blob: 593ba32e745b22c4f39c68b88d4845ebd90a753a [file] [log] [blame]
/* Copyright (C) 2007-2010 The Android Open Source Project
**
** This software is licensed under the terms of the GNU General Public
** License version 2, as published by the Free Software Foundation, and
** may be copied, distributed, and modified under those terms.
**
** 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.
*/
/*
* Contains implementation of routines related to process management in
* memchecker framework.
*/
/* This file should compile iff qemu is built with memory checking
* configuration turned on. */
#ifndef CONFIG_MEMCHECK
#error CONFIG_MEMCHECK is not defined.
#endif // CONFIG_MEMCHECK
#include "elff/elff_api.h"
#include "memcheck.h"
#include "memcheck_proc_management.h"
#include "memcheck_logging.h"
#include "memcheck_util.h"
/* Current thread id.
* This value is updated with each call to memcheck_switch, saving here
* ID of the thread that becomes current. */
static uint32_t current_tid = 0;
/* Current thread descriptor.
* This variable is used to cache current thread descriptor. This value gets
* initialized on "as needed" basis, when descriptor for the current thread
* is requested for the first time.
* Note that every time memcheck_switch routine is called, this value gets
* NULL'ed, since another thread becomes current. */
static ThreadDesc* current_thread = NULL;
/* Current process descriptor.
* This variable is used to cache current process descriptor. This value gets
* initialized on "as needed" basis, when descriptor for the current process
* is requested for the first time.
* Note that every time memcheck_switch routine is called, this value gets
* NULL'ed, since new thread becomes current, thus process switch may have
* occurred as well. */
static ProcDesc* current_process = NULL;
/* List of running processes. */
static QLIST_HEAD(proc_list, ProcDesc) proc_list;
/* List of running threads. */
static QLIST_HEAD(thread_list, ThreadDesc) thread_list;
// =============================================================================
// Static routines
// =============================================================================
/* Creates and lists thread descriptor for a new thread.
* This routine will allocate and initialize new thread descriptor. After that
* this routine will insert the descriptor into the global list of running
* threads, as well as thread list in the process descriptor of the process
* in context of which this thread is created.
* Param:
* proc - Process descriptor of the process, in context of which new thread
* is created.
* tid - Thread ID of the thread that's being created.
* Return:
* New thread descriptor on success, or NULL on failure.
*/
static ThreadDesc*
create_new_thread(ProcDesc* proc, uint32_t tid)
{
ThreadDesc* new_thread = (ThreadDesc*)qemu_malloc(sizeof(ThreadDesc));
if (new_thread == NULL) {
ME("memcheck: Unable to allocate new thread descriptor.");
return NULL;
}
new_thread->tid = tid;
new_thread->process = proc;
new_thread->call_stack = NULL;
new_thread->call_stack_count = 0;
new_thread->call_stack_max = 0;
QLIST_INSERT_HEAD(&thread_list, new_thread, global_entry);
QLIST_INSERT_HEAD(&proc->threads, new_thread, proc_entry);
return new_thread;
}
/* Creates and lists process descriptor for a new process.
* This routine will allocate and initialize new process descriptor. After that
* this routine will create main thread descriptor for the process (with the
* thread ID equal to the new process ID), and then new process descriptor will
* be inserted into the global list of running processes.
* Param:
* pid - Process ID of the process that's being created.
* parent_pid - Process ID of the parent process.
* Return:
* New process descriptor on success, or NULL on failure.
*/
static ProcDesc*
create_new_process(uint32_t pid, uint32_t parent_pid)
{
// Create and init new process descriptor.
ProcDesc* new_proc = (ProcDesc*)qemu_malloc(sizeof(ProcDesc));
if (new_proc == NULL) {
ME("memcheck: Unable to allocate new process descriptor");
return NULL;
}
QLIST_INIT(&new_proc->threads);
allocmap_init(&new_proc->alloc_map);
mmrangemap_init(&new_proc->mmrange_map);
new_proc->pid = pid;
new_proc->parent_pid = parent_pid;
new_proc->image_path = NULL;
new_proc->flags = 0;
if (parent_pid != 0) {
/* If new process has been forked, it inherits a copy of parent's
* process heap, as well as parent's mmaping of loaded modules. So, on
* fork we're required to copy parent's allocation descriptors map, as
* well as parent's mmapping map to the new process. */
int failed;
ProcDesc* parent = get_process_from_pid(parent_pid);
if (parent == NULL) {
ME("memcheck: Unable to get parent process pid=%u for new process pid=%u",
parent_pid, pid);
qemu_free(new_proc);
return NULL;
}
/* Copy parent's allocation map, setting "inherited" flag, and clearing
* parent's "transition" flag in the copied entries. */
failed = allocmap_copy(&new_proc->alloc_map, &parent->alloc_map,
MDESC_FLAG_INHERITED_ON_FORK,
MDESC_FLAG_TRANSITION_ENTRY);
if (failed) {
ME("memcheck: Unable to copy process' %s[pid=%u] allocation map to new process pid=%u",
parent->image_path, parent_pid, pid);
allocmap_empty(&new_proc->alloc_map);
qemu_free(new_proc);
return NULL;
}
// Copy parent's memory mappings map.
