
 122 +       KEEP(*(__##name##_of_table))                                    \
 123 +       KEEP(*(__##name##_of_table_end))
 124
 125  #define CLKSRC_OF_TABLES()     OF_TABLE(CONFIG_CLKSRC_OF, clksrc)
 126  #define IRQCHIP_OF_MATCH_TABLE() OF_TABLE(CONFIG_IRQCHIP, irqchip)
 127 @@ -172,7 +172,7 @@
 128  #define KERNEL_DTB()                                                   \
 129         STRUCT_ALIGN();                                                 \
 130         VMLINUX_SYMBOL(__dtb_start) = .;                                \
 131 -       *(.dtb.init.rodata)                                             \
 132 +       KEEP(*(.dtb.init.rodata))                                       \
 133         VMLINUX_SYMBOL(__dtb_end) = .;
 134
 135  /* .data section */
 136 @@ -188,16 +188,17 @@
 137         /* implement dynamic printk debug */                            \
 138         . = ALIGN(8);                                                   \
 139         VMLINUX_SYMBOL(__start___jump_table) = .;                       \
 140 -       *(__jump_table)                                                 \
 141 +       KEEP(*(__jump_table))                                           \
 142         VMLINUX_SYMBOL(__stop___jump_table) = .;                        \
 143         . = ALIGN(8);                                                   \
 144         VMLINUX_SYMBOL(__start___verbose) = .;                          \
 145 -       *(__verbose)                                                    \
 146 +       KEEP(*(__verbose))                                              \
 147         VMLINUX_SYMBOL(__stop___verbose) = .;                           \
 148         LIKELY_PROFILE()                                                \
 149         BRANCH_PROFILE()                                                \
 150         TRACE_PRINTKS()                                                 \
 151 -       TRACEPOINT_STR()
 152 +       TRACEPOINT_STR()                                                \
 153 +       *(.data.[a-zA-Z_]*)
 154
 155  /*
 156   * Data section helpers
 157 @@ -251,35 +252,35 @@
 158         /* PCI quirks */                                                \
 159         .pci_fixup        : AT(ADDR(.pci_fixup) - LOAD_OFFSET) {        \
 160                 VMLINUX_SYMBOL(__start_pci_fixups_early) = .;           \
 161 -               *(.pci_fixup_early)                                     \
 162 +               KEEP(*(.pci_fixup_early))                               \
 163                 VMLINUX_SYMBOL(__end_pci_fixups_early) = .;             \
 164                 VMLINUX_SYMBOL(__start_pci_fixups_header) = .;          \
 165 -               *(.pci_fixup_header)                                    \
 166 +               KEEP(*(.pci_fixup_header))                              \
 167                 VMLINUX_SYMBOL(__end_pci_fixups_header) = .;            \
 168                 VMLINUX_SYMBOL(__start_pci_fixups_final) = .;           \
 169 -               *(.pci_fixup_final)                                     \
 170 +               KEEP(*(.pci_fixup_final))                               \
 171                 VMLINUX_SYMBOL(__end_pci_fixups_final) = .;             \
 172                 VMLINUX_SYMBOL(__start_pci_fixups_enable) = .;          \
 173 -               *(.pci_fixup_enable)                                    \
 174 +               KEEP(*(.pci_fixup_enable))                              \
 175                 VMLINUX_SYMBOL(__end_pci_fixups_enable) = .;            \
 176                 VMLINUX_SYMBOL(__start_pci_fixups_resume) = .;          \
 177 -               *(.pci_fixup_resume)                                    \
 178 +               KEEP(*(.pci_fixup_resume))                              \
 179                 VMLINUX_SYMBOL(__end_pci_fixups_resume) = .;            \
 180                 VMLINUX_SYMBOL(__start_pci_fixups_resume_early) = .;    \
 181 -               *(.pci_fixup_resume_early)                              \
 182 +               KEEP(*(.pci_fixup_resume_early))                        \
 183                 VMLINUX_SYMBOL(__end_pci_fixups_resume_early) = .;      \
 184                 VMLINUX_SYMBOL(__start_pci_fixups_suspend) = .;         \
 185 -               *(.pci_fixup_suspend)                                   \
 186 +               KEEP(*(.pci_fixup_suspend))                             \
 187                 VMLINUX_SYMBOL(__end_pci_fixups_suspend) = .;           \
 188                 VMLINUX_SYMBOL(__start_pci_fixups_suspend_late) = .;    \
 189 -               *(.pci_fixup_suspend_late)                              \
 190 +               KEEP(*(.pci_fixup_suspend_late))                        \
 191                 VMLINUX_SYMBOL(__end_pci_fixups_suspend_late) = .;      \
 192         }                                                               \
