src/patches/suse-2.6.27.25/patches.trace/s390-utrace-enablement.patch

   1 Subject: Backport s390 kernel components required for utrace enablement
   2
   3 From: Ananth N. Mavinakayanahalli <ananth@in.ibm.com>
   4
   5 References: bnc#442709
   6
   7 Acked-by: John Jolly <jjolly@novell.com>
   8 ---
   9  arch/s390/Kconfig                   |    1
  10  arch/s390/include/asm/ptrace.h      |    1
  11  arch/s390/include/asm/syscall.h     |   80 ++++++++++++++++++++++++++++++++++++
  12  arch/s390/include/asm/thread_info.h |    2
  13  arch/s390/kernel/entry.S            |   50 ++++++++++++++++++----
  14  arch/s390/kernel/entry64.S          |   42 ++++++++++++++----
  15  arch/s390/kernel/ptrace.c           |   75 +++++++++++++++++++++------------
  16  arch/s390/kernel/signal.c           |   13 +++++
  17  8 files changed, 216 insertions(+), 48 deletions(-)
  18
  19 --- a/arch/s390/include/asm/ptrace.h
  20 +++ b/arch/s390/include/asm/ptrace.h
  21 @@ -490,6 +490,7 @@ extern void user_disable_single_step(str
  22
  23  #define user_mode(regs) (((regs)->psw.mask & PSW_MASK_PSTATE) != 0)
  24  #define instruction_pointer(regs) ((regs)->psw.addr & PSW_ADDR_INSN)
  25 +#define user_stack_pointer(regs)((regs)->gprs[15])
  26  #define regs_return_value(regs)((regs)->gprs[2])
  27  #define profile_pc(regs) instruction_pointer(regs)
  28  extern void show_regs(struct pt_regs * regs);
  29 --- /dev/null
  30 +++ b/arch/s390/include/asm/syscall.h
  31 @@ -0,0 +1,80 @@
  32 +/*
  33 + * Access to user system call parameters and results
  34 + *
  35 + *  Copyright IBM Corp. 2008
  36 + *  Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
  37 + *
  38 + * This program is free software; you can redistribute it and/or modify
  39 + * it under the terms of the GNU General Public License (version 2 only)
  40 + * as published by the Free Software Foundation.
  41 + */
  42 +
  43 +#ifndef _ASM_SYSCALL_H
  44 +#define _ASM_SYSCALL_H 1
  45 +
  46 +#include <asm/ptrace.h>
  47 +
  48 +static inline long syscall_get_nr(struct task_struct *task,
  49 +                                 struct pt_regs *regs)
  50 +{
  51 +       if (regs->trap != __LC_SVC_OLD_PSW)
  52 +               return -1;
  53 +       return regs->gprs[2];
  54 +}
  55 +
  56 +static inline void syscall_rollback(struct task_struct *task,
  57 +                                   struct pt_regs *regs)
  58 +{
  59 +       regs->gprs[2] = regs->orig_gpr2;
  60 +}
  61 +
  62 +static inline long syscall_get_error(struct task_struct *task,
  63 +                                    struct pt_regs *regs)
  64 +{
  65 +       return (regs->gprs[2] >= -4096UL) ? -regs->gprs[2] : 0;
  66 +}
  67 +
  68 +static inline long syscall_get_return_value(struct task_struct *task,
  69 +                                           struct pt_regs *regs)
  70 +{
  71 +       return regs->gprs[2];
  72 +}
  73 +
  74 +static inline void syscall_set_return_value(struct task_struct *task,
  75 +                                           struct pt_regs *regs,
  76 +                                           int error, long val)
  77 +{
  78 +       regs->gprs[2] = error ? -error : val;
  79 +}
  80 +
