target/linux/generic/patches-4.1/220-gc_sections.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   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@nbd.name>
   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  #
  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 @@ -123,10 +123,10 @@
  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                         VMLINUX_SYMBOL(__start_ftrace_enum_maps) = .;   \
  97 -                       *(_ftrace_enum_map)                             \
  98 +                       KEEP(*(_ftrace_enum_map))                       \
  99                         VMLINUX_SYMBOL(__stop_ftrace_enum_maps) = .;
 100  #else
 101  #define FTRACE_EVENTS()
 102 @@ -134,7 +134,7 @@
 103
 104  #ifdef CONFIG_TRACING
 105  #define TRACE_PRINTKS() VMLINUX_SYMBOL(__start___trace_bprintk_fmt) = .;      \
 106 -                        *(__trace_printk_fmt) /* Trace_printk fmt' pointer */ \
 107 +                        KEEP(*(__trace_printk_fmt)) /* Trace_printk fmt' pointer */ \
 108                          VMLINUX_SYMBOL(__stop___trace_bprintk_fmt) = .;
 109  #define TRACEPOINT_STR() VMLINUX_SYMBOL(__start___tracepoint_str) = .; \
 110                          *(__tracepoint_str) /* Trace_printk fmt' pointer */ \
 111 @@ -147,7 +147,7 @@
 112  #ifdef CONFIG_FTRACE_SYSCALLS
 113  #define TRACE_SYSCALLS() . = ALIGN(8);                                 \
 114                          VMLINUX_SYMBOL(__start_syscalls_metadata) = .; \
 115 -                        *(__syscalls_metadata)                         \
 116 +                        KEEP(*(__syscalls_metadata))                   \
 117                          VMLINUX_SYMBOL(__stop_syscalls_metadata) = .;
 118  #else
 119  #define TRACE_SYSCALLS()
 120 @@ -169,8 +169,8 @@
 121  #define _OF_TABLE_1(name)                                              \
 122         . = ALIGN(8);                                                   \
 123         VMLINUX_SYMBOL(__##name##_of_table) = .;                        \
 124 -       *(__##name##_of_table)                                          \
 125 -       *(__##name##_of_table_end)
 126 +       KEEP(*(__##name##_of_table))                                    \
 127 +       KEEP(*(__##name##_of_table_end))
 128
 129  #define CLKSRC_OF_TABLES()     OF_TABLE(CONFIG_CLKSRC_OF, clksrc)
 130  #define IRQCHIP_OF_MATCH_TABLE() OF_TABLE(CONFIG_IRQCHIP, irqchip)
 131 @@ -184,7 +184,7 @@
 132  #define KERNEL_DTB()                                                   \
 133         STRUCT_ALIGN();                                                 \
 134         VMLINUX_SYMBOL(__dtb_start) = .;                                \
 135 -       *(.dtb.init.rodata)                                             \
 136 +       KEEP(*(.dtb.init.rodata))                                       \
 137         VMLINUX_SYMBOL(__dtb_end) = .;
 138
 139  /* .data section */
 140 @@ -200,16 +200,17 @@
 141         /* implement dynamic printk debug */                            \
 142         . = ALIGN(8);                                                   \
 143         VMLINUX_SYMBOL(__start___jump_table) = .;                       \
 144 -       *(__jump_table)                                                 \
 145 +       KEEP(*(__jump_table))                                           \
 146         VMLINUX_SYMBOL(__stop___jump_table) = .;                        \
 147         . = ALIGN(8);                                                   \
 148         VMLINUX_SYMBOL(__start___verbose) = .;                          \
 149 -       *(__verbose)                                                    \
 150 +       KEEP(*(__verbose))                                              \
 151         VMLINUX_SYMBOL(__stop___verbose) = .;                           \
 152         LIKELY_PROFILE()                                                \
 153         BRANCH_PROFILE()                                                \
 154         TRACE_PRINTKS()                                                 \
 155 -       TRACEPOINT_STR()
 156 +       TRACEPOINT_STR()                                                \
 157 +       *(.data.[a-zA-Z_]*)
 158
 159  /*
 160   * Data section helpers
 161 @@ -263,35 +264,35 @@
 162         /* PCI quirks */                                                \
 163         .pci_fixup        : AT(ADDR(.pci_fixup) - LOAD_OFFSET) {        \
