mirror of
https://github.com/torvalds/linux.git
synced 2024-12-25 12:21:37 +00:00
7ba6db2d68
Currently we always execute all insns out-of-line, including relative jmp's and call's. This assumes that even if regs->ip points to nowhere after the single-step, default_post_xol_op(UPROBE_FIX_IP) logic will update it correctly. However, this doesn't work if this regs->ip == xol_vaddr + insn_offset is not canonical. In this case CPU generates #GP and general_protection() kills the task which tries to execute this insn out-of-line. Now that we have uprobe_xol_ops we can teach uprobes to emulate these insns and solve the problem. This patch adds branch_xol_ops which has a single branch_emulate_op() hook, so far it can only handle rel8/32 relative jmp's. TODO: move ->fixup into the union along with rip_rela_target_address. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Jonathan Lebon <jlebon@redhat.com> Reviewed-by: Jim Keniston <jkenisto@us.ibm.com>
67 lines
1.6 KiB
C
67 lines
1.6 KiB
C
#ifndef _ASM_UPROBES_H
|
|
#define _ASM_UPROBES_H
|
|
/*
|
|
* User-space Probes (UProbes) for x86
|
|
*
|
|
* 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, 2008-2011
|
|
* Authors:
|
|
* Srikar Dronamraju
|
|
* Jim Keniston
|
|
*/
|
|
|
|
#include <linux/notifier.h>
|
|
|
|
typedef u8 uprobe_opcode_t;
|
|
|
|
#define MAX_UINSN_BYTES 16
|
|
#define UPROBE_XOL_SLOT_BYTES 128 /* to keep it cache aligned */
|
|
|
|
#define UPROBE_SWBP_INSN 0xcc
|
|
#define UPROBE_SWBP_INSN_SIZE 1
|
|
|
|
struct uprobe_xol_ops;
|
|
|
|
struct arch_uprobe {
|
|
union {
|
|
u8 insn[MAX_UINSN_BYTES];
|
|
u8 ixol[MAX_UINSN_BYTES];
|
|
};
|
|
|
|
u16 fixups;
|
|
const struct uprobe_xol_ops *ops;
|
|
|
|
union {
|
|
#ifdef CONFIG_X86_64
|
|
unsigned long rip_rela_target_address;
|
|
#endif
|
|
struct {
|
|
s32 offs;
|
|
u8 ilen;
|
|
} branch;
|
|
};
|
|
};
|
|
|
|
struct arch_uprobe_task {
|
|
#ifdef CONFIG_X86_64
|
|
unsigned long saved_scratch_register;
|
|
#endif
|
|
unsigned int saved_trap_nr;
|
|
unsigned int saved_tf;
|
|
};
|
|
|
|
#endif /* _ASM_UPROBES_H */
|