  81 +static inline void syscall_get_arguments(struct task_struct *task,
  82 +                                        struct pt_regs *regs,
  83 +                                        unsigned int i, unsigned int n,
  84 +                                        unsigned long *args)
  85 +{
  86 +       BUG_ON(i + n > 6);
  87 +#ifdef CONFIG_COMPAT
  88 +       if (test_tsk_thread_flag(task, TIF_31BIT)) {
  89 +               if (i + n == 6)
  90 +                       args[--n] = (u32) regs->args[0];
  91 +               while (n-- > 0)
  92 +                       args[n] = (u32) regs->gprs[2 + i + n];
  93 +       }
  94 +#endif
  95 +       if (i + n == 6)
  96 +               args[--n] = regs->args[0];
  97 +       memcpy(args, &regs->gprs[2 + i], n * sizeof(args[0]));
  98 +}
  99 +
 100 +static inline void syscall_set_arguments(struct task_struct *task,
 101 +                                        struct pt_regs *regs,
 102 +                                        unsigned int i, unsigned int n,
 103 +                                        const unsigned long *args)
 104 +{
 105 +       BUG_ON(i + n > 6);
 106 +       if (i + n == 6)
 107 +               regs->args[0] = args[--n];
 108 +       memcpy(&regs->gprs[2 + i], args, n * sizeof(args[0]));
 109 +}
 110 +
 111 +#endif /* _ASM_SYSCALL_H */
 112 --- a/arch/s390/include/asm/thread_info.h
 113 +++ b/arch/s390/include/asm/thread_info.h
 114 @@ -86,6 +86,7 @@ static inline struct thread_info *curren
 115   * thread information flags bit numbers
 116   */
 117  #define TIF_SYSCALL_TRACE      0       /* syscall trace active */
 118 +#define TIF_NOTIFY_RESUME      1       /* callback before returning to user */
 119  #define TIF_SIGPENDING         2       /* signal pending */
 120  #define TIF_NEED_RESCHED       3       /* rescheduling necessary */
 121  #define TIF_RESTART_SVC                4       /* restart svc with new svc number */
 122 @@ -101,6 +102,7 @@ static inline struct thread_info *curren
 123  #define TIF_FREEZE             21
 124
 125  #define _TIF_SYSCALL_TRACE     (1<<TIF_SYSCALL_TRACE)
 126 +#define _TIF_NOTIFY_RESUME     (1<<TIF_NOTIFY_RESUME)
 127  #define _TIF_RESTORE_SIGMASK   (1<<TIF_RESTORE_SIGMASK)
 128  #define _TIF_SIGPENDING                (1<<TIF_SIGPENDING)
 129  #define _TIF_NEED_RESCHED      (1<<TIF_NEED_RESCHED)
 130 --- a/arch/s390/Kconfig
 131 +++ b/arch/s390/Kconfig
 132 @@ -76,6 +76,7 @@ config S390
 133         select HAVE_KPROBES
 134         select HAVE_KRETPROBES
 135         select HAVE_KVM if 64BIT
 136 +       select HAVE_ARCH_TRACEHOOK
 137
 138  source "init/Kconfig"
 139
 140 --- a/arch/s390/kernel/entry64.S
 141 +++ b/arch/s390/kernel/entry64.S
 142 @@ -52,9 +52,9 @@ SP_SIZE      =        STACK_FRAME_OVERHEAD + __
 143  STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
 144  STACK_SIZE  = 1 << STACK_SHIFT
 145
 146 -_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
 147 +_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
 148                  _TIF_MCCK_PENDING | _TIF_RESTART_SVC | _TIF_SINGLE_STEP )
 149 -_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
 150 +_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
 151                  _TIF_MCCK_PENDING)
