target/linux/generic/patches-3.10/220-gc_sections.patch

   1 From: Felix Fietkau <nbd@openwrt.org>
   2
   3 use -ffunction-sections, -fdata-sections and --gc-sections
   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
  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  cflags-y += -ffreestanding
  29
  30  #
  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 @@ -95,7 +95,7 @@
  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 @@ -103,7 +103,7 @@
  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 @@ -111,7 +111,7 @@
  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 @@ -120,7 +120,7 @@
  81  #ifdef CONFIG_EVENT_TRACING
  82  #define FTRACE_EVENTS()        . = ALIGN(8);                                   \
  83                         VMLINUX_SYMBOL(__start_ftrace_events) = .;      \
  84 -                       *(_ftrace_events)                               \
  85 +                       KEEP(*(_ftrace_events))                         \
  86                         VMLINUX_SYMBOL(__stop_ftrace_events) = .;
  87  #else
  88  #define FTRACE_EVENTS()
  89 @@ -128,7 +128,7 @@
  90
  91  #ifdef CONFIG_TRACING
  92  #define TRACE_PRINTKS() VMLINUX_SYMBOL(__start___trace_bprintk_fmt) = .;      \
  93 -                        *(__trace_printk_fmt) /* Trace_printk fmt' pointer */ \
  94 +                        KEEP(*(__trace_printk_fmt)) /* Trace_printk fmt' pointer */ \
  95                          VMLINUX_SYMBOL(__stop___trace_bprintk_fmt) = .;
  96  #else
  97  #define TRACE_PRINTKS()
  98 @@ -137,7 +137,7 @@
  99  #ifdef CONFIG_FTRACE_SYSCALLS
 100  #define TRACE_SYSCALLS() . = ALIGN(8);                                 \
 101                          VMLINUX_SYMBOL(__start_syscalls_metadata) = .; \
 102 -                        *(__syscalls_metadata)                         \
 103 +                        KEEP(*(__syscalls_metadata))                   \
 104                          VMLINUX_SYMBOL(__stop_syscalls_metadata) = .;
 105  #else
 106  #define TRACE_SYSCALLS()
 107 @@ -146,8 +146,8 @@
 108  #ifdef CONFIG_CLKSRC_OF
 109  #define CLKSRC_OF_TABLES() . = ALIGN(8);                               \
 110                            VMLINUX_SYMBOL(__clksrc_of_table) = .;       \
 111 -                          *(__clksrc_of_table)                         \
 112 -                          *(__clksrc_of_table_end)
 113 +                          KEEP(*(__clksrc_of_table))                   \
 114 +                          KEEP(*(__clksrc_of_table_end))
 115  #else
 116  #define CLKSRC_OF_TABLES()
 117  #endif
 118 @@ -156,8 +156,8 @@
 119  #define IRQCHIP_OF_MATCH_TABLE()                                       \
 120         . = ALIGN(8);                                                   \
 121         VMLINUX_SYMBOL(__irqchip_begin) = .;                            \
 122 -       *(__irqchip_of_table)                                           \
 123 -       *(__irqchip_of_end)
 124 +       KEEP(*(__irqchip_of_table))                                     \
 125 +       KEEP(*(__irqchip_of_end))
 126  #else
 127  #define IRQCHIP_OF_MATCH_TABLE()
 128  #endif
 129 @@ -165,8 +165,8 @@
 130  #ifdef CONFIG_COMMON_CLK
 131  #define CLK_OF_TABLES() . = ALIGN(8);                          \
 132                         VMLINUX_SYMBOL(__clk_of_table) = .;     \
 133 -                       *(__clk_of_table)                       \
 134 -                       *(__clk_of_table_end)
 135 +                       KEEP(*(__clk_of_table))                 \
 136 +                       KEEP(*(__clk_of_table_end))
 137  #else
 138  #define CLK_OF_TABLES()
 139  #endif
 140 @@ -174,7 +174,7 @@
 141  #define KERNEL_DTB()                                                   \
 142         STRUCT_ALIGN();                                                 \
 143         VMLINUX_SYMBOL(__dtb_start) = .;                                \
 144 -       *(.dtb.init.rodata)                                             \
 145 +       KEEP(*(.dtb.init.rodata))                                       \
 146         VMLINUX_SYMBOL(__dtb_end) = .;
 147
 148  /* .data section */
 149 @@ -194,15 +194,16 @@
 150         /* implement dynamic printk debug */                            \
 151         . = ALIGN(8);                                                   \
 152         VMLINUX_SYMBOL(__start___jump_table) = .;                       \
 153 -       *(__jump_table)                                                 \
 154 +       KEEP(*(__jump_table))                                           \
 155         VMLINUX_SYMBOL(__stop___jump_table) = .;                        \
