Commit 4ba069b8 authored by Michael Grundy's avatar Michael Grundy Committed by Martin Schwidefsky

[S390] add kprobes support.

Signed-off-by: default avatarMichael Grundy <grundym@us.ibm.com>
Signed-off-by: default avatarDavid Wilder <dwilder@us.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 5432114b
......@@ -487,8 +487,22 @@ source "drivers/net/Kconfig"
source "fs/Kconfig"
menu "Instrumentation Support"
source "arch/s390/oprofile/Kconfig"
config KPROBES
bool "Kprobes (EXPERIMENTAL)"
depends on EXPERIMENTAL && MODULES
help
Kprobes allows you to trap at almost any kernel address and
execute a callback function. register_kprobe() establishes
a probepoint and specifies the callback. Kprobes is useful
for kernel debugging, non-intrusive instrumentation and testing.
If in doubt, say "N".
endmenu
source "arch/s390/Kconfig.debug"
source "security/Kconfig"
......
......@@ -24,6 +24,7 @@ obj-$(CONFIG_COMPAT) += compat_linux.o compat_signal.o \
obj-$(CONFIG_VIRT_TIMER) += vtime.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-$(CONFIG_KPROBES) += kprobes.o
# Kexec part
S390_KEXEC_OBJS := machine_kexec.o crash.o
......
......@@ -505,6 +505,8 @@ pgm_no_vtime2:
mvc __THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS
mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
oi __TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
tm SP_PSW+1(%r15),0x01 # kernel per event ?
bz BASED(kernel_per)
l %r3,__LC_PGM_ILC # load program interruption code
la %r8,0x7f
nr %r8,%r3 # clear per-event-bit and ilc
......@@ -536,6 +538,16 @@ pgm_no_vtime3:
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
b BASED(sysc_do_svc)
#
# per was called from kernel, must be kprobes
#
kernel_per:
mvi SP_TRAP+1(%r15),0x28 # set trap indication to pgm check
la %r2,SP_PTREGS(%r15) # address of register-save area
l %r1,BASED(.Lhandle_per) # load adr. of per handler
la %r14,BASED(sysc_leave) # load adr. of system return
br %r1 # branch to do_single_step
/*
* IO interrupt handler routine
*/
......
......@@ -518,6 +518,8 @@ pgm_no_vtime2:
#endif
lg %r9,__LC_THREAD_INFO # load pointer to thread_info struct
lg %r1,__TI_task(%r9)
tm SP_PSW+1(%r15),0x01 # kernel per event ?
jz kernel_per
mvc __THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID
mvc __THREAD_per+__PER_address(8,%r1),__LC_PER_ADDRESS
mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
......@@ -553,6 +555,16 @@ pgm_no_vtime3:
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
j sysc_do_svc
#
# per was called from kernel, must be kprobes
#
kernel_per:
lhi %r0,__LC_PGM_OLD_PSW
sth %r0,SP_TRAP(%r15) # set trap indication to pgm check
la %r2,SP_PTREGS(%r15) # address of register-save area
larl %r14,sysc_leave # load adr. of system ret, no work
jg do_single_step # branch to do_single_step
/*
* IO interrupt handler routine
*/
......
This diff is collapsed.