 152
 153  #define BASED(name) name-system_call(%r13)
 154 @@ -310,6 +310,8 @@ sysc_work:
 155         jo      sysc_reschedule
 156         tm      __TI_flags+7(%r9),_TIF_SIGPENDING
 157         jnz     sysc_sigpending
 158 +       tm      __TI_flags+7(%r9),_TIF_NOTIFY_RESUME
 159 +       jnz     sysc_notify_resume
 160         tm      __TI_flags+7(%r9),_TIF_RESTART_SVC
 161         jo      sysc_restart
 162         tm      __TI_flags+7(%r9),_TIF_SINGLE_STEP
 163 @@ -345,6 +347,14 @@ sysc_sigpending:
 164         j       sysc_work_loop
 165
 166  #
 167 +# _TIF_NOTIFY_RESUME is set, call do_notify_resume
 168 +#
 169 +sysc_notify_resume:
 170 +       la      %r2,SP_PTREGS(%r15)     # load pt_regs
 171 +       larl    %r14,sysc_work_loop
 172 +       jg      do_notify_resume        # call do_notify_resume
 173 +
 174 +#
 175  # _TIF_RESTART_SVC is set, set up registers and restart svc
 176  #
 177  sysc_restart:
 178 @@ -367,20 +377,19 @@ sysc_singlestep:
 179         jg      do_single_step          # branch to do_sigtrap
 180
 181  #
 182 -# call syscall_trace before and after system call
 183 -# special linkage: %r12 contains the return address for trace_svc
 184 +# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
 185 +# and after the system call
 186  #
 187  sysc_tracesys:
 188         la      %r2,SP_PTREGS(%r15)     # load pt_regs
 189         la      %r3,0
 190         srl     %r7,2
 191         stg     %r7,SP_R2(%r15)
 192 -       brasl   %r14,syscall_trace
 193 +       brasl   %r14,do_syscall_trace_enter
 194         lghi    %r0,NR_syscalls
 195 -       clg     %r0,SP_R2(%r15)
 196 +       clgr    %r0,%r2
 197         jnh     sysc_tracenogo
 198 -       lg      %r7,SP_R2(%r15)         # strace might have changed the
 199 -       sll     %r7,2                   # system call
 200 +       slag    %r7,%r2,2               # *4
 201         lgf     %r8,0(%r7,%r10)
 202  sysc_tracego:
 203         lmg     %r3,%r6,SP_R3(%r15)
 204 @@ -391,9 +400,8 @@ sysc_tracenogo:
 205         tm      __TI_flags+7(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
 206         jz      sysc_return
 207         la      %r2,SP_PTREGS(%r15)     # load pt_regs
 208 -       la      %r3,1
 209         larl    %r14,sysc_return        # return point is sysc_return
 210 -       jg      syscall_trace
 211 +       jg      do_syscall_trace_exit
 212
 213  #
 214  # a new process exits the kernel with ret_from_fork
 215 @@ -672,6 +680,8 @@ io_work_loop:
 216         jo      io_reschedule
 217         tm      __TI_flags+7(%r9),_TIF_SIGPENDING
 218         jnz     io_sigpending
 219 +       tm      __TI_flags+7(%r9),_TIF_NOTIFY_RESUME
 220 +       jnz     io_notify_resume
 221         j       io_restore
 222  io_work_done:
 223
 224 @@ -712,6 +722,18 @@ io_sigpending:
 225         TRACE_IRQS_OFF
 226         j       io_work_loop
 227
 228 +#
 229 +# _TIF_NOTIFY_RESUME or is set, call do_notify_resume
 230 +#
 231 +io_notify_resume:
 232 +       TRACE_IRQS_ON
 233 +       stosm   __SF_EMPTY(%r15),0x03   # reenable interrupts
 234 +       la      %r2,SP_PTREGS(%r15)     # load pt_regs
 235 +       brasl   %r14,do_notify_resume   # call do_notify_resume
