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c4f6699dfc
linux-brain/include/asm-generic/vmlinux.lds.h
Alexei Starovoitov c4f6699dfc bpf: introduce BPF_RAW_TRACEPOINT 
Introduce BPF_PROG_TYPE_RAW_TRACEPOINT bpf program type to access
kernel internal arguments of the tracepoints in their raw form.

>From bpf program point of view the access to the arguments look like:
struct bpf_raw_tracepoint_args {
       __u64 args[0];
};

int bpf_prog(struct bpf_raw_tracepoint_args *ctx)
{
  // program can read args[N] where N depends on tracepoint
  // and statically verified at program load+attach time
}

kprobe+bpf infrastructure allows programs access function arguments.
This feature allows programs access raw tracepoint arguments.

Similar to proposed 'dynamic ftrace events' there are no abi guarantees
to what the tracepoints arguments are and what their meaning is.
The program needs to type cast args properly and use bpf_probe_read()
helper to access struct fields when argument is a pointer.

For every tracepoint __bpf_trace_##call function is prepared.
In assembler it looks like:
(gdb) disassemble __bpf_trace_xdp_exception
Dump of assembler code for function __bpf_trace_xdp_exception:
   0xffffffff81132080 <+0>:     mov    %ecx,%ecx
   0xffffffff81132082 <+2>:     jmpq   0xffffffff811231f0 <bpf_trace_run3>

where

TRACE_EVENT(xdp_exception,
        TP_PROTO(const struct net_device *dev,
                 const struct bpf_prog *xdp, u32 act),

The above assembler snippet is casting 32-bit 'act' field into 'u64'
to pass into bpf_trace_run3(), while 'dev' and 'xdp' args are passed as-is.
All of ~500 of __bpf_trace_*() functions are only 5-10 byte long
and in total this approach adds 7k bytes to .text.

This approach gives the lowest possible overhead
while calling trace_xdp_exception() from kernel C code and
transitioning into bpf land.
Since tracepoint+bpf are used at speeds of 1M+ events per second
this is valuable optimization.

The new BPF_RAW_TRACEPOINT_OPEN sys_bpf command is introduced
that returns anon_inode FD of 'bpf-raw-tracepoint' object.

The user space looks like:
// load bpf prog with BPF_PROG_TYPE_RAW_TRACEPOINT type
prog_fd = bpf_prog_load(...);
// receive anon_inode fd for given bpf_raw_tracepoint with prog attached
raw_tp_fd = bpf_raw_tracepoint_open("xdp_exception", prog_fd);

Ctrl-C of tracing daemon or cmdline tool that uses this feature
will automatically detach bpf program, unload it and
unregister tracepoint probe.

On the kernel side the __bpf_raw_tp_map section of pointers to
tracepoint definition and to __bpf_trace_*() probe function is used
to find a tracepoint with "xdp_exception" name and
corresponding __bpf_trace_xdp_exception() probe function
which are passed to tracepoint_probe_register() to connect probe
with tracepoint.

Addition of bpf_raw_tracepoint doesn't interfere with ftrace and perf
tracepoint mechanisms. perf_event_open() can be used in parallel
on the same tracepoint.
Multiple bpf_raw_tracepoint_open("xdp_exception", prog_fd) are permitted.
Each with its own bpf program. The kernel will execute
all tracepoint probes and all attached bpf programs.

In the future bpf_raw_tracepoints can be extended with
query/introspection logic.

