Commit 753c4dd6 authored by Martin Schwidefsky's avatar Martin Schwidefsky

[S390] ptrace changes

* System call parameter and result access functions
* Add tracehook calls
* Split syscall_trace into two functions do_syscall_trace_enter and
  do_syscall_trace_exit
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent d86730bb
......@@ -74,6 +74,7 @@ config S390
select HAVE_KPROBES
select HAVE_KRETPROBES
select HAVE_KVM if 64BIT
select HAVE_ARCH_TRACEHOOK
source "init/Kconfig"
......
......@@ -490,6 +490,7 @@ extern void user_disable_single_step(struct task_struct *);
#define user_mode(regs) (((regs)->psw.mask & PSW_MASK_PSTATE) != 0)
#define instruction_pointer(regs) ((regs)->psw.addr & PSW_ADDR_INSN)
#define user_stack_pointer(regs)((regs)->gprs[15])
#define regs_return_value(regs)((regs)->gprs[2])
#define profile_pc(regs) instruction_pointer(regs)
extern void show_regs(struct pt_regs * regs);
......
/*
* Access to user system call parameters and results
*
* Copyright IBM Corp. 2008
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License (version 2 only)
* as published by the Free Software Foundation.
*/
#ifndef _ASM_SYSCALL_H
#define _ASM_SYSCALL_H 1
#include <asm/ptrace.h>
static inline long syscall_get_nr(struct task_struct *task,
struct pt_regs *regs)
{
if (regs->trap != __LC_SVC_OLD_PSW)
return -1;
return regs->gprs[2];
}
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
regs->gprs[2] = regs->orig_gpr2;
}
static inline long syscall_get_error(struct task_struct *task,
struct pt_regs *regs)
{
return (regs->gprs[2] >= -4096UL) ? -regs->gprs[2] : 0;
}
static inline long syscall_get_return_value(struct task_struct *task,
struct pt_regs *regs)
{
return regs->gprs[2];
}
static inline void syscall_set_return_value(struct task_struct *task,
struct pt_regs *regs,
int error, long val)
{
regs->gprs[2] = error ? -error : val;
}
static inline void syscall_get_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned int i, unsigned int n,
unsigned long *args)
{
BUG_ON(i + n > 6);
#ifdef CONFIG_COMPAT
if (test_tsk_thread_flag(task, TIF_31BIT)) {
if (i + n == 6)
args[--n] = (u32) regs->args[0];
while (n-- > 0)
args[n] = (u32) regs->gprs[2 + i + n];
}
#endif
if (i + n == 6)
args[--n] = regs->args[0];
memcpy(args, &regs->gprs[2 + i], n * sizeof(args[0]));
}
static inline void syscall_set_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned int i, unsigned int n,
const unsigned long *args)
{
BUG_ON(i + n > 6);
if (i + n == 6)
regs->args[0] = args[--n];
memcpy(&regs->gprs[2 + i], args, n * sizeof(args[0]));
}
#endif /* _ASM_SYSCALL_H */
......@@ -86,6 +86,7 @@ static inline struct thread_info *current_thread_info(void)
* thread information flags bit numbers
*/
#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
#define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
#define TIF_SIGPENDING 2 /* signal pending */
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
#define TIF_RESTART_SVC 4 /* restart svc with new svc number */
......@@ -100,6 +101,7 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_RESTORE_SIGMASK 20 /* restore signal mask in do_signal() */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
......
