coregrind/pub_core_aspacemgr.h

   1
   2 /*--------------------------------------------------------------------*/
   3 /*--- The address space manager.              pub_core_aspacemgr.h ---*/
   4 /*--------------------------------------------------------------------*/
   5
   6 /*
   7    This file is part of Valgrind, a dynamic binary instrumentation
   8    framework.
   9
  10    Copyright (C) 2000-2017 Julian Seward
  11       jseward@acm.org
  12
  13    This program is free software; you can redistribute it and/or
  14    modify it under the terms of the GNU General Public License as
  15    published by the Free Software Foundation; either version 2 of the
  16    License, or (at your option) any later version.
  17
  18    This program is distributed in the hope that it will be useful, but
  19    WITHOUT ANY WARRANTY; without even the implied warranty of
  20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  21    General Public License for more details.
  22
  23    You should have received a copy of the GNU General Public License
  24    along with this program; if not, write to the Free Software
  25    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  26    02111-1307, USA.
  27
  28    The GNU General Public License is contained in the file COPYING.
  29 */
  30
  31 #ifndef __PUB_CORE_ASPACEMGR_H
  32 #define __PUB_CORE_ASPACEMGR_H
  33
  34 //--------------------------------------------------------------------
  35 // PURPOSE: This module deals with management of the entire process
  36 // address space.  Almost everything depends upon it, including dynamic
  37 // memory management.  Hence this module is almost completely
  38 // standalone; the only module it uses is m_debuglog.  DO NOT CHANGE
  39 // THIS.
  40 //--------------------------------------------------------------------
  41
  42 #include "pub_tool_aspacemgr.h"
  43
  44 //--------------------------------------------------------------
  45 // Definition of address-space segments
  46
  47 /* types SegKind, ShrinkMode and NSegment are described in
  48    the tool-visible header file, not here. */
  49
  50
  51 //--------------------------------------------------------------
  52 // Initialisation
  53
  54 /* Initialise the address space manager, setting up the initial
  55    segment list, and reading /proc/self/maps into it.  This must
  56    be called before any other function.
  57
  58    Takes a pointer to the SP at the time V gained control.  This is
  59    taken to be the highest usable address (more or less).  Based on
  60    that (and general consultation of tea leaves, etc) return a
  61    suggested end address (highest addressable byte) for the client's stack. */
  62 extern Addr VG_(am_startup) ( Addr sp_at_startup );
  63
  64 /* Check whether ADDR is OK to be used as aspacem_minAddr. If not, *ERRMSG
  65    will be set to identify what's wrong. ERRMSG may be NULL. */
  66 extern Bool VG_(am_is_valid_for_aspacem_minAddr)( Addr addr,
  67                                                   const HChar **errmsg );
  68
  69 //--------------------------------------------------------------
  70 // Querying current status
  71
  72
  73 /* Finds an anonymous segment containing 'a'. Returned pointer is read only. */
  74 extern NSegment const *VG_(am_find_anon_segment) ( Addr a );
  75
  76 /* Find the next segment along from 'here', if it is a file/anon/resvn
  77    segment. */
  78 extern NSegment const* VG_(am_next_nsegment) ( const NSegment* here,
  79                                                Bool fwds );
  80
  81 /* Is the area [start .. start+len-1] validly accessible by
  82    valgrind with at least the permissions 'prot' ?  To find out
  83    simply if said area merely belongs to valgrind, pass
  84    VKI_PROT_NONE as 'prot'.  Will return False if any part of the
  85    area does not belong to valgrind or does not have at least
  86    the stated permissions. */
  87 extern Bool VG_(am_is_valid_for_valgrind)
  88    ( Addr start, SizeT len, UInt prot );
  89
  90 /* Variant of VG_(am_is_valid_for_client) which allows free areas to
  91    be consider part of the client's addressable space.  It also
  92    considers reservations to be allowable, since from the client's
  93    point of view they don't exist. */
  94 extern Bool VG_(am_is_valid_for_client_or_free_or_resvn)
  95    ( Addr start, SizeT len, UInt prot );
  96
  97 /* Checks if a piece of memory consists of either free or reservation
  98    segments. */
  99 extern Bool VG_(am_is_free_or_resvn)( Addr start, SizeT len );
 100
 101 /* Check whether ADDR looks like an address or address-to-be located in an
 102    extensible client stack segment. */
 103 extern Bool VG_(am_addr_is_in_extensible_client_stack)( Addr addr );
 104
 105 /* Trivial fn: return the total amount of space in anonymous mappings,
 106    both for V and the client.  Is used for printing stats in
 107    out-of-memory messages. */
 108 extern ULong VG_(am_get_anonsize_total)( void );
 109
 110 /* Show the segment array on the debug log, at given loglevel. */
 111 extern void VG_(am_show_nsegments) ( Int logLevel, const HChar* who );
 112
 113 /* VG_(am_get_segment_starts) is also part of this section, but its
 114    prototype is tool-visible, hence not in this header file. */
 115
 116 /* Sanity check: check that Valgrind and the kernel agree on the
 117    address space layout.  Prints offending segments and call point if
 118    a discrepancy is detected, but does not abort the system.  Returned
 119    Bool is False if a discrepancy was found. */
 120
 121 extern Bool VG_(am_do_sync_check) ( const HChar* fn,
 122                                     const HChar* file, Int line );
 123
 124 //--------------------------------------------------------------
 125 // Functions pertaining to the central query-notify mechanism
 126 // used to handle mmap/munmap/mprotect resulting from client
 127 // syscalls.