__bpf_raw_tp_map section logic was contributed by Steven Rostedt

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-28 22:55:19 +02:00

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/*
* Helper macros to support writing architecture specific
* linker scripts.
*
* A minimal linker scripts has following content:
* [This is a sample, architectures may have special requiriements]
*
* OUTPUT_FORMAT(...)
* OUTPUT_ARCH(...)
* ENTRY(...)
* SECTIONS
* {
* . = START;
* __init_begin = .;
* HEAD_TEXT_SECTION
* INIT_TEXT_SECTION(PAGE_SIZE)
* INIT_DATA_SECTION(...)
* PERCPU_SECTION(CACHELINE_SIZE)
* __init_end = .;
*
* _stext = .;
* TEXT_SECTION = 0
* _etext = .;
*
* _sdata = .;
* RO_DATA_SECTION(PAGE_SIZE)
* RW_DATA_SECTION(...)
* _edata = .;
*
* EXCEPTION_TABLE(...)
* NOTES
*
* BSS_SECTION(0, 0, 0)
* _end = .;
*
* STABS_DEBUG
* DWARF_DEBUG
*
* DISCARDS // must be the last
* }
*
* [__init_begin, __init_end] is the init section that may be freed after init
* // __init_begin and __init_end should be page aligned, so that we can
* // free the whole .init memory
* [_stext, _etext] is the text section
* [_sdata, _edata] is the data section
*
* Some of the included output section have their own set of constants.
* Examples are: [__initramfs_start, __initramfs_end] for initramfs and
* [__nosave_begin, __nosave_end] for the nosave data
*/
#ifndef LOAD_OFFSET
#define LOAD_OFFSET 0
#endif
#include <linux/export.h>
/* Align . to a 8 byte boundary equals to maximum function alignment. */
#define ALIGN_FUNCTION() . = ALIGN(8)
/*
* LD_DEAD_CODE_DATA_ELIMINATION option enables -fdata-sections, which
* generates .data.identifier sections, which need to be pulled in with
* .data. We don't want to pull in .data..other sections, which Linux
* has defined. Same for text and bss.
*/
#ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
#define TEXT_MAIN .text .text.[0-9a-zA-Z_]*
#define DATA_MAIN .data .data.[0-9a-zA-Z_]*
#define BSS_MAIN .bss .bss.[0-9a-zA-Z_]*
#else
#define TEXT_MAIN .text
#define DATA_MAIN .data
#define BSS_MAIN .bss
#endif
/*
* Align to a 32 byte boundary equal to the
* alignment gcc 4.5 uses for a struct
*/
#define STRUCT_ALIGNMENT 32
#define STRUCT_ALIGN() . = ALIGN(STRUCT_ALIGNMENT)
/* The actual configuration determine if the init/exit sections
* are handled as text/data or they can be discarded (which
* often happens at runtime)
*/
#ifdef CONFIG_HOTPLUG_CPU
#define CPU_KEEP(sec) *(.cpu##sec)
#define CPU_DISCARD(sec)
#else
#define CPU_KEEP(sec)
#define CPU_DISCARD(sec) *(.cpu##sec)
#endif
#if defined(CONFIG_MEMORY_HOTPLUG)
#define MEM_KEEP(sec) *(.mem##sec)
#define MEM_DISCARD(sec)
#else
#define MEM_KEEP(sec)
#define MEM_DISCARD(sec) *(.mem##sec)
#endif
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
#define MCOUNT_REC() . = ALIGN(8); \
VMLINUX_SYMBOL(__start_mcount_loc) = .; \
*(__mcount_loc) \
VMLINUX_SYMBOL(__stop_mcount_loc) = .;
#else
#define MCOUNT_REC()
#endif
#ifdef CONFIG_TRACE_BRANCH_PROFILING
#define LIKELY_PROFILE() VMLINUX_SYMBOL(__start_annotated_branch_profile) = .; \
*(_ftrace_annotated_branch) \
VMLINUX_SYMBOL(__stop_annotated_branch_profile) = .;
#else
#define LIKELY_PROFILE()
#endif
#ifdef CONFIG_PROFILE_ALL_BRANCHES
#define BRANCH_PROFILE() VMLINUX_SYMBOL(__start_branch_profile) = .; \
*(_ftrace_branch) \
VMLINUX_SYMBOL(__stop_branch_profile) = .;
#else
#define BRANCH_PROFILE()
#endif
#ifdef CONFIG_KPROBES
#define KPROBE_BLACKLIST() . = ALIGN(8); \
VMLINUX_SYMBOL(__start_kprobe_blacklist) = .; \
KEEP(*(_kprobe_blacklist)) \
VMLINUX_SYMBOL(__stop_kprobe_blacklist) = .;
#else
#define KPROBE_BLACKLIST()
#endif
#ifdef CONFIG_FUNCTION_ERROR_INJECTION
#define ERROR_INJECT_WHITELIST() STRUCT_ALIGN(); \
VMLINUX_SYMBOL(__start_error_injection_whitelist) = .;\
KEEP(*(_error_injection_whitelist)) \
VMLINUX_SYMBOL(__stop_error_injection_whitelist) = .;
#else
#define ERROR_INJECT_WHITELIST()
#endif
#ifdef CONFIG_EVENT_TRACING
