1 /** @file
2 PE/Coff Extra Action library instances.
3
4 Copyright (c) 2010 - 2018, Intel Corporation. All rights reserved.<BR>
5 SPDX-License-Identifier: BSD-2-Clause-Patent
6
7 **/
8
9 #include <PeCoffExtraActionLib.h>
10
11 /**
12 Check if the hardware breakpoint in Drx is enabled by checking the Lx and Gx bit in Dr7.
13
14 It assumes that DebugAgent will set both Lx and Gx bit when setting up the hardware breakpoint.
15
16
17 @param RegisterIndex Index of Dr register. The value range is from 0 to 3.
18 @param Dr7 Value of Dr7 register.
19
20 @return TRUE The hardware breakpoint specified in the Drx is enabled.
21 @return FALSE The hardware breakpoint specified in the Drx is disabled.
22
23 **/
24 BOOLEAN
IsDrxEnabled(IN UINT8 RegisterIndex,IN UINTN Dr7)25 IsDrxEnabled (
26 IN UINT8 RegisterIndex,
27 IN UINTN Dr7
28 )
29 {
30 return (BOOLEAN) (((Dr7 >> (RegisterIndex * 2)) & (BIT0 | BIT1)) == (BIT0 | BIT1));
31 }
32
33 /**
34 Common routine to report the PE/COFF image loading/relocating or unloading event.
35
36 If ImageContext is NULL, then ASSERT().
37
38 @param ImageContext Pointer to the image context structure that describes the
39 PE/COFF image.
40 @param Signature IMAGE_LOAD_SIGNATURE or IMAGE_UNLOAD_SIGNATURE.
41
42 **/
43 VOID
PeCoffLoaderExtraActionCommon(IN OUT PE_COFF_LOADER_IMAGE_CONTEXT * ImageContext,IN UINTN Signature)44 PeCoffLoaderExtraActionCommon (
45 IN OUT PE_COFF_LOADER_IMAGE_CONTEXT *ImageContext,
46 IN UINTN Signature
47 )
48 {
49 BOOLEAN InterruptState;
50 UINTN Dr0;
51 UINTN Dr1;
52 UINTN Dr2;
53 UINTN Dr3;
54 UINTN Dr7;
55 UINTN Cr4;
56 UINTN NewDr7;
57 UINT8 LoadImageMethod;
58 UINT8 DebugAgentStatus;
59 IA32_DESCRIPTOR IdtDescriptor;
60 IA32_IDT_GATE_DESCRIPTOR OriginalIdtEntry;
61 BOOLEAN IdtEntryHooked;
62 UINT32 RegEdx;
63
64 ASSERT (ImageContext != NULL);
65
66 if (ImageContext->PdbPointer != NULL) {
67 DEBUG((EFI_D_ERROR, " PDB = %a\n", ImageContext->PdbPointer));
68 }
69
70 //
71 // Disable interrupts and save the current interrupt state
72 //
73 InterruptState = SaveAndDisableInterrupts ();
74
75 IdtEntryHooked = FALSE;
76 LoadImageMethod = PcdGet8 (PcdDebugLoadImageMethod);
77 if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_IO_HW_BREAKPOINT) {
78 //
79 // If the CPU does not support Debug Extensions(CPUID:01 EDX:BIT2)
80 // then force use of DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3
81 //
82 AsmCpuid (1, NULL, NULL, NULL, &RegEdx);
83 if ((RegEdx & BIT2) == 0) {
84 LoadImageMethod = DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3;
85 }
86 }
87 AsmReadIdtr (&IdtDescriptor);
88 if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3) {
89 if (!CheckDebugAgentHandler (&IdtDescriptor, SOFT_INT_VECTOR_NUM)) {
90 //
91 // Do not trigger INT3 if Debug Agent did not setup IDT entries.