 128
 129 /* Describes a request for VG_(am_get_advisory). */
 130 typedef
 131    struct {
 132       /* Note: if rkind == MAlign then start specifies alignment. This is
 133          Solaris specific. */
 134       enum { MFixed, MHint, MAny, MAlign } rkind;
 135       Addr start;
 136       Addr len;
 137    }
 138    MapRequest;
 139
 140 /* Query aspacem to ask where a mapping should go.  On success, the
 141    advised placement is returned, and *ok is set to True.  On failure,
 142    zero is returned and *ok is set to False.  Note that *ok must be
 143    consulted by the caller to establish success or failure; that
 144    cannot be established reliably from the returned value.  If *ok is
 145    set to False, it means aspacem has vetoed the mapping, and so the
 146    caller should not proceed with it. */
 147 extern Addr VG_(am_get_advisory)
 148    ( const MapRequest* req, Bool forClient, /*OUT*/Bool* ok );
 149
 150 /* Convenience wrapper for VG_(am_get_advisory) for client floating or
 151    fixed requests.  If start is zero, a floating request is issued; if
 152    nonzero, a fixed request at that address is issued.  Same comments
 153    about return values apply. */
 154 extern Addr VG_(am_get_advisory_client_simple)
 155    ( Addr start, SizeT len, /*OUT*/Bool* ok );
 156
 157 /* Returns True if [start, start + len - 1] is covered by a single
 158    free segment, otherwise returns False.
 159    This allows to check the following case:
 160    VG_(am_get_advisory_client_simple) (first arg == 0, meaning
 161    this-or-nothing) is too lenient, and may allow us to trash
 162    the next segment along.  So make very sure that the proposed
 163    new area really is free.  This is perhaps overly
 164    conservative, but it fixes #129866. */
 165 extern Bool VG_(am_covered_by_single_free_segment)
 166    ( Addr start, SizeT len);
 167
 168 /* Notifies aspacem that the client completed an mmap successfully.
 169    The segment array is updated accordingly.  If the returned Bool is
 170    True, the caller should immediately discard translations from the
 171    specified address range. */
 172 extern Bool VG_(am_notify_client_mmap)
 173    ( Addr a, SizeT len, UInt prot, UInt flags, Int fd, Off64T offset );
 174
 175 /* Notifies aspacem that the client completed a shmat successfully.
 176    The segment array is updated accordingly.  If the returned Bool is
 177    True, the caller should immediately discard translations from the
 178    specified address range. */
 179 extern Bool VG_(am_notify_client_shmat)( Addr a, SizeT len, UInt prot );
 180
 181 /* Notifies aspacem that an mprotect was completed successfully.  The
 182    segment array is updated accordingly.  Note, as with
 183    VG_(am_notify_munmap), it is not the job of this function to reject
 184    stupid mprotects, for example the client doing mprotect of
 185    non-client areas.  Such requests should be intercepted earlier, by
 186    the syscall wrapper for mprotect.  This function merely records
 187    whatever it is told.  If the returned Bool is True, the caller
 188    should immediately discard translations from the specified address
 189    range. */
 190 extern Bool VG_(am_notify_mprotect)( Addr start, SizeT len, UInt prot );
 191
 192 /* Notifies aspacem that an munmap completed successfully.  The
 193    segment array is updated accordingly.  As with
 194    VG_(am_notify_mprotect), we merely record the given info, and don't
 195    check it for sensibleness.  If the returned Bool is True, the
 196    caller should immediately discard translations from the specified
 197    address range. */
 198 extern Bool VG_(am_notify_munmap)( Addr start, SizeT len );
 199
 200 /* Hand a raw mmap to the kernel, without aspacem updating the segment
 201    array.  THIS FUNCTION IS DANGEROUS -- it will cause aspacem's view
 202    of the address space to diverge from that of the kernel.  DO NOT
 203    USE IT UNLESS YOU UNDERSTAND the request-notify model used by
 204    aspacem.  In short, DO NOT USE THIS FUNCTION. */
 205 extern SysRes VG_(am_do_mmap_NO_NOTIFY)
 206    ( Addr start, SizeT length, UInt prot, UInt flags, Int fd, Off64T offset);
 207
 208
 209 //--------------------------------------------------------------
 210 // Dealing with mappings which do not arise directly from the
 211 // simulation of the client.  These are typically used for
 212 // loading the client and building its stack/data segment, before
 213 // execution begins.  Also for V's own administrative use.
