diff options
-rw-r--r-- | arch/x86/kernel/entry_64.S | 444 |
1 files changed, 220 insertions, 224 deletions
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index f2d546e16354..38fcd0517c31 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S | |||
@@ -1002,7 +1002,7 @@ END(\sym) | |||
1002 | .endm | 1002 | .endm |
1003 | 1003 | ||
1004 | .macro paranoidzeroentry sym do_sym | 1004 | .macro paranoidzeroentry sym do_sym |
1005 | KPROBE_ENTRY(\sym) | 1005 | ENTRY(\sym) |
1006 | INTR_FRAME | 1006 | INTR_FRAME |
1007 | PARAVIRT_ADJUST_EXCEPTION_FRAME | 1007 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
1008 | pushq $-1 /* ORIG_RAX: no syscall to restart */ | 1008 | pushq $-1 /* ORIG_RAX: no syscall to restart */ |
@@ -1015,11 +1015,11 @@ KPROBE_ENTRY(\sym) | |||
1015 | call \do_sym | 1015 | call \do_sym |
1016 | jmp paranoid_exit /* %ebx: no swapgs flag */ | 1016 | jmp paranoid_exit /* %ebx: no swapgs flag */ |
1017 | CFI_ENDPROC | 1017 | CFI_ENDPROC |
1018 | KPROBE_END(\sym) | 1018 | END(\sym) |
1019 | .endm | 1019 | .endm |
1020 | 1020 | ||
1021 | .macro paranoidzeroentry_ist sym do_sym ist | 1021 | .macro paranoidzeroentry_ist sym do_sym ist |
1022 | KPROBE_ENTRY(\sym) | 1022 | ENTRY(\sym) |
1023 | INTR_FRAME | 1023 | INTR_FRAME |
1024 | PARAVIRT_ADJUST_EXCEPTION_FRAME | 1024 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
1025 | pushq $-1 /* ORIG_RAX: no syscall to restart */ | 1025 | pushq $-1 /* ORIG_RAX: no syscall to restart */ |
@@ -1035,15 +1035,11 @@ KPROBE_ENTRY(\sym) | |||
1035 | addq $EXCEPTION_STKSZ, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp) | 1035 | addq $EXCEPTION_STKSZ, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp) |
1036 | jmp paranoid_exit /* %ebx: no swapgs flag */ | 1036 | jmp paranoid_exit /* %ebx: no swapgs flag */ |
1037 | CFI_ENDPROC | 1037 | CFI_ENDPROC |
1038 | KPROBE_END(\sym) | 1038 | END(\sym) |
1039 | .endm | 1039 | .endm |
1040 | 1040 | ||
1041 | .macro errorentry sym do_sym entry=0 | 1041 | .macro errorentry sym do_sym |
1042 | .if \entry | ||
1043 | KPROBE_ENTRY(\sym) | ||
1044 | .else | ||
1045 | ENTRY(\sym) | 1042 | ENTRY(\sym) |
1046 | .endif | ||
1047 | XCPT_FRAME | 1043 | XCPT_FRAME |
1048 | PARAVIRT_ADJUST_EXCEPTION_FRAME | 1044 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
1049 | subq $15*8,%rsp | 1045 | subq $15*8,%rsp |
@@ -1056,20 +1052,12 @@ ENTRY(\sym) | |||
1056 | call \do_sym | 1052 | call \do_sym |
1057 | jmp error_exit /* %ebx: no swapgs flag */ | 1053 | jmp error_exit /* %ebx: no swapgs flag */ |
1058 | CFI_ENDPROC | 1054 | CFI_ENDPROC |
1059 | .if \entry | ||
1060 | KPROBE_END(\sym) | ||
1061 | .else | ||
1062 | END(\sym) | 1055 | END(\sym) |
1063 | .endif | ||
