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Root/branches/meklort/i386/boot2/kernel_patcher.c

Source at commit 429 created 13 years 8 months ago.
By meklort, Updated module system. Hooks can now be used within modules when cetaion functions are called in chameleon. Note that onle two hooks currently exist, more need to be added. I also updated the HelloWorld module to use a hook instead of print out right away.
1/*␊
2 * Copyright (c) 2009 Evan Lojewski. All rights reserved.␊
3 *␊
4 */␊
5␊
6#include "libsaio.h"␊
7#include "kernel_patcher.h"␊
8#include "platform.h"␊
9␊
10extern PlatformInfo_t Platform;␊
11␊
12␊
13#define SYMBOL_CPUID_SET_INFO␉␉␉␉0␊
14#define SYMBOL_PANIC␉␉␉␉␉␉1␊
15#define SYMBOL_PMCPUEXITHALTTOOFF␉␉␉2␊
16#define SYMBOL_LAPIC_INIT␉␉␉␉␉3␊
17#define SYMBOL_COMMPAGE_STUFF_ROUTINE␉␉4␊
18#define NUM_SYMBOLS␉␉␉␉␉␉␉5␊
19␊
20#define SYMBOL_CPUID_SET_INFO_STRING␉␉"_cpuid_set_info"␊
21#define SYMBOL_PANIC_STRING␉␉␉␉␉"_panic"␊
22#define SYMBOL_PMCPUEXITHALTTOOFF_STRING␉"_pmCPUExitHaltToOff"␊
23#define SYMBOL_LAPIC_INIT_STRING␉␉␉"_lapic_init"␊
24#define SYMBOL_COMMPAGE_STUFF_ROUTINE_STRING␉"_commpage_stuff_routine"␊
25␊
26char* kernelSymbols[NUM_SYMBOLS] = {␊
27␉SYMBOL_CPUID_SET_INFO_STRING,␊
28␉SYMBOL_PANIC_STRING,␊
29␉SYMBOL_PMCPUEXITHALTTOOFF_STRING,␊
30␉SYMBOL_LAPIC_INIT_STRING,␊
31␉SYMBOL_COMMPAGE_STUFF_ROUTINE_STRING␊
32};␊
33␊
34UInt32 kernelSymbolAddresses[NUM_SYMBOLS] = {␊
35␉0,␊
36␉0,␊
37␉0,␊
38␉0,␊
39␉0␊
40};␊
41␊
42␊
43UInt32 textSection = 0;␊
44UInt32 textAddress = 0;␊
45␊
46␊
47void patch_kernel(void* kernelData)␊
48{␊
49␉switch (locate_symbols((void*)kernelData)) {␊
50␉␉case KERNEL_32:␊
51␉␉␉patch_kernel_32((void*)kernelData);␊
52␉␉␉break;␊
53␉␉␉␊
54␉␉case KERNEL_64:␊
55␉␉default:␊
56␉␉␉patch_kernel_64((void*)kernelData);␊
57␉␉␉break;␊
58␉}␊
59}␊
60␊
61// patches a 64bit kernel.␊
62void patch_kernel_64(void* kernelData)␊
63{␊
64␉// At the moment, the kernel patching code fails when used␊
65␉// in 64bit mode, so we don't patch it. This is due to 32bit vs 64bit␊
66␉// pointers as well as changes in structure sizes␊
67␉printf("Unable to patch 64bit kernel. Please use arch=i386.\n");␊
68}␊
69␊
70␊
71/**␊
72 ** patch_kernel_32␊
73 **␉␉patches kernel based on cpu info determined earlier in the boot process.␊
74 **␉␉It the machine is vmware, remove the artificial lapic panic␊
75 **␉␉If the CPU is not supported, remove the cpuid_set_info panic␊
76 **␉␉If the CPU is and Intel Atom, inject the penryn cpuid info.␊
77 **/␊
78void patch_kernel_32(void* kernelData)␊
79{␊
80␉// Remove panic in commpage␊
81␉patch_commpage_stuff_routine(kernelData);␊
82␉␊
83␉//patch_pmCPUExitHaltToOff(kernelData);␉// Not working as intended, disabled for now␊
