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Code Issues Releases Activity

Fix page protection bug causing a rare startup crash (bug 5133, r=fyren).

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This commit is contained in:
David Anderson 2011-10-15 22:16:50 -07:00
parent 2c693a4d25
commit 3cdeb6d0d2
4 changed files with 272 additions and 2 deletions
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123
core-legacy/sourcehook/sh_memory.h
View File

@ -47,6 +47,116 @@
namespace SourceHook
{
static inline bool GetPageBits(void *addr, int *bits)
{
#if SH_SYS == SH_SYS_LINUX
// On linux, first check /proc/self/maps
unsigned long laddr = reinterpret_cast<unsigned long>(addr);
FILE *pF = fopen("/proc/self/maps", "r");
if (pF) {
// Linux /proc/self/maps -> parse
// Format:
// lower upper prot stuff path
// 08048000-0804c000 r-xp 00000000 03:03 1010107 /bin/cat
unsigned long rlower, rupper;
char r, w, x;
while (fscanf(pF, "%lx-%lx %c%c%c", &rlower, &rupper, &r, &w, &x) != EOF) {
// Check whether we're IN THERE!
if (laddr >= rlower && laddr < rupper) {
fclose(pF);
*bits = 0;
if (r == 'r')
*bits |= SH_MEM_READ;
if (w == 'w')
*bits |= SH_MEM_WRITE;
if (x == 'x')
*bits |= SH_MEM_EXEC;
return true;
}
// Read to end of line
int c;
while ((c = fgetc(pF)) != '\n') {
if (c == EOF)
break;
}
if (c == EOF)
break;
}
fclose(pF);
return false;
}
pF = fopen("/proc/curproc/map", "r");
if (pF) {
// FreeBSD /proc/curproc/map -> parse
// 0x804800 0x805500 13 15 0xc6e18960 r-x 21 0x0 COW NC vnode
unsigned long rlower, rupper, ignoreLong;
int ignoreInt;
char r, w, x;
while (fscanf(pF, "0x%lx 0x%lx %d %d 0x%lx %c%c%c", &rlower, &rupper, &ignoreInt,
&ignoreInt, &ignoreLong, &r, &w, &x) != EOF) {
// Check whether we're IN THERE!
if (laddr >= rlower && laddr < rupper) {
fclose(pF);
*bits = 0;
if (r == 'r')
*bits |= SH_MEM_READ;
if (r == 'w')
*bits |= SH_MEM_WRITE;
if (r == 'x')
*bits |= SH_MEM_EXEC;
return true;
}
// Read to end of line
int c;
while ((c = fgetc(pF)) != '\n') {
if (c == EOF)
break;
}
if (c == EOF)
break;
}
fclose(pF);
return false;
}
return false;
#elif SH_SYS == SH_SYS_APPLE
#elif SH_XP == SH_XP_WINAPI
SYSTEM_INFO info;
GetSystemInfo(&info);
MEMORY_BASIC_INFORMATION mem;
size_t base = size_t(addr) & ~size_t(info.dwPageSize - 1);
if (!VirtualQuery((void *)base, &mem, sizeof(mem)))
return false;
switch (mem.Protect) {
case PAGE_EXECUTE:
*bits = SH_MEM_EXEC;
break;
case PAGE_EXECUTE_READ:
*bits = SH_MEM_EXEC | SH_MEM_READ;
break;
case PAGE_EXECUTE_READWRITE:
case PAGE_EXECUTE_WRITECOPY:
*bits = SH_MEM_EXEC | SH_MEM_READ | SH_MEM_WRITE;
break;
case PAGE_NOACCESS:
*bits = 0;
break;
case PAGE_READONLY:
*bits = SH_MEM_READ;
break;
case PAGE_READWRITE:
case PAGE_WRITECOPY:
*bits = SH_MEM_READ | SH_MEM_WRITE;
break;
default:
return false;
}
return true;
#endif
}
inline bool SetMemAccess(void *addr, size_t len, int access)
{
# if SH_XP == SH_XP_POSIX
@ -70,6 +180,19 @@ namespace SourceHook
# endif
}
inline bool MakePageWritable(void *addr)
{
int bits;
if (GetPageBits(addr, &bits)) {
if (bits & SH_MEM_WRITE)
return true;
bits |= SH_MEM_WRITE;
} else {
bits = SH_MEM_READ | SH_MEM_WRITE | SH_MEM_EXEC;
}
return SetMemAccess(addr, sizeof(void *), bits);
}
#if SH_XP == SH_XP_POSIX
namespace
{

2
core-legacy/sourcehook/sourcehook.cpp
View File

@ -366,7 +366,7 @@ namespace SourceHook
CVfnPtr vfp(cur_vfnptr, &m_OneIgnore);
// Alter vtable entry
if (!SetMemAccess(cur_vtptr, sizeof(void*) * (tmp.m_VtblIdx + 1), SH_MEM_READ | SH_MEM_WRITE))
if (!MakePageWritable(cur_vtptr))
return 0;
*reinterpret_cast<void**>(cur_vfnptr) = *reinterpret_cast<void**>(hookman->m_HookfuncVfnptr);

