target/linux/generic/patches-3.14/220-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  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 @@ -87,7 +87,7 @@
  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 @@ -95,7 +95,7 @@
  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 @@ -103,7 +103,7 @@
  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 @@ -112,7 +112,7 @@
  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 @@ -120,7 +120,7 @@
  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  #define TRACEPOINT_STR() VMLINUX_SYMBOL(__start___tracepoint_str) = .; \
  97                          *(__tracepoint_str) /* Trace_printk fmt' pointer */ \
  98 @@ -133,7 +133,7 @@
  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 @@ -142,8 +142,8 @@
 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 @@ -152,8 +152,8 @@
 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 @@ -161,8 +161,8 @@
 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 @@ -170,7 +170,7 @@
 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 @@ -186,16 +186,17 @@
 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 -       TRACEPOINT_STR()
 165 +       TRACEPOINT_STR()                                                \
 166 +       *(.data.[a-zA-Z_]*)
 167
 168  /*
 169   * Data section helpers
 170 @@ -249,32 +250,32 @@
 171         /* PCI quirks */                                                \
 172         .pci_fixup        : AT(ADDR(.pci_fixup) - LOAD_OFFSET) {        \
 173                 VMLINUX_SYMBOL(__start_pci_fixups_early) = .;           \
 174 -               *(.pci_fixup_early)                                     \
 175 +               KEEP(*(.pci_fixup_early))                               \
 176                 VMLINUX_SYMBOL(__end_pci_fixups_early) = .;             \
 177                 VMLINUX_SYMBOL(__start_pci_fixups_header) = .;          \
 178 -               *(.pci_fixup_header)                                    \
 179 +               KEEP(*(.pci_fixup_header))                              \
 180                 VMLINUX_SYMBOL(__end_pci_fixups_header) = .;            \
 181                 VMLINUX_SYMBOL(__start_pci_fixups_final) = .;           \
 182 -               *(.pci_fixup_final)                                     \
 183 +               KEEP(*(.pci_fixup_final))                               \
 184                 VMLINUX_SYMBOL(__end_pci_fixups_final) = .;             \
 185                 VMLINUX_SYMBOL(__start_pci_fixups_enable) = .;          \
 186 -               *(.pci_fixup_enable)                                    \
 187 +               KEEP(*(.pci_fixup_enable))                              \
 188                 VMLINUX_SYMBOL(__end_pci_fixups_enable) = .;            \
 189                 VMLINUX_SYMBOL(__start_pci_fixups_resume) = .;          \
 190 -               *(.pci_fixup_resume)                                    \
 191 +               KEEP(*(.pci_fixup_resume))                              \
 192                 VMLINUX_SYMBOL(__end_pci_fixups_resume) = .;            \
 193                 VMLINUX_SYMBOL(__start_pci_fixups_resume_early) = .;    \
 194 -               *(.pci_fixup_resume_early)                              \
 195 +               KEEP(*(.pci_fixup_resume_early))                        \
 196                 VMLINUX_SYMBOL(__end_pci_fixups_resume_early) = .;      \
 197                 VMLINUX_SYMBOL(__start_pci_fixups_suspend) = .;         \
 198 -               *(.pci_fixup_suspend)                                   \
 199 +               KEEP(*(.pci_fixup_suspend))                             \
 200                 VMLINUX_SYMBOL(__end_pci_fixups_suspend) = .;           \
 201         }                                                               \
 202                                                                         \
 203         /* Built-in firmware blobs */                                   \
 204         .builtin_fw        : AT(ADDR(.builtin_fw) - LOAD_OFFSET) {      \
 205                 VMLINUX_SYMBOL(__start_builtin_fw) = .;                 \
 206 -               *(.builtin_fw)                                          \
 207 +               KEEP(*(.builtin_fw))                                    \
 208                 VMLINUX_SYMBOL(__end_builtin_fw) = .;                   \
 209         }                                                               \
 210                                                                         \
 211 @@ -283,49 +284,49 @@
 212         /* Kernel symbol table: Normal symbols */                       \
 213         __ksymtab         : AT(ADDR(__ksymtab) - LOAD_OFFSET) {         \