......@@ -49,9 +49,9 @@ SP_ILC = STACK_FRAME_OVERHEAD + __PT_ILC
SP_TRAP = STACK_FRAME_OVERHEAD + __PT_TRAP
SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE
_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
_TIF_MCCK_PENDING | _TIF_RESTART_SVC | _TIF_SINGLE_STEP )
_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
_TIF_MCCK_PENDING)
STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
......@@ -318,6 +318,8 @@ sysc_work:
bo BASED(sysc_reschedule)
tm __TI_flags+3(%r9),_TIF_SIGPENDING
bnz BASED(sysc_sigpending)
tm __TI_flags+3(%r9),_TIF_NOTIFY_RESUME
bnz BASED(sysc_notify_resume)
tm __TI_flags+3(%r9),_TIF_RESTART_SVC
bo BASED(sysc_restart)
tm __TI_flags+3(%r9),_TIF_SINGLE_STEP
......@@ -355,6 +357,16 @@ sysc_sigpending:
bo BASED(sysc_singlestep)
b BASED(sysc_work_loop)
#
# _TIF_NOTIFY_RESUME is set, call do_notify_resume
#
sysc_notify_resume:
la %r2,SP_PTREGS(%r15) # load pt_regs
l %r1,BASED(.Ldo_notify_resume)
la %r14,BASED(sysc_work_loop)
br %r1 # call do_notify_resume
#
# _TIF_RESTART_SVC is set, set up registers and restart svc
#
......@@ -378,20 +390,21 @@ sysc_singlestep:
br %r1 # branch to do_single_step
#
# call trace before and after sys_call
# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
# and after the system call
#
sysc_tracesys:
l %r1,BASED(.Ltrace)
l %r1,BASED(.Ltrace_entry)
la %r2,SP_PTREGS(%r15) # load pt_regs
la %r3,0
srl %r7,2
st %r7,SP_R2(%r15)
basr %r14,%r1
clc SP_R2(4,%r15),BASED(.Lnr_syscalls)
cl %r2,BASED(.Lnr_syscalls)
bnl BASED(sysc_tracenogo)
l %r8,BASED(.Lsysc_table)
l %r7,SP_R2(%r15) # strace might have changed the
sll %r7,2 # system call
lr %r7,%r2
sll %r7,2 # *4
l %r8,0(%r7,%r8)
sysc_tracego:
lm %r3,%r6,SP_R3(%r15)
......@@ -401,9 +414,8 @@ sysc_tracego:
sysc_tracenogo:
tm __TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
bz BASED(sysc_return)
l %r1,BASED(.Ltrace)
l %r1,BASED(.Ltrace_exit)
la %r2,SP_PTREGS(%r15) # load pt_regs
la %r3,1
la %r14,BASED(sysc_return)
br %r1
......@@ -666,6 +678,8 @@ io_work_loop:
bo BASED(io_reschedule)
tm __TI_flags+3(%r9),_TIF_SIGPENDING
bnz BASED(io_sigpending)
tm __TI_flags+3(%r9),_TIF_NOTIFY_RESUME
bnz BASED(io_notify_resume)
b BASED(io_restore)
io_work_done:
......@@ -704,6 +718,19 @@ io_sigpending:
TRACE_IRQS_OFF
b BASED(io_work_loop)
#
# _TIF_SIGPENDING is set, call do_signal
#
io_notify_resume:
TRACE_IRQS_ON
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
la %r2,SP_PTREGS(%r15) # load pt_regs
l %r1,BASED(.Ldo_notify_resume)
basr %r14,%r1 # call do_signal
stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
TRACE_IRQS_OFF
b BASED(io_work_loop)
/*
* External interrupt handler routine
*/
......@@ -1070,6 +1097,8 @@ cleanup_io_leave_insn:
.Ldo_IRQ: .long do_IRQ
.Ldo_extint: .long do_extint
.Ldo_signal: .long do_signal
.Ldo_notify_resume:
.long do_notify_resume
.Lhandle_per: .long do_single_step
.Ldo_execve: .long do_execve
.Lexecve_tail: .long execve_tail
......@@ -1079,7 +1108,8 @@ cleanup_io_leave_insn:
.Lpreempt_schedule_irq:
.long preempt_schedule_irq
#endif
.Ltrace: .long syscall_trace
.Ltrace_entry: .long do_syscall_trace_enter
.Ltrace_exit: .long do_syscall_trace_exit
.Lschedtail: .long schedule_tail
.Lsysc_table: .long sys_call_table
#ifdef CONFIG_TRACE_IRQFLAGS
......
......@@ -52,9 +52,9 @@ SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE
STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
STACK_SIZE = 1 << STACK_SHIFT
_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
_TIF_MCCK_PENDING | _TIF_RESTART_SVC | _TIF_SINGLE_STEP )
_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
_TIF_MCCK_PENDING)
#define BASED(name) name-system_call(%r13)
......@@ -310,6 +310,8 @@ sysc_work:
jo sysc_reschedule
tm __TI_flags+7(%r9),_TIF_SIGPENDING
jnz sysc_sigpending
tm __TI_flags+7(%r9),_TIF_NOTIFY_RESUME
jnz sysc_notify_resume
tm __TI_flags+7(%r9),_TIF_RESTART_SVC
jo sysc_restart
tm __TI_flags+7(%r9),_TIF_SINGLE_STEP
......@@ -344,6 +346,14 @@ sysc_sigpending:
jo sysc_singlestep
j sysc_work_loop
#
# _TIF_NOTIFY_RESUME is set, call do_notify_resume
#
sysc_notify_resume:
la %r2,SP_PTREGS(%r15) # load pt_regs
larl %r14,sysc_work_loop
jg do_notify_resume # call do_notify_resume
#
# _TIF_RESTART_SVC is set, set up registers and restart svc
#
......@@ -367,20 +377,19 @@ sysc_singlestep:
jg do_single_step # branch to do_sigtrap
#
# call syscall_trace before and after system call
# special linkage: %r12 contains the return address for trace_svc
# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