1064 | .endm | 1056 | .endm |
1065 | 1057 | ||
1066 | /* error code is on the stack already */ | 1058 | /* error code is on the stack already */ |
1067 | .macro paranoiderrorentry sym do_sym entry=1 | 1059 | .macro paranoiderrorentry sym do_sym |
1068 | .if \entry | ||
1069 | KPROBE_ENTRY(\sym) | ||
1070 | .else | ||
1071 | ENTRY(\sym) | 1060 | ENTRY(\sym) |
1072 | .endif | ||
1073 | XCPT_FRAME | 1061 | XCPT_FRAME |
1074 | PARAVIRT_ADJUST_EXCEPTION_FRAME | 1062 | PARAVIRT_ADJUST_EXCEPTION_FRAME |
1075 | subq $15*8,%rsp | 1063 | subq $15*8,%rsp |
@@ -1083,166 +1071,23 @@ ENTRY(\sym) | |||
1083 | call \do_sym | 1071 | call \do_sym |
1084 | jmp paranoid_exit /* %ebx: no swapgs flag */ | 1072 | jmp paranoid_exit /* %ebx: no swapgs flag */ |
1085 | CFI_ENDPROC | 1073 | CFI_ENDPROC |
1086 | .if \entry | ||
1087 | KPROBE_END(\sym) | ||
1088 | .else | ||
1089 | END(\sym) | 1074 | END(\sym) |
1090 | .endif | ||
1091 | .endm | 1075 | .endm |
1092 | 1076 | ||
1093 | zeroentry divide_error do_divide_error | 1077 | zeroentry divide_error do_divide_error |
1094 | paranoidzeroentry_ist debug do_debug DEBUG_STACK | ||
1095 | paranoidzeroentry_ist int3 do_int3 DEBUG_STACK | ||
1096 | zeroentry overflow do_overflow | 1078 | zeroentry overflow do_overflow |
1097 | zeroentry bounds do_bounds | 1079 | zeroentry bounds do_bounds |
1098 | zeroentry invalid_op do_invalid_op | 1080 | zeroentry invalid_op do_invalid_op |
1099 | zeroentry device_not_available do_device_not_available | 1081 | zeroentry device_not_available do_device_not_available |
1100 | paranoiderrorentry double_fault do_double_fault 0 | 1082 | paranoiderrorentry double_fault do_double_fault |
1101 | zeroentry coprocessor_segment_overrun do_coprocessor_segment_overrun | 1083 | zeroentry coprocessor_segment_overrun do_coprocessor_segment_overrun |
1102 | errorentry invalid_TSS do_invalid_TSS | 1084 | errorentry invalid_TSS do_invalid_TSS |
1103 | errorentry segment_not_present do_segment_not_present | 1085 | errorentry segment_not_present do_segment_not_present |
1104 | paranoiderrorentry stack_segment do_stack_segment | ||
1105 | errorentry general_protection do_general_protection 1 | ||
1106 | errorentry page_fault do_page_fault 1 | ||
1107 | zeroentry spurious_interrupt_bug do_spurious_interrupt_bug | 1086 | zeroentry spurious_interrupt_bug do_spurious_interrupt_bug |
1108 | zeroentry coprocessor_error do_coprocessor_error | 1087 | zeroentry coprocessor_error do_coprocessor_error |
1109 | errorentry alignment_check do_alignment_check | 1088 | errorentry alignment_check do_alignment_check |
1110 | #ifdef CONFIG_X86_MCE | ||
1111 | paranoidzeroentry machine_check do_machine_check | ||
1112 | #endif | ||