#define FTRACE_EVENTS() . = ALIGN(8); \
VMLINUX_SYMBOL(__start_ftrace_events) = .; \
KEEP(*(_ftrace_events)) \
VMLINUX_SYMBOL(__stop_ftrace_events) = .; \
VMLINUX_SYMBOL(__start_ftrace_eval_maps) = .; \
KEEP(*(_ftrace_eval_map)) \
VMLINUX_SYMBOL(__stop_ftrace_eval_maps) = .;
#else
#define FTRACE_EVENTS()
#endif
#ifdef CONFIG_TRACING
#define TRACE_PRINTKS() VMLINUX_SYMBOL(__start___trace_bprintk_fmt) = .; \
KEEP(*(__trace_printk_fmt)) /* Trace_printk fmt' pointer */ \
VMLINUX_SYMBOL(__stop___trace_bprintk_fmt) = .;
#define TRACEPOINT_STR() VMLINUX_SYMBOL(__start___tracepoint_str) = .; \
KEEP(*(__tracepoint_str)) /* Trace_printk fmt' pointer */ \
VMLINUX_SYMBOL(__stop___tracepoint_str) = .;
#else
#define TRACE_PRINTKS()
#define TRACEPOINT_STR()
#endif
#ifdef CONFIG_FTRACE_SYSCALLS
#define TRACE_SYSCALLS() . = ALIGN(8); \
VMLINUX_SYMBOL(__start_syscalls_metadata) = .; \
KEEP(*(__syscalls_metadata)) \
VMLINUX_SYMBOL(__stop_syscalls_metadata) = .;
#else
#define TRACE_SYSCALLS()
#endif
#ifdef CONFIG_BPF_EVENTS
#define BPF_RAW_TP() STRUCT_ALIGN(); \
VMLINUX_SYMBOL(__start__bpf_raw_tp) = .; \
KEEP(*(__bpf_raw_tp_map)) \
VMLINUX_SYMBOL(__stop__bpf_raw_tp) = .;
#else
#define BPF_RAW_TP()
#endif
#ifdef CONFIG_SERIAL_EARLYCON
#define EARLYCON_TABLE() STRUCT_ALIGN(); \
VMLINUX_SYMBOL(__earlycon_table) = .; \
KEEP(*(__earlycon_table)) \
VMLINUX_SYMBOL(__earlycon_table_end) = .;
#else
#define EARLYCON_TABLE()
#endif
#define ___OF_TABLE(cfg, name) _OF_TABLE_##cfg(name)
#define __OF_TABLE(cfg, name) ___OF_TABLE(cfg, name)
#define OF_TABLE(cfg, name) __OF_TABLE(IS_ENABLED(cfg), name)
#define _OF_TABLE_0(name)
#define _OF_TABLE_1(name) \
. = ALIGN(8); \
VMLINUX_SYMBOL(__##name##_of_table) = .; \
KEEP(*(__##name##_of_table)) \
KEEP(*(__##name##_of_table_end))
#define TIMER_OF_TABLES() OF_TABLE(CONFIG_TIMER_OF, timer)
#define IRQCHIP_OF_MATCH_TABLE() OF_TABLE(CONFIG_IRQCHIP, irqchip)
#define CLK_OF_TABLES() OF_TABLE(CONFIG_COMMON_CLK, clk)
#define IOMMU_OF_TABLES() OF_TABLE(CONFIG_OF_IOMMU, iommu)
#define RESERVEDMEM_OF_TABLES() OF_TABLE(CONFIG_OF_RESERVED_MEM, reservedmem)
#define CPU_METHOD_OF_TABLES() OF_TABLE(CONFIG_SMP, cpu_method)
#define CPUIDLE_METHOD_OF_TABLES() OF_TABLE(CONFIG_CPU_IDLE, cpuidle_method)
#ifdef CONFIG_ACPI
#define ACPI_PROBE_TABLE(name) \
. = ALIGN(8); \
VMLINUX_SYMBOL(__##name##_acpi_probe_table) = .; \
KEEP(*(__##name##_acpi_probe_table)) \
VMLINUX_SYMBOL(__##name##_acpi_probe_table_end) = .;
#else
#define ACPI_PROBE_TABLE(name)
#endif
#define KERNEL_DTB() \
STRUCT_ALIGN(); \
VMLINUX_SYMBOL(__dtb_start) = .; \
KEEP(*(.dtb.init.rodata)) \
VMLINUX_SYMBOL(__dtb_end) = .;
/*
* .data section
*/
#define DATA_DATA \
*(.xiptext) \
*(DATA_MAIN) \
*(.ref.data) \
*(.data..shared_aligned) /* percpu related */ \
MEM_KEEP(init.data) \
MEM_KEEP(exit.data) \
*(.data.unlikely) \
VMLINUX_SYMBOL(__start_once) = .; \
*(.data.once) \
VMLINUX_SYMBOL(__end_once) = .; \
STRUCT_ALIGN(); \
*(__tracepoints) \
/* implement dynamic printk debug */ \
. = ALIGN(8); \
VMLINUX_SYMBOL(__start___jump_table) = .; \
KEEP(*(__jump_table)) \
VMLINUX_SYMBOL(__stop___jump_table) = .; \
. = ALIGN(8); \
VMLINUX_SYMBOL(__start___verbose) = .; \
KEEP(*(__verbose)) \
VMLINUX_SYMBOL(__stop___verbose) = .; \
LIKELY_PROFILE() \
BRANCH_PROFILE() \
TRACE_PRINTKS() \
BPF_RAW_TP() \
TRACEPOINT_STR()
/*
* Data section helpers
*/
#define NOSAVE_DATA \
. = ALIGN(PAGE_SIZE); \
VMLINUX_SYMBOL(__nosave_begin) = .; \
*(.data..nosave) \
. = ALIGN(PAGE_SIZE); \
VMLINUX_SYMBOL(__nosave_end) = .;
#define PAGE_ALIGNED_DATA(page_align) \
. = ALIGN(page_align); \
*(.data..page_aligned)
#define READ_MOSTLY_DATA(align) \
. = ALIGN(align); \
*(.data..read_mostly) \
. = ALIGN(align);
#define CACHELINE_ALIGNED_DATA(align) \
. = ALIGN(align); \
*(.data..cacheline_aligned)
#define INIT_TASK_DATA(align) \
. = ALIGN(align); \
VMLINUX_SYMBOL(__start_init_task) = .; \
VMLINUX_SYMBOL(init_thread_union) = .; \