147
core/sourcehook/sh_memory.h
View File

@ -43,11 +43,145 @@
# else
# error Unsupported OS/Compiler
# endif
#if SH_SYS == SH_SYS_APPLE
# include <mach/mach.h>
# include <mach/vm_region.h>
# include <mach/mach_traps.h>
#endif
#include "sh_list.h"
namespace SourceHook
{
static inline bool GetPageBits(void *addr, int *bits)
{
#if SH_SYS == SH_SYS_LINUX
// On linux, first check /proc/self/maps
unsigned long laddr = reinterpret_cast<unsigned long>(addr);
FILE *pF = fopen("/proc/self/maps", "r");
if (pF) {
// Linux /proc/self/maps -> parse
// Format:
// lower upper prot stuff path
// 08048000-0804c000 r-xp 00000000 03:03 1010107 /bin/cat
unsigned long rlower, rupper;
char r, w, x;
while (fscanf(pF, "%lx-%lx %c%c%c", &rlower, &rupper, &r, &w, &x) != EOF) {
// Check whether we're IN THERE!
if (laddr >= rlower && laddr < rupper) {
fclose(pF);
*bits = 0;
if (r == 'r')
*bits |= SH_MEM_READ;
if (w == 'w')
*bits |= SH_MEM_WRITE;
if (x == 'x')
*bits |= SH_MEM_EXEC;
return true;
}
// Read to end of line
int c;
while ((c = fgetc(pF)) != '\n') {
if (c == EOF)
break;
}
if (c == EOF)
break;
}
fclose(pF);
return false;
}
pF = fopen("/proc/curproc/map", "r");
if (pF) {
// FreeBSD /proc/curproc/map -> parse
// 0x804800 0x805500 13 15 0xc6e18960 r-x 21 0x0 COW NC vnode
unsigned long rlower, rupper, ignoreLong;
int ignoreInt;
char r, w, x;
while (fscanf(pF, "0x%lx 0x%lx %d %d 0x%lx %c%c%c", &rlower, &rupper, &ignoreInt,
&ignoreInt, &ignoreLong, &r, &w, &x) != EOF) {
// Check whether we're IN THERE!
if (laddr >= rlower && laddr < rupper) {
fclose(pF);
*bits = 0;
if (r == 'r')
*bits |= SH_MEM_READ;
if (r == 'w')
*bits |= SH_MEM_WRITE;
if (r == 'x')
*bits |= SH_MEM_EXEC;
return true;
}
// Read to end of line
int c;
while ((c = fgetc(pF)) != '\n') {
if (c == EOF)
break;
}
if (c == EOF)
break;
}
fclose(pF);
return false;
}
return false;
#elif SH_SYS == SH_SYS_APPLE
vm_size_t ignoreSize;
vm_address_t vmaddr = (vm_address_t)addr;
vm_region_basic_info_data_t info;
vm_region_flavor_t flavor = VM_REGION_BASIC_INFO;
memory_object_name_t obj;
mach_msg_type_number_t count = VM_REGION_BASIC_INFO_COUNT;
kern_return_t kr = vm_region(mach_task_self(), &vmaddr, &ignoreSize, flavor,
(vm_region_info_t)&info, &count, &obj);
if (kr != KERN_SUCCESS)
return false;
*bits = 0;
if (info.protection & VM_PROT_READ)
*bits |= SH_MEM_READ;
if (info.protection & VM_PROT_WRITE)
*bits |= SH_MEM_WRITE;
if (info.protection & VM_PROT_EXECUTE)
*bits |= SH_MEM_EXEC;
return true;
#elif SH_XP == SH_XP_WINAPI
SYSTEM_INFO info;
GetSystemInfo(&info);
MEMORY_BASIC_INFORMATION mem;
size_t base = size_t(addr) & ~size_t(info.dwPageSize - 1);
if (!VirtualQuery((void *)base, &mem, sizeof(mem)))
return false;
switch (mem.Protect) {
case PAGE_EXECUTE:
*bits = SH_MEM_EXEC;
break;
case PAGE_EXECUTE_READ:
*bits = SH_MEM_EXEC | SH_MEM_READ;
break;
case PAGE_EXECUTE_READWRITE:
case PAGE_EXECUTE_WRITECOPY:
*bits = SH_MEM_EXEC | SH_MEM_READ | SH_MEM_WRITE;
break;
case PAGE_NOACCESS:
*bits = 0;
break;
case PAGE_READONLY:
*bits = SH_MEM_READ;
break;
case PAGE_READWRITE:
case PAGE_WRITECOPY:
*bits = SH_MEM_READ | SH_MEM_WRITE;
break;
default:
return false;
}
return true;
#endif
}
inline bool SetMemAccess(void *addr, size_t len, int access)
{
# if SH_XP == SH_XP_POSIX
@ -71,6 +205,19 @@ namespace SourceHook
# endif
}
inline bool MakePageWritable(void *addr)
{
int bits;
if (GetPageBits(addr, &bits)) {
if (bits & SH_MEM_WRITE)
return true;
bits |= SH_MEM_WRITE;
} else {
bits = SH_MEM_READ | SH_MEM_WRITE | SH_MEM_EXEC;
}
return SetMemAccess(addr, sizeof(void *), bits);
}
#if SH_XP == SH_XP_POSIX
namespace
{

2
core/sourcehook/sourcehook_impl_cvfnptr.cpp
View File

@ -217,7 +217,7 @@ namespace SourceHook
bool CVfnPtr::Patch(void *newValue)
{
if (!SetMemAccess(m_Ptr, sizeof(void*), SH_MEM_READ | SH_MEM_WRITE))
if (!MakePageWritable(m_Ptr))
{
return false;
}