failed = mmrangemap_copy(&new_proc->mmrange_map, &parent->mmrange_map);
if (failed) {
ME("memcheck: Unable to copy process' %s[pid=%u] mmrange map to new process pid=%u",
parent->image_path, parent_pid, pid);
mmrangemap_empty(&new_proc->mmrange_map);
allocmap_empty(&new_proc->alloc_map);
qemu_free(new_proc);
return NULL;
}
}
// Create and register main thread descriptor for new process.
if(create_new_thread(new_proc, pid) == NULL) {
mmrangemap_empty(&new_proc->mmrange_map);
allocmap_empty(&new_proc->alloc_map);
qemu_free(new_proc);
return NULL;
}
// List new process.
QLIST_INSERT_HEAD(&proc_list, new_proc, global_entry);
return new_proc;
}
/* Finds thread descriptor for a thread id in the global list of running
* threads.
* Param:
* tid - Thread ID to look up thread descriptor for.
* Return:
* Found thread descriptor, or NULL if thread descriptor has not been found.
*/
static ThreadDesc*
get_thread_from_tid(uint32_t tid)
{
ThreadDesc* thread;
/* There is a pretty good chance that when this call is made, it's made
* to get descriptor for the current thread. Lets see if it is so, so
* we don't have to iterate through the entire list. */
if (tid == current_tid && current_thread != NULL) {
return current_thread;
}
QLIST_FOREACH(thread, &thread_list, global_entry) {
if (tid == thread->tid) {
if (tid == current_tid) {
current_thread = thread;
}
return thread;
}
}
return NULL;
}
/* Gets thread descriptor for the current thread.
* Return:
* Found thread descriptor, or NULL if thread descriptor has not been found.
*/
ThreadDesc*
get_current_thread(void)
{
// Lets see if current thread descriptor has been cached.
if (current_thread == NULL) {
/* Descriptor is not cached. Look it up in the list. Note that
* get_thread_from_tid(current_tid) is not used here in order to
* optimize this code for performance, as this routine is called from
* the performance sensitive path. */
ThreadDesc* thread;
QLIST_FOREACH(thread, &thread_list, global_entry) {
if (current_tid == thread->tid) {
current_thread = thread;
return current_thread;
}
}
}
return current_thread;
}
/* Finds process descriptor for a thread id.
* Param:
* tid - Thread ID to look up process descriptor for.
* Return:
* Process descriptor for the thread, or NULL, if process descriptor
* has not been found.
*/
static inline ProcDesc*
get_process_from_tid(uint32_t tid)
{
const ThreadDesc* thread = get_thread_from_tid(tid);
return (thread != NULL) ? thread->process : NULL;
}
/* Sets, or replaces process image path in process descriptor.
* Generally, new process' image path is unknown untill we calculate it in
* the handler for TRACE_DEV_REG_CMDLINE event. This routine is called from
* TRACE_DEV_REG_CMDLINE event handler to set, or replace process image path.
* Param:
* proc - Descriptor of the process where to set, or replace image path.
* image_path - Image path to the process, transmitted with
* TRACE_DEV_REG_CMDLINE event.
* set_flags_on_replace - Flags to be set when current image path for the
* process has been actually replaced with the new one.
* Return:
* Zero on success, or -1 on failure.