 164                 VMLINUX_SYMBOL(__start_pci_fixups_early) = .;           \
 165 -               *(.pci_fixup_early)                                     \
 166 +               KEEP(*(.pci_fixup_early))                               \
 167                 VMLINUX_SYMBOL(__end_pci_fixups_early) = .;             \
 168                 VMLINUX_SYMBOL(__start_pci_fixups_header) = .;          \
 169 -               *(.pci_fixup_header)                                    \
 170 +               KEEP(*(.pci_fixup_header))                              \
 171                 VMLINUX_SYMBOL(__end_pci_fixups_header) = .;            \
 172                 VMLINUX_SYMBOL(__start_pci_fixups_final) = .;           \
 173 -               *(.pci_fixup_final)                                     \
 174 +               KEEP(*(.pci_fixup_final))                               \
 175                 VMLINUX_SYMBOL(__end_pci_fixups_final) = .;             \
 176                 VMLINUX_SYMBOL(__start_pci_fixups_enable) = .;          \
 177 -               *(.pci_fixup_enable)                                    \
 178 +               KEEP(*(.pci_fixup_enable))                              \
 179                 VMLINUX_SYMBOL(__end_pci_fixups_enable) = .;            \
 180                 VMLINUX_SYMBOL(__start_pci_fixups_resume) = .;          \
 181 -               *(.pci_fixup_resume)                                    \
 182 +               KEEP(*(.pci_fixup_resume))                              \
 183                 VMLINUX_SYMBOL(__end_pci_fixups_resume) = .;            \
 184                 VMLINUX_SYMBOL(__start_pci_fixups_resume_early) = .;    \
 185 -               *(.pci_fixup_resume_early)                              \
 186 +               KEEP(*(.pci_fixup_resume_early))                        \
 187                 VMLINUX_SYMBOL(__end_pci_fixups_resume_early) = .;      \
 188                 VMLINUX_SYMBOL(__start_pci_fixups_suspend) = .;         \
 189 -               *(.pci_fixup_suspend)                                   \
 190 +               KEEP(*(.pci_fixup_suspend))                             \
 191                 VMLINUX_SYMBOL(__end_pci_fixups_suspend) = .;           \
 192                 VMLINUX_SYMBOL(__start_pci_fixups_suspend_late) = .;    \
 193 -               *(.pci_fixup_suspend_late)                              \
 194 +               KEEP(*(.pci_fixup_suspend_late))                        \
 195                 VMLINUX_SYMBOL(__end_pci_fixups_suspend_late) = .;      \
 196         }                                                               \
 197                                                                         \
 198         /* Built-in firmware blobs */                                   \
 199         .builtin_fw        : AT(ADDR(.builtin_fw) - LOAD_OFFSET) {      \
 200                 VMLINUX_SYMBOL(__start_builtin_fw) = .;                 \
 201 -               *(.builtin_fw)                                          \
 202 +               KEEP(*(.builtin_fw))                                    \
 203                 VMLINUX_SYMBOL(__end_builtin_fw) = .;                   \
 204         }                                                               \
 205                                                                         \
 206 @@ -300,49 +301,49 @@
 207         /* Kernel symbol table: Normal symbols */                       \
 208         __ksymtab         : AT(ADDR(__ksymtab) - LOAD_OFFSET) {         \
 209                 VMLINUX_SYMBOL(__start___ksymtab) = .;                  \
 210 -               *(SORT(___ksymtab+*))                                   \
 211 +               KEEP(*(SORT(___ksymtab+*)))                             \
 212                 VMLINUX_SYMBOL(__stop___ksymtab) = .;                   \
 213         }                                                               \
 214                                                                         \
 215         /* Kernel symbol table: GPL-only symbols */                     \
 216         __ksymtab_gpl     : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) {     \
 217                 VMLINUX_SYMBOL(__start___ksymtab_gpl) = .;              \
 218 -               *(SORT(___ksymtab_gpl+*))                               \
 219 +               KEEP(*(SORT(___ksymtab_gpl+*)))                         \
 220                 VMLINUX_SYMBOL(__stop___ksymtab_gpl) = .;               \