 214                 VMLINUX_SYMBOL(__start___ksymtab) = .;                  \
 215 -               *(SORT(___ksymtab+*))                                   \
 216 +               KEEP(*(SORT(___ksymtab+*)))                             \
 217                 VMLINUX_SYMBOL(__stop___ksymtab) = .;                   \
 218         }                                                               \
 219                                                                         \
 220         /* Kernel symbol table: GPL-only symbols */                     \
 221         __ksymtab_gpl     : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) {     \
 222                 VMLINUX_SYMBOL(__start___ksymtab_gpl) = .;              \
 223 -               *(SORT(___ksymtab_gpl+*))                               \
 224 +               KEEP(*(SORT(___ksymtab_gpl+*)))                         \
 225                 VMLINUX_SYMBOL(__stop___ksymtab_gpl) = .;               \
 226         }                                                               \
 227                                                                         \
 228         /* Kernel symbol table: Normal unused symbols */                \
 229         __ksymtab_unused  : AT(ADDR(__ksymtab_unused) - LOAD_OFFSET) {  \
 230                 VMLINUX_SYMBOL(__start___ksymtab_unused) = .;           \
 231 -               *(SORT(___ksymtab_unused+*))                            \
 232 +               KEEP(*(SORT(___ksymtab_unused+*)))                      \
 233                 VMLINUX_SYMBOL(__stop___ksymtab_unused) = .;            \
 234         }                                                               \
 235                                                                         \
 236         /* Kernel symbol table: GPL-only unused symbols */              \
 237         __ksymtab_unused_gpl : AT(ADDR(__ksymtab_unused_gpl) - LOAD_OFFSET) { \
 238                 VMLINUX_SYMBOL(__start___ksymtab_unused_gpl) = .;       \
 239 -               *(SORT(___ksymtab_unused_gpl+*))                        \
 240 +               KEEP(*(SORT(___ksymtab_unused_gpl+*)))                  \
 241                 VMLINUX_SYMBOL(__stop___ksymtab_unused_gpl) = .;        \
 242         }                                                               \
 243                                                                         \
 244         /* Kernel symbol table: GPL-future-only symbols */              \
 245         __ksymtab_gpl_future : AT(ADDR(__ksymtab_gpl_future) - LOAD_OFFSET) { \
 246                 VMLINUX_SYMBOL(__start___ksymtab_gpl_future) = .;       \
 247 -               *(SORT(___ksymtab_gpl_future+*))                        \
 248 +               KEEP(*(SORT(___ksymtab_gpl_future+*)))                  \
 249                 VMLINUX_SYMBOL(__stop___ksymtab_gpl_future) = .;        \
 250         }                                                               \
 251                                                                         \
 252         /* Kernel symbol table: Normal symbols */                       \
 253         __kcrctab         : AT(ADDR(__kcrctab) - LOAD_OFFSET) {         \
 254                 VMLINUX_SYMBOL(__start___kcrctab) = .;                  \
 255 -               *(SORT(___kcrctab+*))                                   \
 256 +               KEEP(*(SORT(___kcrctab+*)))                             \
 257                 VMLINUX_SYMBOL(__stop___kcrctab) = .;                   \
 258         }                                                               \
 259                                                                         \
 260         /* Kernel symbol table: GPL-only symbols */                     \
 261         __kcrctab_gpl     : AT(ADDR(__kcrctab_gpl) - LOAD_OFFSET) {     \
 262                 VMLINUX_SYMBOL(__start___kcrctab_gpl) = .;              \
 263 -               *(SORT(___kcrctab_gpl+*))                               \
 264 +               KEEP(*(SORT(___kcrctab_gpl+*)))                         \
 265                 VMLINUX_SYMBOL(__stop___kcrctab_gpl) = .;               \
 266         }                                                               \
 267                                                                         \
 268 @@ -339,14 +340,14 @@
 269         /* Kernel symbol table: GPL-only unused symbols */              \
 270         __kcrctab_unused_gpl : AT(ADDR(__kcrctab_unused_gpl) - LOAD_OFFSET) { \
 271                 VMLINUX_SYMBOL(__start___kcrctab_unused_gpl) = .;       \
 272 -               *(SORT(___kcrctab_unused_gpl+*))                        \