VMLINUX_SYMBOL(init_stack) = .; \
*(.data..init_task) \
*(.data..init_thread_info) \
. = VMLINUX_SYMBOL(__start_init_task) + THREAD_SIZE; \
VMLINUX_SYMBOL(__end_init_task) = .;
/*
* Allow architectures to handle ro_after_init data on their
* own by defining an empty RO_AFTER_INIT_DATA.
*/
#ifndef RO_AFTER_INIT_DATA
#define RO_AFTER_INIT_DATA \
VMLINUX_SYMBOL(__start_ro_after_init) = .; \
*(.data..ro_after_init) \
VMLINUX_SYMBOL(__end_ro_after_init) = .;
#endif
/*
* Read only Data
*/
#define RO_DATA_SECTION(align) \
. = ALIGN((align)); \
.rodata : AT(ADDR(.rodata) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start_rodata) = .; \
*(.rodata) *(.rodata.*) \
RO_AFTER_INIT_DATA /* Read only after init */ \
KEEP(*(__vermagic)) /* Kernel version magic */ \
. = ALIGN(8); \
VMLINUX_SYMBOL(__start___tracepoints_ptrs) = .; \
KEEP(*(__tracepoints_ptrs)) /* Tracepoints: pointer array */ \
VMLINUX_SYMBOL(__stop___tracepoints_ptrs) = .; \
*(__tracepoints_strings)/* Tracepoints: strings */ \
} \
\
.rodata1 : AT(ADDR(.rodata1) - LOAD_OFFSET) { \
*(.rodata1) \
} \
\
/* PCI quirks */ \
.pci_fixup : AT(ADDR(.pci_fixup) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start_pci_fixups_early) = .; \
KEEP(*(.pci_fixup_early)) \
VMLINUX_SYMBOL(__end_pci_fixups_early) = .; \
VMLINUX_SYMBOL(__start_pci_fixups_header) = .; \
KEEP(*(.pci_fixup_header)) \
VMLINUX_SYMBOL(__end_pci_fixups_header) = .; \
VMLINUX_SYMBOL(__start_pci_fixups_final) = .; \
KEEP(*(.pci_fixup_final)) \
VMLINUX_SYMBOL(__end_pci_fixups_final) = .; \
VMLINUX_SYMBOL(__start_pci_fixups_enable) = .; \
KEEP(*(.pci_fixup_enable)) \
VMLINUX_SYMBOL(__end_pci_fixups_enable) = .; \
VMLINUX_SYMBOL(__start_pci_fixups_resume) = .; \
KEEP(*(.pci_fixup_resume)) \
VMLINUX_SYMBOL(__end_pci_fixups_resume) = .; \
VMLINUX_SYMBOL(__start_pci_fixups_resume_early) = .; \
KEEP(*(.pci_fixup_resume_early)) \
VMLINUX_SYMBOL(__end_pci_fixups_resume_early) = .; \
VMLINUX_SYMBOL(__start_pci_fixups_suspend) = .; \
KEEP(*(.pci_fixup_suspend)) \
VMLINUX_SYMBOL(__end_pci_fixups_suspend) = .; \
VMLINUX_SYMBOL(__start_pci_fixups_suspend_late) = .; \
KEEP(*(.pci_fixup_suspend_late)) \
VMLINUX_SYMBOL(__end_pci_fixups_suspend_late) = .; \
} \
\
/* Built-in firmware blobs */ \
.builtin_fw : AT(ADDR(.builtin_fw) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start_builtin_fw) = .; \
KEEP(*(.builtin_fw)) \
VMLINUX_SYMBOL(__end_builtin_fw) = .; \
} \
\
TRACEDATA \
\
/* Kernel symbol table: Normal symbols */ \
__ksymtab : AT(ADDR(__ksymtab) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___ksymtab) = .; \
KEEP(*(SORT(___ksymtab+*))) \
VMLINUX_SYMBOL(__stop___ksymtab) = .; \
} \
\
/* Kernel symbol table: GPL-only symbols */ \
__ksymtab_gpl : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___ksymtab_gpl) = .; \
KEEP(*(SORT(___ksymtab_gpl+*))) \
VMLINUX_SYMBOL(__stop___ksymtab_gpl) = .; \
} \
\
/* Kernel symbol table: Normal unused symbols */ \
__ksymtab_unused : AT(ADDR(__ksymtab_unused) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___ksymtab_unused) = .; \
KEEP(*(SORT(___ksymtab_unused+*))) \
VMLINUX_SYMBOL(__stop___ksymtab_unused) = .; \
} \
\
/* Kernel symbol table: GPL-only unused symbols */ \
__ksymtab_unused_gpl : AT(ADDR(__ksymtab_unused_gpl) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___ksymtab_unused_gpl) = .; \
KEEP(*(SORT(___ksymtab_unused_gpl+*))) \
VMLINUX_SYMBOL(__stop___ksymtab_unused_gpl) = .; \
} \
\
/* Kernel symbol table: GPL-future-only symbols */ \
__ksymtab_gpl_future : AT(ADDR(__ksymtab_gpl_future) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___ksymtab_gpl_future) = .; \
KEEP(*(SORT(___ksymtab_gpl_future+*))) \
VMLINUX_SYMBOL(__stop___ksymtab_gpl_future) = .; \
} \
\
/* Kernel symbol table: Normal symbols */ \
__kcrctab : AT(ADDR(__kcrctab) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___kcrctab) = .; \
KEEP(*(SORT(___kcrctab+*))) \
VMLINUX_SYMBOL(__stop___kcrctab) = .; \