1113 | zeroentry simd_coprocessor_error do_simd_coprocessor_error | 1089 | zeroentry simd_coprocessor_error do_simd_coprocessor_error |
1114 | 1090 | ||
1115 | /* | ||
1116 | * "Paranoid" exit path from exception stack. | ||
1117 | * Paranoid because this is used by NMIs and cannot take | ||
1118 | * any kernel state for granted. | ||
1119 | * We don't do kernel preemption checks here, because only | ||
1120 | * NMI should be common and it does not enable IRQs and | ||
1121 | * cannot get reschedule ticks. | ||
1122 | * | ||
1123 | * "trace" is 0 for the NMI handler only, because irq-tracing | ||
1124 | * is fundamentally NMI-unsafe. (we cannot change the soft and | ||
1125 | * hard flags at once, atomically) | ||
1126 | */ | ||
1127 | |||
1128 | /* ebx: no swapgs flag */ | ||
1129 | KPROBE_ENTRY(paranoid_exit) | ||
1130 | INTR_FRAME | ||
1131 | DISABLE_INTERRUPTS(CLBR_NONE) | ||
1132 | TRACE_IRQS_OFF | ||
1133 | testl %ebx,%ebx /* swapgs needed? */ | ||
1134 | jnz paranoid_restore | ||
1135 | testl $3,CS(%rsp) | ||
1136 | jnz paranoid_userspace | ||
1137 | paranoid_swapgs: | ||
1138 | TRACE_IRQS_IRETQ 0 | ||
1139 | SWAPGS_UNSAFE_STACK | ||
1140 | paranoid_restore: | ||
1141 | RESTORE_ALL 8 | ||
1142 | jmp irq_return | ||
1143 | paranoid_userspace: | ||
1144 | GET_THREAD_INFO(%rcx) | ||
1145 | movl TI_flags(%rcx),%ebx | ||
1146 | andl $_TIF_WORK_MASK,%ebx | ||
1147 | jz paranoid_swapgs | ||
1148 | movq %rsp,%rdi /* &pt_regs */ | ||
1149 | call sync_regs | ||
1150 | movq %rax,%rsp /* switch stack for scheduling */ | ||
1151 | testl $_TIF_NEED_RESCHED,%ebx | ||
1152 | jnz paranoid_schedule | ||
1153 | movl %ebx,%edx /* arg3: thread flags */ | ||
1154 | TRACE_IRQS_ON | ||
1155 | ENABLE_INTERRUPTS(CLBR_NONE) | ||
1156 | xorl %esi,%esi /* arg2: oldset */ | ||
1157 | movq %rsp,%rdi /* arg1: &pt_regs */ | ||
1158 | call do_notify_resume | ||
1159 | DISABLE_INTERRUPTS(CLBR_NONE) | ||
1160 | TRACE_IRQS_OFF | ||
1161 | jmp paranoid_userspace | ||
1162 | paranoid_schedule: | ||
1163 | TRACE_IRQS_ON | ||
1164 | ENABLE_INTERRUPTS(CLBR_ANY) | ||
1165 | call schedule | ||
1166 | DISABLE_INTERRUPTS(CLBR_ANY) | ||
1167 | TRACE_IRQS_OFF | ||
1168 | jmp paranoid_userspace | ||
1169 | CFI_ENDPROC | ||
1170 | KPROBE_END(paranoid_exit) | ||
1171 | |||
1172 | /* | ||
1173 | * Exception entry point. This expects an error code/orig_rax on the stack. | ||
1174 | * returns in "no swapgs flag" in %ebx. | ||
1175 | */ | ||
1176 | KPROBE_ENTRY(error_entry) | ||
1177 | XCPT_FRAME | ||
1178 | CFI_ADJUST_CFA_OFFSET 15*8 | ||
1179 | /* oldrax contains error code */ | ||
1180 | cld | ||
1181 | movq_cfi rdi, RDI+8 | ||
1182 | movq_cfi rsi, RSI+8 | ||
1183 | movq_cfi rdx, RDX+8 | ||