 156         . = ALIGN(8);                                                   \
 157         VMLINUX_SYMBOL(__start___verbose) = .;                          \
 158 -       *(__verbose)                                                    \
 159 +       KEEP(*(__verbose))                                              \
 160         VMLINUX_SYMBOL(__stop___verbose) = .;                           \
 161         LIKELY_PROFILE()                                                \
 162         BRANCH_PROFILE()                                                \
 163 -       TRACE_PRINTKS()
 164 +       TRACE_PRINTKS()                                                 \
 165 +       *(.data.[a-zA-Z_]*)
 166
 167  /*
 168   * Data section helpers
 169 @@ -256,39 +257,39 @@
 170         /* PCI quirks */                                                \
 171         .pci_fixup        : AT(ADDR(.pci_fixup) - LOAD_OFFSET) {        \
 172                 VMLINUX_SYMBOL(__start_pci_fixups_early) = .;           \
 173 -               *(.pci_fixup_early)                                     \
 174 +               KEEP(*(.pci_fixup_early))                               \
 175                 VMLINUX_SYMBOL(__end_pci_fixups_early) = .;             \
 176                 VMLINUX_SYMBOL(__start_pci_fixups_header) = .;          \
 177 -               *(.pci_fixup_header)                                    \
 178 +               KEEP(*(.pci_fixup_header))                              \
 179                 VMLINUX_SYMBOL(__end_pci_fixups_header) = .;            \
 180                 VMLINUX_SYMBOL(__start_pci_fixups_final) = .;           \
 181 -               *(.pci_fixup_final)                                     \
 182 +               KEEP(*(.pci_fixup_final))                               \
 183                 VMLINUX_SYMBOL(__end_pci_fixups_final) = .;             \
 184                 VMLINUX_SYMBOL(__start_pci_fixups_enable) = .;          \
 185 -               *(.pci_fixup_enable)                                    \
 186 +               KEEP(*(.pci_fixup_enable))                              \
 187                 VMLINUX_SYMBOL(__end_pci_fixups_enable) = .;            \
 188                 VMLINUX_SYMBOL(__start_pci_fixups_resume) = .;          \
 189 -               *(.pci_fixup_resume)                                    \
 190 +               KEEP(*(.pci_fixup_resume))                              \
 191                 VMLINUX_SYMBOL(__end_pci_fixups_resume) = .;            \
 192                 VMLINUX_SYMBOL(__start_pci_fixups_resume_early) = .;    \
 193 -               *(.pci_fixup_resume_early)                              \
 194 +               KEEP(*(.pci_fixup_resume_early))                        \
 195                 VMLINUX_SYMBOL(__end_pci_fixups_resume_early) = .;      \
 196                 VMLINUX_SYMBOL(__start_pci_fixups_suspend) = .;         \
 197 -               *(.pci_fixup_suspend)                                   \
 198 +               KEEP(*(.pci_fixup_suspend))                             \
 199                 VMLINUX_SYMBOL(__end_pci_fixups_suspend) = .;           \
 200         }                                                               \
 201                                                                         \
 202         /* Built-in firmware blobs */                                   \
 203         .builtin_fw        : AT(ADDR(.builtin_fw) - LOAD_OFFSET) {      \
 204                 VMLINUX_SYMBOL(__start_builtin_fw) = .;                 \
 205 -               *(.builtin_fw)                                          \
 206 +               KEEP(*(.builtin_fw))                                    \
 207                 VMLINUX_SYMBOL(__end_builtin_fw) = .;                   \
 208         }                                                               \
 209                                                                         \
 210         /* RapidIO route ops */                                         \
 211         .rio_ops        : AT(ADDR(.rio_ops) - LOAD_OFFSET) {            \
 212                 VMLINUX_SYMBOL(__start_rio_switch_ops) = .;             \
 213 -               *(.rio_switch_ops)                                      \
 214 +               KEEP(*(.rio_switch_ops))                                \
 215                 VMLINUX_SYMBOL(__end_rio_switch_ops) = .;               \
 216         }                                                               \
 217                                                                         \
 218 @@ -297,49 +298,49 @@
 219         /* Kernel symbol table: Normal symbols */                       \
