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Root/branches/azimutz/Chazileon/i386/boot2/kernel_patcher.c

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 //Azi: not needed to boot -legacy␊
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 or -legacy flags.\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␉␉// Locate start of _panic and _cpuid_set_info in the symbol tabe.␊
153␉␉// Load commands should be anded with 0x7FFFFFFF to ignore the␉LC_REQ_DYLD flag␊
154␉␉if((loadCommand->cmd & 0x7FFFFFFF) == LC_SYMTAB)␉␉// We only care about the symtab segment␊
155␉␉{␊
156␉␉␉//printf("Located symtable, length is 0x%X, 0x%X\n", (unsigned int)loadCommand->cmdsize, (unsigned int)sizeof(symtableData));␊
157␉␉␉␊
158␉␉␉symtableData = kernelData + kernelIndex;␊
159␉␉␉kernelIndex += sizeof(struct symtab_command);␊
160␉␉␉␊
161␉␉␉cmdSize -= sizeof(struct symtab_command);␊
162␊
163␉␉␉// Loop through symbol table untill all of the symbols have been found␊
164␉␉␉␊
165␉␉␉symbolString = kernelData + symtableData->stroff; ␊
166␉␉␉␊
167␉␉␉␊
168␉␉␉UInt16 symbolIndex = 0;␊
169␉␉␉UInt8 numSymbolsFound = 0;␊
170␊
171␉␉␉while(symbolIndex < symtableData->nsyms && numSymbolsFound < NUM_SYMBOLS)␉// TODO: for loop␊
172␉␉␉{␊
173␉␉␉␉int i = 0;␊
174␉␉␉␉while(i < NUM_SYMBOLS)␊
175␉␉␉␉{␊
176␉␉␉␉␉if(strcmp(symbolString, kernelSymbols[i]) == 0)␊
177␉␉␉␉␉{␊
178␉␉␉␉␉␉symbolIndexes[i] = symbolIndex;␊
179␉␉␉␉␉␉numSymbolsFound++;␉␉␉␉␊
180␉␉␉␉␉} ␊
181␉␉␉␉␉i++;␊
182␉␉␉␉␉␊
183␉␉␉␉}␊
184␉␉␉␉symbolString += strlen(symbolString) + 1;␊
185␉␉␉␉symbolIndex++;␊
186␉␉␉}␊
187␉␉␉␊
188␉␉␉// loop again␊
189␉␉␉symbolIndex = 0;␊
190␉␉␉numSymbolsFound = 0;␊
191␉␉␉while(symbolIndex < symtableData->nsyms && numSymbolsFound < NUM_SYMBOLS)␉// TODO: for loop␊
192␉␉␉{␊
193␉␉␉␉␊
194␉␉␉␉symbolEntry = kernelData + symtableData->symoff + (symbolIndex * sizeof(struct nlist));␊
195␉␉␉␉␊
196␉␉␉␉int i = 0;␊
197␉␉␉␉while(i < NUM_SYMBOLS)␊
198␉␉␉␉{␊
199␉␉␉␉␉if(symbolIndex == (symbolIndexes[i] - 4))␊
200␉␉␉␉␉{␊
201␉␉␉␉␉␉kernelSymbolAddresses[i] = (UInt32)symbolEntry->n_value;␊
202␉␉␉␉␉␉numSymbolsFound++;␉␉␉␉␊
203␉␉␉␉␉} ␊
204␉␉␉␉␉i++;␊
205␉␉␉␉␉␊
206␉␉␉␉}␊
207␉␉␉␉␊
208␉␉␉␉symbolIndex ++;␊
209␉␉␉}␉␉␉␊
210␉␉// Load commands should be anded with 0x7FFFFFFF to ignore the␉LC_REQ_DYLD flag␊
211␉␉} else if((loadCommand->cmd & 0x7FFFFFFF) == LC_SEGMENT)␉␉// We only care about the __TEXT segment, any other load command can be ignored␊
212␉␉{␊
213␉␉␉␊
214␉␉␉struct segment_command *segCommand;␊
215␉␉␉␊
216␉␉␉segCommand = kernelData + kernelIndex;␊
217␉␉␉␊
218␉␉␉//printf("Segment name is %s\n", segCommand->segname);␊
219␉␉␉␊
220␉␉␉if(strcmp("__TEXT", segCommand->segname) == 0)␊