1184 | movq_cfi rcx, RCX+8 | ||
1185 | movq_cfi rax, RAX+8 | ||
1186 | movq_cfi r8, R8+8 | ||
1187 | movq_cfi r9, R9+8 | ||
1188 | movq_cfi r10, R10+8 | ||
1189 | movq_cfi r11, R11+8 | ||
1190 | movq_cfi rbx, RBX+8 | ||
1191 | movq_cfi rbp, RBP+8 | ||
1192 | movq_cfi r12, R12+8 | ||
1193 | movq_cfi r13, R13+8 | ||
1194 | movq_cfi r14, R14+8 | ||
1195 | movq_cfi r15, R15+8 | ||
1196 | xorl %ebx,%ebx | ||
1197 | testl $3,CS+8(%rsp) | ||
1198 | je error_kernelspace | ||
1199 | error_swapgs: | ||
1200 | SWAPGS | ||
1201 | error_sti: | ||
1202 | TRACE_IRQS_OFF | ||
1203 | ret | ||
1204 | CFI_ENDPROC | ||
1205 | |||
1206 | /* | ||
1207 | * There are two places in the kernel that can potentially fault with | ||
1208 | * usergs. Handle them here. The exception handlers after iret run with | ||
1209 | * kernel gs again, so don't set the user space flag. B stepping K8s | ||
1210 | * sometimes report an truncated RIP for IRET exceptions returning to | ||
1211 | * compat mode. Check for these here too. | ||
1212 | */ | ||
1213 | error_kernelspace: | ||
1214 | incl %ebx | ||
1215 | leaq irq_return(%rip),%rcx | ||
1216 | cmpq %rcx,RIP+8(%rsp) | ||
1217 | je error_swapgs | ||
1218 | movl %ecx,%ecx /* zero extend */ | ||
1219 | cmpq %rcx,RIP+8(%rsp) | ||
1220 | je error_swapgs | ||
1221 | cmpq $gs_change,RIP+8(%rsp) | ||
1222 | je error_swapgs | ||
1223 | jmp error_sti | ||
1224 | KPROBE_END(error_entry) | ||
1225 | |||
1226 | |||
1227 | /* ebx: no swapgs flag (1: don't need swapgs, 0: need it) */ | ||
1228 | KPROBE_ENTRY(error_exit) | ||
1229 | DEFAULT_FRAME | ||
1230 | movl %ebx,%eax | ||
1231 | RESTORE_REST | ||
1232 | DISABLE_INTERRUPTS(CLBR_NONE) | ||
1233 | TRACE_IRQS_OFF | ||
1234 | GET_THREAD_INFO(%rcx) | ||
1235 | testl %eax,%eax | ||
1236 | jne retint_kernel | ||
1237 | LOCKDEP_SYS_EXIT_IRQ | ||
1238 | movl TI_flags(%rcx),%edx | ||
1239 | movl $_TIF_WORK_MASK,%edi | ||
1240 | andl %edi,%edx | ||
1241 | jnz retint_careful | ||
1242 | jmp retint_swapgs | ||
1243 | CFI_ENDPROC | ||
1244 | KPROBE_END(error_exit) | ||
1245 | |||
1246 | /* Reload gs selector with exception handling */ | 1091 | /* Reload gs selector with exception handling */ |
1247 | /* edi: new selector */ | 1092 | /* edi: new selector */ |
1248 | ENTRY(native_load_gs_index) | 1093 | ENTRY(native_load_gs_index) |
@@ -1362,61 +1207,6 @@ ENTRY(kernel_execve) | |||
1362 | CFI_ENDPROC | 1207 | CFI_ENDPROC |
1363 | END(kernel_execve) | 1208 | END(kernel_execve) |
1364 | 1209 | ||
1365 | /* runs on exception stack */ | ||
1366 | KPROBE_ENTRY(nmi) | ||
1367 | INTR_FRAME | ||
1368 | PARAVIRT_ADJUST_EXCEPTION_FRAME | ||
1369 | pushq_cfi $-1 | ||
1370 | subq $15*8, %rsp | ||
1371 | CFI_ADJUST_CFA_OFFSET 15*8 | ||