 220         __ksymtab         : AT(ADDR(__ksymtab) - LOAD_OFFSET) {         \
 221                 VMLINUX_SYMBOL(__start___ksymtab) = .;                  \
 222 -               *(SORT(___ksymtab+*))                                   \
 223 +               KEEP(*(SORT(___ksymtab+*)))                             \
 224                 VMLINUX_SYMBOL(__stop___ksymtab) = .;                   \
 225         }                                                               \
 226                                                                         \
 227         /* Kernel symbol table: GPL-only symbols */                     \
 228         __ksymtab_gpl     : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) {     \
 229                 VMLINUX_SYMBOL(__start___ksymtab_gpl) = .;              \
 230 -               *(SORT(___ksymtab_gpl+*))                               \
 231 +               KEEP(*(SORT(___ksymtab_gpl+*)))                         \
 232                 VMLINUX_SYMBOL(__stop___ksymtab_gpl) = .;               \
 233         }                                                               \
 234                                                                         \
 235         /* Kernel symbol table: Normal unused symbols */                \
 236         __ksymtab_unused  : AT(ADDR(__ksymtab_unused) - LOAD_OFFSET) {  \
 237                 VMLINUX_SYMBOL(__start___ksymtab_unused) = .;           \
 238 -               *(SORT(___ksymtab_unused+*))                            \
 239 +               KEEP(*(SORT(___ksymtab_unused+*)))                      \
 240                 VMLINUX_SYMBOL(__stop___ksymtab_unused) = .;            \
 241         }                                                               \
 242                                                                         \
 243         /* Kernel symbol table: GPL-only unused symbols */              \
 244         __ksymtab_unused_gpl : AT(ADDR(__ksymtab_unused_gpl) - LOAD_OFFSET) { \
 245                 VMLINUX_SYMBOL(__start___ksymtab_unused_gpl) = .;       \
 246 -               *(SORT(___ksymtab_unused_gpl+*))                        \
 247 +               KEEP(*(SORT(___ksymtab_unused_gpl+*)))                  \
 248                 VMLINUX_SYMBOL(__stop___ksymtab_unused_gpl) = .;        \
 249         }                                                               \
 250                                                                         \
 251         /* Kernel symbol table: GPL-future-only symbols */              \
 252         __ksymtab_gpl_future : AT(ADDR(__ksymtab_gpl_future) - LOAD_OFFSET) { \
 253                 VMLINUX_SYMBOL(__start___ksymtab_gpl_future) = .;       \
 254 -               *(SORT(___ksymtab_gpl_future+*))                        \
 255 +               KEEP(*(SORT(___ksymtab_gpl_future+*)))                  \
 256                 VMLINUX_SYMBOL(__stop___ksymtab_gpl_future) = .;        \
 257         }                                                               \
 258                                                                         \
 259         /* Kernel symbol table: Normal symbols */                       \
 260         __kcrctab         : AT(ADDR(__kcrctab) - LOAD_OFFSET) {         \
 261                 VMLINUX_SYMBOL(__start___kcrctab) = .;                  \
 262 -               *(SORT(___kcrctab+*))                                   \
 263 +               KEEP(*(SORT(___kcrctab+*)))                             \
 264                 VMLINUX_SYMBOL(__stop___kcrctab) = .;                   \
 265         }                                                               \
 266                                                                         \
 267         /* Kernel symbol table: GPL-only symbols */                     \
 268         __kcrctab_gpl     : AT(ADDR(__kcrctab_gpl) - LOAD_OFFSET) {     \
 269                 VMLINUX_SYMBOL(__start___kcrctab_gpl) = .;              \
 270 -               *(SORT(___kcrctab_gpl+*))                               \
 271 +               KEEP(*(SORT(___kcrctab_gpl+*)))                         \
 272                 VMLINUX_SYMBOL(__stop___kcrctab_gpl) = .;               \
 273         }                                                               \
 274                                                                         \
 275 @@ -353,14 +354,14 @@
 276         /* Kernel symbol table: GPL-only unused symbols */              \
 277         __kcrctab_unused_gpl : AT(ADDR(__kcrctab_unused_gpl) - LOAD_OFFSET) { \
 278                 VMLINUX_SYMBOL(__start___kcrctab_unused_gpl) = .;       \