 214
 215 /* --- --- --- map, unmap, protect  --- --- --- */
 216
 217 /* Map a file at a fixed address for the client, and update the
 218    segment array accordingly. */
 219 extern SysRes VG_(am_mmap_file_fixed_client)
 220    ( Addr start, SizeT length, UInt prot, Int fd, Off64T offset );
 221 extern SysRes VG_(am_mmap_file_fixed_client_flags)
 222    ( Addr start, SizeT length, UInt prot, UInt flags, Int fd, Off64T offset );
 223 extern SysRes VG_(am_mmap_named_file_fixed_client)
 224    ( Addr start, SizeT length, UInt prot, Int fd,
 225      Off64T offset, const HChar *name );
 226 extern SysRes VG_(am_mmap_named_file_fixed_client_flags)
 227    ( Addr start, SizeT length, UInt prot, UInt flags, Int fd,
 228      Off64T offset, const HChar *name );
 229
 230 /* Map anonymously at a fixed address for the client, and update
 231    the segment array accordingly. */
 232 extern SysRes VG_(am_mmap_anon_fixed_client)
 233    ( Addr start, SizeT length, UInt prot );
 234
 235
 236 /* Map anonymously at an unconstrained address for the client, and
 237    update the segment array accordingly.  */
 238 extern SysRes VG_(am_mmap_anon_float_client) ( SizeT length, Int prot );
 239
 240 /* Map anonymously at an unconstrained address for V, and update the
 241    segment array accordingly.  This is fundamentally how V allocates
 242    itself more address space when needed. */
 243 extern SysRes VG_(am_mmap_anon_float_valgrind)( SizeT cszB );
 244
 245 /* Map privately a file at an unconstrained address for V, and update the
 246    segment array accordingly.  This is used by V for transiently
 247    mapping in object files to read their debug info.  */
 248 extern SysRes VG_(am_mmap_file_float_valgrind)
 249    ( SizeT length, UInt prot, Int fd, Off64T offset );
 250
 251 /* Map shared a file at an unconstrained address for V, and update the
 252    segment array accordingly.  This is used by V for communicating
 253    with vgdb.  */
 254 extern SysRes VG_(am_shared_mmap_file_float_valgrind)
 255    ( SizeT length, UInt prot, Int fd, Off64T offset );
 256
 257 /* Similar to VG_(am_mmap_anon_float_client) but also
 258    marks the segment as containing the client heap. */
 259 extern SysRes VG_(am_mmap_client_heap) ( SizeT length, Int prot );
 260
 261 /* Unmap the given address range and update the segment array
 262    accordingly.  This fails if the range isn't valid for the client.
 263    If *need_discard is True after a successful return, the caller
 264    should immediately discard translations from the specified address
 265    range. */
 266 extern SysRes VG_(am_munmap_client)( /*OUT*/Bool* need_discard,
 267                                      Addr start, SizeT length );
 268
 269 /* Let (start,len) denote an area within a single Valgrind-owned
 270   segment (anon or file).  Change the ownership of [start, start+len)
 271   to the client instead.  Fails if (start,len) does not denote a
 272   suitable segment. */
 273 extern Bool VG_(am_change_ownership_v_to_c)( Addr start, SizeT len );
 274
 275 /* Set the 'hasT' bit on the segment containing ADDR indicating that
 276    translations have or may have been taken from this segment. ADDR is
 277    expected to belong to a client segment. */
 278 extern void VG_(am_set_segment_hasT)( Addr addr );
 279
 280 /* --- --- --- reservations --- --- --- */
 281
 282 /* Create a reservation from START .. START+LENGTH-1, with the given
 283    ShrinkMode.  When checking whether the reservation can be created,
 284    also ensure that at least abs(EXTRA) extra free bytes will remain
 285    above (> 0) or below (< 0) the reservation.