1372 | call save_paranoid | ||
1373 | DEFAULT_FRAME 0 | ||
1374 | /* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */ | ||
1375 | movq %rsp,%rdi | ||
1376 | movq $-1,%rsi | ||
1377 | call do_nmi | ||
1378 | #ifdef CONFIG_TRACE_IRQFLAGS | ||
1379 | /* paranoidexit; without TRACE_IRQS_OFF */ | ||
1380 | /* ebx: no swapgs flag */ | ||
1381 | DISABLE_INTERRUPTS(CLBR_NONE) | ||
1382 | testl %ebx,%ebx /* swapgs needed? */ | ||
1383 | jnz nmi_restore | ||
1384 | testl $3,CS(%rsp) | ||
1385 | jnz nmi_userspace | ||
1386 | nmi_swapgs: | ||
1387 | SWAPGS_UNSAFE_STACK | ||
1388 | nmi_restore: | ||
1389 | RESTORE_ALL 8 | ||
1390 | jmp irq_return | ||
1391 | nmi_userspace: | ||
1392 | GET_THREAD_INFO(%rcx) | ||
1393 | movl TI_flags(%rcx),%ebx | ||
1394 | andl $_TIF_WORK_MASK,%ebx | ||
1395 | jz nmi_swapgs | ||
1396 | movq %rsp,%rdi /* &pt_regs */ | ||
1397 | call sync_regs | ||
1398 | movq %rax,%rsp /* switch stack for scheduling */ | ||
1399 | testl $_TIF_NEED_RESCHED,%ebx | ||
1400 | jnz nmi_schedule | ||
1401 | movl %ebx,%edx /* arg3: thread flags */ | ||
1402 | ENABLE_INTERRUPTS(CLBR_NONE) | ||
1403 | xorl %esi,%esi /* arg2: oldset */ | ||
1404 | movq %rsp,%rdi /* arg1: &pt_regs */ | ||
1405 | call do_notify_resume | ||
1406 | DISABLE_INTERRUPTS(CLBR_NONE) | ||
1407 | jmp nmi_userspace | ||
1408 | nmi_schedule: | ||
1409 | ENABLE_INTERRUPTS(CLBR_ANY) | ||
1410 | call schedule | ||
1411 | DISABLE_INTERRUPTS(CLBR_ANY) | ||
1412 | jmp nmi_userspace | ||
1413 | CFI_ENDPROC | ||
1414 | #else | ||
1415 | jmp paranoid_exit | ||
1416 | CFI_ENDPROC | ||
1417 | #endif | ||
1418 | KPROBE_END(nmi) | ||
1419 | |||
1420 | /* Call softirq on interrupt stack. Interrupts are off. */ | 1210 | /* Call softirq on interrupt stack. Interrupts are off. */ |
1421 | ENTRY(call_softirq) | 1211 | ENTRY(call_softirq) |
1422 | CFI_STARTPROC | 1212 | CFI_STARTPROC |
@@ -1437,13 +1227,6 @@ ENTRY(call_softirq) | |||
1437 | CFI_ENDPROC | 1227 | CFI_ENDPROC |
1438 | END(call_softirq) | 1228 | END(call_softirq) |
1439 | 1229 | ||
1440 | KPROBE_ENTRY(ignore_sysret) | ||
1441 | CFI_STARTPROC | ||
1442 | mov $-ENOSYS,%eax | ||
1443 | sysret | ||
1444 | CFI_ENDPROC | ||
1445 | KPROBE_END(ignore_sysret) | ||
1446 | |||
1447 | #ifdef CONFIG_XEN | 1230 | #ifdef CONFIG_XEN |
1448 | zeroentry xen_hypervisor_callback xen_do_hypervisor_callback | 1231 | zeroentry xen_hypervisor_callback xen_do_hypervisor_callback |
1449 | 1232 | ||
@@ -1540,3 +1323,216 @@ ENTRY(xen_failsafe_callback) | |||
1540 | END(xen_failsafe_callback) | 1323 | END(xen_failsafe_callback) |
1541 | 1324 | ||
1542 | #endif /* CONFIG_XEN */ | 1325 | #endif /* CONFIG_XEN */ |
1326 | |||
1327 | /* | ||
1328 | * Some functions should be protected against kprobes | ||