*/
static int
procdesc_set_image_path(ProcDesc* proc,
const char* image_path,
uint32_t set_flags_on_replace)
{
if (image_path == NULL || proc == NULL) {
return 0;
}
if (proc->image_path != NULL) {
/* Process could have been forked, and inherited image path of the
* parent process. However, it seems that "fork" in terms of TRACE_XXX
* is not necessarly a strict "fork", but rather new process creation
* in general. So, if that's the case we need to override image path
* inherited from the parent process. */
if (!strcmp(proc->image_path, image_path)) {
// Paths are the same. Just bail out.
return 0;
}
qemu_free(proc->image_path);
proc->image_path = NULL;
}
// Save new image path into process' descriptor.
proc->image_path = qemu_malloc(strlen(image_path) + 1);
if (proc->image_path == NULL) {
ME("memcheck: Unable to allocate %u bytes for image path %s to set it for pid=%u",
strlen(image_path) + 1, image_path, proc->pid);
return -1;
}
strcpy(proc->image_path, image_path);
proc->flags |= set_flags_on_replace;
return 0;
}
/* Frees thread descriptor. */
static void
threaddesc_free(ThreadDesc* thread)
{
uint32_t indx;
if (thread == NULL) {
return;
}
if (thread->call_stack != NULL) {
for (indx = 0; indx < thread->call_stack_count; indx++) {
if (thread->call_stack[indx].module_path != NULL) {
qemu_free(thread->call_stack[indx].module_path);
}
}
qemu_free(thread->call_stack);
}
qemu_free(thread);
}
// =============================================================================
// Process management API
// =============================================================================
void
memcheck_init_proc_management(void)
{
QLIST_INIT(&proc_list);
QLIST_INIT(&thread_list);
}
ProcDesc*
get_process_from_pid(uint32_t pid)
{
ProcDesc* proc;
/* Chances are that pid addresses the current process. Lets check this,
* so we don't have to iterate through the entire project list. */
if (current_thread != NULL && current_thread->process->pid == pid) {
current_process = current_thread->process;
return current_process;
}
QLIST_FOREACH(proc, &proc_list, global_entry) {
if (pid == proc->pid) {
break;
}
}
return proc;
}
ProcDesc*
get_current_process(void)
{
if (current_process == NULL) {
const ThreadDesc* cur_thread = get_current_thread();
if (cur_thread != NULL) {
current_process = cur_thread->process;
}
}
return current_process;
}
void
memcheck_on_call(target_ulong from, target_ulong ret)
{
const uint32_t grow_by = 32;
const uint32_t max_stack = grow_by;
ThreadDesc* thread = get_current_thread();
if (thread == NULL) {
return;
}
/* We're not saving call stack until process starts execution. */
if (!procdesc_is_executing(thread->process)) {
return;
}
const MMRangeDesc* rdesc = procdesc_get_range_desc(thread->process, from);
if (rdesc == NULL) {
ME("memcheck: Unable to find mapping for guest PC 0x%08X in process %s[pid=%u]",
from, thread->process->image_path, thread->process->pid);
return;
}
/* Limit calling stack size. There are cases when calling stack can be
* quite deep due to recursion (up to 4000 entries). */
if (thread->call_stack_count >= max_stack) {
#if 0
/* This happens quite often. */
MD("memcheck: Thread stack for %s[pid=%u, tid=%u] is too big: %u",
thread->process->image_path, thread->process->pid, thread->tid,
thread->call_stack_count);
#endif
return;
}
if (thread->call_stack_count >= thread->call_stack_max) {
/* Expand calling stack array buffer. */
thread->call_stack_max += grow_by;
ThreadCallStackEntry* new_array =
qemu_malloc(thread->call_stack_max * sizeof(ThreadCallStackEntry));
if (new_array == NULL) {
ME("memcheck: Unable to allocate %u bytes for calling stack.",
thread->call_stack_max * sizeof(ThreadCallStackEntry));
thread->call_stack_max -= grow_by;
return;
}
if (thread->call_stack_count != 0) {
memcpy(new_array, thread->call_stack,
thread->call_stack_count * sizeof(ThreadCallStackEntry));
}
if (thread->call_stack != NULL) {
qemu_free(thread->call_stack);
}
thread->call_stack = new_array;
}
thread->call_stack[thread->call_stack_count].call_address = from;
thread->call_stack[thread->call_stack_count].call_address_rel =
mmrangedesc_get_module_offset(rdesc, from);
thread->call_stack[thread->call_stack_count].ret_address = ret;
thread->call_stack[thread->call_stack_count].ret_address_rel =
mmrangedesc_get_module_offset(rdesc, ret);
thread->call_stack[thread->call_stack_count].module_path =
qemu_malloc(strlen(rdesc->path) + 1);
if (thread->call_stack[thread->call_stack_count].module_path == NULL) {
ME("memcheck: Unable to allocate %u bytes for module path in the thread calling stack.",
strlen(rdesc->path) + 1);
return;
}
strcpy(thread->call_stack[thread->call_stack_count].module_path,
rdesc->path);
thread->call_stack_count++;
}
void
memcheck_on_ret(target_ulong ret)
{
ThreadDesc* thread = get_current_thread();
if (thread == NULL) {
return;
}
/* We're not saving call stack until process starts execution. */
if (!procdesc_is_executing(thread->process)) {
return;
}
if (thread->call_stack_count > 0) {
int indx = (int)thread->call_stack_count - 1;
for (; indx >= 0; indx--) {
if (thread->call_stack[indx].ret_address == ret) {
thread->call_stack_count = indx;
return;
}
}
}
}
// =============================================================================
// Handlers for events, generated by the kernel.