 221         }                                                               \
 222                                                                         \
 223         /* Kernel symbol table: Normal unused symbols */                \
 224         __ksymtab_unused  : AT(ADDR(__ksymtab_unused) - LOAD_OFFSET) {  \
 225                 VMLINUX_SYMBOL(__start___ksymtab_unused) = .;           \
 226 -               *(SORT(___ksymtab_unused+*))                            \
 227 +               KEEP(*(SORT(___ksymtab_unused+*)))                      \
 228                 VMLINUX_SYMBOL(__stop___ksymtab_unused) = .;            \
 229         }                                                               \
 230                                                                         \
 231         /* Kernel symbol table: GPL-only unused symbols */              \
 232         __ksymtab_unused_gpl : AT(ADDR(__ksymtab_unused_gpl) - LOAD_OFFSET) { \
 233                 VMLINUX_SYMBOL(__start___ksymtab_unused_gpl) = .;       \
 234 -               *(SORT(___ksymtab_unused_gpl+*))                        \
 235 +               KEEP(*(SORT(___ksymtab_unused_gpl+*)))                  \
 236                 VMLINUX_SYMBOL(__stop___ksymtab_unused_gpl) = .;        \
 237         }                                                               \
 238                                                                         \
 239         /* Kernel symbol table: GPL-future-only symbols */              \
 240         __ksymtab_gpl_future : AT(ADDR(__ksymtab_gpl_future) - LOAD_OFFSET) { \
 241                 VMLINUX_SYMBOL(__start___ksymtab_gpl_future) = .;       \
 242 -               *(SORT(___ksymtab_gpl_future+*))                        \
 243 +               KEEP(*(SORT(___ksymtab_gpl_future+*)))                  \
 244                 VMLINUX_SYMBOL(__stop___ksymtab_gpl_future) = .;        \
 245         }                                                               \
 246                                                                         \
 247         /* Kernel symbol table: Normal symbols */                       \
 248         __kcrctab         : AT(ADDR(__kcrctab) - LOAD_OFFSET) {         \
 249                 VMLINUX_SYMBOL(__start___kcrctab) = .;                  \
 250 -               *(SORT(___kcrctab+*))                                   \
 251 +               KEEP(*(SORT(___kcrctab+*)))                             \
 252                 VMLINUX_SYMBOL(__stop___kcrctab) = .;                   \
 253         }                                                               \
 254                                                                         \
 255         /* Kernel symbol table: GPL-only symbols */                     \
 256         __kcrctab_gpl     : AT(ADDR(__kcrctab_gpl) - LOAD_OFFSET) {     \
 257                 VMLINUX_SYMBOL(__start___kcrctab_gpl) = .;              \
 258 -               *(SORT(___kcrctab_gpl+*))                               \
 259 +               KEEP(*(SORT(___kcrctab_gpl+*)))                         \
 260                 VMLINUX_SYMBOL(__stop___kcrctab_gpl) = .;               \
 261         }                                                               \
 262                                                                         \
 263 @@ -356,14 +357,14 @@
 264         /* Kernel symbol table: GPL-only unused symbols */              \
 265         __kcrctab_unused_gpl : AT(ADDR(__kcrctab_unused_gpl) - LOAD_OFFSET) { \
 266                 VMLINUX_SYMBOL(__start___kcrctab_unused_gpl) = .;       \
 267 -               *(SORT(___kcrctab_unused_gpl+*))                        \
 268 +               KEEP(*(SORT(___kcrctab_unused_gpl+*)))                  \
 269                 VMLINUX_SYMBOL(__stop___kcrctab_unused_gpl) = .;        \
 270         }                                                               \
 271                                                                         \
 272         /* Kernel symbol table: GPL-future-only symbols */              \
 273         __kcrctab_gpl_future : AT(ADDR(__kcrctab_gpl_future) - LOAD_OFFSET) { \
 274                 VMLINUX_SYMBOL(__start___kcrctab_gpl_future) = .;       \
 275 -               *(SORT(___kcrctab_gpl_future+*))                        \
 276 +               KEEP(*(SORT(___kcrctab_gpl_future+*)))                  \