84␉␊
85␉//␉if(vmware_detected)␊
86␉{␊
87␉␉patch_lapic_init(kernelData);␊
88␉}␊
89␉␊
90␉switch(Platform.CPU.Model)␊
91␉{␊
92␉␉␉// Known good CPU's, no reason to patch kernel␊
93␉␉case 13:␊
94␉␉case CPUID_MODEL_YONAH:␊
95␉␉case CPUID_MODEL_MEROM:␊
96␉␉case CPUID_MODEL_PENRYN:␊
97␉␉case CPUID_MODEL_NEHALEM:␊
98␉␉case CPUID_MODEL_FIELDS:␊
99␉␉case CPUID_MODEL_DALES:␊
100␉␉case CPUID_MODEL_NEHALEM_EX:␊
101␉␉␉break;␊
102␉␉␉␊
103␉␉␉// Known unsuported CPU's␊
104␉␉case CPUID_MODEL_ATOM:␊
105␉␉␉// TODO: Impersonate CPU based on user selection␊
106␉␉␉patch_cpuid_set_info(kernelData, CPUFAMILY_INTEL_PENRYN, CPUID_MODEL_PENRYN);␉// Impersonate Penryn CPU␊
107␉␉␉break;␊
108␉␉␉␊
109␉␉␉// Unknown CPU's␊
110␉␉default:␉␊
111␉␉␉// TODO: Impersonate CPU based on user selection␊
112␉␉␉patch_cpuid_set_info(kernelData, 0, 0);␉// Remove Panic Call␊
113␉␉␉␊
114␉␉␉break;␊
115␉}␊
116}␊
117␊
118␊
119/**␊
120 **␉␉This functions located the kernelSymbols[i] symbols in the mach-o header.␊
121 **␉␉␉as well as determines the start of the __TEXT segment and __TEXT,__text sections␊
122 **/␊
123int locate_symbols(void* kernelData)␊
124{␊
125␉UInt16 symbolIndexes[NUM_SYMBOLS];␊
126␊
127␉struct load_command *loadCommand;␊
128␉struct symtab_command *symtableData;␊
129␉struct nlist *symbolEntry;␊
130␉␊
131␉char* symbolString;␊
132␊
133␉UInt32 kernelIndex = 0;␊
134␉kernelIndex += sizeof(struct mach_header);␊
135␉␊
136␉if(((struct mach_header*)kernelData)->magic != MH_MAGIC) return KERNEL_64;␊
137␉␊
138␉␊
139␉//printf("%d load commands beginning at 0x%X\n", (unsigned int)header->ncmds, (unsigned int)kernelIndex);␊
140␉//printf("Commands take up %d bytes\n", header->sizeofcmds);␊
141␉␊
142␉␊
143␉int cmd = 0;␊
144␉while(cmd < ((struct mach_header*)kernelData)->ncmds)␉// TODO: for loop instead␊
145␉{␊
146␉␉cmd++;␊
147␉␉␊
148␉␉loadCommand = kernelData + kernelIndex;␊
149␉␉␊
150␉␉UInt cmdSize = loadCommand->cmdsize;␊
151␉␉␊
152␉␉␊
153␉␉// Locate start of _panic and _cpuid_set_info in the symbol tabe.␊
154␉␉// Load commands should be anded with 0x7FFFFFFF to ignore the␉LC_REQ_DYLD flag␊
155␉␉if((loadCommand->cmd & 0x7FFFFFFF) == LC_SYMTAB)␉␉// We only care about the symtab segment␊
156␉␉{␊
157␉␉␉//printf("Located symtable, length is 0x%X, 0x%X\n", (unsigned int)loadCommand->cmdsize, (unsigned int)sizeof(symtableData));␊
158␉␉␉␊
159␉␉␉symtableData = kernelData + kernelIndex;␊
160␉␉␉kernelIndex += sizeof(struct symtab_command);␊
161␉␉␉␊
162␉␉␉cmdSize -= sizeof(struct symtab_command);␊
163␊
164␉␉␉// Loop through symbol table untill all of the symbols have been found␊
165␉␉␉␊
166␉␉␉symbolString = kernelData + symtableData->stroff; ␊
167␉␉␉␊
168␉␉␉␊
169␉␉␉UInt16 symbolIndex = 0;␊
170␉␉␉UInt8 numSymbolsFound = 0;␊