221␉␉␉{␊
222␉␉␉␉UInt32 sectionIndex;␊
223␉␉␉␉␊
224␉␉␉␉sectionIndex = sizeof(struct segment_command);␊
225␉␉␉␉␊
226␉␉␉␉struct section *sect;␊
227␉␉␉␉␊
228␉␉␉␉while(sectionIndex < segCommand->cmdsize)␊
229␉␉␉␉{␊
230␉␉␉␉␉sect = kernelData + kernelIndex + sectionIndex;␊
231␉␉␉␉␉␊
232␉␉␉␉␉sectionIndex += sizeof(struct section);␊
233␉␉␉␉␉␊
234␉␉␉␉␉␊
235␉␉␉␉␉if(strcmp("__text", sect->sectname) == 0)␊
236␉␉␉␉␉{␊
237␉␉␉␉␉␉// __TEXT,__text found, save the offset and address for when looking for the calls.␊
238␉␉␉␉␉␉textSection = sect->offset;␊
239␉␉␉␉␉␉textAddress = sect->addr;␊
240␉␉␉␉␉␉break;␊
241␉␉␉␉␉}␉␉␉␉␉␊
242␉␉␉␉}␊
243␉␉␉}␊
244␉␉␉␊
245␉␉␉␊
246␉␉␉kernelIndex += cmdSize;␊
247␉␉} else {␊
248␉␉␉kernelIndex += cmdSize;␊
249␉␉}␊
250␉}␊
251␉␊
252␉return KERNEL_32;␊
253}␊
254␊
255␊
256/**␊
257 ** Locate the fisrt instance of _panic inside of _cpuid_set_info, and either remove it␊
258 ** Or replace it so that the cpuid is set to a valid value.␊
259 **/␊
260void patch_cpuid_set_info(void* kernelData, UInt32 impersonateFamily, UInt8 impersonateModel)␊
261{␊
262␉UInt8* bytes = (UInt8*)kernelData;␊
263␉UInt32 patchLocation = (kernelSymbolAddresses[SYMBOL_CPUID_SET_INFO] - textAddress + textSection);␊
264␉UInt32 jumpLocation = 0;␊
265␉UInt32 panicAddr = kernelSymbolAddresses[SYMBOL_PANIC] - textAddress;␊
266␉if(kernelSymbolAddresses[SYMBOL_CPUID_SET_INFO] == 0)␊
267␉{␊
268␉␉printf("Unable to locate _cpuid_set_info\n");␊
269␉␉return;␊
270␉␉␊
271␉}␊
272␉if(kernelSymbolAddresses[SYMBOL_PANIC] == 0)␊
273␉{␊
274␉␉printf("Unable to locate _panic\n");␊
275␉␉return;␊
276␉}␊
277␉␊
278␉//TODO: don't assume it'll always work (Look for *next* function address in symtab and fail once it's been reached)␊
279␉while( ␊
280␉␉ (bytes[patchLocation -1] != 0xE8) ||␊
281␉␉ ( ( (UInt32)(panicAddr - patchLocation - 4) + textSection ) != (UInt32)((bytes[patchLocation + 0] << 0 | ␊
282␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation + 1] << 8 | ␊
283␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation + 2] << 16 |␊
284␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation + 3] << 24)))␊
285␉␉ )␊
286␉{␊
287␉␉patchLocation++;␊
288␉}␊
289␉patchLocation--;␊
290␉␊
291␉␊
292␉// Remove panic call, just in case the following patch routines fail␊
293␉bytes[patchLocation + 0] = 0x90;␊
294␉bytes[patchLocation + 1] = 0x90;␊
295␉bytes[patchLocation + 2] = 0x90;␊
296␉bytes[patchLocation + 3] = 0x90;␊
297␉bytes[patchLocation + 4] = 0x90;␊
298␉␊
299␉␊
300␉// Locate the jump call, so that 10 bytes can be reclamed.␊
301␉// NOTE: This will *NOT* be located on pre 10.6.2 kernels␊
302␉jumpLocation = patchLocation - 15;␊