 279 -               *(SORT(___kcrctab_unused_gpl+*))                        \
 280 +               KEEP(*(SORT(___kcrctab_unused_gpl+*)))                  \
 281                 VMLINUX_SYMBOL(__stop___kcrctab_unused_gpl) = .;        \
 282         }                                                               \
 283                                                                         \
 284         /* Kernel symbol table: GPL-future-only symbols */              \
 285         __kcrctab_gpl_future : AT(ADDR(__kcrctab_gpl_future) - LOAD_OFFSET) { \
 286                 VMLINUX_SYMBOL(__start___kcrctab_gpl_future) = .;       \
 287 -               *(SORT(___kcrctab_gpl_future+*))                        \
 288 +               KEEP(*(SORT(___kcrctab_gpl_future+*)))                  \
 289                 VMLINUX_SYMBOL(__stop___kcrctab_gpl_future) = .;        \
 290         }                                                               \
 291                                                                         \
 292 @@ -383,14 +384,14 @@
 293         /* Built-in module parameters. */                               \
 294         __param : AT(ADDR(__param) - LOAD_OFFSET) {                     \
 295                 VMLINUX_SYMBOL(__start___param) = .;                    \
 296 -               *(__param)                                              \
 297 +               KEEP(*(__param))                                        \
 298                 VMLINUX_SYMBOL(__stop___param) = .;                     \
 299         }                                                               \
 300                                                                         \
 301         /* Built-in module versions. */                                 \
 302         __modver : AT(ADDR(__modver) - LOAD_OFFSET) {                   \
 303                 VMLINUX_SYMBOL(__start___modver) = .;                   \
 304 -               *(__modver)                                             \
 305 +               KEEP(*(__modver))                                       \
 306                 VMLINUX_SYMBOL(__stop___modver) = .;                    \
 307                 . = ALIGN((align));                                     \
 308                 VMLINUX_SYMBOL(__end_rodata) = .;                       \
 309 @@ -450,7 +451,7 @@
 310  #define ENTRY_TEXT                                                     \
 311                 ALIGN_FUNCTION();                                       \
 312                 VMLINUX_SYMBOL(__entry_text_start) = .;                 \
 313 -               *(.entry.text)                                          \
 314 +               KEEP(*(.entry.text))                                    \
 315                 VMLINUX_SYMBOL(__entry_text_end) = .;
 316
 317  #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 318 @@ -478,7 +479,7 @@
 319         . = ALIGN(align);                                               \
 320         __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {               \
 321                 VMLINUX_SYMBOL(__start___ex_table) = .;                 \
 322 -               *(__ex_table)                                           \
 323 +               KEEP(*(__ex_table))                                             \
 324                 VMLINUX_SYMBOL(__stop___ex_table) = .;                  \
 325         }
 326
 327 @@ -494,7 +495,7 @@
 328  #ifdef CONFIG_CONSTRUCTORS
 329  #define KERNEL_CTORS() . = ALIGN(8);                      \
 330                         VMLINUX_SYMBOL(__ctors_start) = .; \
 331 -                       *(.ctors)                          \
 332 +                       KEEP(*(.ctors))                    \
 333                         VMLINUX_SYMBOL(__ctors_end) = .;
 334  #else
 335  #define KERNEL_CTORS()
 336 @@ -550,7 +551,7 @@
 337  #define SBSS(sbss_align)                                               \
 338         . = ALIGN(sbss_align);                                          \
 339         .sbss : AT(ADDR(.sbss) - LOAD_OFFSET) {                         \
 340 -               *(.sbss)                                                \
 341 +               *(.sbss .sbss.*)                                        \
 342                 *(.scommon)                                             \
 343         }
 344
 345 @@ -568,7 +569,7 @@
 346                 BSS_FIRST_SECTIONS                                      \
 347                 *(.bss..page_aligned)                                   \
 348                 *(.dynbss)                                              \