171␊
172␉␉␉while(symbolIndex < symtableData->nsyms && numSymbolsFound < NUM_SYMBOLS)␉// TODO: for loop␊
173␉␉␉{␊
174␉␉␉␉int i = 0;␊
175␉␉␉␉while(i < NUM_SYMBOLS)␊
176␉␉␉␉{␊
177␉␉␉␉␉if(strcmp(symbolString, kernelSymbols[i]) == 0)␊
178␉␉␉␉␉{␊
179␉␉␉␉␉␉symbolIndexes[i] = symbolIndex;␊
180␉␉␉␉␉␉numSymbolsFound++;␉␉␉␉␊
181␉␉␉␉␉} ␊
182␉␉␉␉␉i++;␊
183␉␉␉␉␉␊
184␉␉␉␉}␊
185␉␉␉␉symbolString += strlen(symbolString) + 1;␊
186␉␉␉␉symbolIndex++;␊
187␉␉␉}␊
188␉␉␉␊
189␉␉␉// loop again␊
190␉␉␉symbolIndex = 0;␊
191␉␉␉numSymbolsFound = 0;␊
192␉␉␉while(symbolIndex < symtableData->nsyms && numSymbolsFound < NUM_SYMBOLS)␉// TODO: for loop␊
193␉␉␉{␊
194␉␉␉␉␊
195␉␉␉␉symbolEntry = kernelData + symtableData->symoff + (symbolIndex * sizeof(struct nlist));␊
196␉␉␉␉␊
197␉␉␉␉int i = 0;␊
198␉␉␉␉while(i < NUM_SYMBOLS)␊
199␉␉␉␉{␊
200␉␉␉␉␉if(symbolIndex == (symbolIndexes[i] - 4))␊
201␉␉␉␉␉{␊
202␉␉␉␉␉␉kernelSymbolAddresses[i] = (UInt32)symbolEntry->n_value;␊
203␉␉␉␉␉␉numSymbolsFound++;␉␉␉␉␊
204␉␉␉␉␉} ␊
205␉␉␉␉␉i++;␊
206␉␉␉␉␉␊
207␉␉␉␉}␊
208␉␉␉␉␊
209␉␉␉␉symbolIndex ++;␊
210␉␉␉}␉␉␉␊
211␉␉// Load commands should be anded with 0x7FFFFFFF to ignore the␉LC_REQ_DYLD flag␊
212␉␉} else if((loadCommand->cmd & 0x7FFFFFFF) == LC_SEGMENT)␉␉// We only care about the __TEXT segment, any other load command can be ignored␊
213␉␉{␊
214␉␉␉␊
215␉␉␉struct segment_command *segCommand;␊
216␉␉␉␊
217␉␉␉segCommand = kernelData + kernelIndex;␊
218␉␉␉␊
219␉␉␉//printf("Segment name is %s\n", segCommand->segname);␊
220␉␉␉␊
221␉␉␉if(strcmp("__TEXT", segCommand->segname) == 0)␊
222␉␉␉{␊
223␉␉␉␉UInt32 sectionIndex;␊
224␉␉␉␉␊
225␉␉␉␉sectionIndex = sizeof(struct segment_command);␊
226␉␉␉␉␊
227␉␉␉␉struct section *sect;␊
228␉␉␉␉␊
229␉␉␉␉while(sectionIndex < segCommand->cmdsize)␊
230␉␉␉␉{␊
231␉␉␉␉␉sect = kernelData + kernelIndex + sectionIndex;␊
232␉␉␉␉␉␊
233␉␉␉␉␉sectionIndex += sizeof(struct section);␊
234␉␉␉␉␉␊
235␉␉␉␉␉␊
236␉␉␉␉␉if(strcmp("__text", sect->sectname) == 0)␊
237␉␉␉␉␉{␊
238␉␉␉␉␉␉// __TEXT,__text found, save the offset and address for when looking for the calls.␊
239␉␉␉␉␉␉textSection = sect->offset;␊
240␉␉␉␉␉␉textAddress = sect->addr;␊
241␉␉␉␉␉␉break;␊
242␉␉␉␉␉}␉␉␉␉␉␊
243␉␉␉␉}␊
244␉␉␉}␊
245␉␉␉␊
246␉␉␉␊
247␉␉␉kernelIndex += cmdSize;␊
248␉␉} else {␊
249␉␉␉kernelIndex += cmdSize;␊
250␉␉}␊
251␉}␊
252␉␊
253␉return KERNEL_32;␊
254}␊
255␊
256␊
257/**␊
258 ** Locate the fisrt instance of _panic inside of _cpuid_set_info, and either remove it␊
259 ** Or replace it so that the cpuid is set to a valid value.␊
260 **/␊
261void patch_cpuid_set_info(void* kernelData, UInt32 impersonateFamily, UInt8 impersonateModel)␊
262{␊
263␉UInt8* bytes = (UInt8*)kernelData;␊