303␉while((bytes[jumpLocation - 1] != 0x77 ||␊
304␉␉ bytes[jumpLocation] != (patchLocation - jumpLocation - -8)) &&␊
305␉␉ (patchLocation - jumpLocation) < 0xF0)␊
306␉{␊
307␉␉jumpLocation--;␊
308␉}␊
309␉␊
310␉printf("Mode: %d Family %d P - JMP: 0x%X\n", impersonateModel, impersonateFamily, patchLocation - jumpLocation);␊
311␉// If found... AND we want to impersonate a specific cpumodel / family...␊
312␉if(impersonateFamily &&␊
313␉ impersonateModel &&␊
314␉ ((patchLocation - jumpLocation) < 0xF0))␊
315␉{␊
316␉␉printf("Patching CPUID to %d.%d\n", impersonateFamily, impersonateModel);␊
317␉␉␊
318␉␉bytes[jumpLocation] -= 10;␉␉// sizeof(movl␉$0x6b5a4cd2,0x00872eb4) = 10bytes␊
319␉␉␊
320␉␉/* ␊
321␉␉ * Inpersonate the specified CPU FAMILY and CPU Model␊
322␉␉ */␊
323␊
324␉␉// bytes[patchLocation - 17] = 0xC7;␉// already here... not needed to be done␊
325␉␉// bytes[patchLocation - 16] = 0x05;␉// see above␊
326␉␉UInt32 cpuid_cpufamily_addr =␉bytes[patchLocation - 15] << 0 |␊
327␉␉␉␉␉␉␉␉␉␉bytes[patchLocation - 14] << 8 |␊
328␉␉␉␉␉␉␉␉␉␉bytes[patchLocation - 13] << 16 |␊
329␉␉␉␉␉␉␉␉␉␉bytes[patchLocation - 12] << 24;␊
330␉␉␊
331␉␉// NOTE: may change, determined based on cpuid_info struct␊
332␉␉UInt32 cpuid_model_addr = cpuid_cpufamily_addr - 299; ␊
333␉␉␊
334␉␉␊
335␉␉// cpufamily = CPUFAMILY_INTEL_PENRYN␊
336␉␉bytes[patchLocation - 11] = (impersonateFamily & 0x000000FF) >> 0;␊
337␉␉bytes[patchLocation - 10] = (impersonateFamily & 0x0000FF00) >> 8;␊
338␉␉bytes[patchLocation - 9] = (impersonateFamily & 0x00FF0000) >> 16;␉␊
339␉␉bytes[patchLocation - 8] = (impersonateFamily & 0xFF000000) >> 24;␊
340␉␉␊
341␉␉// NOPS, just in case if the jmp call wasn't patched, we'll jump to a␊
342␉␉// nop and continue with the rest of the patch␊
343␉␉// Yay two free bytes :), 10 more can be reclamed if needed, as well as a few␊
344␉␉// from the above code (only cpuid_model needs to be set.␊
345␉␉bytes[patchLocation - 7] = 0x90;␊
346␉␉bytes[patchLocation - 6] = 0x90;␊
347␉␉␊
348␉␉bytes[patchLocation - 5] = 0xC7;␊
349␉␉bytes[patchLocation - 4] = 0x05;␊
350␉␉bytes[patchLocation - 3] = (cpuid_model_addr & 0x000000FF) >> 0;␊
351␉␉bytes[patchLocation - 2] = (cpuid_model_addr & 0x0000FF00) >> 8;␉␊
352␉␉bytes[patchLocation - 1] = (cpuid_model_addr & 0x00FF0000) >> 16;␊
353␉␉bytes[patchLocation - 0] = (cpuid_model_addr & 0xFF000000) >> 24;␊
354␉␉␊
355␉␉// Note: I could have just copied the 8bit cpuid_model in and saved about 4 bytes␊
356␉␉// so if this function need a different patch it's still possible. Also, about ten bytes previous can be freed.␊
357␉␉bytes[patchLocation + 1] = impersonateModel;␉// cpuid_model␊
358␉␉bytes[patchLocation + 2] = 0x01;␉// cpuid_extmodel␊