 349 -               *(.bss)                                                 \
 350 +               *(.bss .bss.*)                                          \
 351                 *(COMMON)                                               \
 352         }
 353
 354 @@ -617,7 +618,7 @@
 355         . = ALIGN(8);                                                   \
 356         __bug_table : AT(ADDR(__bug_table) - LOAD_OFFSET) {             \
 357                 VMLINUX_SYMBOL(__start___bug_table) = .;                \
 358 -               *(__bug_table)                                          \
 359 +               KEEP(*(__bug_table))                                    \
 360                 VMLINUX_SYMBOL(__stop___bug_table) = .;                 \
 361         }
 362  #else
 363 @@ -629,7 +630,7 @@
 364         . = ALIGN(4);                                                   \
 365         .tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) {               \
 366                 VMLINUX_SYMBOL(__tracedata_start) = .;                  \
 367 -               *(.tracedata)                                           \
 368 +               KEEP(*(.tracedata))                                     \
 369                 VMLINUX_SYMBOL(__tracedata_end) = .;                    \
 370         }
 371  #else
 372 @@ -646,17 +647,17 @@
 373  #define INIT_SETUP(initsetup_align)                                    \
 374                 . = ALIGN(initsetup_align);                             \
 375                 VMLINUX_SYMBOL(__setup_start) = .;                      \
 376 -               *(.init.setup)                                          \
 377 +               KEEP(*(.init.setup))                                    \
 378                 VMLINUX_SYMBOL(__setup_end) = .;
 379
 380  #define INIT_CALLS_LEVEL(level)                                                \
 381                 VMLINUX_SYMBOL(__initcall##level##_start) = .;          \
 382 -               *(.initcall##level##.init)                              \
 383 -               *(.initcall##level##s.init)                             \
 384 +               KEEP(*(.initcall##level##.init))                        \
 385 +               KEEP(*(.initcall##level##s.init))                       \
 386
 387  #define INIT_CALLS                                                     \
 388                 VMLINUX_SYMBOL(__initcall_start) = .;                   \
 389 -               *(.initcallearly.init)                                  \
 390 +               KEEP(*(.initcallearly.init))                            \
 391                 INIT_CALLS_LEVEL(0)                                     \
 392                 INIT_CALLS_LEVEL(1)                                     \
 393                 INIT_CALLS_LEVEL(2)                                     \
 394 @@ -670,21 +671,21 @@
 395
 396  #define CON_INITCALL                                                   \
 397                 VMLINUX_SYMBOL(__con_initcall_start) = .;               \
 398 -               *(.con_initcall.init)                                   \
 399 +               KEEP(*(.con_initcall.init))                             \
 400                 VMLINUX_SYMBOL(__con_initcall_end) = .;
 401
 402  #define SECURITY_INITCALL                                              \
 403                 VMLINUX_SYMBOL(__security_initcall_start) = .;          \
 404 -               *(.security_initcall.init)                              \
 405 +               KEEP(*(.security_initcall.init))                        \
 406                 VMLINUX_SYMBOL(__security_initcall_end) = .;
 407
 408  #ifdef CONFIG_BLK_DEV_INITRD
 409  #define INIT_RAM_FS                                                    \
 410         . = ALIGN(4);                                                   \
 411         VMLINUX_SYMBOL(__initramfs_start) = .;                          \
 412 -       *(.init.ramfs)                                                  \
 413 +       KEEP(*(.init.ramfs))                                            \
 414         . = ALIGN(8);                                                   \
 415 -       *(.init.ramfs.info)
 416 +       KEEP(*(.init.ramfs.info))
 417  #else
 418  #define INIT_RAM_FS
 419  #endif
 420 --- a/arch/arm/Makefile
 421 +++ b/arch/arm/Makefile
 422 @@ -17,11 +17,16 @@ LDFLAGS_vmlinux     :=-p --no-undefined -X
 423  ifeq ($(CONFIG_CPU_ENDIAN_BE8),y)
 424  LDFLAGS_vmlinux        += --be8
 425  endif
 426 +LDFLAGS_vmlinux += --gc-sections
 427
 428  OBJCOPYFLAGS   :=-O binary -R .comment -S
 429  GZFLAGS                :=-9
 430  #KBUILD_CFLAGS +=-pipe
 431
 432 +ifndef CONFIG_FUNCTION_TRACER