 277                 VMLINUX_SYMBOL(__stop___kcrctab_gpl_future) = .;        \
 278         }                                                               \
 279                                                                         \
 280 @@ -382,14 +383,14 @@
 281         /* Built-in module parameters. */                               \
 282         __param : AT(ADDR(__param) - LOAD_OFFSET) {                     \
 283                 VMLINUX_SYMBOL(__start___param) = .;                    \
 284 -               *(__param)                                              \
 285 +               KEEP(*(__param))                                        \
 286                 VMLINUX_SYMBOL(__stop___param) = .;                     \
 287         }                                                               \
 288                                                                         \
 289         /* Built-in module versions. */                                 \
 290         __modver : AT(ADDR(__modver) - LOAD_OFFSET) {                   \
 291                 VMLINUX_SYMBOL(__start___modver) = .;                   \
 292 -               *(__modver)                                             \
 293 +               KEEP(*(__modver))                                       \
 294                 VMLINUX_SYMBOL(__stop___modver) = .;                    \
 295                 . = ALIGN((align));                                     \
 296                 VMLINUX_SYMBOL(__end_rodata) = .;                       \
 297 @@ -445,7 +446,7 @@
 298  #define ENTRY_TEXT                                                     \
 299                 ALIGN_FUNCTION();                                       \
 300                 VMLINUX_SYMBOL(__entry_text_start) = .;                 \
 301 -               *(.entry.text)                                          \
 302 +               KEEP(*(.entry.text))                                    \
 303                 VMLINUX_SYMBOL(__entry_text_end) = .;
 304
 305  #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 306 @@ -473,7 +474,7 @@
 307         . = ALIGN(align);                                               \
 308         __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {               \
 309                 VMLINUX_SYMBOL(__start___ex_table) = .;                 \
 310 -               *(__ex_table)                                           \
 311 +               KEEP(*(__ex_table))                                             \
 312                 VMLINUX_SYMBOL(__stop___ex_table) = .;                  \
 313         }
 314
 315 @@ -489,9 +490,9 @@
 316  #ifdef CONFIG_CONSTRUCTORS
 317  #define KERNEL_CTORS() . = ALIGN(8);                      \
 318                         VMLINUX_SYMBOL(__ctors_start) = .; \
 319 -                       *(.ctors)                          \
 320 +                       KEEP(*(.ctors))                    \
 321                         *(SORT(.init_array.*))             \
 322 -                       *(.init_array)                     \
 323 +                       KEEP(*(.init_array))               \
 324                         VMLINUX_SYMBOL(__ctors_end) = .;
 325  #else
 326  #define KERNEL_CTORS()
 327 @@ -542,7 +543,7 @@
 328  #define SBSS(sbss_align)                                               \
 329         . = ALIGN(sbss_align);                                          \
 330         .sbss : AT(ADDR(.sbss) - LOAD_OFFSET) {                         \
 331 -               *(.sbss)                                                \
 332 +               *(.sbss .sbss.*)                                        \
 333                 *(.scommon)                                             \
 334         }
 335
 336 @@ -560,7 +561,7 @@
 337                 BSS_FIRST_SECTIONS                                      \
 338                 *(.bss..page_aligned)                                   \
 339                 *(.dynbss)                                              \
 340 -               *(.bss)                                                 \
 341 +               *(.bss .bss.*)                                          \
 342                 *(COMMON)                                               \
 343         }
 344
 345 @@ -609,7 +610,7 @@
 346         . = ALIGN(8);                                                   \
 347         __bug_table : AT(ADDR(__bug_table) - LOAD_OFFSET) {             \
