linux/arch/s390/kernel/entry.h
Martin Schwidefsky ce3dc44749 s390: add support for virtually mapped kernel stacks
With virtually mapped kernel stacks the kernel stack overflow detection
is now fault based, every stack has a guard page in the vmalloc space.
The panic_stack is renamed to nodat_stack and is used for all function
that need to run without DAT, e.g. memcpy_real or do_start_kdump.

The main effect is a reduction in the kernel image size as with vmap
stacks the old style overflow checking that adds two instructions per
function is not needed anymore. Result from bloat-o-meter:

add/remove: 20/1 grow/shrink: 13/26854 up/down: 2198/-216240 (-214042)

In regard to performance the micro-benchmark for fork has a hit of a
few microseconds, allocating 4 pages in vmalloc space is more expensive
compare to an order-2 page allocation. But with real workload I could
not find a noticeable difference.

Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-10-09 11:20:57 +02:00

93 lines
3.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ENTRY_H
#define _ENTRY_H
#include <linux/percpu.h>
#include <linux/types.h>
#include <linux/signal.h>
#include <asm/ptrace.h>
#include <asm/idle.h>
extern void *restart_stack;
extern unsigned long suspend_zero_pages;
void system_call(void);
void pgm_check_handler(void);
void ext_int_handler(void);
void io_int_handler(void);
void mcck_int_handler(void);
void restart_int_handler(void);
void restart_call_handler(void);
asmlinkage long do_syscall_trace_enter(struct pt_regs *regs);
asmlinkage void do_syscall_trace_exit(struct pt_regs *regs);
void do_protection_exception(struct pt_regs *regs);
void do_dat_exception(struct pt_regs *regs);
void addressing_exception(struct pt_regs *regs);
void data_exception(struct pt_regs *regs);
void default_trap_handler(struct pt_regs *regs);
void divide_exception(struct pt_regs *regs);
void execute_exception(struct pt_regs *regs);
void hfp_divide_exception(struct pt_regs *regs);
void hfp_overflow_exception(struct pt_regs *regs);
void hfp_significance_exception(struct pt_regs *regs);
void hfp_sqrt_exception(struct pt_regs *regs);
void hfp_underflow_exception(struct pt_regs *regs);
void illegal_op(struct pt_regs *regs);
void operand_exception(struct pt_regs *regs);
void overflow_exception(struct pt_regs *regs);
void privileged_op(struct pt_regs *regs);
void space_switch_exception(struct pt_regs *regs);
void special_op_exception(struct pt_regs *regs);
void specification_exception(struct pt_regs *regs);
void transaction_exception(struct pt_regs *regs);
void translation_exception(struct pt_regs *regs);
void vector_exception(struct pt_regs *regs);
void do_per_trap(struct pt_regs *regs);
void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str);
void syscall_trace(struct pt_regs *regs, int entryexit);
void kernel_stack_overflow(struct pt_regs * regs);
void do_signal(struct pt_regs *regs);
void handle_signal32(struct ksignal *ksig, sigset_t *oldset,
struct pt_regs *regs);
void do_notify_resume(struct pt_regs *regs);
void __init init_IRQ(void);
void do_IRQ(struct pt_regs *regs, int irq);
void do_restart(void);
void __init startup_init_nobss(void);
void __init startup_init(void);
void die(struct pt_regs *regs, const char *str);
int setup_profiling_timer(unsigned int multiplier);
void __init time_init(void);
int pfn_is_nosave(unsigned long);
void s390_early_resume(void);
unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip);
struct s390_mmap_arg_struct;
struct fadvise64_64_args;
struct old_sigaction;
long sys_rt_sigreturn(void);
long sys_sigreturn(void);
long sys_s390_personality(unsigned int personality);
long sys_s390_runtime_instr(int command, int signum);
long sys_s390_guarded_storage(int command, struct gs_cb __user *);
long sys_s390_pci_mmio_write(unsigned long, const void __user *, size_t);
long sys_s390_pci_mmio_read(unsigned long, void __user *, size_t);
long sys_s390_sthyi(unsigned long function_code, void __user *buffer, u64 __user *return_code, unsigned long flags);
DECLARE_PER_CPU(u64, mt_cycles[8]);
void gs_load_bc_cb(struct pt_regs *regs);
void set_fs_fixup(void);
unsigned long stack_alloc(void);
void stack_free(unsigned long stack);
#endif /* _ENTRY_H */