264␉UInt32 patchLocation = (kernelSymbolAddresses[SYMBOL_CPUID_SET_INFO] - textAddress + textSection);␊
265␉UInt32 jumpLocation = 0;␊
266␉UInt32 panicAddr = kernelSymbolAddresses[SYMBOL_PANIC] - textAddress;␊
267␉if(kernelSymbolAddresses[SYMBOL_CPUID_SET_INFO] == 0)␊
268␉{␊
269␉␉printf("Unable to locate _cpuid_set_info\n");␊
270␉␉return;␊
271␉␉␊
272␉}␊
273␉if(kernelSymbolAddresses[SYMBOL_PANIC] == 0)␊
274␉{␊
275␉␉printf("Unable to locate _panic\n");␊
276␉␉return;␊
277␉}␊
278␉␊
279␉//TODO: don't assume it'll always work (Look for *next* function address in symtab and fail once it's been reached)␊
280␉while( ␊
281␉␉ (bytes[patchLocation -1] != 0xE8) ||␊
282␉␉ ( ( (UInt32)(panicAddr - patchLocation - 4) + textSection ) != (UInt32)((bytes[patchLocation + 0] << 0 | ␊
283␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation + 1] << 8 | ␊
284␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation + 2] << 16 |␊
285␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation + 3] << 24)))␊
286␉␉ )␊
287␉{␊
288␉␉patchLocation++;␊
289␉}␊
290␉patchLocation--;␊
291␉␊
292␉␊
293␉// Remove panic call, just in case the following patch routines fail␊
294␉bytes[patchLocation + 0] = 0x90;␊
295␉bytes[patchLocation + 1] = 0x90;␊
296␉bytes[patchLocation + 2] = 0x90;␊
297␉bytes[patchLocation + 3] = 0x90;␊
298␉bytes[patchLocation + 4] = 0x90;␊
299␉␊
300␉␊
301␉// Locate the jump call, so that 10 bytes can be reclamed.␊
302␉// NOTE: This will *NOT* be located on pre 10.6.2 kernels␊
303␉jumpLocation = patchLocation - 15;␊
304␉while((bytes[jumpLocation - 1] != 0x77 ||␊
305␉␉ bytes[jumpLocation] != (patchLocation - jumpLocation - -8)) &&␊
306␉␉ (patchLocation - jumpLocation) < 0xF0)␊
307␉{␊
308␉␉jumpLocation--;␊
309␉}␊
310␉␊
311␉// If found... AND we want to impersonate a specific cpumodel / family...␊
312␉if(impersonateFamily &&␊
313␉ impersonateModel &&␊
314␉ ((patchLocation - jumpLocation) < 0xF0))␊
315␉{␊
316␉␉␊
317␉␉bytes[jumpLocation] -= 10;␉␉// sizeof(movl␉$0x6b5a4cd2,0x00872eb4) = 10bytes␊
318␉␉␊
319␉␉/* ␊
320␉␉ * Inpersonate the specified CPU FAMILY and CPU Model␊
321␉␉ */␊
322␊
323␉␉// bytes[patchLocation - 17] = 0xC7;␉// already here... not needed to be done␊
324␉␉// bytes[patchLocation - 16] = 0x05;␉// see above␊
325␉␉UInt32 cpuid_cpufamily_addr =␉bytes[patchLocation - 15] << 0 |␊
326␉␉␉␉␉␉␉␉␉␉bytes[patchLocation - 14] << 8 |␊
327␉␉␉␉␉␉␉␉␉␉bytes[patchLocation - 13] << 16 |␊
328␉␉␉␉␉␉␉␉␉␉bytes[patchLocation - 12] << 24;␊
329␉␉␊
330␉␉// NOTE: may change, determined based on cpuid_info struct␊
331␉␉UInt32 cpuid_model_addr = cpuid_cpufamily_addr - 299; ␊
332␉␉␊
333␉␉␊
334␉␉// cpufamily = CPUFAMILY_INTEL_PENRYN␊
335␉␉bytes[patchLocation - 11] = (impersonateFamily & 0x000000FF) >> 0;␊