 273 +               KEEP(*(SORT(___kcrctab_unused_gpl+*)))                  \
 274                 VMLINUX_SYMBOL(__stop___kcrctab_unused_gpl) = .;        \
 275         }                                                               \
 276                                                                         \
 277         /* Kernel symbol table: GPL-future-only symbols */              \
 278         __kcrctab_gpl_future : AT(ADDR(__kcrctab_gpl_future) - LOAD_OFFSET) { \
 279                 VMLINUX_SYMBOL(__start___kcrctab_gpl_future) = .;       \
 280 -               *(SORT(___kcrctab_gpl_future+*))                        \
 281 +               KEEP(*(SORT(___kcrctab_gpl_future+*)))                  \
 282                 VMLINUX_SYMBOL(__stop___kcrctab_gpl_future) = .;        \
 283         }                                                               \
 284                                                                         \
 285 @@ -365,14 +366,14 @@
 286         /* Built-in module parameters. */                               \
 287         __param : AT(ADDR(__param) - LOAD_OFFSET) {                     \
 288                 VMLINUX_SYMBOL(__start___param) = .;                    \
 289 -               *(__param)                                              \
 290 +               KEEP(*(__param))                                        \
 291                 VMLINUX_SYMBOL(__stop___param) = .;                     \
 292         }                                                               \
 293                                                                         \
 294         /* Built-in module versions. */                                 \
 295         __modver : AT(ADDR(__modver) - LOAD_OFFSET) {                   \
 296                 VMLINUX_SYMBOL(__start___modver) = .;                   \
 297 -               *(__modver)                                             \
 298 +               KEEP(*(__modver))                                       \
 299                 VMLINUX_SYMBOL(__stop___modver) = .;                    \
 300                 . = ALIGN((align));                                     \
 301                 VMLINUX_SYMBOL(__end_rodata) = .;                       \
 302 @@ -428,7 +429,7 @@
 303  #define ENTRY_TEXT                                                     \
 304                 ALIGN_FUNCTION();                                       \
 305                 VMLINUX_SYMBOL(__entry_text_start) = .;                 \
 306 -               *(.entry.text)                                          \
 307 +               KEEP(*(.entry.text))                                    \
 308                 VMLINUX_SYMBOL(__entry_text_end) = .;
 309
 310  #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 311 @@ -456,7 +457,7 @@
 312         . = ALIGN(align);                                               \
 313         __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {               \
 314                 VMLINUX_SYMBOL(__start___ex_table) = .;                 \
 315 -               *(__ex_table)                                           \
 316 +               KEEP(*(__ex_table))                                             \
 317                 VMLINUX_SYMBOL(__stop___ex_table) = .;                  \
 318         }
 319
 320 @@ -472,8 +473,8 @@
 321  #ifdef CONFIG_CONSTRUCTORS
 322  #define KERNEL_CTORS() . = ALIGN(8);                      \
 323                         VMLINUX_SYMBOL(__ctors_start) = .; \
 324 -                       *(.ctors)                          \
 325 -                       *(.init_array)                     \
 326 +                       KEEP(*(.ctors))                    \
 327 +                       KEEP(*(.init_array))               \
 328                         VMLINUX_SYMBOL(__ctors_end) = .;
 329  #else
 330  #define KERNEL_CTORS()
 331 @@ -517,7 +518,7 @@
 332  #define SBSS(sbss_align)                                               \
 333         . = ALIGN(sbss_align);                                          \
 334         .sbss : AT(ADDR(.sbss) - LOAD_OFFSET) {                         \
 335 -               *(.sbss)                                                \
 336 +               *(.sbss .sbss.*)                                        \
 337                 *(.scommon)                                             \
 338         }
 339
 340 @@ -535,7 +536,7 @@
 341                 BSS_FIRST_SECTIONS                                      \
 342                 *(.bss..page_aligned)                                   \
 343                 *(.dynbss)                                              \
