and .sizeof.

). Along those lines use .sizeof.* where section sizes get calculated from the difference of section and and section start symbols. Note that this would be nice for the build-id section too, but: - The generated (by ld) section names differ between ELF and COFF/PE (ELF: .note.gnu.build-id; COFF/PE[2.26+]: .buildid), yet we compile version.c just once (and hence can use only either of the necessary .startof./.sizeof. forms). - The ELF section name needs to be quoted in the .startof./.sizeof. expressions, yet that quoting is supported only by gas 2.26+. Signed-off-by: Jan Beulich --- v2: Also replace __base_relocs_{start,end}. Comment out linker script assertion on .bss start alignment. --- a/xen/arch/arm/arm32/head.S +++ b/xen/arch/arm/arm32/head.S @@ -184,10 +184,10 @@ hyp: PRINT("- Xen starting in Hyp mod bne skip_bss PRINT("- Zero BSS -\r\n") - ldr r0, =__bss_start /* Load start & end of bss */ - ldr r1, =__bss_end + ldr r0, =.startof.(.bss) /* Load start & size of bss */ + ldr r1, =.sizeof.(.bss) add r0, r0, r10 /* Apply physical offset */ - add r1, r1, r10 + add r1, r1, r0 /* Calculate end of bss */ mov r2, #0 1: str r2, [r0], #4 --- a/xen/arch/arm/arm64/head.S +++ b/xen/arch/arm/arm64/head.S @@ -318,10 +318,10 @@ el2: PRINT("- Xen starting at EL2 -\r cbnz x22, skip_bss PRINT("- Zero BSS -\r\n") - ldr x0, =__bss_start /* Load start & end of bss */ - ldr x1, =__bss_end + ldr x0, =.startof.(.bss) /* Load start & size of bss */ + ldr x1, =.sizeof.(.bss) add x0, x0, x20 /* Apply physical offset */ - add x1, x1, x20 + add x1, x1, x0 /* Calculate end of .bss */ 1: str xzr, [x0], #8 cmp x0, x1 --- a/xen/arch/arm/device.c +++ b/xen/arch/arm/device.c @@ -21,8 +21,8 @@ #include #include -extern const struct device_desc _sdevice[], _edevice[]; -extern const struct acpi_device_desc _asdevice[], _aedevice[]; +extern const struct device_desc _sdevice[] asm(".startof.(.dev.info)"); +extern const struct device_desc _edevice[]; int __init device_init(struct dt_device_node *dev, enum device_class class, const void *data) @@ -51,6 +51,11 @@ int __init device_init(struct dt_device_ return -EBADF; } +#ifdef CONFIG_ACPI + +extern const struct acpi_device_desc _asdevice[] asm(".startof.(.adev.info)"); +extern const struct acpi_device_desc _aedevice[]; + int __init acpi_device_init(enum device_class class, const void *data, int class_type) { const struct acpi_device_desc *desc; @@ -68,6 +73,8 @@ int __init acpi_device_init(enum device_ return -EBADF; } +#endif + enum device_class device_get_class(const struct dt_device_node *dev) { const struct device_desc *desc; --- a/xen/arch/arm/domain_build.c +++ b/xen/arch/arm/domain_build.c @@ -2058,7 +2058,7 @@ static void __init find_gnttab_region(st * enough space for a large grant table */ kinfo->gnttab_start = __pa(_stext); - kinfo->gnttab_size = (_etext - _stext) & PAGE_MASK; + kinfo->gnttab_size = _sizeof_text & PAGE_MASK; /* Make sure the grant table will fit in the region */ if ( (kinfo->gnttab_size >> PAGE_SHIFT) < max_grant_frames ) --- a/xen/arch/arm/platform.c +++ b/xen/arch/arm/platform.c @@ -22,7 +22,8 @@ #include #include -extern const struct platform_desc _splatform[], _eplatform[]; +extern const struct platform_desc _splatform[] asm(".startof.