336␉␉bytes[patchLocation - 10] = (impersonateFamily & 0x0000FF00) >> 8;␊
337␉␉bytes[patchLocation - 9] = (impersonateFamily & 0x00FF0000) >> 16;␉␊
338␉␉bytes[patchLocation - 8] = (impersonateFamily & 0xFF000000) >> 24;␊
339␉␉␊
340␉␉// NOPS, just in case if the jmp call wasn't patched, we'll jump to a␊
341␉␉// nop and continue with the rest of the patch␊
342␉␉// Yay two free bytes :), 10 more can be reclamed if needed, as well as a few␊
343␉␉// from the above code (only cpuid_model needs to be set.␊
344␉␉bytes[patchLocation - 7] = 0x90;␊
345␉␉bytes[patchLocation - 6] = 0x90;␊
346␉␉␊
347␉␉bytes[patchLocation - 5] = 0xC7;␊
348␉␉bytes[patchLocation - 4] = 0x05;␊
349␉␉bytes[patchLocation - 3] = (cpuid_model_addr & 0x000000FF) >> 0;␊
350␉␉bytes[patchLocation - 2] = (cpuid_model_addr & 0x0000FF00) >> 8;␉␊
351␉␉bytes[patchLocation - 1] = (cpuid_model_addr & 0x00FF0000) >> 16;␊
352␉␉bytes[patchLocation - 0] = (cpuid_model_addr & 0xFF000000) >> 24;␊
353␉␉␊
354␉␉// Note: I could have just copied the 8bit cpuid_model in and saved about 4 bytes␊
355␉␉// so if this function need a different patch it's still possible. Also, about ten bytes previous can be freed.␊
356␉␉bytes[patchLocation + 1] = impersonateModel;␉// cpuid_model␊
357␉␉bytes[patchLocation + 2] = 0x01;␉// cpuid_extmodel␊
358␉␉bytes[patchLocation + 3] = 0x00;␉// cpuid_extfamily␊
359␉␉bytes[patchLocation + 4] = 0x02;␉// cpuid_stepping␊
360␉␉␊
361␉}␊
362␉else if(impersonateFamily && impersonateModel)␊
363␉{␊
364␉␉// pre 10.6.2 kernel␊
365␉␉// Locate the jump to directly *after* the panic call,␊
366␉␉jumpLocation = patchLocation - 4;␊
367␉␉while((bytes[jumpLocation - 1] != 0x77 ||␊
368␉␉␉ bytes[jumpLocation] != (patchLocation - jumpLocation + 4)) &&␊
369␉␉␉ (patchLocation - jumpLocation) < 0x20)␊
370␉␉{␊
371␉␉␉jumpLocation--;␊
372␉␉}␊
373␉␉// NOTE above isn't needed (I was going to use it, but I'm not, so instead,␊
374␉␉// I'll just leave it to verify the binary stucture.␊
375␉␉␊
376␉␉// NOTE: the cpumodel_familt data is not set in _cpuid_set_info␊
377␉␉// so we don't need to set it here, I'll get set later based on the model␊
378␉␉// we set now.␊
379␉␉␊
380␉␉if((patchLocation - jumpLocation) < 0x20)␊
381␉␉{␊
382␉␉␉UInt32 cpuid_model_addr =␉(bytes[patchLocation - 14] << 0 |␊
383␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation - 13] << 8 |␊
384␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation - 12] << 16 |␊
385␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation - 11] << 24);␊
386␉␉␉// Remove jump␊
387␉␉␉bytes[patchLocation - 9] = 0x90;␉␉/// Was a jump if supported cpu␊
388␉␉␉bytes[patchLocation - 8] = 0x90;␉␉// jumped past the panic call, we want to override the panic␊
389␊
390␉␉␉bytes[patchLocation - 7] = 0x90;␊