 344 -               *(.bss)                                                 \
 345 +               *(.bss .bss.*)                                          \
 346                 *(COMMON)                                               \
 347         }
 348
 349 @@ -584,7 +585,7 @@
 350         . = ALIGN(8);                                                   \
 351         __bug_table : AT(ADDR(__bug_table) - LOAD_OFFSET) {             \
 352                 VMLINUX_SYMBOL(__start___bug_table) = .;                \
 353 -               *(__bug_table)                                          \
 354 +               KEEP(*(__bug_table))    \
 355                 VMLINUX_SYMBOL(__stop___bug_table) = .;                 \
 356         }
 357  #else
 358 @@ -596,7 +597,7 @@
 359         . = ALIGN(4);                                                   \
 360         .tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) {               \
 361                 VMLINUX_SYMBOL(__tracedata_start) = .;                  \
 362 -               *(.tracedata)                                           \
 363 +               KEEP(*(.tracedata))                                     \
 364                 VMLINUX_SYMBOL(__tracedata_end) = .;                    \
 365         }
 366  #else
 367 @@ -613,17 +614,17 @@
 368  #define INIT_SETUP(initsetup_align)                                    \
 369                 . = ALIGN(initsetup_align);                             \
 370                 VMLINUX_SYMBOL(__setup_start) = .;                      \
 371 -               *(.init.setup)                                          \
 372 +               KEEP(*(.init.setup))                                    \
 373                 VMLINUX_SYMBOL(__setup_end) = .;
 374
 375  #define INIT_CALLS_LEVEL(level)                                                \
 376                 VMLINUX_SYMBOL(__initcall##level##_start) = .;          \
 377 -               *(.initcall##level##.init)                              \
 378 -               *(.initcall##level##s.init)                             \
 379 +               KEEP(*(.initcall##level##.init))                        \
 380 +               KEEP(*(.initcall##level##s.init))                       \
 381
 382  #define INIT_CALLS                                                     \
 383                 VMLINUX_SYMBOL(__initcall_start) = .;                   \
 384 -               *(.initcallearly.init)                                  \
 385 +               KEEP(*(.initcallearly.init))                            \
 386                 INIT_CALLS_LEVEL(0)                                     \
 387                 INIT_CALLS_LEVEL(1)                                     \
 388                 INIT_CALLS_LEVEL(2)                                     \
 389 @@ -637,21 +638,21 @@
 390
 391  #define CON_INITCALL                                                   \
 392                 VMLINUX_SYMBOL(__con_initcall_start) = .;               \
 393 -               *(.con_initcall.init)                                   \
 394 +               KEEP(*(.con_initcall.init))                             \
 395                 VMLINUX_SYMBOL(__con_initcall_end) = .;
 396
 397  #define SECURITY_INITCALL                                              \
 398                 VMLINUX_SYMBOL(__security_initcall_start) = .;          \
 399 -               *(.security_initcall.init)                              \
 400 +               KEEP(*(.security_initcall.init))                        \
 401                 VMLINUX_SYMBOL(__security_initcall_end) = .;
 402
 403  #ifdef CONFIG_BLK_DEV_INITRD
 404  #define INIT_RAM_FS                                                    \
 405         . = ALIGN(4);                                                   \
 406         VMLINUX_SYMBOL(__initramfs_start) = .;                          \
 407 -       *(.init.ramfs)                                                  \
 408 +       KEEP(*(.init.ramfs))                                            \
 409         . = ALIGN(8);                                                   \
 410 -       *(.init.ramfs.info)
 411 +       KEEP(*(.init.ramfs.info))
 412  #else
 413  #define INIT_RAM_FS
 414  #endif
 415 --- a/arch/arm/Makefile
 416 +++ b/arch/arm/Makefile
 417 @@ -18,11 +18,16 @@ ifeq ($(CONFIG_CPU_ENDIAN_BE8),y)
 418  LDFLAGS_vmlinux        += --be8
 419  LDFLAGS_MODULE += --be8
 420  endif
 421 +LDFLAGS_vmlinux += --gc-sections --sort-section=name
 422
 423  OBJCOPYFLAGS   :=-O binary -R .comment -S
 424  GZFLAGS                :=-9
 425  #KBUILD_CFLAGS +=-pipe
 426
 427 +ifndef CONFIG_FUNCTION_TRACER
