mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-27 19:25:05 +07:00
c05b8c4474
ftrace_caller() depends on a modified regs->nip to detect if a certain
function has been livepatched. However, with KPROBES_ON_FTRACE, it is
possible for regs->nip to have been modified by the kprobes pre_handler
(jprobes, for instance). In this case, we do not want to invoke the
livepatch_handler so as not to consume the livepatch stack.
To distinguish between the two (kprobes and livepatch), we check if
there is an active kprobe on the current function. If there is, then we
know for sure that it must have modified the NIP as we don't support
livepatching a kprobe'd function. In this case, we simply skip the
livepatch_handler and branch to the new NIP. Otherwise, the
livepatch_handler is invoked.
Fixes: ead514d5fb ("powerpc/kprobes: Add support for KPROBES_ON_FTRACE")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
123 lines
3.8 KiB
C
123 lines
3.8 KiB
C
#ifndef _ASM_POWERPC_KPROBES_H
|
|
#define _ASM_POWERPC_KPROBES_H
|
|
|
|
#include <asm-generic/kprobes.h>
|
|
|
|
#ifdef __KERNEL__
|
|
/*
|
|
* Kernel Probes (KProbes)
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
*
|
|
* Copyright (C) IBM Corporation, 2002, 2004
|
|
*
|
|
* 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
|
|
* Probes initial implementation ( includes suggestions from
|
|
* Rusty Russell).
|
|
* 2004-Nov Modified for PPC64 by Ananth N Mavinakayanahalli
|
|
* <ananth@in.ibm.com>
|
|
*/
|
|
#include <linux/types.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/percpu.h>
|
|
#include <linux/module.h>
|
|
#include <asm/probes.h>
|
|
#include <asm/code-patching.h>
|
|
|
|
#ifdef CONFIG_KPROBES
|
|
#define __ARCH_WANT_KPROBES_INSN_SLOT
|
|
|
|
struct pt_regs;
|
|
struct kprobe;
|
|
|
|
typedef ppc_opcode_t kprobe_opcode_t;
|
|
|
|
extern kprobe_opcode_t optinsn_slot;
|
|
|
|
/* Optinsn template address */
|
|
extern kprobe_opcode_t optprobe_template_entry[];
|
|
extern kprobe_opcode_t optprobe_template_op_address[];
|
|
extern kprobe_opcode_t optprobe_template_call_handler[];
|
|
extern kprobe_opcode_t optprobe_template_insn[];
|
|
extern kprobe_opcode_t optprobe_template_call_emulate[];
|
|
extern kprobe_opcode_t optprobe_template_ret[];
|
|
extern kprobe_opcode_t optprobe_template_end[];
|
|
|
|
/* Fixed instruction size for powerpc */
|
|
#define MAX_INSN_SIZE 1
|
|
#define MAX_OPTIMIZED_LENGTH sizeof(kprobe_opcode_t) /* 4 bytes */
|
|
#define MAX_OPTINSN_SIZE (optprobe_template_end - optprobe_template_entry)
|
|
#define RELATIVEJUMP_SIZE sizeof(kprobe_opcode_t) /* 4 bytes */
|
|
|
|
#define flush_insn_slot(p) do { } while (0)
|
|
#define kretprobe_blacklist_size 0
|
|
|
|
void kretprobe_trampoline(void);
|
|
extern void arch_remove_kprobe(struct kprobe *p);
|
|
|
|
/* Architecture specific copy of original instruction */
|
|
struct arch_specific_insn {
|
|
/* copy of original instruction */
|
|
kprobe_opcode_t *insn;
|
|
/*
|
|
* Set in kprobes code, initially to 0. If the instruction can be
|
|
* eumulated, this is set to 1, if not, to -1.
|
|
*/
|
|
int boostable;
|
|
};
|
|
|
|
struct prev_kprobe {
|
|
struct kprobe *kp;
|
|
unsigned long status;
|
|
unsigned long saved_msr;
|
|
};
|
|
|
|
/* per-cpu kprobe control block */
|
|
struct kprobe_ctlblk {
|
|
unsigned long kprobe_status;
|
|
unsigned long kprobe_saved_msr;
|
|
struct pt_regs jprobe_saved_regs;
|
|
struct prev_kprobe prev_kprobe;
|
|
};
|
|
|
|
struct arch_optimized_insn {
|
|
kprobe_opcode_t copied_insn[1];
|
|
/* detour buffer */
|
|
kprobe_opcode_t *insn;
|
|
};
|
|
|
|
extern int kprobe_exceptions_notify(struct notifier_block *self,
|
|
unsigned long val, void *data);
|
|
extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
|
|
extern int kprobe_handler(struct pt_regs *regs);
|
|
extern int kprobe_post_handler(struct pt_regs *regs);
|
|
extern int is_current_kprobe_addr(unsigned long addr);
|
|
#ifdef CONFIG_KPROBES_ON_FTRACE
|
|
extern int skip_singlestep(struct kprobe *p, struct pt_regs *regs,
|
|
struct kprobe_ctlblk *kcb);
|
|
#else
|
|
static inline int skip_singlestep(struct kprobe *p, struct pt_regs *regs,
|
|
struct kprobe_ctlblk *kcb)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
#else
|
|
static inline int kprobe_handler(struct pt_regs *regs) { return 0; }
|
|
static inline int kprobe_post_handler(struct pt_regs *regs) { return 0; }
|
|
#endif /* CONFIG_KPROBES */
|
|
#endif /* __KERNEL__ */
|
|
#endif /* _ASM_POWERPC_KPROBES_H */
|