 193                                                                         \
 194         /* Built-in firmware blobs */                                   \
 195         .builtin_fw        : AT(ADDR(.builtin_fw) - LOAD_OFFSET) {      \
 196                 VMLINUX_SYMBOL(__start_builtin_fw) = .;                 \
 197 -               *(.builtin_fw)                                          \
 198 +               KEEP(*(.builtin_fw))                                    \
 199                 VMLINUX_SYMBOL(__end_builtin_fw) = .;                   \
 200         }                                                               \
 201                                                                         \
 202 @@ -288,49 +289,49 @@
 203         /* Kernel symbol table: Normal symbols */                       \
 204         __ksymtab         : AT(ADDR(__ksymtab) - LOAD_OFFSET) {         \
 205                 VMLINUX_SYMBOL(__start___ksymtab) = .;                  \
 206 -               *(SORT(___ksymtab+*))                                   \
 207 +               KEEP(*(SORT(___ksymtab+*)))                             \
 208                 VMLINUX_SYMBOL(__stop___ksymtab) = .;                   \
 209         }                                                               \
 210                                                                         \
 211         /* Kernel symbol table: GPL-only symbols */                     \
 212         __ksymtab_gpl     : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) {     \
 213                 VMLINUX_SYMBOL(__start___ksymtab_gpl) = .;              \
 214 -               *(SORT(___ksymtab_gpl+*))                               \
 215 +               KEEP(*(SORT(___ksymtab_gpl+*)))                         \
 216                 VMLINUX_SYMBOL(__stop___ksymtab_gpl) = .;               \
 217         }                                                               \
 218                                                                         \
 219         /* Kernel symbol table: Normal unused symbols */                \
 220         __ksymtab_unused  : AT(ADDR(__ksymtab_unused) - LOAD_OFFSET) {  \
 221                 VMLINUX_SYMBOL(__start___ksymtab_unused) = .;           \
 222 -               *(SORT(___ksymtab_unused+*))                            \
 223 +               KEEP(*(SORT(___ksymtab_unused+*)))                      \
 224                 VMLINUX_SYMBOL(__stop___ksymtab_unused) = .;            \
 225         }                                                               \
 226                                                                         \
 227         /* Kernel symbol table: GPL-only unused symbols */              \
 228         __ksymtab_unused_gpl : AT(ADDR(__ksymtab_unused_gpl) - LOAD_OFFSET) { \
 229                 VMLINUX_SYMBOL(__start___ksymtab_unused_gpl) = .;       \
 230 -               *(SORT(___ksymtab_unused_gpl+*))                        \
 231 +               KEEP(*(SORT(___ksymtab_unused_gpl+*)))                  \
 232                 VMLINUX_SYMBOL(__stop___ksymtab_unused_gpl) = .;        \
 233         }                                                               \
 234                                                                         \
 235         /* Kernel symbol table: GPL-future-only symbols */              \
 236         __ksymtab_gpl_future : AT(ADDR(__ksymtab_gpl_future) - LOAD_OFFSET) { \
 237                 VMLINUX_SYMBOL(__start___ksymtab_gpl_future) = .;       \
 238 -               *(SORT(___ksymtab_gpl_future+*))                        \
 239 +               KEEP(*(SORT(___ksymtab_gpl_future+*)))                  \
 240                 VMLINUX_SYMBOL(__stop___ksymtab_gpl_future) = .;        \
 241         }                                                               \
 242                                                                         \
 243         /* Kernel symbol table: Normal symbols */                       \
 244         __kcrctab         : AT(ADDR(__kcrctab) - LOAD_OFFSET) {         \
 245                 VMLINUX_SYMBOL(__start___kcrctab) = .;                  \
 246 -               *(SORT(___kcrctab+*))                                   \
 247 +               KEEP(*(SORT(___kcrctab+*)))                             \
 248                 VMLINUX_SYMBOL(__stop___kcrctab) = .;                   \
 249         }                                                               \
 250                                                                         \
 251         /* Kernel symbol table: GPL-only symbols */                     \
 252         __kcrctab_gpl     : AT(ADDR(__kcrctab_gpl) - LOAD_OFFSET) {     \
 253                 VMLINUX_SYMBOL(__start___kcrctab_gpl) = .;              \
 254 -               *(SORT(___kcrctab_gpl+*))                               \