 433 +KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
 434 +endif
 435 +
 436  # Never generate .eh_frame
 437  KBUILD_CFLAGS  += $(call cc-option,-fno-dwarf2-cfi-asm)
 438
 439 --- a/arch/arm/kernel/vmlinux.lds.S
 440 +++ b/arch/arm/kernel/vmlinux.lds.S
 441 @@ -12,13 +12,13 @@
 442  #define PROC_INFO                                                      \
 443         . = ALIGN(4);                                                   \
 444         VMLINUX_SYMBOL(__proc_info_begin) = .;                          \
 445 -       *(.proc.info.init)                                              \
 446 +       KEEP(*(.proc.info.init))                                        \
 447         VMLINUX_SYMBOL(__proc_info_end) = .;
 448
 449  #define IDMAP_TEXT                                                     \
 450         ALIGN_FUNCTION();                                               \
 451         VMLINUX_SYMBOL(__idmap_text_start) = .;                         \
 452 -       *(.idmap.text)                                                  \
 453 +       KEEP(*(.idmap.text))                                            \
 454         VMLINUX_SYMBOL(__idmap_text_end) = .;                           \
 455         . = ALIGN(32);                                                  \
 456         VMLINUX_SYMBOL(__hyp_idmap_text_start) = .;                     \
 457 @@ -97,7 +97,7 @@ SECTIONS
 458         .text : {                       /* Real text segment            */
 459                 _stext = .;             /* Text and read-only data      */
 460                         __exception_text_start = .;
 461 -                       *(.exception.text)
 462 +                       KEEP(*(.exception.text))
 463                         __exception_text_end = .;
 464                         IRQENTRY_TEXT
 465                         TEXT_TEXT
 466 @@ -122,7 +122,7 @@ SECTIONS
 467         __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
 468                 __start___ex_table = .;
 469  #ifdef CONFIG_MMU
 470 -               *(__ex_table)
 471 +               KEEP(*(__ex_table))
 472  #endif
 473                 __stop___ex_table = .;
 474         }
 475 @@ -134,12 +134,12 @@ SECTIONS
 476         . = ALIGN(8);
 477         .ARM.unwind_idx : {
 478                 __start_unwind_idx = .;
 479 -               *(.ARM.exidx*)
 480 +               KEEP(*(.ARM.exidx*))
 481                 __stop_unwind_idx = .;
 482         }
 483         .ARM.unwind_tab : {
 484                 __start_unwind_tab = .;
 485 -               *(.ARM.extab*)
 486 +               KEEP(*(.ARM.extab*))
 487                 __stop_unwind_tab = .;
 488         }
 489  #endif
 490 @@ -158,14 +158,14 @@ SECTIONS
 491          */
 492         __vectors_start = .;
 493         .vectors 0 : AT(__vectors_start) {
 494 -               *(.vectors)
 495 +               KEEP(*(.vectors))
 496         }
 497         . = __vectors_start + SIZEOF(.vectors);
 498         __vectors_end = .;
 499
 500         __stubs_start = .;
 501         .stubs 0x1000 : AT(__stubs_start) {
 502 -               *(.stubs)
 503 +               KEEP(*(.stubs))
 504         }
 505         . = __stubs_start + SIZEOF(.stubs);
 506         __stubs_end = .;
 507 @@ -179,24 +179,24 @@ SECTIONS
 508         }
 509         .init.arch.info : {
 510                 __arch_info_begin = .;
 511 -               *(.arch.info.init)
 512 +               KEEP(*(.arch.info.init))
 513                 __arch_info_end = .;
 514         }
 515         .init.tagtable : {
 516                 __tagtable_begin = .;
 517 -               *(.taglist.init)
 518 +               KEEP(*(.taglist.init))
 519                 __tagtable_end = .;
 520         }
 521  #ifdef CONFIG_SMP_ON_UP
 522         .init.smpalt : {
 523                 __smpalt_begin = .;
 524 -               *(.alt.smp.init)
 525 +               KEEP(*(.alt.smp.init))
 526                 __smpalt_end = .;
 527         }
 528  #endif
 529         .init.pv_table : {
 530                 __pv_table_begin = .;
 531 -               *(.pv_table)
 532 +               KEEP(*(.pv_table))
 533                 __pv_table_end = .;
 534         }
 535         .init.data : {
 536 --- a/arch/arm/boot/compressed/Makefile
 537 +++ b/arch/arm/boot/compressed/Makefile
 538 @@ -123,6 +123,7 @@ ifeq ($(CONFIG_FUNCTION_TRACER),y)
 539  ORIG_CFLAGS := $(KBUILD_CFLAGS)
 540  KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS))
 541  endif
 542 +KBUILD_CFLAGS_KERNEL := $(patsubst -f%-sections,,$(KBUILD_CFLAGS_KERNEL))
 543
 544  ccflags-y := -fpic -mno-single-pic-base -fno-builtin -I$(obj)
 545  asflags-y := -DZIMAGE