......@@ -29,6 +29,7 @@
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/reboot.h>
#include <linux/kprobes.h>
#include <asm/system.h>
#include <asm/uaccess.h>
......@@ -39,6 +40,7 @@
#include <asm/s390_ext.h>
#include <asm/lowcore.h>
#include <asm/debug.h>
#include <asm/kdebug.h>
/* Called from entry.S only */
extern void handle_per_exception(struct pt_regs *regs);
......@@ -74,6 +76,20 @@ static int kstack_depth_to_print = 12;
static int kstack_depth_to_print = 20;
#endif /* CONFIG_64BIT */
ATOMIC_NOTIFIER_HEAD(s390die_chain);
int register_die_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_register(&s390die_chain, nb);
}
EXPORT_SYMBOL(register_die_notifier);
int unregister_die_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_unregister(&s390die_chain, nb);
}
EXPORT_SYMBOL(unregister_die_notifier);
/*
* For show_trace we have tree different stack to consider:
* - the panic stack which is used if the kernel stack has overflown
......@@ -305,8 +321,9 @@ report_user_fault(long interruption_code, struct pt_regs *regs)
#endif
}
static void inline do_trap(long interruption_code, int signr, char *str,
struct pt_regs *regs, siginfo_t *info)
static void __kprobes inline do_trap(long interruption_code, int signr,
char *str, struct pt_regs *regs,
siginfo_t *info)
{
/*
* We got all needed information from the lowcore and can
......@@ -315,6 +332,10 @@ static void inline do_trap(long interruption_code, int signr, char *str,
if (regs->psw.mask & PSW_MASK_PSTATE)
local_irq_enable();
if (notify_die(DIE_TRAP, str, regs, interruption_code,
interruption_code, signr) == NOTIFY_STOP)
return;
if (regs->psw.mask & PSW_MASK_PSTATE) {
struct task_struct *tsk = current;
......@@ -336,8 +357,12 @@ static inline void __user *get_check_address(struct pt_regs *regs)
return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
}
void do_single_step(struct pt_regs *regs)
void __kprobes do_single_step(struct pt_regs *regs)
{
if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
SIGTRAP) == NOTIFY_STOP){
return;
}
if ((current->ptrace & PT_PTRACED) != 0)
force_sig(SIGTRAP, current);
}
......
......@@ -24,6 +24,7 @@ SECTIONS
*(.text)
SCHED_TEXT
LOCK_TEXT
KPROBES_TEXT
*(.fixup)
*(.gnu.warning)
} = 0x0700
......
......@@ -25,10 +25,12 @@
#include <linux/console.h>
#include <linux/module.h>
#include <linux/hardirq.h>
#include <linux/kprobes.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/kdebug.h>
#ifndef CONFIG_64BIT
#define __FAIL_ADDR_MASK 0x7ffff000
......@@ -48,6 +50,38 @@ extern int sysctl_userprocess_debug;
extern void die(const char *,struct pt_regs *,long);
#ifdef CONFIG_KPROBES
ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
int register_page_fault_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_register(&notify_page_fault_chain, nb);
}
int unregister_page_fault_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_unregister(&notify_page_fault_chain, nb);
}
static inline int notify_page_fault(enum die_val val, const char *str,
struct pt_regs *regs, long err, int trap, int sig)
{
struct die_args args = {
.regs = regs,
.str = str,
.err = err,
.trapnr = trap,
.signr = sig
};
return atomic_notifier_call_chain(&notify_page_fault_chain, val, &args);
}
#else
static inline int notify_page_fault(enum die_val val, const char *str,
struct pt_regs *regs, long err, int trap, int sig)
{
return NOTIFY_DONE;
}
#endif
extern spinlock_t timerlist_lock;
/*
......@@ -159,7 +193,7 @@ static void do_sigsegv(struct pt_regs *regs, unsigned long error_code,
* 11 Page translation -> Not present (nullification)
* 3b Region third trans. -> Not present (nullification)
*/
static inline void
static inline void __kprobes
do_exception(struct pt_regs *regs, unsigned long error_code, int is_protection)
{
struct task_struct *tsk;
......@@ -173,6 +207,10 @@ do_exception(struct pt_regs *regs, unsigned long error_code, int is_protection)
tsk = current;
mm = tsk->mm;
if (notify_page_fault(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,
SIGSEGV) == NOTIFY_STOP)
return;
/*
* Check for low-address protection. This needs to be treated
* as a special case because the translation exception code
......
#ifndef _S390_KDEBUG_H
#define _S390_KDEBUG_H
/*
* Feb 2006 Ported to s390 <grundym@us.ibm.com>
*/
#include <linux/notifier.h>
struct pt_regs;
struct die_args {
struct pt_regs *regs;
const char *str;
long err;
int trapnr;
int signr;
};
/* Note - you should never unregister because that can race with NMIs.