 348                 VMLINUX_SYMBOL(__start___bug_table) = .;                \
 349 -               *(__bug_table)                                          \
 350 +               KEEP(*(__bug_table))                                    \
 351                 VMLINUX_SYMBOL(__stop___bug_table) = .;                 \
 352         }
 353  #else
 354 @@ -621,7 +622,7 @@
 355         . = ALIGN(4);                                                   \
 356         .tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) {               \
 357                 VMLINUX_SYMBOL(__tracedata_start) = .;                  \
 358 -               *(.tracedata)                                           \
 359 +               KEEP(*(.tracedata))                                     \
 360                 VMLINUX_SYMBOL(__tracedata_end) = .;                    \
 361         }
 362  #else
 363 @@ -638,17 +639,17 @@
 364  #define INIT_SETUP(initsetup_align)                                    \
 365                 . = ALIGN(initsetup_align);                             \
 366                 VMLINUX_SYMBOL(__setup_start) = .;                      \
 367 -               *(.init.setup)                                          \
 368 +               KEEP(*(.init.setup))                                    \
 369                 VMLINUX_SYMBOL(__setup_end) = .;
 370
 371  #define INIT_CALLS_LEVEL(level)                                                \
 372                 VMLINUX_SYMBOL(__initcall##level##_start) = .;          \
 373 -               *(.initcall##level##.init)                              \
 374 -               *(.initcall##level##s.init)                             \
 375 +               KEEP(*(.initcall##level##.init))                        \
 376 +               KEEP(*(.initcall##level##s.init))                       \
 377
 378  #define INIT_CALLS                                                     \
 379                 VMLINUX_SYMBOL(__initcall_start) = .;                   \
 380 -               *(.initcallearly.init)                                  \
 381 +               KEEP(*(.initcallearly.init))                            \
 382                 INIT_CALLS_LEVEL(0)                                     \
 383                 INIT_CALLS_LEVEL(1)                                     \
 384                 INIT_CALLS_LEVEL(2)                                     \
 385 @@ -662,21 +663,21 @@
 386
 387  #define CON_INITCALL                                                   \
 388                 VMLINUX_SYMBOL(__con_initcall_start) = .;               \
 389 -               *(.con_initcall.init)                                   \
 390 +               KEEP(*(.con_initcall.init))                             \
 391                 VMLINUX_SYMBOL(__con_initcall_end) = .;
 392
 393  #define SECURITY_INITCALL                                              \
 394                 VMLINUX_SYMBOL(__security_initcall_start) = .;          \
 395 -               *(.security_initcall.init)                              \
 396 +               KEEP(*(.security_initcall.init))                        \
 397                 VMLINUX_SYMBOL(__security_initcall_end) = .;
 398
 399  #ifdef CONFIG_BLK_DEV_INITRD
 400  #define INIT_RAM_FS                                                    \
 401         . = ALIGN(4);                                                   \
 402         VMLINUX_SYMBOL(__initramfs_start) = .;                          \
 403 -       *(.init.ramfs)                                                  \
 404 +       KEEP(*(.init.ramfs))                                            \
 405         . = ALIGN(8);                                                   \
 406 -       *(.init.ramfs.info)
 407 +       KEEP(*(.init.ramfs.info))
 408  #else
 409  #define INIT_RAM_FS
 410  #endif
 411 --- a/arch/arm/Makefile
 412 +++ b/arch/arm/Makefile
 413 @@ -18,11 +18,16 @@ ifeq ($(CONFIG_CPU_ENDIAN_BE8),y)
 414  LDFLAGS_vmlinux        += --be8
 415  LDFLAGS_MODULE += --be8
 416  endif
 417 +LDFLAGS_vmlinux += --gc-sections
 418
 419  OBJCOPYFLAGS   :=-O binary -R .comment -S
 420  GZFLAGS                :=-9
 421  #KBUILD_CFLAGS +=-pipe
 422
 423 +ifndef CONFIG_FUNCTION_TRACER
 424 +KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
 425 +endif
 426 +
 427  # Never generate .eh_frame
 428  KBUILD_CFLAGS  += $(call cc-option,-fno-dwarf2-cfi-asm)
 429