 428 +KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
 429 +endif
 430 +
 431  # Never generate .eh_frame
 432  KBUILD_CFLAGS  += $(call cc-option,-fno-dwarf2-cfi-asm)
 433
 434 --- a/arch/arm/kernel/vmlinux.lds.S
 435 +++ b/arch/arm/kernel/vmlinux.lds.S
 436 @@ -12,13 +12,13 @@
 437  #define PROC_INFO                                                      \
 438         . = ALIGN(4);                                                   \
 439         VMLINUX_SYMBOL(__proc_info_begin) = .;                          \
 440 -       *(.proc.info.init)                                              \
 441 +       KEEP(*(.proc.info.init))                                        \
 442         VMLINUX_SYMBOL(__proc_info_end) = .;
 443
 444  #define IDMAP_TEXT                                                     \
 445         ALIGN_FUNCTION();                                               \
 446         VMLINUX_SYMBOL(__idmap_text_start) = .;                         \
 447 -       *(.idmap.text)                                                  \
 448 +       KEEP(*(.idmap.text))                                            \
 449         VMLINUX_SYMBOL(__idmap_text_end) = .;                           \
 450         . = ALIGN(32);                                                  \
 451         VMLINUX_SYMBOL(__hyp_idmap_text_start) = .;                     \
 452 @@ -93,7 +93,7 @@ SECTIONS
 453         .text : {                       /* Real text segment            */
 454                 _stext = .;             /* Text and read-only data      */
 455                         __exception_text_start = .;
 456 -                       *(.exception.text)
 457 +                       KEEP(*(.exception.text))
 458                         __exception_text_end = .;
 459                         IRQENTRY_TEXT
 460                         TEXT_TEXT
 461 @@ -118,7 +118,7 @@ SECTIONS
 462         __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
 463                 __start___ex_table = .;
 464  #ifdef CONFIG_MMU
 465 -               *(__ex_table)
 466 +               KEEP(*(__ex_table))
 467  #endif
 468                 __stop___ex_table = .;
 469         }
 470 @@ -130,12 +130,12 @@ SECTIONS
 471         . = ALIGN(8);
 472         .ARM.unwind_idx : {
 473                 __start_unwind_idx = .;
 474 -               *(.ARM.exidx*)
 475 +               KEEP(*(.ARM.exidx*))
 476                 __stop_unwind_idx = .;
 477         }
 478         .ARM.unwind_tab : {
 479                 __start_unwind_tab = .;
 480 -               *(.ARM.extab*)
 481 +               KEEP(*(.ARM.extab*))
 482                 __stop_unwind_tab = .;
 483         }
 484  #endif
 485 @@ -154,14 +154,14 @@ SECTIONS
 486          */
 487         __vectors_start = .;
 488         .vectors 0 : AT(__vectors_start) {
 489 -               *(.vectors)
 490 +               KEEP(*(.vectors))
 491         }
 492         . = __vectors_start + SIZEOF(.vectors);
 493         __vectors_end = .;
 494
 495         __stubs_start = .;
 496         .stubs 0x1000 : AT(__stubs_start) {
 497 -               *(.stubs)
 498 +               KEEP(*(.stubs))
 499         }
 500         . = __stubs_start + SIZEOF(.stubs);
 501         __stubs_end = .;
 502 @@ -175,24 +175,24 @@ SECTIONS
 503         }
 504         .init.arch.info : {
 505                 __arch_info_begin = .;
 506 -               *(.arch.info.init)
 507 +               KEEP(*(.arch.info.init))
 508                 __arch_info_end = .;
 509         }
 510         .init.tagtable : {
 511                 __tagtable_begin = .;
 512 -               *(.taglist.init)
 513 +               KEEP(*(.taglist.init))
 514                 __tagtable_end = .;
 515         }
 516  #ifdef CONFIG_SMP_ON_UP
 517         .init.smpalt : {
 518                 __smpalt_begin = .;
 519 -               *(.alt.smp.init)
 520 +               KEEP(*(.alt.smp.init))
 521                 __smpalt_end = .;
 522         }
 523  #endif
 524         .init.pv_table : {
 525                 __pv_table_begin = .;
 526 -               *(.pv_table)
 527 +               KEEP(*(.pv_table))
 528                 __pv_table_end = .;
 529         }
 530         .init.data : {
 531 --- a/arch/arm/boot/compressed/Makefile
 532 +++ b/arch/arm/boot/compressed/Makefile
 533 @@ -120,6 +120,7 @@ ifeq ($(CONFIG_FUNCTION_TRACER),y)
 534  ORIG_CFLAGS := $(KBUILD_CFLAGS)
 535  KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS))
 536  endif
 537 +KBUILD_CFLAGS_KERNEL := $(patsubst -f%-sections,,$(KBUILD_CFLAGS_KERNEL))
 538
 539  ccflags-y := -fpic -mno-single-pic-base -fno-builtin -I$(obj)
 540  asflags-y := -DZIMAGE