(.arch.info)"); +extern const struct platform_desc _eplatform[]; /* Pointer to the current platform description */ static const struct platform_desc *platform; --- a/xen/arch/arm/xen.lds.S +++ b/xen/arch/arm/xen.lds.S @@ -31,7 +31,6 @@ SECTIONS . = XEN_VIRT_START; _start = .; .text : /* XXX should be AT ( XEN_PHYS_START ) */ { - _stext = .; /* Text section */ *(.text) *(.text.cold) *(.text.unlikely) @@ -42,7 +41,6 @@ SECTIONS . = ALIGN(PAGE_SIZE); .rodata : { - _srodata = .; /* Read-only data */ /* Bug frames table */ __start_bug_frames = .; *(.bug_frames.0) @@ -104,21 +102,18 @@ SECTIONS . = ALIGN(8); .arch.info : { - _splatform = .; *(.arch.info) _eplatform = .; } :text . = ALIGN(8); .dev.info : { - _sdevice = .; *(.dev.info) _edevice = .; } :text . = ALIGN(8); .adev.info : { - _asdevice = .; *(.adev.info) _aedevice = .; } :text @@ -126,7 +121,6 @@ SECTIONS . = ALIGN(PAGE_SIZE); /* Init code and data */ __init_begin = .; .init.text : { - _sinittext = .; *(.init.text) _einittext = .; } :text @@ -174,7 +168,6 @@ SECTIONS __init_end = .; .bss : { /* BSS */ - __bss_start = .; *(.bss.stack_aligned) . = ALIGN(PAGE_SIZE); *(.bss.page_aligned) @@ -186,7 +179,6 @@ SECTIONS *(.bss.percpu.read_mostly) . = ALIGN(SMP_CACHE_BYTES); __per_cpu_data_end = .; - __bss_end = .; } :text _end = . ; --- a/xen/arch/x86/boot/head.S +++ b/xen/arch/x86/boot/head.S @@ -124,9 +124,8 @@ __start: mov %eax,sym_phys(multiboot_ptr) /* Initialize BSS (no nasty surprises!) */ - mov $sym_phys(__bss_start),%edi - mov $sym_phys(__bss_end),%ecx - sub %edi,%ecx + mov $sym_phys(.startof.(.bss)),%edi + mov $.sizeof.(.bss),%ecx xor %eax,%eax shr $2,%ecx rep stosl --- a/xen/arch/x86/efi/efi-boot.h +++ b/xen/arch/x86/efi/efi-boot.h @@ -39,13 +39,17 @@ extern const struct pe_base_relocs { u32 rva; u32 size; u16 entries[]; -} __base_relocs_start[], __base_relocs_end[]; +} base_relocs_start[] asm(".startof.(.reloc)"); static void __init efi_arch_relocate_image(unsigned long delta) { - const struct pe_base_relocs *base_relocs; + const struct pe_base_relocs *base_relocs = base_relocs_start; + const struct pe_base_relocs *base_relocs_end = base_relocs; - for ( base_relocs = __base_relocs_start; base_relocs < __base_relocs_end; ) + /* Can't do without asm() due to -fPIC. */ + asm ( "add $.sizeof.(.reloc),%0" : "+g" (base_relocs_end) ); + + while ( base_relocs < base_relocs_end ) { unsigned int i = 0, n; --- a/xen/arch/x86/efi/mkreloc.c +++ b/xen/arch/x86/efi/mkreloc.c @@ -314,9 +314,7 @@ int main(int argc, char *argv[]) } puts("\t.section .reloc, \"a\", @progbits\n" - "\t.balign 4\n" - "\t.globl __base_relocs_start, __base_relocs_end\n" - "__base_relocs_start:"); + "\t.balign 4"); for ( i = 0; i < nsec; ++i ) { @@ -368,8 +366,6 @@ int main(int argc, char *argv[]) diff_sections(NULL, NULL, NULL, 0, 0, 0, 0); - puts("__base_relocs_end:"); - close(in1); close(in2); --- a/xen/arch/x86/efi/relocs-dummy.S +++ b/xen/arch/x86/efi/relocs-dummy.S @@ -2,10 +2,8 @@ .section .reloc, "a", @progbits .balign 4 -GLOBAL(__base_relocs_start) .long 0 .long 8 -GLOBAL(__base_relocs_end) .globl VIRT_START, ALT_START .equ VIRT_START, XEN_VIRT_START --- a/xen/arch/x86/setup.c +++ b/xen/arch/x86/setup.c @@ -181,7 +181,7 @@ void __init discard_initial_images(void) initial_images = NULL; } -extern char __init_begin[], __init_end[], __bss_start[], __bss_end[]; +extern char __init_begin[], __init_end[], __bss_end[]; static void __init init_idle_domain(void) { --- a/xen/arch/x86/tboot.c +++ b/xen/arch/x86/tboot.c @@ -48,7 +48,7 @@ static uint64_t __initdata sinit_base, _ #define TXTCR_HEAP_BASE 0x0300 #define TXTCR_HEAP_SIZE 0x0308 -extern char __init_begin[], __bss_start[], __bss_end[]; +extern char __init_begin[]; #define SHA1_SIZE 20 typedef uint8_t sha1_hash_t[SHA1_SIZE]; @@ -376,7 +376,12 @@ void tboot_shutdown(uint32_t shutdown_ty __pa(&_stext); /* bss */ g_tboot_shared->mac_regions[2].start = (uint64_t)__pa(&__bss_start); - g_tboot_shared->mac_regions[2].size = __pa(&__bss_end) - __pa(&__bss_start); +#if 0 /* This doesn't work due to -fPIC. */ + g_tboot_shared->mac_regions[2].size = _sizeof_bss; +#else + asm ( "movl $.sizeof.