Files
linux/arch/powerpc/include/asm/livepatch.h
Christophe Leroy a4520b2527 powerpc/ftrace: Add support for livepatch to PPC32
PPC64 needs some special logic to properly set up the TOC.
See commit 85baa09549 ("powerpc/livepatch: Add live patching support
on ppc64le") for details.

PPC32 doesn't have TOC so it doesn't need that logic, so adding
LIVEPATCH support is straight forward.

Add CONFIG_LIVEPATCH_64 and move livepatch stack logic into that item.

Livepatch sample modules all work.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/63cb094125b6a6038c65eeac2abaabbabe63addd.1640017960.git.christophe.leroy@csgroup.eu
2022-02-07 21:03:10 +11:00

44 lines
1.2 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
static inline void klp_arch_set_pc(struct ftrace_regs *fregs, unsigned long ip)
{
struct pt_regs *regs = ftrace_get_regs(fregs);
regs_set_return_ip(regs, ip);
}
#define klp_get_ftrace_location klp_get_ftrace_location
static inline unsigned long klp_get_ftrace_location(unsigned long faddr)
{
/*
* Live patch works on PPC32 and only with -mprofile-kernel on PPC64. In
* both cases, the ftrace location is always within the first 16 bytes.
*/
return ftrace_location_range(faddr, faddr + 16);
}
#endif /* CONFIG_LIVEPATCH */
#ifdef CONFIG_LIVEPATCH_64
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
#endif /* _ASM_POWERPC_LIVEPATCH_H */