} \
\
/* Kernel symbol table: GPL-only symbols */ \
__kcrctab_gpl : AT(ADDR(__kcrctab_gpl) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___kcrctab_gpl) = .; \
KEEP(*(SORT(___kcrctab_gpl+*))) \
VMLINUX_SYMBOL(__stop___kcrctab_gpl) = .; \
} \
\
/* Kernel symbol table: Normal unused symbols */ \
__kcrctab_unused : AT(ADDR(__kcrctab_unused) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___kcrctab_unused) = .; \
KEEP(*(SORT(___kcrctab_unused+*))) \
VMLINUX_SYMBOL(__stop___kcrctab_unused) = .; \
} \
\
/* Kernel symbol table: GPL-only unused symbols */ \
__kcrctab_unused_gpl : AT(ADDR(__kcrctab_unused_gpl) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___kcrctab_unused_gpl) = .; \
KEEP(*(SORT(___kcrctab_unused_gpl+*))) \
VMLINUX_SYMBOL(__stop___kcrctab_unused_gpl) = .; \
} \
\
/* Kernel symbol table: GPL-future-only symbols */ \
__kcrctab_gpl_future : AT(ADDR(__kcrctab_gpl_future) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___kcrctab_gpl_future) = .; \
KEEP(*(SORT(___kcrctab_gpl_future+*))) \
VMLINUX_SYMBOL(__stop___kcrctab_gpl_future) = .; \
} \
\
/* Kernel symbol table: strings */ \
__ksymtab_strings : AT(ADDR(__ksymtab_strings) - LOAD_OFFSET) { \
*(__ksymtab_strings) \
} \
\
/* __*init sections */ \
__init_rodata : AT(ADDR(__init_rodata) - LOAD_OFFSET) { \
*(.ref.rodata) \
MEM_KEEP(init.rodata) \
MEM_KEEP(exit.rodata) \
} \
\
/* Built-in module parameters. */ \
__param : AT(ADDR(__param) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___param) = .; \
KEEP(*(__param)) \
VMLINUX_SYMBOL(__stop___param) = .; \
} \
\
/* Built-in module versions. */ \
__modver : AT(ADDR(__modver) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___modver) = .; \
KEEP(*(__modver)) \
VMLINUX_SYMBOL(__stop___modver) = .; \
. = ALIGN((align)); \
VMLINUX_SYMBOL(__end_rodata) = .; \
} \
. = ALIGN((align));
/* RODATA & RO_DATA provided for backward compatibility.
* All archs are supposed to use RO_DATA() */
#define RODATA RO_DATA_SECTION(4096)
#define RO_DATA(align) RO_DATA_SECTION(align)
#define SECURITY_INIT \
.security_initcall.init : AT(ADDR(.security_initcall.init) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__security_initcall_start) = .; \
KEEP(*(.security_initcall.init)) \
VMLINUX_SYMBOL(__security_initcall_end) = .; \
}
/*
* .text section. Map to function alignment to avoid address changes
* during second ld run in second ld pass when generating System.map
*
* TEXT_MAIN here will match .text.fixup and .text.unlikely if dead
* code elimination is enabled, so these sections should be converted
* to use ".." first.
*/
#define TEXT_TEXT \
ALIGN_FUNCTION(); \
*(.text.hot TEXT_MAIN .text.fixup .text.unlikely) \
*(.text..refcount) \
*(.ref.text) \
MEM_KEEP(init.text) \
MEM_KEEP(exit.text) \
/* sched.text is aling to function alignment to secure we have same
* address even at second ld pass when generating System.map */
#define SCHED_TEXT \
ALIGN_FUNCTION(); \
VMLINUX_SYMBOL(__sched_text_start) = .; \
*(.sched.text) \
VMLINUX_SYMBOL(__sched_text_end) = .;
/* spinlock.text is aling to function alignment to secure we have same
* address even at second ld pass when generating System.map */
#define LOCK_TEXT \
ALIGN_FUNCTION(); \
VMLINUX_SYMBOL(__lock_text_start) = .; \
*(.spinlock.text) \
VMLINUX_SYMBOL(__lock_text_end) = .;
#define CPUIDLE_TEXT \
ALIGN_FUNCTION(); \
VMLINUX_SYMBOL(__cpuidle_text_start) = .; \
*(.cpuidle.text) \
VMLINUX_SYMBOL(__cpuidle_text_end) = .;
#define KPROBES_TEXT \
ALIGN_FUNCTION(); \
VMLINUX_SYMBOL(__kprobes_text_start) = .; \
*(.kprobes.text) \
VMLINUX_SYMBOL(__kprobes_text_end) = .;
#define ENTRY_TEXT \
ALIGN_FUNCTION(); \
VMLINUX_SYMBOL(__entry_text_start) = .; \
*(.entry.text) \
VMLINUX_SYMBOL(__entry_text_end) = .;
#define IRQENTRY_TEXT \
ALIGN_FUNCTION(); \
VMLINUX_SYMBOL(__irqentry_text_start) = .; \
*(.irqentry.text) \
VMLINUX_SYMBOL(__irqentry_text_end) = .;
#define SOFTIRQENTRY_TEXT \
ALIGN_FUNCTION(); \