 255 +               KEEP(*(SORT(___kcrctab_gpl+*)))                         \
 256                 VMLINUX_SYMBOL(__stop___kcrctab_gpl) = .;               \
 257         }                                                               \
 258                                                                         \
 259 @@ -344,14 +345,14 @@
 260         /* Kernel symbol table: GPL-only unused symbols */              \
 261         __kcrctab_unused_gpl : AT(ADDR(__kcrctab_unused_gpl) - LOAD_OFFSET) { \
 262                 VMLINUX_SYMBOL(__start___kcrctab_unused_gpl) = .;       \
 263 -               *(SORT(___kcrctab_unused_gpl+*))                        \
 264 +               KEEP(*(SORT(___kcrctab_unused_gpl+*)))                  \
 265                 VMLINUX_SYMBOL(__stop___kcrctab_unused_gpl) = .;        \
 266         }                                                               \
 267                                                                         \
 268         /* Kernel symbol table: GPL-future-only symbols */              \
 269         __kcrctab_gpl_future : AT(ADDR(__kcrctab_gpl_future) - LOAD_OFFSET) { \
 270                 VMLINUX_SYMBOL(__start___kcrctab_gpl_future) = .;       \
 271 -               *(SORT(___kcrctab_gpl_future+*))                        \
 272 +               KEEP(*(SORT(___kcrctab_gpl_future+*)))                  \
 273                 VMLINUX_SYMBOL(__stop___kcrctab_gpl_future) = .;        \
 274         }                                                               \
 275                                                                         \
 276 @@ -370,14 +371,14 @@
 277         /* Built-in module parameters. */                               \
 278         __param : AT(ADDR(__param) - LOAD_OFFSET) {                     \
 279                 VMLINUX_SYMBOL(__start___param) = .;                    \
 280 -               *(__param)                                              \
 281 +               KEEP(*(__param))                                        \
 282                 VMLINUX_SYMBOL(__stop___param) = .;                     \
 283         }                                                               \
 284                                                                         \
 285         /* Built-in module versions. */                                 \
 286         __modver : AT(ADDR(__modver) - LOAD_OFFSET) {                   \
 287                 VMLINUX_SYMBOL(__start___modver) = .;                   \
 288 -               *(__modver)                                             \
 289 +               KEEP(*(__modver))                                       \
 290                 VMLINUX_SYMBOL(__stop___modver) = .;                    \
 291                 . = ALIGN((align));                                     \
 292                 VMLINUX_SYMBOL(__end_rodata) = .;                       \
 293 @@ -433,7 +434,7 @@
 294  #define ENTRY_TEXT                                                     \
 295                 ALIGN_FUNCTION();                                       \
 296                 VMLINUX_SYMBOL(__entry_text_start) = .;                 \
 297 -               *(.entry.text)                                          \
 298 +               KEEP(*(.entry.text))                                    \
 299                 VMLINUX_SYMBOL(__entry_text_end) = .;
 300
 301  #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 302 @@ -461,7 +462,7 @@
 303         . = ALIGN(align);                                               \
 304         __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {               \
 305                 VMLINUX_SYMBOL(__start___ex_table) = .;                 \
 306 -               *(__ex_table)                                           \
 307 +               KEEP(*(__ex_table))                                             \
 308                 VMLINUX_SYMBOL(__stop___ex_table) = .;                  \
 309         }
 310
 311 @@ -477,9 +478,9 @@
 312  #ifdef CONFIG_CONSTRUCTORS
 313  #define KERNEL_CTORS() . = ALIGN(8);                      \
 314                         VMLINUX_SYMBOL(__ctors_start) = .; \
 315 -                       *(.ctors)                          \
 316 +                       KEEP(*(.ctors))                    \
 317                         *(SORT(.init_array.*))             \
 318 -                       *(.init_array)                     \
 319 +                       KEEP(*(.init_array))               \
 320                         VMLINUX_SYMBOL(__ctors_end) = .;
 321  #else
 322  #define KERNEL_CTORS()
 323 @@ -528,7 +529,7 @@
 324  #define SBSS(sbss_align)                                               \
 325         . = ALIGN(sbss_align);                                          \
 326         .sbss : AT(ADDR(.sbss) - LOAD_OFFSET) {                         \
 327 -               *(.sbss)                                                \