 286
 287    The reservation will only be created if it, plus the extra-zone,
 288    falls entirely within a single free segment.  The returned Bool
 289    indicates whether the creation succeeded. */
 290 extern Bool VG_(am_create_reservation)
 291    ( Addr start, SizeT length, ShrinkMode smode, SSizeT extra );
 292
 293 /* ADDR is the start address of an anonymous client mapping.  This fn extends
 294    the mapping by DELTA bytes, taking the space from a reservation section
 295    which must be adjacent.  If DELTA is positive, the segment is
 296    extended forwards in the address space, and the reservation must be
 297    the next one along.  If DELTA is negative, the segment is extended
 298    backwards in the address space and the reservation must be the
 299    previous one.  DELTA must be page aligned.  abs(DELTA) must not
 300    exceed the size of the reservation segment minus one page, that is,
 301    the reservation segment after the operation must be at least one
 302    page long. The function returns a pointer to the resized segment. */
 303 extern const NSegment *VG_(am_extend_into_adjacent_reservation_client)
 304    ( Addr addr, SSizeT delta, /*OUT*/Bool *overflow );
 305
 306 /* --- --- --- resizing/move a mapping --- --- --- */
 307
 308 /* This function grows a client mapping in place into an adjacent free segment.
 309    ADDR is the client mapping's start address and DELTA, which must be page
 310    aligned, is the growth amount. The function returns a pointer to the
 311    resized segment. The function is used in support of mremap. */
 312 extern const NSegment *VG_(am_extend_map_client)( Addr addr, SizeT delta );
 313
 314 /* Remap the old address range to the new address range.  Fails if any
 315    parameter is not page aligned, if the either size is zero, if any
 316    wraparound is implied, if the old address range does not fall
 317    entirely within a single segment, if the new address range overlaps
 318    with the old one, or if the old address range is not a valid client
 319    mapping.  If *need_discard is True after a successful return, the
 320    caller should immediately discard translations from both specified
 321    address ranges.  */
 322 extern Bool VG_(am_relocate_nooverlap_client)( /*OUT*/Bool* need_discard,
 323                                                Addr old_addr, SizeT old_len,
 324                                                Addr new_addr, SizeT new_len );
 325
 326 //--------------------------------------------------------------
 327 // Valgrind (non-client) thread stacks.  V itself runs on such
 328 // stacks.  The address space manager provides and suitably
 329 // protects such stacks.
 330
 331 // VG_DEFAULT_STACK_ACTIVE_SZB is the default size of a Valgrind stack.
 332 // The effectively used size is controlled by the command line options
 333 // --valgrind-stack-size=xxxx (which must be page aligned).
 334 // Note that m_main.c needs an interim stack (just to startup), before
 335 // any command line option can be processed. This interim stack
 336 // (declared in m_main.c) will use the size VG_DEFAULT_STACK_ACTIVE_SZB.
 337 #if defined(VGP_ppc32_linux) \
 338     || defined(VGP_ppc64be_linux) || defined(VGP_ppc64le_linux) \
 339     || defined(VGP_mips32_linux) || defined(VGP_mips64_linux) \
 340     || defined(VGP_arm64_linux)
 341 # define VG_STACK_GUARD_SZB  65536  // 1 or 16 pages
 342 #else
 343 # define VG_STACK_GUARD_SZB  8192   // 2 pages
 344 #endif
 345 # define VG_DEFAULT_STACK_ACTIVE_SZB 1048576 // (4096 * 256) = 1Mb
 346
 347 typedef struct _VgStack VgStack;
 348
 349
 350 /* Allocate and initialise a VgStack (anonymous valgrind space).
 351    Protect the stack active area and the guard areas appropriately.
 352    Returns NULL on failure, else the address of the bottom of the
 353    stack.  On success, also sets *initial_sp to what the stack pointer
 354    should be set to. */
 355
 356 extern VgStack* VG_(am_alloc_VgStack)( /*OUT*/Addr* initial_sp );
 357
 358 /* Figure out how many bytes of the stack's active area have not been
 359    used.  Used for estimating if we are close to overflowing it.  If
 360    the free area is larger than 'limit', just return 'limit'. */
 361 extern SizeT VG_(am_get_VgStack_unused_szB)( const VgStack* stack,
 362                                              SizeT limit );
 363
 364 // DDD: this is ugly
 365 #if defined(VGO_darwin)
 366 typedef
 367    struct {
 368       Bool   is_added;  // Added or removed seg?
 369       Addr   start;
 370       SizeT  end;
 371       UInt   prot;      // Not used for removed segs.
 372       Off64T offset;    // Not used for removed segs.
 373    }
 374    ChangedSeg;
 375
 376 extern Bool VG_(get_changed_segments)(
 377       const HChar* when, const HChar* where, /*OUT*/ChangedSeg* css,
 378       Int css_size, /*OUT*/Int* css_used);
 379 #endif
 380
 381 #if defined(VGO_solaris)
 382 extern Bool VG_(am_search_for_new_segment)(Addr *start, SizeT *size,
 383                                            UInt *prot);
 384 #endif
 385
 386 #endif   // __PUB_CORE_ASPACEMGR_H
 387
 388 /*--------------------------------------------------------------------*/
 389 /*--- end                                                          ---*/
 390 /*--------------------------------------------------------------------*/