 236 +       stnsm   __SF_EMPTY(%r15),0xfc   # disable I/O and ext. interrupts
 237 +       TRACE_IRQS_OFF
 238 +       j       io_work_loop
 239 +
 240  /*
 241   * External interrupt handler routine
 242   */
 243 --- a/arch/s390/kernel/entry.S
 244 +++ b/arch/s390/kernel/entry.S
 245 @@ -49,9 +49,9 @@ SP_ILC             =  STACK_FRAME_OVERHEAD + __P
 246  SP_TRAP      = STACK_FRAME_OVERHEAD + __PT_TRAP
 247  SP_SIZE      = STACK_FRAME_OVERHEAD + __PT_SIZE
 248
 249 -_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
 250 +_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
 251                  _TIF_MCCK_PENDING | _TIF_RESTART_SVC | _TIF_SINGLE_STEP )
 252 -_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
 253 +_TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
 254                  _TIF_MCCK_PENDING)
 255
 256  STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
 257 @@ -318,6 +318,8 @@ sysc_work:
 258         bo      BASED(sysc_reschedule)
 259         tm      __TI_flags+3(%r9),_TIF_SIGPENDING
 260         bnz     BASED(sysc_sigpending)
 261 +       tm      __TI_flags+3(%r9),_TIF_NOTIFY_RESUME
 262 +       bnz     BASED(sysc_notify_resume)
 263         tm      __TI_flags+3(%r9),_TIF_RESTART_SVC
 264         bo      BASED(sysc_restart)
 265         tm      __TI_flags+3(%r9),_TIF_SINGLE_STEP
 266 @@ -356,6 +358,16 @@ sysc_sigpending:
 267         b       BASED(sysc_work_loop)
 268
 269  #
 270 +# _TIF_NOTIFY_RESUME is set, call do_notify_resume
 271 +#
 272 +sysc_notify_resume:
 273 +       la      %r2,SP_PTREGS(%r15)     # load pt_regs
 274 +       l       %r1,BASED(.Ldo_notify_resume)
 275 +       la      %r14,BASED(sysc_work_loop)
 276 +       br      %r1                     # call do_notify_resume
 277 +
 278 +
 279 +#
 280  # _TIF_RESTART_SVC is set, set up registers and restart svc
 281  #
 282  sysc_restart:
 283 @@ -378,20 +390,21 @@ sysc_singlestep:
 284         br      %r1                     # branch to do_single_step
 285
 286  #
 287 -# call trace before and after sys_call
 288 +# call tracehook_report_syscall_entry/tracehook_report_syscall_exit before
 289 +# and after the system call
 290  #
 291  sysc_tracesys:
 292 -       l       %r1,BASED(.Ltrace)
 293 +       l       %r1,BASED(.Ltrace_entry)
 294         la      %r2,SP_PTREGS(%r15)     # load pt_regs
 295         la      %r3,0
 296         srl     %r7,2
 297         st      %r7,SP_R2(%r15)
 298         basr    %r14,%r1
 299 -       clc     SP_R2(4,%r15),BASED(.Lnr_syscalls)
 300 +       cl      %r2,BASED(.Lnr_syscalls)
 301         bnl     BASED(sysc_tracenogo)
 302         l       %r8,BASED(.Lsysc_table)
 303 -       l       %r7,SP_R2(%r15)         # strace might have changed the
 304 -       sll     %r7,2                   #  system call
 305 +       lr      %r7,%r2
 306 +       sll     %r7,2                   # *4
 307         l       %r8,0(%r7,%r8)
 308  sysc_tracego:
 309         lm      %r3,%r6,SP_R3(%r15)
 310 @@ -401,9 +414,8 @@ sysc_tracego:
 311  sysc_tracenogo:
 312         tm      __TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
 313         bz      BASED(sysc_return)
 314 -       l       %r1,BASED(.Ltrace)
 315 +       l       %r1,BASED(.Ltrace_exit)