VMLINUX_SYMBOL(__softirqentry_text_start) = .; \
*(.softirqentry.text) \
VMLINUX_SYMBOL(__softirqentry_text_end) = .;
/* Section used for early init (in .S files) */
#define HEAD_TEXT *(.head.text)
#define HEAD_TEXT_SECTION \
.head.text : AT(ADDR(.head.text) - LOAD_OFFSET) { \
HEAD_TEXT \
}
/*
* Exception table
*/
#define EXCEPTION_TABLE(align) \
. = ALIGN(align); \
__ex_table : AT(ADDR(__ex_table) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___ex_table) = .; \
KEEP(*(__ex_table)) \
VMLINUX_SYMBOL(__stop___ex_table) = .; \
}
/*
* Init task
*/
#define INIT_TASK_DATA_SECTION(align) \
. = ALIGN(align); \
.data..init_task : AT(ADDR(.data..init_task) - LOAD_OFFSET) { \
INIT_TASK_DATA(align) \
}
#ifdef CONFIG_CONSTRUCTORS
#define KERNEL_CTORS() . = ALIGN(8); \
VMLINUX_SYMBOL(__ctors_start) = .; \
KEEP(*(.ctors)) \
KEEP(*(SORT(.init_array.*))) \
KEEP(*(.init_array)) \
VMLINUX_SYMBOL(__ctors_end) = .;
#else
#define KERNEL_CTORS()
#endif
/* init and exit section handling */
#define INIT_DATA \
KEEP(*(SORT(___kentry+*))) \
*(.init.data) \
MEM_DISCARD(init.data) \
KERNEL_CTORS() \
MCOUNT_REC() \
*(.init.rodata) \
FTRACE_EVENTS() \
TRACE_SYSCALLS() \
KPROBE_BLACKLIST() \
ERROR_INJECT_WHITELIST() \
MEM_DISCARD(init.rodata) \
CLK_OF_TABLES() \
RESERVEDMEM_OF_TABLES() \
TIMER_OF_TABLES() \
IOMMU_OF_TABLES() \
CPU_METHOD_OF_TABLES() \
CPUIDLE_METHOD_OF_TABLES() \
KERNEL_DTB() \
IRQCHIP_OF_MATCH_TABLE() \
ACPI_PROBE_TABLE(irqchip) \
ACPI_PROBE_TABLE(timer) \
ACPI_PROBE_TABLE(iort) \
EARLYCON_TABLE()
#define INIT_TEXT \
*(.init.text) \
*(.text.startup) \
MEM_DISCARD(init.text)
#define EXIT_DATA \
*(.exit.data) \
*(.fini_array) \
*(.dtors) \
MEM_DISCARD(exit.data) \
MEM_DISCARD(exit.rodata)
#define EXIT_TEXT \
*(.exit.text) \
*(.text.exit) \
MEM_DISCARD(exit.text)
#define EXIT_CALL \
*(.exitcall.exit)
/*
* bss (Block Started by Symbol) - uninitialized data
* zeroed during startup
*/
#define SBSS(sbss_align) \
. = ALIGN(sbss_align); \
.sbss : AT(ADDR(.sbss) - LOAD_OFFSET) { \
*(.dynsbss) \
*(.sbss) \
*(.scommon) \
}
/*
* Allow archectures to redefine BSS_FIRST_SECTIONS to add extra
* sections to the front of bss.
*/
#ifndef BSS_FIRST_SECTIONS
#define BSS_FIRST_SECTIONS
#endif
#define BSS(bss_align) \
. = ALIGN(bss_align); \
.bss : AT(ADDR(.bss) - LOAD_OFFSET) { \
BSS_FIRST_SECTIONS \
*(.bss..page_aligned) \
*(.dynbss) \
*(BSS_MAIN) \
*(COMMON) \
}
/*
* DWARF debug sections.
* Symbols in the DWARF debugging sections are relative to
* the beginning of the section so we begin them at 0.
*/
#define DWARF_DEBUG \
/* DWARF 1 */ \
.debug 0 : { *(.debug) } \
.line 0 : { *(.line) } \
/* GNU DWARF 1 extensions */ \
.debug_srcinfo 0 : { *(.debug_srcinfo) } \
.debug_sfnames 0 : { *(.debug_sfnames) } \
/* DWARF 1.1 and DWARF 2 */ \
.debug_aranges 0 : { *(.debug_aranges) } \
.debug_pubnames 0 : { *(.debug_pubnames) } \
/* DWARF 2 */ \
.debug_info 0 : { *(.debug_info \
.gnu.linkonce.wi.*) } \
.debug_abbrev 0 : { *(.debug_abbrev) } \
.debug_line 0 : { *(.debug_line) } \
.debug_frame 0 : { *(.debug_frame) } \
.debug_str 0 : { *(.debug_str) } \
.debug_loc 0 : { *(.debug_loc) } \
.debug_macinfo 0 : { *(.debug_macinfo) } \
.debug_pubtypes 0 : { *(.debug_pubtypes) } \
/* DWARF 3 */ \
.debug_ranges 0 : { *(.debug_ranges) } \
/* SGI/MIPS DWARF 2 extensions */ \
.debug_weaknames 0 : { *(.debug_weaknames) } \
.debug_funcnames 0 : { *(.debug_funcnames) } \
.debug_typenames 0 : { *(.debug_typenames) } \
.debug_varnames 0 : { *(.debug_varnames) } \
/* GNU DWARF 2 extensions */ \
.debug_gnu_pubnames 0 : { *(.debug_gnu_pubnames) } \
.debug_gnu_pubtypes 0 : { *(.debug_gnu_pubtypes) } \
/* DWARF 4 */ \
.debug_types 0 : { *(.debug_types) } \
/* DWARF 5 */ \
.debug_macro 0 : { *(.debug_macro) } \
.debug_addr 0 : { *(.debug_addr) }
/* Stabs debugging sections. */
#define STABS_DEBUG \
.stab 0 : { *(.stab) } \
.stabstr 0 : { *(.stabstr) } \
.stab.excl 0 : { *(.stab.excl) } \
