forked from Minki/linux
bc3703f21c
Using perf probe and libdw on kernel modules failed to find CFI data for symbols. The CFI data is stored in the .eh_frame section. The elfutils libdw is not able to extract the CFI data correctly, because the .eh_frame section requires "non-simple" relocations for kernel modules. The suggestion is to avoid these "non-simple" relocations by emitting the CFI data in the .debug_frame section. Let gcc emit respective directives by specifying the -fno-asynchronous-unwind-tables option. Using the .debug_frame section for CFI data, the .eh_frame section becomes unused and, thus, discard it for kernel and modules builds The vDSO requires the .eh_frame section and, hence, emit the CFI data in both, the .eh_frame and .debug_frame sections. See also discussion on elfutils/libdw bugzilla: https://sourceware.org/bugzilla/show_bug.cgi?id=22452 Suggested-by: Mark Wielaard <mark@klomp.org> Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
148 lines
3.1 KiB
ArmAsm
148 lines
3.1 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/* ld script to make s390 Linux kernel
|
|
* Written by Martin Schwidefsky (schwidefsky@de.ibm.com)
|
|
*/
|
|
|
|
#include <asm/thread_info.h>
|
|
#include <asm/page.h>
|
|
|
|
/*
|
|
* Put .bss..swapper_pg_dir as the first thing in .bss. This will
|
|
* make sure it has 16k alignment.
|
|
*/
|
|
#define BSS_FIRST_SECTIONS *(.bss..swapper_pg_dir)
|
|
|
|
/* Handle ro_after_init data on our own. */
|
|
#define RO_AFTER_INIT_DATA
|
|
|
|
#include <asm-generic/vmlinux.lds.h>
|
|
|
|
OUTPUT_FORMAT("elf64-s390", "elf64-s390", "elf64-s390")
|
|
OUTPUT_ARCH(s390:64-bit)
|
|
ENTRY(startup)
|
|
jiffies = jiffies_64;
|
|
|
|
PHDRS {
|
|
text PT_LOAD FLAGS(5); /* R_E */
|
|
data PT_LOAD FLAGS(7); /* RWE */
|
|
note PT_NOTE FLAGS(0); /* ___ */
|
|
}
|
|
|
|
SECTIONS
|
|
{
|
|
. = 0x00000000;
|
|
.text : {
|
|
/* Text and read-only data */
|
|
HEAD_TEXT
|
|
/*
|
|
* E.g. perf doesn't like symbols starting at address zero,
|
|
* therefore skip the initial PSW and channel program located
|
|
* at address zero and let _text start at 0x200.
|
|
*/
|
|
_text = 0x200;
|
|
TEXT_TEXT
|
|
SCHED_TEXT
|
|
CPUIDLE_TEXT
|
|
LOCK_TEXT
|
|
KPROBES_TEXT
|
|
IRQENTRY_TEXT
|
|
SOFTIRQENTRY_TEXT
|
|
*(.fixup)
|
|
*(.gnu.warning)
|
|
} :text = 0x0700
|
|
|
|
. = ALIGN(PAGE_SIZE);
|
|
_etext = .; /* End of text section */
|
|
|
|
NOTES :text :note
|
|
|
|
.dummy : { *(.dummy) } :data
|
|
|
|
RO_DATA_SECTION(PAGE_SIZE)
|
|
|
|
. = ALIGN(PAGE_SIZE);
|
|
_sdata = .; /* Start of data section */
|
|
|
|
. = ALIGN(PAGE_SIZE);
|
|
__start_ro_after_init = .;
|
|
.data..ro_after_init : {
|
|
*(.data..ro_after_init)
|
|
}
|
|
EXCEPTION_TABLE(16)
|
|
. = ALIGN(PAGE_SIZE);
|
|
__end_ro_after_init = .;
|
|
|
|
RW_DATA_SECTION(0x100, PAGE_SIZE, THREAD_SIZE)
|
|
|
|
_edata = .; /* End of data section */
|
|
|
|
/* will be freed after init */
|
|
. = ALIGN(PAGE_SIZE); /* Init code and data */
|
|
__init_begin = .;
|
|
|
|
. = ALIGN(PAGE_SIZE);
|
|
.init.text : AT(ADDR(.init.text) - LOAD_OFFSET) {
|
|
VMLINUX_SYMBOL(_sinittext) = . ;
|
|
INIT_TEXT
|
|
. = ALIGN(PAGE_SIZE);
|
|
VMLINUX_SYMBOL(_einittext) = . ;
|
|
}
|
|
|
|
/*
|
|
* .exit.text is discarded at runtime, not link time,
|
|
* to deal with references from __bug_table
|
|
*/
|
|
.exit.text : {
|
|
EXIT_TEXT
|
|
}
|
|
|
|
.exit.data : {
|
|
EXIT_DATA
|
|
}
|
|
|
|
/*
|
|
* struct alt_inst entries. From the header (alternative.h):
|
|
* "Alternative instructions for different CPU types or capabilities"
|
|
* Think locking instructions on spinlocks.
|
|
* Note, that it is a part of __init region.
|
|
*/
|
|
. = ALIGN(8);
|
|
.altinstructions : {
|
|
__alt_instructions = .;
|
|
*(.altinstructions)
|
|
__alt_instructions_end = .;
|
|
}
|
|
|
|
/*
|
|
* And here are the replacement instructions. The linker sticks
|
|
* them as binary blobs. The .altinstructions has enough data to
|
|
* get the address and the length of them to patch the kernel safely.
|
|
* Note, that it is a part of __init region.
|
|
*/
|
|
.altinstr_replacement : {
|
|
*(.altinstr_replacement)
|
|
}
|
|
|
|
/* early.c uses stsi, which requires page aligned data. */
|
|
. = ALIGN(PAGE_SIZE);
|
|
INIT_DATA_SECTION(0x100)
|
|
|
|
PERCPU_SECTION(0x100)
|
|
. = ALIGN(PAGE_SIZE);
|
|
__init_end = .; /* freed after init ends here */
|
|
|
|
BSS_SECTION(PAGE_SIZE, 4 * PAGE_SIZE, PAGE_SIZE)
|
|
|
|
_end = . ;
|
|
|
|
/* Debugging sections. */
|
|
STABS_DEBUG
|
|
DWARF_DEBUG
|
|
|
|
/* Sections to be discarded */
|
|
DISCARDS
|
|
/DISCARD/ : {
|
|
*(.eh_frame)
|
|
}
|
|
}
|