 316         la      %r2,SP_PTREGS(%r15)     # load pt_regs
 317 -       la      %r3,1
 318         la      %r14,BASED(sysc_return)
 319         br      %r1
 320
 321 @@ -666,6 +678,8 @@ io_work_loop:
 322         bo      BASED(io_reschedule)
 323         tm      __TI_flags+3(%r9),_TIF_SIGPENDING
 324         bnz     BASED(io_sigpending)
 325 +       tm      __TI_flags+3(%r9),_TIF_NOTIFY_RESUME
 326 +       bnz     BASED(io_notify_resume)
 327         b       BASED(io_restore)
 328  io_work_done:
 329
 330 @@ -704,6 +718,19 @@ io_sigpending:
 331         TRACE_IRQS_OFF
 332         b       BASED(io_work_loop)
 333
 334 +#
 335 +# _TIF_SIGPENDING is set, call do_signal
 336 +#
 337 +io_notify_resume:
 338 +       TRACE_IRQS_ON
 339 +       stosm   __SF_EMPTY(%r15),0x03   # reenable interrupts
 340 +       la      %r2,SP_PTREGS(%r15)     # load pt_regs
 341 +       l       %r1,BASED(.Ldo_notify_resume)
 342 +       basr    %r14,%r1                # call do_signal
 343 +       stnsm   __SF_EMPTY(%r15),0xfc   # disable I/O and ext. interrupts
 344 +       TRACE_IRQS_OFF
 345 +       b       BASED(io_work_loop)
 346 +
 347  /*
 348   * External interrupt handler routine
 349   */
 350 @@ -1070,6 +1097,8 @@ cleanup_io_leave_insn:
 351  .Ldo_IRQ:      .long   do_IRQ
 352  .Ldo_extint:   .long   do_extint
 353  .Ldo_signal:   .long   do_signal
 354 +.Ldo_notify_resume:
 355 +               .long   do_notify_resume
 356  .Lhandle_per:  .long   do_single_step
 357  .Ldo_execve:   .long   do_execve
 358  .Lexecve_tail: .long   execve_tail
 359 @@ -1079,7 +1108,8 @@ cleanup_io_leave_insn:
 360  .Lpreempt_schedule_irq:
 361                 .long   preempt_schedule_irq
 362  #endif
 363 -.Ltrace:       .long   syscall_trace
 364 +.Ltrace_entry: .long   do_syscall_trace_enter
 365 +.Ltrace_exit:  .long   do_syscall_trace_exit
 366  .Lschedtail:   .long   schedule_tail
 367  .Lsysc_table:  .long   sys_call_table
 368  #ifdef CONFIG_TRACE_IRQFLAGS
 369 --- a/arch/s390/kernel/ptrace.c
 370 +++ b/arch/s390/kernel/ptrace.c
 371 @@ -35,6 +35,7 @@
 372  #include <linux/signal.h>
 373  #include <linux/elf.h>
 374  #include <linux/regset.h>
 375 +#include <linux/tracehook.h>
 376
 377  #include <asm/segment.h>
 378  #include <asm/page.h>
 379 @@ -639,40 +640,58 @@ long compat_arch_ptrace(struct task_stru
 380  }
 381  #endif
 382
 383 -asmlinkage void
 384 -syscall_trace(struct pt_regs *regs, int entryexit)
 385 +asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 386  {
 387 -       if (unlikely(current->audit_context) && entryexit)
 388 -               audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]), regs->gprs[2]);
 389 -
 390 -       if (!test_thread_flag(TIF_SYSCALL_TRACE))
 391 -               goto out;
 392 -       if (!(current->ptrace & PT_PTRACED))
 393 -               goto out;
 394 -       ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 395 -                                ? 0x80 : 0));
 396 +       long ret;
 397
 398         /*
 399 -        * If the debuffer has set an invalid system call number,
 400 -        * we prepare to skip the system call restart handling.
 401 +        * The sysc_tracesys code in entry.S stored the system
 402 +        * call number to gprs[2].