// =============================================================================
void
memcheck_init_pid(uint32_t new_pid)
{
create_new_process(new_pid, 0);
T(PROC_NEW_PID, "memcheck: init_pid(pid=%u) in current thread tid=%u\n",
new_pid, current_tid);
}
void
memcheck_switch(uint32_t tid)
{
/* Since new thread became active, we have to invalidate cached
* descriptors for current thread and process. */
current_thread = NULL;
current_process = NULL;
current_tid = tid;
}
void
memcheck_fork(uint32_t tgid, uint32_t new_pid)
{
ProcDesc* parent_proc;
ProcDesc* new_proc;
/* tgid may match new_pid, in which case current process is the
* one that's being forked, otherwise tgid identifies process
* that's being forked. */
if (new_pid == tgid) {
parent_proc = get_current_process();
} else {
parent_proc = get_process_from_tid(tgid);
}
if (parent_proc == NULL) {
ME("memcheck: FORK(%u, %u): Unable to look up parent process. Current tid=%u",
tgid, new_pid, current_tid);
return;
}
if (parent_proc->pid != get_current_process()->pid) {
MD("memcheck: FORK(%u, %u): parent %s[pid=%u] is not the current process %s[pid=%u]",
tgid, new_pid, parent_proc->image_path, parent_proc->pid,
get_current_process()->image_path, get_current_process()->pid);
}
new_proc = create_new_process(new_pid, parent_proc->pid);
if (new_proc == NULL) {
return;
}
/* Since we're possibly forking parent process, we need to inherit
* parent's image path in the forked process. */
procdesc_set_image_path(new_proc, parent_proc->image_path, 0);
T(PROC_FORK, "memcheck: FORK(tgid=%u, new_pid=%u) by %s[pid=%u] (tid=%u)\n",
tgid, new_pid, parent_proc->image_path, parent_proc->pid, current_tid);
}
void
memcheck_clone(uint32_t tgid, uint32_t new_tid)
{
ProcDesc* parent_proc;
/* tgid may match new_pid, in which case current process is the
* one that creates thread, otherwise tgid identifies process
* that creates thread. */
if (new_tid == tgid) {
parent_proc = get_current_process();
} else {
parent_proc = get_process_from_tid(tgid);
}
if (parent_proc == NULL) {
ME("memcheck: CLONE(%u, %u) Unable to look up parent process. Current tid=%u",
tgid, new_tid, current_tid);
return;
}
if (parent_proc->pid != get_current_process()->pid) {
ME("memcheck: CLONE(%u, %u): parent %s[pid=%u] is not the current process %s[pid=%u]",
tgid, new_tid, parent_proc->image_path, parent_proc->pid,
get_current_process()->image_path, get_current_process()->pid);
}
create_new_thread(parent_proc, new_tid);
T(PROC_CLONE, "memcheck: CLONE(tgid=%u, new_tid=%u) by %s[pid=%u] (tid=%u)\n",
tgid, new_tid, parent_proc->image_path, parent_proc->pid, current_tid);
}
void
memcheck_set_cmd_line(const char* cmd_arg, unsigned cmdlen)
{
char parsed[4096];
int n;
ProcDesc* current_proc = get_current_process();
if (current_proc == NULL) {
ME("memcheck: CMDL(%s, %u): Unable to look up process for current tid=%3u",
cmd_arg, cmdlen, current_tid);
return;
}
/* Image path is the first agrument in cmd line. Note that due to
* limitations of TRACE_XXX cmdlen can never exceed CLIENT_PAGE_SIZE */
memcpy(parsed, cmd_arg, cmdlen);
// Cut first argument off the entire command line.
for (n = 0; n < cmdlen; n++) {
if (parsed[n] == ' ') {
break;
}
}
parsed[n] = '\0';
// Save process' image path into descriptor.