391␉␉␉bytes[patchLocation - 6] = 0x90;␊
392␉␉␉␊
393␉␉␉bytes[patchLocation - 5] = 0xC7;␊
394␉␉␉bytes[patchLocation - 4] = 0x05;␊
395␉␉␉bytes[patchLocation - 3] = (cpuid_model_addr & 0x000000FF) >> 0;␊
396␉␉␉bytes[patchLocation - 2] = (cpuid_model_addr & 0x0000FF00) >> 8;␉␊
397␉␉␉bytes[patchLocation - 1] = (cpuid_model_addr & 0x00FF0000) >> 16;␊
398␉␉␉bytes[patchLocation - 0] = (cpuid_model_addr & 0xFF000000) >> 24;␊
399␉␉␉␊
400␉␉␉// Note: I could have just copied the 8bit cpuid_model in and saved about 4 bytes␊
401␉␉␉// so if this function need a different patch it's still possible. Also, about ten bytes previous can be freed.␊
402␉␉␉bytes[patchLocation + 1] = impersonateModel;␉// cpuid_model␊
403␉␉␉bytes[patchLocation + 2] = 0x01;␉// cpuid_extmodel␊
404␉␉␉bytes[patchLocation + 3] = 0x00;␉// cpuid_extfamily␊
405␉␉␉bytes[patchLocation + 4] = 0x02;␉// cpuid_stepping␊
406␉␉␉␊
407␉␉␉␊
408␉␉␉␊
409␉␉␉patchLocation = jumpLocation;␊
410␉␉␉// We now have 14 bytes available for a patch␊
411␉␉␉␊
412␉␉}␊
413␉␉else ␊
414␉␉{␊
415␉␉␉// Patching failed, using NOP replacement done initialy␊
416␉␉}␊
417␉}␊
418␉else ␊
419␉{␊
420␉␉// Either We were unable to change the jump call due to the function's sctructure␊
421␉␉// changing, or the user did not request a patch. As such, resort to just ␊
422␉␉// removing the panic call (using NOP replacement above). Note that the␊
423␉␉// IntelCPUPM kext may still panic due to the cpu's Model ID not being patched␊
424␉}␊
425}␊
426␊
427␊
428/**␊
429 ** SleepEnabler.kext replacement (for those that need it)␊
430 ** Located the KERN_INVALID_ARGUMENT return and replace it with KERN_SUCCESS␊
431 **/␊
432void patch_pmCPUExitHaltToOff(void* kernelData)␊
433{␊
434␉UInt8* bytes = (UInt8*)kernelData;␊
435␉UInt32 patchLocation = (kernelSymbolAddresses[SYMBOL_PMCPUEXITHALTTOOFF] - textAddress + textSection);␊
436␊
437␉if(kernelSymbolAddresses[SYMBOL_PMCPUEXITHALTTOOFF] == 0)␊
438␉{␊
439␉␉printf("Unable to locate _pmCPUExitHaltToOff\n");␊
440␉␉return;␊
441␉}␊
442␉␊
443␉while(bytes[patchLocation - 1]␉!= 0xB8 ||␊
444␉␉ bytes[patchLocation]␉␉!= 0x04 ||␉// KERN_INVALID_ARGUMENT (0x00000004)␊
445␉␉ bytes[patchLocation + 1]␉!= 0x00 ||␉// KERN_INVALID_ARGUMENT␊
446␉␉ bytes[patchLocation + 2]␉!= 0x00 ||␉// KERN_INVALID_ARGUMENT␊
447␉␉ bytes[patchLocation + 3]␉!= 0x00)␉// KERN_INVALID_ARGUMENT␊
448␊
449␉{␊
450␉␉patchLocation++;␊
451␉}␊
452␉bytes[patchLocation] = 0x00;␉// KERN_SUCCESS;␊
453}␊
454␊
455void patch_lapic_init(void* kernelData)␊
456{␊
457␉UInt8 panicIndex = 0;␊
458␉UInt8* bytes = (UInt8*)kernelData;␊
459␉UInt32 patchLocation = (kernelSymbolAddresses[SYMBOL_LAPIC_INIT] - textAddress + textSection);␊
460␉UInt32 panicAddr = kernelSymbolAddresses[SYMBOL_PANIC] - textAddress;␊