# and after the system call
#
sysc_tracesys:
la %r2,SP_PTREGS(%r15) # load pt_regs
la %r3,0
srl %r7,2
stg %r7,SP_R2(%r15)
brasl %r14,syscall_trace
brasl %r14,do_syscall_trace_enter
lghi %r0,NR_syscalls
clg %r0,SP_R2(%r15)
clgr %r0,%r2
jnh sysc_tracenogo
lg %r7,SP_R2(%r15) # strace might have changed the
sll %r7,2 # system call
slag %r7,%r2,2 # *4
lgf %r8,0(%r7,%r10)
sysc_tracego:
lmg %r3,%r6,SP_R3(%r15)
......@@ -391,9 +400,8 @@ sysc_tracenogo:
tm __TI_flags+7(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
jz sysc_return
la %r2,SP_PTREGS(%r15) # load pt_regs
la %r3,1
larl %r14,sysc_return # return point is sysc_return
jg syscall_trace
jg do_syscall_trace_exit
#
# a new process exits the kernel with ret_from_fork
......@@ -672,6 +680,8 @@ io_work_loop:
jo io_reschedule
tm __TI_flags+7(%r9),_TIF_SIGPENDING
jnz io_sigpending
tm __TI_flags+7(%r9),_TIF_NOTIFY_RESUME
jnz io_notify_resume
j io_restore
io_work_done:
......@@ -712,6 +722,18 @@ io_sigpending:
TRACE_IRQS_OFF
j io_work_loop
#
# _TIF_NOTIFY_RESUME or is set, call do_notify_resume
#
io_notify_resume:
TRACE_IRQS_ON
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
la %r2,SP_PTREGS(%r15) # load pt_regs
brasl %r14,do_notify_resume # call do_notify_resume
stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
TRACE_IRQS_OFF
j io_work_loop
/*
* External interrupt handler routine
*/
......
......@@ -35,6 +35,7 @@
#include <linux/signal.h>
#include <linux/elf.h>
#include <linux/regset.h>
#include <linux/tracehook.h>
#include <asm/segment.h>
#include <asm/page.h>
......@@ -639,40 +640,44 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
}
#endif
asmlinkage void
syscall_trace(struct pt_regs *regs, int entryexit)
asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
{
if (unlikely(current->audit_context) && entryexit)
audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]), regs->gprs[2]);
if (!test_thread_flag(TIF_SYSCALL_TRACE))
goto out;
if (!(current->ptrace & PT_PTRACED))
goto out;
ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
? 0x80 : 0));
long ret;
/*
* If the debuffer has set an invalid system call number,
* we prepare to skip the system call restart handling.
* The sysc_tracesys code in entry.S stored the system
* call number to gprs[2].
*/
if (!entryexit && regs->gprs[2] >= NR_syscalls)
ret = regs->gprs[2];
if (test_thread_flag(TIF_SYSCALL_TRACE) &&
(tracehook_report_syscall_entry(regs) ||
regs->gprs[2] >= NR_syscalls)) {
/*
* Tracing decided this syscall should not happen or the
* debugger stored an invalid system call number. Skip
* the system call and the system call restart handling.
*/
regs->trap = -1;
/*
* this isn't the same as continuing with a signal, but it will do
* for normal use. strace only continues with a signal if the
* stopping signal is not SIGTRAP. -brl
*/
if (current->exit_code) {
send_sig(current->exit_code, current, 1);
current->exit_code = 0;
ret = -1;
}
out:
if (unlikely(current->audit_context) && !entryexit)
audit_syscall_entry(test_thread_flag(TIF_31BIT)?AUDIT_ARCH_S390:AUDIT_ARCH_S390X,
regs->gprs[2], regs->orig_gpr2, regs->gprs[3],
regs->gprs[4], regs->gprs[5]);
if (unlikely(current->audit_context))
audit_syscall_entry(test_thread_flag(TIF_31BIT) ?
AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
regs->gprs[2], regs->orig_gpr2,
regs->gprs[3], regs->gprs[4],
regs->gprs[5]);
return ret;
}
asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
{
if (unlikely(current->audit_context))
audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
regs->gprs[2]);
if (test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, 0);
}
/*
......
......@@ -24,6 +24,7 @@
#include <linux/tty.h>
#include <linux/personality.h>
#include <linux/binfmts.h>
#include <linux/tracehook.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/lowcore.h>
......@@ -507,6 +508,12 @@ void do_signal(struct pt_regs *regs)
*/
if (current->thread.per_info.single_step)
set_thread_flag(TIF_SINGLE_STEP);
/*
* Let tracing know that we've done the handler setup.
*/
tracehook_signal_handler(signr, &info, &ka, regs,
test_thread_flag(TIF_SINGLE_STEP));
}
return;
}
......@@ -526,3 +533,9 @@ void do_signal(struct pt_regs *regs)
set_thread_flag(TIF_RESTART_SVC);
}
}
void do_notify_resume(struct pt_regs *regs)
{
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
}
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