procdesc_set_image_path(current_proc, parsed,
PROC_FLAG_IMAGE_PATH_REPLACED);
current_proc->flags |= PROC_FLAG_EXECUTING;
/* At this point we need to discard memory mappings inherited from
* the parent process, since this process has become "independent" from
* its parent. */
mmrangemap_empty(&current_proc->mmrange_map);
T(PROC_START, "memcheck: Executing process %s[pid=%u]\n",
current_proc->image_path, current_proc->pid);
}
void
memcheck_exit(uint32_t exit_code)
{
ProcDesc* proc;
int leaks_reported = 0;
MallocDescEx leaked_alloc;
// Exiting thread descriptor.
ThreadDesc* thread = get_current_thread();
if (thread == NULL) {
ME("memcheck: EXIT(%u): Unable to look up thread for current tid=%u",
exit_code, current_tid);
return;
}
proc = thread->process;
// Since current thread is exiting, we need to NULL its cached descriptor.
current_thread = NULL;
// Unlist the thread from its process as well as global lists.
QLIST_REMOVE(thread, proc_entry);
QLIST_REMOVE(thread, global_entry);
threaddesc_free(thread);
/* Lets see if this was last process thread, which would indicate
* process termination. */
if (!QLIST_EMPTY(&proc->threads)) {
return;
}
// Process is terminating. Report leaks and free resources.
proc->flags |= PROC_FLAG_EXITING;
/* Empty allocation descriptors map for the exiting process,
* reporting leaking blocks in the process. */
while (!allocmap_pull_first(&proc->alloc_map, &leaked_alloc)) {
/* We should "forgive" blocks that were inherited from the
* parent process on fork, or were allocated while process was
* in "transition" state. */
if (!mallocdescex_is_inherited_on_fork(&leaked_alloc) &&
!mallocdescex_is_transition_entry(&leaked_alloc)) {
if (!leaks_reported) {
// First leak detected. Print report's header.
T(CHECK_LEAK, "memcheck: Process %s[pid=%u] is exiting leaking allocated blocks:\n",
proc->image_path, proc->pid);
}
if (trace_flags & TRACE_CHECK_LEAK_ENABLED) {
// Dump leaked block information.
printf(" Leaked block %u:\n", leaks_reported + 1);
memcheck_dump_malloc_desc(&leaked_alloc, 0, 0);
if (leaked_alloc.call_stack != NULL) {
const int max_stack = 24;
if (max_stack >= leaked_alloc.call_stack_count) {
printf(" Call stack:\n");
} else {
printf(" Call stack (first %u of %u entries):\n",
max_stack, leaked_alloc.call_stack_count);
}
uint32_t stk;
for (stk = 0;
stk < leaked_alloc.call_stack_count && stk < max_stack;
stk++) {
const MMRangeDesc* rdesc =
procdesc_find_mapentry(proc,
leaked_alloc.call_stack[stk]);
if (rdesc != NULL) {
Elf_AddressInfo elff_info;
ELFF_HANDLE elff_handle = NULL;
uint32_t rel =
mmrangedesc_get_module_offset(rdesc,
leaked_alloc.call_stack[stk]);
printf(" Frame %u: PC=0x%08X (relative 0x%08X) in module %s\n",
stk, leaked_alloc.call_stack[stk], rel,
rdesc->path);
if (memcheck_get_address_info(leaked_alloc.call_stack[stk],
rdesc, &elff_info,
&elff_handle) == 0) {
printf(" Routine %s @ %s/%s:%u\n",
elff_info.routine_name,
elff_info.dir_name,
elff_info.file_name,
elff_info.line_number);
elff_free_pc_address_info(elff_handle,
&elff_info);
elff_close(elff_handle);
}
} else {
printf(" Frame %u: PC=0x%08X in module <unknown>\n",
stk, leaked_alloc.call_stack[stk]);
}
}
}
}
leaks_reported++;
}
}
if (leaks_reported) {
T(CHECK_LEAK, "memcheck: Process %s[pid=%u] is leaking %u allocated blocks.\n",
proc->image_path, proc->pid, leaks_reported);
}
T(PROC_EXIT, "memcheck: Exiting process %s[pid=%u] in thread %u. Memory leaks detected: %u\n",
proc->image_path, proc->pid, current_tid, leaks_reported);
/* Since current process is exiting, we need to NULL its cached descriptor,
* and unlist it from the list of running processes. */
current_process = NULL;
QLIST_REMOVE(proc, global_entry);
// Empty process' mmapings map.