461␊
462␉if(kernelSymbolAddresses[SYMBOL_LAPIC_INIT] == 0)␊
463␉{␊
464␉␉printf("Unable to locate %s\n", SYMBOL_LAPIC_INIT_STRING);␊
465␉␉return;␊
466␉␉␊
467␉}␊
468␉if(kernelSymbolAddresses[SYMBOL_PANIC] == 0)␊
469␉{␊
470␉␉printf("Unable to locate %s\n", SYMBOL_PANIC_STRING);␊
471␉␉return;␊
472␉}␊
473␉␊
474␉␊
475␉␊
476␉// Locate the (panicIndex + 1) panic call␊
477␉while(panicIndex < 3)␉// Find the third panic call␊
478␉{␊
479␉␉while( ␊
480␉␉␉ (bytes[patchLocation -1] != 0xE8) ||␊
481␉␉␉ ( ( (UInt32)(panicAddr - patchLocation - 4) + textSection ) != (UInt32)((bytes[patchLocation + 0] << 0 | ␊
482␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation + 1] << 8 | ␊
483␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation + 2] << 16 |␊
484␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation + 3] << 24)))␊
485␉␉␉ )␊
486␉␉{␊
487␉␉␉patchLocation++;␊
488␉␉}␊
489␉␉patchLocation++;␊
490␉␉panicIndex++;␊
491␉}␊
492␉patchLocation--;␉// Remove extra increment from the < 3 while loop␊
493␉␊
494␉bytes[--patchLocation] = 0x90;␉␊
495␉bytes[++patchLocation] = 0x90;␊
496␉bytes[++patchLocation] = 0x90;␊
497␉bytes[++patchLocation] = 0x90;␊
498␉bytes[++patchLocation] = 0x90;␊
499␉␊
500␉␊
501}␊
502␊
503␊
504void patch_commpage_stuff_routine(void* kernelData)␊
505{␊
506␉UInt8* bytes = (UInt8*)kernelData;␊
507␉UInt32 patchLocation = (kernelSymbolAddresses[SYMBOL_COMMPAGE_STUFF_ROUTINE] - textAddress + textSection);␊
508␉UInt32 panicAddr = kernelSymbolAddresses[SYMBOL_PANIC] - textAddress;␊
509␉␊
510␉if(kernelSymbolAddresses[SYMBOL_COMMPAGE_STUFF_ROUTINE] == 0)␊
511␉{␊
512␉␉printf("Unable to locate %s\n", SYMBOL_COMMPAGE_STUFF_ROUTINE_STRING);␊
513␉␉return;␊
514␉␉␊
515␉}␊
516␉if(kernelSymbolAddresses[SYMBOL_PANIC] == 0)␊
517␉{␊
518␉␉printf("Unable to locate %s\n", SYMBOL_PANIC_STRING);␊
519␉␉return;␊
520␉}␊
521␉␊
522␉␊
523␉while( ␊
524␉␉ (bytes[patchLocation -1] != 0xE8) ||␊
525␉␉ ( ( (UInt32)(panicAddr - patchLocation - 4) + textSection ) != (UInt32)((bytes[patchLocation + 0] << 0 | ␊
526␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation + 1] << 8 | ␊
527␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation + 2] << 16 |␊
528␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation + 3] << 24)))␊
529␉␉ )␊
530␉{␊
531␉␉patchLocation++;␊
532␉}␊
533␉patchLocation--;␊
534␉␊
535␉␊
536␉// Remove panic call, just in case the following patch routines fail␊
537␉bytes[patchLocation + 0] = 0x90;␊
538␉bytes[patchLocation + 1] = 0x90;␊
539␉bytes[patchLocation + 2] = 0x90;␊
540␉bytes[patchLocation + 3] = 0x90;␊
541␉bytes[patchLocation + 4] = 0x90;␊
542␉␊
543␉␊
544}␊
545

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