92 //
93 return;
94 }
95 } else {
96 if (!CheckDebugAgentHandler (&IdtDescriptor, IO_HW_BREAKPOINT_VECTOR_NUM)) {
97 //
98 // Save and update IDT entry for INT1
99 //
100 SaveAndUpdateIdtEntry1 (&IdtDescriptor, &OriginalIdtEntry);
101 IdtEntryHooked = TRUE;
102 }
103 }
104
105 //
106 // Save Debug Register State
107 //
108 Dr0 = AsmReadDr0 ();
109 Dr1 = AsmReadDr1 ();
110 Dr2 = AsmReadDr2 ();
111 Dr3 = AsmReadDr3 ();
112 Dr7 = AsmReadDr7 () | BIT10; // H/w sets bit 10, some simulators don't
113 Cr4 = AsmReadCr4 ();
114
115 //
116 // DR0 = Signature
117 // DR1 = The address of the Null-terminated ASCII string for the PE/COFF image's PDB file name
118 // DR2 = The pointer to the ImageContext structure
119 // DR3 = IO_PORT_BREAKPOINT_ADDRESS
120 // DR7 = Disables all HW breakpoints except for DR3 I/O port access of length 1 byte
121 // CR4 = Make sure DE(BIT3) is set
122 //
123 AsmWriteDr7 (BIT10);
124 AsmWriteDr0 (Signature);
125 AsmWriteDr1 ((UINTN) ImageContext->PdbPointer);
126 AsmWriteDr2 ((UINTN) ImageContext);
127 AsmWriteDr3 (IO_PORT_BREAKPOINT_ADDRESS);
128
129 if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_IO_HW_BREAKPOINT) {
130 AsmWriteDr7 (0x20000480);
131 AsmWriteCr4 (Cr4 | BIT3);
132 //
133 // Do an IN from IO_PORT_BREAKPOINT_ADDRESS to generate a HW breakpoint until the port
134 // returns a read value other than DEBUG_AGENT_IMAGE_WAIT
135 //
136 do {
137 DebugAgentStatus = IoRead8 (IO_PORT_BREAKPOINT_ADDRESS);
138 } while (DebugAgentStatus == DEBUG_AGENT_IMAGE_WAIT);
139
140 } else if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3) {
141 //
142 // Generate a software break point.
143 //
144 CpuBreakpoint ();
145 }
146
147 //
148 // Restore Debug Register State only when Host didn't change it inside exception handler.
149 // E.g.: User halts the target and sets the HW breakpoint while target is
150 // in the above exception handler
151 //
152 NewDr7 = AsmReadDr7 () | BIT10; // H/w sets bit 10, some simulators don't
153 if (!IsDrxEnabled (0, NewDr7) && (AsmReadDr0 () == 0 || AsmReadDr0 () == Signature)) {
154 //
155 // If user changed Dr3 (by setting HW bp in the above exception handler,
156 // we will not set Dr0 to 0 in GO/STEP handler because the break cause is not IMAGE_LOAD/_UNLOAD.
157 //
158 AsmWriteDr0 (Dr0);
159 }
160 if (!IsDrxEnabled (1, NewDr7) && (AsmReadDr1 () == (UINTN) ImageContext->PdbPointer)) {
161 AsmWriteDr1 (Dr1);
162 }
163 if (!IsDrxEnabled (2, NewDr7) && (AsmReadDr2 () == (UINTN) ImageContext)) {
164 AsmWriteDr2 (Dr2);
165 }
166 if (!IsDrxEnabled (3, NewDr7) && (AsmReadDr3 () == IO_PORT_BREAKPOINT_ADDRESS)) {
167 AsmWriteDr3 (Dr3);
168 }
169 if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_IO_HW_BREAKPOINT) {
170 if (AsmReadCr4 () == (Cr4 | BIT3)) {
171 AsmWriteCr4 (Cr4);
172 }
173 if (NewDr7 == 0x20000480) {
174 AsmWriteDr7 (Dr7);
175 }
176 } else if (LoadImageMethod == DEBUG_LOAD_IMAGE_METHOD_SOFT_INT3) {
177 if (NewDr7 == BIT10) {
178 AsmWriteDr7 (Dr7);
179 }
180 }
181 //
182 // Restore original IDT entry for INT1 if it was hooked.
183 //
184 if (IdtEntryHooked) {
185 RestoreIdtEntry1 (&IdtDescriptor, &OriginalIdtEntry);
186 }
187 //
188 // Restore the interrupt state
189 //
190 SetInterruptState (InterruptState);
191 }
192
193 /**
194 Performs additional actions after a PE/COFF image has been loaded and relocated.
195
196 @param ImageContext Pointer to the image context structure that describes the
197 PE/COFF image that has already been loaded and relocated.
198
199 **/
200 VOID
201 EFIAPI
PeCoffLoaderRelocateImageExtraAction(IN OUT PE_COFF_LOADER_IMAGE_CONTEXT * ImageContext)202 PeCoffLoaderRelocateImageExtraAction (
203 IN OUT PE_COFF_LOADER_IMAGE_CONTEXT *ImageContext
204 )
205 {
206 PeCoffLoaderExtraActionCommon (ImageContext, IMAGE_LOAD_SIGNATURE);
207 }
208
209 /**
210 Performs additional actions just before a PE/COFF image is unloaded. Any resources
211 that were allocated by PeCoffLoaderRelocateImageExtraAction() must be freed.
212
213 @param ImageContext Pointer to the image context structure that describes the
214 PE/COFF image that is being unloaded.
215
216 **/
217 VOID
218 EFIAPI
PeCoffLoaderUnloadImageExtraAction(IN OUT PE_COFF_LOADER_IMAGE_CONTEXT * ImageContext)219 PeCoffLoaderUnloadImageExtraAction (
220 IN OUT PE_COFF_LOADER_IMAGE_CONTEXT *ImageContext
221 )
222 {
223 PeCoffLoaderExtraActionCommon (ImageContext, IMAGE_UNLOAD_SIGNATURE);
224 }
225