 430 --- a/arch/arm/kernel/vmlinux.lds.S
 431 +++ b/arch/arm/kernel/vmlinux.lds.S
 432 @@ -15,13 +15,13 @@
 433  #define PROC_INFO                                                      \
 434         . = ALIGN(4);                                                   \
 435         VMLINUX_SYMBOL(__proc_info_begin) = .;                          \
 436 -       *(.proc.info.init)                                              \
 437 +       KEEP(*(.proc.info.init))                                        \
 438         VMLINUX_SYMBOL(__proc_info_end) = .;
 439
 440  #define IDMAP_TEXT                                                     \
 441         ALIGN_FUNCTION();                                               \
 442         VMLINUX_SYMBOL(__idmap_text_start) = .;                         \
 443 -       *(.idmap.text)                                                  \
 444 +       KEEP(*(.idmap.text))                                            \
 445         VMLINUX_SYMBOL(__idmap_text_end) = .;                           \
 446         . = ALIGN(PAGE_SIZE);                                           \
 447         VMLINUX_SYMBOL(__hyp_idmap_text_start) = .;                     \
 448 @@ -102,7 +102,7 @@ SECTIONS
 449                 _stext = .;             /* Text and read-only data      */
 450                         IDMAP_TEXT
 451                         __exception_text_start = .;
 452 -                       *(.exception.text)
 453 +                       KEEP(*(.exception.text))
 454                         __exception_text_end = .;
 455                         IRQENTRY_TEXT
 456                         TEXT_TEXT
 457 @@ -126,7 +126,7 @@ SECTIONS
 458         __ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) {
 459                 __start___ex_table = .;
 460  #ifdef CONFIG_MMU
 461 -               *(__ex_table)
 462 +               KEEP(*(__ex_table))
 463  #endif
 464                 __stop___ex_table = .;
 465         }
 466 @@ -138,12 +138,12 @@ SECTIONS
 467         . = ALIGN(8);
 468         .ARM.unwind_idx : {
 469                 __start_unwind_idx = .;
 470 -               *(.ARM.exidx*)
 471 +               KEEP(*(.ARM.exidx*))
 472                 __stop_unwind_idx = .;
 473         }
 474         .ARM.unwind_tab : {
 475                 __start_unwind_tab = .;
 476 -               *(.ARM.extab*)
 477 +               KEEP(*(.ARM.extab*))
 478                 __stop_unwind_tab = .;
 479         }
 480  #endif
 481 @@ -166,14 +166,14 @@ SECTIONS
 482          */
 483         __vectors_start = .;
 484         .vectors 0 : AT(__vectors_start) {
 485 -               *(.vectors)
 486 +               KEEP(*(.vectors))
 487         }
 488         . = __vectors_start + SIZEOF(.vectors);
 489         __vectors_end = .;
 490
 491         __stubs_start = .;
 492         .stubs 0x1000 : AT(__stubs_start) {
 493 -               *(.stubs)
 494 +               KEEP(*(.stubs))
 495         }
 496         . = __stubs_start + SIZEOF(.stubs);
 497         __stubs_end = .;
 498 @@ -187,24 +187,24 @@ SECTIONS
 499         }
 500         .init.arch.info : {
 501                 __arch_info_begin = .;
 502 -               *(.arch.info.init)
 503 +               KEEP(*(.arch.info.init))
 504                 __arch_info_end = .;
 505         }
 506         .init.tagtable : {
 507                 __tagtable_begin = .;
 508 -               *(.taglist.init)
 509 +               KEEP(*(.taglist.init))
 510                 __tagtable_end = .;
 511         }
 512  #ifdef CONFIG_SMP_ON_UP
 513         .init.smpalt : {
 514                 __smpalt_begin = .;
 515 -               *(.alt.smp.init)
 516 +               KEEP(*(.alt.smp.init))
 517                 __smpalt_end = .;
 518         }
 519  #endif
 520         .init.pv_table : {
 521                 __pv_table_begin = .;
 522 -               *(.pv_table)
 523 +               KEEP(*(.pv_table))
 524                 __pv_table_end = .;
 525         }
 526         .init.data : {
 527 --- a/arch/arm/boot/compressed/Makefile
 528 +++ b/arch/arm/boot/compressed/Makefile
 529 @@ -107,6 +107,7 @@ ifeq ($(CONFIG_FUNCTION_TRACER),y)
 530  ORIG_CFLAGS := $(KBUILD_CFLAGS)
 531  KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS))
 532  endif
 533 +KBUILD_CFLAGS_KERNEL := $(patsubst -f%-sections,,$(KBUILD_CFLAGS_KERNEL))
 534
 535  ccflags-y := -fpic -mno-single-pic-base -fno-builtin -I$(obj)
 536  asflags-y := -DZIMAGE