.stab.exclstr 0 : { *(.stab.exclstr) } \
.stab.index 0 : { *(.stab.index) } \
.stab.indexstr 0 : { *(.stab.indexstr) } \
.comment 0 : { *(.comment) }
#ifdef CONFIG_GENERIC_BUG
#define BUG_TABLE \
. = ALIGN(8); \
__bug_table : AT(ADDR(__bug_table) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start___bug_table) = .; \
KEEP(*(__bug_table)) \
VMLINUX_SYMBOL(__stop___bug_table) = .; \
}
#else
#define BUG_TABLE
#endif
#ifdef CONFIG_UNWINDER_ORC
#define ORC_UNWIND_TABLE \
. = ALIGN(4); \
.orc_unwind_ip : AT(ADDR(.orc_unwind_ip) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start_orc_unwind_ip) = .; \
KEEP(*(.orc_unwind_ip)) \
VMLINUX_SYMBOL(__stop_orc_unwind_ip) = .; \
} \
. = ALIGN(6); \
.orc_unwind : AT(ADDR(.orc_unwind) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start_orc_unwind) = .; \
KEEP(*(.orc_unwind)) \
VMLINUX_SYMBOL(__stop_orc_unwind) = .; \
} \
. = ALIGN(4); \
.orc_lookup : AT(ADDR(.orc_lookup) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(orc_lookup) = .; \
. += (((SIZEOF(.text) + LOOKUP_BLOCK_SIZE - 1) / \
LOOKUP_BLOCK_SIZE) + 1) * 4; \
VMLINUX_SYMBOL(orc_lookup_end) = .; \
}
#else
#define ORC_UNWIND_TABLE
#endif
#ifdef CONFIG_PM_TRACE
#define TRACEDATA \
. = ALIGN(4); \
.tracedata : AT(ADDR(.tracedata) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__tracedata_start) = .; \
KEEP(*(.tracedata)) \
VMLINUX_SYMBOL(__tracedata_end) = .; \
}
#else
#define TRACEDATA
#endif
#define NOTES \
.notes : AT(ADDR(.notes) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start_notes) = .; \
*(.note.*) \
VMLINUX_SYMBOL(__stop_notes) = .; \
}
#define INIT_SETUP(initsetup_align) \
. = ALIGN(initsetup_align); \
VMLINUX_SYMBOL(__setup_start) = .; \
KEEP(*(.init.setup)) \
VMLINUX_SYMBOL(__setup_end) = .;
#define INIT_CALLS_LEVEL(level) \
VMLINUX_SYMBOL(__initcall##level##_start) = .; \
KEEP(*(.initcall##level##.init)) \
KEEP(*(.initcall##level##s.init)) \
#define INIT_CALLS \
VMLINUX_SYMBOL(__initcall_start) = .; \
KEEP(*(.initcallearly.init)) \
INIT_CALLS_LEVEL(0) \
INIT_CALLS_LEVEL(1) \
INIT_CALLS_LEVEL(2) \
INIT_CALLS_LEVEL(3) \
INIT_CALLS_LEVEL(4) \
INIT_CALLS_LEVEL(5) \
INIT_CALLS_LEVEL(rootfs) \
INIT_CALLS_LEVEL(6) \
INIT_CALLS_LEVEL(7) \
VMLINUX_SYMBOL(__initcall_end) = .;
#define CON_INITCALL \
VMLINUX_SYMBOL(__con_initcall_start) = .; \
KEEP(*(.con_initcall.init)) \
VMLINUX_SYMBOL(__con_initcall_end) = .;
#define SECURITY_INITCALL \
VMLINUX_SYMBOL(__security_initcall_start) = .; \
KEEP(*(.security_initcall.init)) \
VMLINUX_SYMBOL(__security_initcall_end) = .;
#ifdef CONFIG_BLK_DEV_INITRD
#define INIT_RAM_FS \
. = ALIGN(4); \
VMLINUX_SYMBOL(__initramfs_start) = .; \
KEEP(*(.init.ramfs)) \
. = ALIGN(8); \
KEEP(*(.init.ramfs.info))
#else
#define INIT_RAM_FS
#endif
/*
* Memory encryption operates on a page basis. Since we need to clear
* the memory encryption mask for this section, it needs to be aligned
* on a page boundary and be a page-size multiple in length.
*
* Note: We use a separate section so that only this section gets
* decrypted to avoid exposing more than we wish.
*/
#ifdef CONFIG_AMD_MEM_ENCRYPT
#define PERCPU_DECRYPTED_SECTION \
. = ALIGN(PAGE_SIZE); \
*(.data..percpu..decrypted) \
. = ALIGN(PAGE_SIZE);
#else
#define PERCPU_DECRYPTED_SECTION
#endif
/*
* Default discarded sections.
*
* Some archs want to discard exit text/data at runtime rather than
* link time due to cross-section references such as alt instructions,
* bug table, eh_frame, etc. DISCARDS must be the last of output
* section definitions so that such archs put those in earlier section
* definitions.
*/
#define DISCARDS \
/DISCARD/ : { \
EXIT_TEXT \
EXIT_DATA \
EXIT_CALL \
*(.discard) \
*(.discard.*) \
}
/**
* PERCPU_INPUT - the percpu input sections
* @cacheline: cacheline size
*
* The core percpu section names and core symbols which do not rely
* directly upon load addresses.
*
* @cacheline is used to align subsections to avoid false cacheline