 328 +               *(.sbss .sbss.*)                                        \
 329                 *(.scommon)                                             \
 330         }
 331
 332 @@ -546,7 +547,7 @@
 333                 BSS_FIRST_SECTIONS                                      \
 334                 *(.bss..page_aligned)                                   \
 335                 *(.dynbss)                                              \
 336 -               *(.bss)                                                 \
 337 +               *(.bss .bss.*)                                          \
 338                 *(COMMON)                                               \
 339         }
 340
 341 @@ -595,7 +596,7 @@
 342         . = ALIGN(8);                                                   \
 343         __bug_table : AT(ADDR(__bug_table) - LOAD_OFFSET) {             \
 344                 VMLINUX_SYMBOL(__start___bug_table) = .;                \
 345 -               *(__bug_table)                                          \
 346 +               KEEP(*(__bug_table))                                    \
 347                 VMLINUX_SYMBOL(__stop___bug_table) = .;                 \
 348         }
 349  #else
 350 @@ -607,7 +608,7 @@
 351         . = ALIGN(4);                                                   \
 352         .tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) {               \
 353                 VMLINUX_SYMBOL(__tracedata_start) = .;                  \
 354 -               *(.tracedata)                                           \
 355 +               KEEP(*(.tracedata))                                     \
 356                 VMLINUX_SYMBOL(__tracedata_end) = .;                    \
 357         }
 358  #else
 359 @@ -624,17 +625,17 @@
 360  #define INIT_SETUP(initsetup_align)                                    \
 361                 . = ALIGN(initsetup_align);                             \
 362                 VMLINUX_SYMBOL(__setup_start) = .;                      \
 363 -               *(.init.setup)                                          \
 364 +               KEEP(*(.init.setup))                                    \
 365                 VMLINUX_SYMBOL(__setup_end) = .;
 366
 367  #define INIT_CALLS_LEVEL(level)                                                \
 368                 VMLINUX_SYMBOL(__initcall##level##_start) = .;          \
 369 -               *(.initcall##level##.init)                              \
 370 -               *(.initcall##level##s.init)                             \
 371 +               KEEP(*(.initcall##level##.init))                        \
 372 +               KEEP(*(.initcall##level##s.init))                       \
 373
 374  #define INIT_CALLS                                                     \
 375                 VMLINUX_SYMBOL(__initcall_start) = .;                   \
 376 -               *(.initcallearly.init)                                  \
 377 +               KEEP(*(.initcallearly.init))                            \
 378                 INIT_CALLS_LEVEL(0)                                     \
 379                 INIT_CALLS_LEVEL(1)                                     \
 380                 INIT_CALLS_LEVEL(2)                                     \
 381 @@ -648,21 +649,21 @@
 382
 383  #define CON_INITCALL                                                   \
 384                 VMLINUX_SYMBOL(__con_initcall_start) = .;               \
 385 -               *(.con_initcall.init)                                   \
 386 +               KEEP(*(.con_initcall.init))                             \
 387                 VMLINUX_SYMBOL(__con_initcall_end) = .;
 388
 389  #define SECURITY_INITCALL                                              \
 390                 VMLINUX_SYMBOL(__security_initcall_start) = .;          \
 391 -               *(.security_initcall.init)                              \
 392 +               KEEP(*(.security_initcall.init))                        \
 393                 VMLINUX_SYMBOL(__security_initcall_end) = .;
 394
 395  #ifdef CONFIG_BLK_DEV_INITRD
 396  #define INIT_RAM_FS                                                    \
 397         . = ALIGN(4);                                                   \
 398         VMLINUX_SYMBOL(__initramfs_start) = .;                          \
 399 -       *(.init.ramfs)                                                  \
 400 +       KEEP(*(.init.ramfs))                                            \
 401         . = ALIGN(8);                                                   \
 402 -       *(.init.ramfs.info)
 403 +       KEEP(*(.init.ramfs.info))
 404  #else
 405  #define INIT_RAM_FS
 406  #endif
 407 --- a/arch/arm/Makefile
 408 +++ b/arch/arm/Makefile
 409 @@ -18,11 +18,16 @@ ifeq ($(CONFIG_CPU_ENDIAN_BE8),y)
 410  LDFLAGS_vmlinux        += --be8