* If you really want to do it first unregister - then synchronize_sched
* - then free.
*/
extern int register_die_notifier(struct notifier_block *);
extern int unregister_die_notifier(struct notifier_block *);
extern int register_page_fault_notifier(struct notifier_block *);
extern int unregister_page_fault_notifier(struct notifier_block *);
extern struct atomic_notifier_head s390die_chain;
enum die_val {
DIE_OOPS = 1,
DIE_BPT,
DIE_SSTEP,
DIE_PANIC,
DIE_NMI,
DIE_DIE,
DIE_NMIWATCHDOG,
DIE_KERNELDEBUG,
DIE_TRAP,
DIE_GPF,
DIE_CALL,
DIE_NMI_IPI,
DIE_PAGE_FAULT,
};
static inline int notify_die(enum die_val val, const char *str,
struct pt_regs *regs, long err, int trap, int sig)
{
struct die_args args = {
.regs = regs,
.str = str,
.err = err,
.trapnr = trap,
.signr = sig
};
return atomic_notifier_call_chain(&s390die_chain, val, &args);
}
#endif
#ifndef _ASM_S390_KPROBES_H
#define _ASM_S390_KPROBES_H
/*
* 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, 2006
*
* 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>
* 2005-Dec Used as a template for s390 by Mike Grundy
* <grundym@us.ibm.com>
*/
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/percpu.h>
#define __ARCH_WANT_KPROBES_INSN_SLOT
struct pt_regs;
struct kprobe;
typedef u16 kprobe_opcode_t;
#define BREAKPOINT_INSTRUCTION 0x0002
/* Maximum instruction size is 3 (16bit) halfwords: */
#define MAX_INSN_SIZE 0x0003
#define MAX_STACK_SIZE 64
#define MIN_STACK_SIZE(ADDR) (((MAX_STACK_SIZE) < \
(((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR))) \
? (MAX_STACK_SIZE) \
: (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR)))
#define JPROBE_ENTRY(pentry) (kprobe_opcode_t *)(pentry)
#define ARCH_SUPPORTS_KRETPROBES
#define ARCH_INACTIVE_KPROBE_COUNT 0
#define KPROBE_SWAP_INST 0x10
#define FIXUP_PSW_NORMAL 0x08
#define FIXUP_BRANCH_NOT_TAKEN 0x04
#define FIXUP_RETURN_REGISTER 0x02
#define FIXUP_NOT_REQUIRED 0x01
/* Architecture specific copy of original instruction */
struct arch_specific_insn {
/* copy of original instruction */
kprobe_opcode_t *insn;
int fixup;
int ilen;
int reg;
};
struct ins_replace_args {
kprobe_opcode_t *ptr;
kprobe_opcode_t old;
kprobe_opcode_t new;
};
struct prev_kprobe {
struct kprobe *kp;
unsigned long status;
unsigned long saved_psw;
unsigned long kprobe_saved_imask;
unsigned long kprobe_saved_ctl[3];
};
/* per-cpu kprobe control block */
struct kprobe_ctlblk {
unsigned long kprobe_status;
unsigned long kprobe_saved_imask;
unsigned long kprobe_saved_ctl[3];
struct pt_regs jprobe_saved_regs;
unsigned long jprobe_saved_r14;
unsigned long jprobe_saved_r15;
struct prev_kprobe prev_kprobe;
kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
};
void arch_remove_kprobe(struct kprobe *p);
void kretprobe_trampoline(void);
int is_prohibited_opcode(kprobe_opcode_t *instruction);
void get_instruction_type(struct arch_specific_insn *ainsn);
#define flush_insn_slot(p) do { } while (0)
#endif /* _ASM_S390_KPROBES_H */
#ifdef CONFIG_KPROBES
extern int kprobe_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data);
#else /* !CONFIG_KPROBES */
static inline int kprobe_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data)
{
return 0;
}
#endif
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