* sharing between subsections for different purposes.
*/
#define PERCPU_INPUT(cacheline) \
VMLINUX_SYMBOL(__per_cpu_start) = .; \
*(.data..percpu..first) \
. = ALIGN(PAGE_SIZE); \
*(.data..percpu..page_aligned) \
. = ALIGN(cacheline); \
*(.data..percpu..read_mostly) \
. = ALIGN(cacheline); \
*(.data..percpu) \
*(.data..percpu..shared_aligned) \
PERCPU_DECRYPTED_SECTION \
VMLINUX_SYMBOL(__per_cpu_end) = .;
/**
* PERCPU_VADDR - define output section for percpu area
* @cacheline: cacheline size
* @vaddr: explicit base address (optional)
* @phdr: destination PHDR (optional)
*
* Macro which expands to output section for percpu area.
*
* @cacheline is used to align subsections to avoid false cacheline
* sharing between subsections for different purposes.
*
* If @vaddr is not blank, it specifies explicit base address and all
* percpu symbols will be offset from the given address. If blank,
* @vaddr always equals @laddr + LOAD_OFFSET.
*
* @phdr defines the output PHDR to use if not blank. Be warned that
* output PHDR is sticky. If @phdr is specified, the next output
* section in the linker script will go there too. @phdr should have
* a leading colon.
*
* Note that this macros defines __per_cpu_load as an absolute symbol.
* If there is no need to put the percpu section at a predetermined
* address, use PERCPU_SECTION.
*/
#define PERCPU_VADDR(cacheline, vaddr, phdr) \
VMLINUX_SYMBOL(__per_cpu_load) = .; \
.data..percpu vaddr : AT(VMLINUX_SYMBOL(__per_cpu_load) \
- LOAD_OFFSET) { \
PERCPU_INPUT(cacheline) \
} phdr \
. = VMLINUX_SYMBOL(__per_cpu_load) + SIZEOF(.data..percpu);
/**
* PERCPU_SECTION - define output section for percpu area, simple version
* @cacheline: cacheline size
*
* Align to PAGE_SIZE and outputs output section for percpu area. This
* macro doesn't manipulate @vaddr or @phdr and __per_cpu_load and
* __per_cpu_start will be identical.
*
* This macro is equivalent to ALIGN(PAGE_SIZE); PERCPU_VADDR(@cacheline,,)
* except that __per_cpu_load is defined as a relative symbol against
* .data..percpu which is required for relocatable x86_32 configuration.
*/
#define PERCPU_SECTION(cacheline) \
. = ALIGN(PAGE_SIZE); \
.data..percpu : AT(ADDR(.data..percpu) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__per_cpu_load) = .; \
PERCPU_INPUT(cacheline) \
}
/*
* Definition of the high level *_SECTION macros
* They will fit only a subset of the architectures
*/
/*
* Writeable data.
* All sections are combined in a single .data section.
* The sections following CONSTRUCTORS are arranged so their
* typical alignment matches.
* A cacheline is typical/always less than a PAGE_SIZE so
* the sections that has this restriction (or similar)
* is located before the ones requiring PAGE_SIZE alignment.
* NOSAVE_DATA starts and ends with a PAGE_SIZE alignment which
* matches the requirement of PAGE_ALIGNED_DATA.
*
* use 0 as page_align if page_aligned data is not used */
#define RW_DATA_SECTION(cacheline, pagealigned, inittask) \
. = ALIGN(PAGE_SIZE); \
.data : AT(ADDR(.data) - LOAD_OFFSET) { \
INIT_TASK_DATA(inittask) \
NOSAVE_DATA \
PAGE_ALIGNED_DATA(pagealigned) \
CACHELINE_ALIGNED_DATA(cacheline) \
READ_MOSTLY_DATA(cacheline) \
DATA_DATA \
CONSTRUCTORS \
} \
BUG_TABLE \
#define INIT_TEXT_SECTION(inittext_align) \
. = ALIGN(inittext_align); \
.init.text : AT(ADDR(.init.text) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(_sinittext) = .; \
INIT_TEXT \
VMLINUX_SYMBOL(_einittext) = .; \
}
#define INIT_DATA_SECTION(initsetup_align) \
.init.data : AT(ADDR(.init.data) - LOAD_OFFSET) { \
INIT_DATA \
INIT_SETUP(initsetup_align) \
INIT_CALLS \
CON_INITCALL \
SECURITY_INITCALL \
INIT_RAM_FS \
}
#define BSS_SECTION(sbss_align, bss_align, stop_align) \
. = ALIGN(sbss_align); \
VMLINUX_SYMBOL(__bss_start) = .; \
SBSS(sbss_align) \
BSS(bss_align) \
. = ALIGN(stop_align); \
VMLINUX_SYMBOL(__bss_stop) = .;
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