(.bss),%0" + : "=m" (g_tboot_shared->mac_regions[2].size) ); +#endif /* * MAC domains and other Xen memory --- a/xen/arch/x86/xen.lds.S +++ b/xen/arch/x86/xen.lds.S @@ -58,7 +58,6 @@ SECTIONS . = __XEN_VIRT_START + MB(1); _start = .; .text : { - _stext = .; /* Text and read-only data */ *(.text) *(.text.cold) *(.text.unlikely) @@ -77,7 +76,6 @@ SECTIONS __2M_rodata_start = .; /* Start of 2M superpages, mapped RO. */ .rodata : { - _srodata = .; /* Bug frames table */ . = ALIGN(4); __start_bug_frames = .; @@ -149,7 +147,6 @@ SECTIONS . = ALIGN(PAGE_SIZE); /* Init code and data */ __init_begin = .; .init.text : { - _sinittext = .; *(.init.text) /* * Here are the replacement instructions. The linker sticks them @@ -230,7 +227,6 @@ SECTIONS } :text .bss : { /* BSS */ - __bss_start = .; *(.bss.stack_aligned) *(.bss.page_aligned*) *(.bss) @@ -253,7 +249,6 @@ SECTIONS __2M_rwdata_end = .; #ifdef EFI - . = ALIGN(4); .reloc : { *(.reloc) } :text @@ -323,5 +318,7 @@ ASSERT(IS_ALIGNED(__init_end, PAGE_SIZ ASSERT(IS_ALIGNED(trampoline_start, 4), "trampoline_start misaligned") ASSERT(IS_ALIGNED(trampoline_end, 4), "trampoline_end misaligned") -ASSERT(IS_ALIGNED(__bss_start, 4), "__bss_start misaligned") +/* This would be nice, but fails with older ld (observed on 2.20). +ASSERT(IS_ALIGNED(.startof..bss, 4), ".bss misaligned") + */ ASSERT(IS_ALIGNED(__bss_end, 4), "__bss_end misaligned") --- a/xen/include/xen/kernel.h +++ b/xen/include/xen/kernel.h @@ -71,24 +71,34 @@ extern char _start[], _end[], start[]; (__p >= _start) && (__p < _end); \ }) -extern char _stext[], _etext[]; +extern const char _stext[] asm(".startof.(.text)"); +extern const char _etext[]; #define is_kernel_text(p) ({ \ char *__p = (char *)(unsigned long)(p); \ (__p >= _stext) && (__p < _etext); \ }) -extern const char _srodata[], _erodata[]; +extern const char _sizeof_text[] asm(".sizeof.(.text)"); +#define _sizeof_text ((unsigned long)_sizeof_text) + +extern const char _srodata[] asm(".startof.(.rodata)"); +extern const char _erodata[]; #define is_kernel_rodata(p) ({ \ const char *__p = (const char *)(unsigned long)(p); \ (__p >= _srodata) && (__p < _erodata); \ }) -extern char _sinittext[], _einittext[]; +extern const char _sinittext[] asm(".startof.(.init.text)"); +extern const char _einittext[]; #define is_kernel_inittext(p) ({ \ char *__p = (char *)(unsigned long)(p); \ (__p >= _sinittext) && (__p < _einittext); \ }) +extern char __bss_start[] asm(".startof.(.bss)"); +extern const char _sizeof_bss[] asm(".sizeof.(.bss)"); +#define _sizeof_bss ((unsigned long)_sizeof_bss) + extern enum system_state { SYS_STATE_early_boot, SYS_STATE_boot, --- a/xen/tools/symbols.c +++ b/xen/tools/symbols.c @@ -143,11 +143,12 @@ static int read_symbol(FILE *in, struct sym++; /* Ignore most absolute/undefined (?) symbols. */ - if (strcmp(sym, "_stext") == 0) + if (strcmp(sym, "_stext") == 0 || strcmp(sym, ".startof..text") == 0) _stext = s->addr; else if (strcmp(sym, "_etext") == 0) _etext = s->addr; - else if (strcmp(sym, "_sinittext") == 0) + else if (strcmp(sym, "_sinittext") == 0 || + strcmp(sym, ".startof..init.text") == 0) _sinittext = s->addr; else if (strcmp(sym, "_einittext") == 0) _einittext = s->addr; @@ -168,6 +169,9 @@ static int read_symbol(FILE *in, struct /* exclude also MIPS ELF local symbols ($L123 instead of .L123) */ else if (str[0] == '$') goto skip_tail; + /* Also strip .startof. symbols. */ + if (strncmp(sym, ".startof.", 9) == 0) + goto skip_tail; /* include the type field in the symbol name, so that it gets * compressed together */