2026-01-21 18:59:54 +08:00

123 lines
3.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* livepatch.h - powerpc-specific Kernel Live Patching Core
*
* Copyright (C) 2015-2016, SUSE, IBM Corp.
*/
#ifndef _ASM_POWERPC_LIVEPATCH_H
#define _ASM_POWERPC_LIVEPATCH_H
#include <linux/module.h>
#include <linux/ftrace.h>
#include <linux/sched/task_stack.h>
#ifdef CONFIG_LIVEPATCH
#ifdef CONFIG_LIVEPATCH_FTRACE
static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)
{
regs->nip = ip;
}
#define klp_get_ftrace_location klp_get_ftrace_location
static inline unsigned long klp_get_ftrace_location(unsigned long faddr)
{
/*
* Live patch works only with -mprofile-kernel on PPC. In this case,
* the ftrace location is always within the first 16 bytes.
*/
return ftrace_location_range(faddr, faddr + 16);
}
#elif defined(CONFIG_LIVEPATCH_WO_FTRACE)
struct klp_func;
/* kernel livepatch instruction barrier */
#define klp_smp_isb() __smp_lwsync()
int arch_klp_patch_func(struct klp_func *func);
void arch_klp_unpatch_func(struct klp_func *func);
#if defined(CONFIG_PPC64)
/*
* use the livepatch stub to jump to the trampoline.
* It is similar to stub, but does not need to save
* and load R2.
* struct ppc64_klp_bstub_entry
*/
struct ppc64_klp_bstub_entry {
u32 jump[5];
u32 magic;
/* address for livepatch trampoline */
u64 trampoline;
};
#ifdef PPC64_ELF_ABI_v1
struct ppc64_klp_btramp_entry {
u32 jump[18];
u32 magic;
union {
struct ppc64_opd_entry funcdata;
unsigned long saved_entry[2];
};
};
#endif /* PPC64_ELF_ABI_v1 */
#define PPC64_INSN_SIZE 4
#define LJMP_INSN_SIZE (sizeof(struct ppc64_klp_bstub_entry) / PPC64_INSN_SIZE)
/* STUB_MAGIC 0x73747562 "stub" */
#define BRANCH_STUB_MAGIC 0x73747563 /* stub + 1 */
#define BRANCH_TRAMPOLINE_MAGIC 0x73747564 /* stub + 2 */
extern void livepatch_branch_stub(void);
extern void livepatch_branch_stub_end(void);
#ifdef PPC64_ELF_ABI_v1
extern void livepatch_branch_trampoline(void);
extern void livepatch_branch_trampoline_end(void);
#endif /* PPC64_ELF_ABI_v1 */
int livepatch_create_branch(unsigned long pc,
unsigned long trampoline,
unsigned long addr,
struct module *me);
struct arch_klp_data {
u32 old_insns[LJMP_INSN_SIZE];
#ifdef PPC64_ELF_ABI_v1
struct ppc64_klp_btramp_entry trampoline;
#else
unsigned long trampoline;
#endif /* PPC64_ELF_ABI_v1 */
};
#elif defined(CONFIG_PPC32)
#define PPC32_INSN_SIZE 4
#define LJMP_INSN_SIZE 4
struct arch_klp_data {
u32 old_insns[LJMP_INSN_SIZE];
};
#endif /* CONFIG_PPC64 */
long arch_klp_save_old_code(struct arch_klp_data *arch_data, void *old_func);
#endif /* CONFIG_LIVEPATCH_FTRACE */
#ifdef CONFIG_LIVEPATCH_STOP_MACHINE_CONSISTENCY
struct klp_patch;
int klp_check_calltrace(struct klp_patch *patch, int enable);
#endif
static inline void klp_init_thread_info(struct task_struct *p)
{
/* + 1 to account for STACK_END_MAGIC */
task_thread_info(p)->livepatch_sp = end_of_stack(p) + 1;
}
#else
static inline void klp_init_thread_info(struct task_struct *p) { }
#endif /* CONFIG_LIVEPATCH */
#endif /* _ASM_POWERPC_LIVEPATCH_H */