359␉␉bytes[patchLocation + 3] = 0x00;␉// cpuid_extfamily␊
360␉␉bytes[patchLocation + 4] = 0x02;␉// cpuid_stepping␊
361␉␉␊
362␉}␊
363␉else if(impersonateFamily && impersonateModel)␊
364␉{␊
365␉␉// pre 10.6.2 kernel␊
366␉␉// Locate the jump to directly *after* the panic call,␊
367␉␉jumpLocation = patchLocation - 4;␊
368␉␉while((bytes[jumpLocation - 1] != 0x77 ||␊
369␉␉␉ bytes[jumpLocation] != (patchLocation - jumpLocation + 4)) &&␊
370␉␉␉ (patchLocation - jumpLocation) < 0x20)␊
371␉␉{␊
372␉␉␉jumpLocation--;␊
373␉␉}␊
374␉␉// NOTE above isn't needed (I was going to use it, but I'm not, so instead,␊
375␉␉// I'll just leave it to verify the binary stucture.␊
376␉␉␊
377␉␉// NOTE: the cpumodel_familt data is not set in _cpuid_set_info␊
378␉␉// so we don't need to set it here, I'll get set later based on the model␊
379␉␉// we set now.␊
380␉␉␊
381␉␉if((patchLocation - jumpLocation) < 0x20)␊
382␉␉{␊
383␉␉␉UInt32 cpuid_model_addr =␉(bytes[patchLocation - 14] << 0 |␊
384␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation - 13] << 8 |␊
385␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation - 12] << 16 |␊
386␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation - 11] << 24);␊
387␉␉␉// Remove jump␊
388␉␉␉bytes[patchLocation - 9] = 0x90;␉␉/// Was a jump if supported cpu␊
389␉␉␉bytes[patchLocation - 8] = 0x90;␉␉// jumped past the panic call, we want to override the panic␊
390␊
391␉␉␉bytes[patchLocation - 7] = 0x90;␊
392␉␉␉bytes[patchLocation - 6] = 0x90;␊
393␉␉␉␊
394␉␉␉bytes[patchLocation - 5] = 0xC7;␊
395␉␉␉bytes[patchLocation - 4] = 0x05;␊
396␉␉␉bytes[patchLocation - 3] = (cpuid_model_addr & 0x000000FF) >> 0;␊
397␉␉␉bytes[patchLocation - 2] = (cpuid_model_addr & 0x0000FF00) >> 8;␉␊
398␉␉␉bytes[patchLocation - 1] = (cpuid_model_addr & 0x00FF0000) >> 16;␊
399␉␉␉bytes[patchLocation - 0] = (cpuid_model_addr & 0xFF000000) >> 24;␊
400␉␉␉␊
401␉␉␉// Note: I could have just copied the 8bit cpuid_model in and saved about 4 bytes␊
402␉␉␉// so if this function need a different patch it's still possible. Also, about ten bytes previous can be freed.␊
403␉␉␉bytes[patchLocation + 1] = impersonateModel;␉// cpuid_model␊
404␉␉␉bytes[patchLocation + 2] = 0x01;␉// cpuid_extmodel␊
405␉␉␉bytes[patchLocation + 3] = 0x00;␉// cpuid_extfamily␊
406␉␉␉bytes[patchLocation + 4] = 0x02;␉// cpuid_stepping␊
407␉␉␉␊
408␉␉␉␊
409␉␉␉␊
410␉␉␉patchLocation = jumpLocation;␊
411␉␉␉// We now have 14 bytes available for a patch␊
412␉␉␉␊
413␉␉}␊
414␉␉else ␊
415␉␉{␊
416␉␉␉// Patching failed, using NOP replacement done initialy␊
417␉␉}␊
418␉}␊
419␉else ␊
420␉{␊
421␉␉// Either We were unable to change the jump call due to the function's sctructure␊