mmrangemap_empty(&proc->mmrange_map);
if (proc->image_path != NULL) {
qemu_free(proc->image_path);
}
qemu_free(proc);
}
void
memcheck_mmap_exepath(target_ulong vstart,
target_ulong vend,
target_ulong exec_offset,
const char* path)
{
MMRangeDesc desc;
MMRangeDesc replaced;
RBTMapResult ins_res;
ProcDesc* proc = get_current_process();
if (proc == NULL) {
ME("memcheck: MMAP(0x%08X, 0x%08X, 0x%08X, %s) Unable to look up current process. Current tid=%u",
vstart, vend, exec_offset, path, current_tid);
return;
}
/* First, unmap an overlapped section */
memcheck_unmap(vstart, vend);
/* Add new mapping. */
desc.map_start = vstart;
desc.map_end = vend;
desc.exec_offset = exec_offset;
desc.path = qemu_malloc(strlen(path) + 1);
if (desc.path == NULL) {
ME("memcheck: MMAP(0x%08X, 0x%08X, 0x%08X, %s) Unable to allocate path for the entry.",
vstart, vend, exec_offset, path);
return;
}
strcpy(desc.path, path);
ins_res = mmrangemap_insert(&proc->mmrange_map, &desc, &replaced);
if (ins_res == RBT_MAP_RESULT_ERROR) {
ME("memcheck: %s[pid=%u] unable to insert memory mapping entry: 0x%08X - 0x%08X",
proc->image_path, proc->pid, vstart, vend);
qemu_free(desc.path);
return;
}
if (ins_res == RBT_MAP_RESULT_ENTRY_REPLACED) {
MD("memcheck: %s[pid=%u] MMRANGE %s[0x%08X - 0x%08X] is replaced with %s[0x%08X - 0x%08X]",
proc->image_path, proc->pid, replaced.path, replaced.map_start,
replaced.map_end, desc.path, desc.map_start, desc.map_end);
qemu_free(replaced.path);
}
T(PROC_MMAP, "memcheck: %s[pid=%u] %s is mapped: 0x%08X - 0x%08X + 0x%08X\n",
proc->image_path, proc->pid, path, vstart, vend, exec_offset);
}
void
memcheck_unmap(target_ulong vstart, target_ulong vend)
{
MMRangeDesc desc;
ProcDesc* proc = get_current_process();
if (proc == NULL) {
ME("memcheck: UNMAP(0x%08X, 0x%08X) Unable to look up current process. Current tid=%u",
vstart, vend, current_tid);
return;
}
if (mmrangemap_pull(&proc->mmrange_map, vstart, vend, &desc)) {
return;
}
if (desc.map_start >= vstart && desc.map_end <= vend) {
/* Entire mapping has been deleted. */
T(PROC_MMAP, "memcheck: %s[pid=%u] %s is unmapped: [0x%08X - 0x%08X + 0x%08X]\n",
proc->image_path, proc->pid, desc.path, vstart, vend, desc.exec_offset);
qemu_free(desc.path);
return;
}
/* This can be first stage of "remap" request, when part of the existing
* mapping has been unmapped. If that's so, lets cut unmapped part from the
* block that we just pulled, and add whatever's left back to the map. */
T(PROC_MMAP, "memcheck: REMAP(0x%08X, 0x%08X + 0x%08X) -> (0x%08X, 0x%08X)\n",
desc.map_start, desc.map_end, desc.exec_offset, vstart, vend);
if (desc.map_start == vstart) {
/* We cut part from the beginning. Add the tail back. */
desc.exec_offset += vend - desc.map_start;
desc.map_start = vend;
mmrangemap_insert(&proc->mmrange_map, &desc, NULL);
} else if (desc.map_end == vend) {
/* We cut part from the tail. Add the beginning back. */
desc.map_end = vstart;
mmrangemap_insert(&proc->mmrange_map, &desc, NULL);
} else {
/* We cut piece in the middle. */
MMRangeDesc tail;
tail.map_start = vend;
tail.map_end = desc.map_end;
tail.exec_offset = vend - desc.map_start + desc.exec_offset;
tail.path = qemu_malloc(strlen(desc.path) + 1);
strcpy(tail.path, desc.path);
mmrangemap_insert(&proc->mmrange_map, &tail, NULL);
desc.map_end = vstart;
mmrangemap_insert(&proc->mmrange_map, &desc, NULL);
}
}