 411  LDFLAGS_MODULE += --be8
 412  endif
 413 +LDFLAGS_vmlinux += --gc-sections --sort-section=name
 414
 415  OBJCOPYFLAGS   :=-O binary -R .comment -S
 416  GZFLAGS                :=-9
 417  #KBUILD_CFLAGS +=-pipe
 418
 419 +ifndef CONFIG_FUNCTION_TRACER
 420 +KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
 421 +endif
 422 +
 423  # Never generate .eh_frame
 424  KBUILD_CFLAGS  += $(call cc-option,-fno-dwarf2-cfi-asm)
 425
 426 --- a/arch/arm/kernel/vmlinux.lds.S
 427 +++ b/arch/arm/kernel/vmlinux.lds.S
 428 @@ -15,13 +15,13 @@
 429  #define PROC_INFO                                                      \
 430         . = ALIGN(4);                                                   \
 431         VMLINUX_SYMBOL(__proc_info_begin) = .;                          \
 432 -       *(.proc.info.init)                                              \
 433 +       KEEP(*(.proc.info.init))                                        \
 434         VMLINUX_SYMBOL(__proc_info_end) = .;
 435
 436  #define IDMAP_TEXT                                                     \
 437         ALIGN_FUNCTION();                                               \
 438         VMLINUX_SYMBOL(__idmap_text_start) = .;                         \
 439 -       *(.idmap.text)                                                  \
 440 +       KEEP(*(.idmap.text))                                            \
 441         VMLINUX_SYMBOL(__idmap_text_end) = .;                           \
 442         . = ALIGN(32);                                                  \
 443         VMLINUX_SYMBOL(__hyp_idmap_text_start) = .;                     \
 444 @@ -101,7 +101,7 @@ SECTIONS
 445         .text : {                       /* Real text segment            */
 446                 _stext = .;             /* Text and read-only data      */
 447                         __exception_text_start = .;
 448 -                       *(.exception.text)
 449 +                       KEEP(*(.exception.text))
 450                         __exception_text_end = .;
 451                         IRQENTRY_TEXT
 452                         TEXT_TEXT
 453 @@ -129,7 +129,7 @@ SECTIONS
 454         __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
 455                 __start___ex_table = .;
 456  #ifdef CONFIG_MMU
 457 -               *(__ex_table)
 458 +               KEEP(*(__ex_table))
 459  #endif
 460                 __stop___ex_table = .;
 461         }
 462 @@ -141,12 +141,12 @@ SECTIONS
 463         . = ALIGN(8);
 464         .ARM.unwind_idx : {
 465                 __start_unwind_idx = .;
 466 -               *(.ARM.exidx*)
 467 +               KEEP(*(.ARM.exidx*))
 468                 __stop_unwind_idx = .;
 469         }
 470         .ARM.unwind_tab : {
 471                 __start_unwind_tab = .;
 472 -               *(.ARM.extab*)
 473 +               KEEP(*(.ARM.extab*))
 474                 __stop_unwind_tab = .;
 475         }
 476  #endif
 477 @@ -169,14 +169,14 @@ SECTIONS
 478          */
 479         __vectors_start = .;
 480         .vectors 0 : AT(__vectors_start) {
 481 -               *(.vectors)
 482 +               KEEP(*(.vectors))
 483         }
 484         . = __vectors_start + SIZEOF(.vectors);
 485         __vectors_end = .;
 486
 487         __stubs_start = .;
 488         .stubs 0x1000 : AT(__stubs_start) {
 489 -               *(.stubs)
 490 +               KEEP(*(.stubs))
 491         }
 492         . = __stubs_start + SIZEOF(.stubs);
 493         __stubs_end = .;
 494 @@ -190,24 +190,24 @@ SECTIONS
 495         }
 496         .init.arch.info : {
 497                 __arch_info_begin = .;
 498 -               *(.arch.info.init)
 499 +               KEEP(*(.arch.info.init))
 500                 __arch_info_end = .;
 501         }
 502         .init.tagtable : {
 503                 __tagtable_begin = .;
 504 -               *(.taglist.init)
 505 +               KEEP(*(.taglist.init))
 506                 __tagtable_end = .;
 507         }
 508  #ifdef CONFIG_SMP_ON_UP
 509         .init.smpalt : {
 510                 __smpalt_begin = .;
 511 -               *(.alt.smp.init)
 512 +               KEEP(*(.alt.smp.init))
 513                 __smpalt_end = .;
 514         }
 515  #endif
 516         .init.pv_table : {
 517                 __pv_table_begin = .;
 518 -               *(.pv_table)
 519 +               KEEP(*(.pv_table))
 520                 __pv_table_end = .;
 521         }
 522         .init.data : {
 523 --- a/arch/arm/boot/compressed/Makefile
 524 +++ b/arch/arm/boot/compressed/Makefile
 525 @@ -122,6 +122,7 @@ ifeq ($(CONFIG_FUNCTION_TRACER),y)
 526  ORIG_CFLAGS := $(KBUILD_CFLAGS)
 527  KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS))
 528  endif
 529 +KBUILD_CFLAGS_KERNEL := $(patsubst -f%-sections,,$(KBUILD_CFLAGS_KERNEL))
 530
 531  ccflags-y := -fpic -mno-single-pic-base -fno-builtin -I$(obj)
 532  asflags-y := -DZIMAGE