422␉␉// changing, or the user did not request a patch. As such, resort to just ␊
423␉␉// removing the panic call (using NOP replacement above). Note that the␊
424␉␉// IntelCPUPM kext may still panic due to the cpu's Model ID not being patched␊
425␉}␊
426}␊
427␊
428␊
429/**␊
430 ** SleepEnabler.kext replacement (for those that need it)␊
431 ** Located the KERN_INVALID_ARGUMENT return and replace it with KERN_SUCCESS␊
432 **/␊
433void patch_pmCPUExitHaltToOff(void* kernelData)␊
434{␊
435␉UInt8* bytes = (UInt8*)kernelData;␊
436␉UInt32 patchLocation = (kernelSymbolAddresses[SYMBOL_PMCPUEXITHALTTOOFF] - textAddress + textSection);␊
437␊
438␉if(kernelSymbolAddresses[SYMBOL_PMCPUEXITHALTTOOFF] == 0)␊
439␉{␊
440␉␉printf("Unable to locate _pmCPUExitHaltToOff\n");␊
441␉␉return;␊
442␉}␊
443␉␊
444␉while(bytes[patchLocation - 1]␉!= 0xB8 ||␊
445␉␉ bytes[patchLocation]␉␉!= 0x04 ||␉// KERN_INVALID_ARGUMENT (0x00000004)␊
446␉␉ bytes[patchLocation + 1]␉!= 0x00 ||␉// KERN_INVALID_ARGUMENT␊
447␉␉ bytes[patchLocation + 2]␉!= 0x00 ||␉// KERN_INVALID_ARGUMENT␊
448␉␉ bytes[patchLocation + 3]␉!= 0x00)␉// KERN_INVALID_ARGUMENT␊
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␊
503void patch_commpage_stuff_routine(void* kernelData)␊
504{␊
505␉UInt8* bytes = (UInt8*)kernelData;␊
506␉UInt32 patchLocation = (kernelSymbolAddresses[SYMBOL_COMMPAGE_STUFF_ROUTINE] - textAddress + textSection);␊
507␉UInt32 panicAddr = kernelSymbolAddresses[SYMBOL_PANIC] - textAddress;␊
508␉␊
509␉if(kernelSymbolAddresses[SYMBOL_COMMPAGE_STUFF_ROUTINE] == 0)␊
510␉{␊
511␉␉printf("Unable to locate %s\n", SYMBOL_COMMPAGE_STUFF_ROUTINE_STRING);␊
512␉␉return;␊
513␉␉␊
514␉}␊
515␉if(kernelSymbolAddresses[SYMBOL_PANIC] == 0)␊
516␉{␊
517␉␉printf("Unable to locate %s\n", SYMBOL_PANIC_STRING);␊
518␉␉return;␊
519␉}␊
520␉␊
521␉␊
522␉while( ␊
523␉␉ (bytes[patchLocation -1] != 0xE8) ||␊
524␉␉ ( ( (UInt32)(panicAddr - patchLocation - 4) + textSection ) != (UInt32)((bytes[patchLocation + 0] << 0 | ␊
525␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation + 1] << 8 | ␊
526␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation + 2] << 16 |␊
527␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉␉bytes[patchLocation + 3] << 24)))␊
528␉␉ )␊
529␉{␊
530␉␉patchLocation++;␊
531␉}␊
532␉patchLocation--;␊
533␉␊
534␉␊
535␉// Remove panic call, just in case the following patch routines fail␊
536␉bytes[patchLocation + 0] = 0x90;␊
537␉bytes[patchLocation + 1] = 0x90;␊
538␉bytes[patchLocation + 2] = 0x90;␊
539␉bytes[patchLocation + 3] = 0x90;␊
540␉bytes[patchLocation + 4] = 0x90;␊
541␉␊
542␉␊
543}␊
544

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