 403          */
 404 -       if (!entryexit && regs->gprs[2] >= NR_syscalls)
 405 +
 406 +       if (is_self_ptracing(regs->gprs[2])) {
 407 +               struct siginfo info;
 408 +
 409 +               memset(&info, 0, sizeof(struct siginfo));
 410 +               info.si_signo = SIGSYS;
 411 +               info.si_code = SYS_SYSCALL;
 412 +               info.si_errno = regs->gprs[2];
 413 +               info.si_addr = (void *)regs->orig_gpr2;
 414 +               send_sig_info(SIGSYS, &info, current);
 415 +               regs->gprs[2] = -1;
 416 +               return -1L;
 417 +       }
 418 +
 419 +       ret = regs->gprs[2];
 420 +       if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 421 +               (tracehook_report_syscall_entry(regs) ||
 422 +                regs->gprs[2] >= NR_syscalls)) {
 423 +               /*
 424 +                * Tracing decided this syscall should not happen or the
 425 +                * debugger stored an invalid system call number. Skip
 426 +                * the system call and the system call restart handling.
 427 +                */
 428                 regs->trap = -1;
 429 +               ret = -1;
 430 +       }
 431
 432 -       /*
 433 -        * this isn't the same as continuing with a signal, but it will do
 434 -        * for normal use.  strace only continues with a signal if the
 435 -        * stopping signal is not SIGTRAP.  -brl
 436 -        */
 437 -       if (current->exit_code) {
 438 -               send_sig(current->exit_code, current, 1);
 439 -               current->exit_code = 0;
 440 -       }
 441 - out:
 442 -       if (unlikely(current->audit_context) && !entryexit)
 443 -               audit_syscall_entry(test_thread_flag(TIF_31BIT)?AUDIT_ARCH_S390:AUDIT_ARCH_S390X,
 444 -                                   regs->gprs[2], regs->orig_gpr2, regs->gprs[3],
 445 -                                   regs->gprs[4], regs->gprs[5]);
 446 +       if (unlikely(current->audit_context))
 447 +               audit_syscall_entry(test_thread_flag(TIF_31BIT) ?
 448 +                               AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 449 +                       regs->gprs[2], regs->orig_gpr2,
 450 +                       regs->gprs[3], regs->gprs[4],
 451 +                       regs->gprs[5]);
 452 +       return ret;
 453 +}
 454 +
 455 +asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 456 +{
 457 +       if (unlikely(current->audit_context))
 458 +               audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
 459 +                               regs->gprs[2]);
 460 +
 461 +       if (test_thread_flag(TIF_SYSCALL_TRACE))
 462 +               tracehook_report_syscall_exit(regs, 0);
 463  }
 464
 465  /*
 466 --- a/arch/s390/kernel/signal.c
 467 +++ b/arch/s390/kernel/signal.c
 468 @@ -25,6 +25,7 @@
 469  #include <linux/personality.h>
 470  #include <linux/binfmts.h>
 471  #include <linux/syscalls.h>
 472 +#include <linux/tracehook.h>
 473  #include <asm/ucontext.h>
 474  #include <asm/uaccess.h>
 475  #include <asm/lowcore.h>
 476 @@ -504,6 +505,12 @@ void do_signal(struct pt_regs *regs)
 477                          */
 478                         if (current->thread.per_info.single_step)
 479                                 set_thread_flag(TIF_SINGLE_STEP);
 480 +
 481 +                       /*
 482 +                        * Let tracing know that we've done the handler setup.
 483 +                        */
 484 +                       tracehook_signal_handler(signr, &info, &ka, regs,
 485 +                                        test_thread_flag(TIF_SINGLE_STEP));
 486                 }
 487                 return;
 488         }
 489 @@ -523,3 +530,9 @@ void do_signal(struct pt_regs *regs)
 490                 set_thread_flag(TIF_RESTART_SVC);
 491         }
 492  }
 493 +
 494 +void do_notify_resume(struct pt_regs *regs)
 495 +{
 496 +       clear_thread_flag(TIF_NOTIFY_RESUME);
 497 +       tracehook_notify_resume(regs);
 498 +}