1329 | */ | ||
1330 | .pushsection .kprobes.text, "ax" | ||
1331 | |||
1332 | paranoidzeroentry_ist debug do_debug DEBUG_STACK | ||
1333 | paranoidzeroentry_ist int3 do_int3 DEBUG_STACK | ||
1334 | paranoiderrorentry stack_segment do_stack_segment | ||
1335 | errorentry general_protection do_general_protection | ||
1336 | errorentry page_fault do_page_fault | ||
1337 | #ifdef CONFIG_X86_MCE | ||
1338 | paranoidzeroentry machine_check do_machine_check | ||
1339 | #endif | ||
1340 | |||
1341 | /* | ||
1342 | * "Paranoid" exit path from exception stack. | ||
1343 | * Paranoid because this is used by NMIs and cannot take | ||
1344 | * any kernel state for granted. | ||
1345 | * We don't do kernel preemption checks here, because only | ||
1346 | * NMI should be common and it does not enable IRQs and | ||
1347 | * cannot get reschedule ticks. | ||
1348 | * | ||
1349 | * "trace" is 0 for the NMI handler only, because irq-tracing | ||
1350 | * is fundamentally NMI-unsafe. (we cannot change the soft and | ||
1351 | * hard flags at once, atomically) | ||
1352 | */ | ||
1353 | |||
1354 | /* ebx: no swapgs flag */ | ||
1355 | ENTRY(paranoid_exit) | ||
1356 | INTR_FRAME | ||
1357 | DISABLE_INTERRUPTS(CLBR_NONE) | ||
1358 | TRACE_IRQS_OFF | ||
1359 | testl %ebx,%ebx /* swapgs needed? */ | ||
1360 | jnz paranoid_restore | ||
1361 | testl $3,CS(%rsp) | ||
1362 | jnz paranoid_userspace | ||
1363 | paranoid_swapgs: | ||
1364 | TRACE_IRQS_IRETQ 0 | ||
1365 | SWAPGS_UNSAFE_STACK | ||
1366 | paranoid_restore: | ||
1367 | RESTORE_ALL 8 | ||
1368 | jmp irq_return | ||
1369 | paranoid_userspace: | ||
1370 | GET_THREAD_INFO(%rcx) | ||
1371 | movl TI_flags(%rcx),%ebx | ||
1372 | andl $_TIF_WORK_MASK,%ebx | ||
1373 | jz paranoid_swapgs | ||
1374 | movq %rsp,%rdi /* &pt_regs */ | ||
1375 | call sync_regs | ||
1376 | movq %rax,%rsp /* switch stack for scheduling */ | ||
1377 | testl $_TIF_NEED_RESCHED,%ebx | ||
1378 | jnz paranoid_schedule | ||
1379 | movl %ebx,%edx /* arg3: thread flags */ | ||
1380 | TRACE_IRQS_ON | ||
1381 | ENABLE_INTERRUPTS(CLBR_NONE) | ||
1382 | xorl %esi,%esi /* arg2: oldset */ | ||
1383 | movq %rsp,%rdi /* arg1: &pt_regs */ | ||
1384 | call do_notify_resume | ||
1385 | DISABLE_INTERRUPTS(CLBR_NONE) | ||
1386 | TRACE_IRQS_OFF | ||
1387 | jmp paranoid_userspace | ||
1388 | paranoid_schedule: | ||
1389 | TRACE_IRQS_ON | ||
1390 | ENABLE_INTERRUPTS(CLBR_ANY) | ||
1391 | call schedule | ||
1392 | DISABLE_INTERRUPTS(CLBR_ANY) | ||
1393 | TRACE_IRQS_OFF | ||
1394 | jmp paranoid_userspace | ||
1395 | CFI_ENDPROC | ||
1396 | END(paranoid_exit) | ||
1397 | |||
1398 | /* | ||
1399 | * Exception entry point. This expects an error code/orig_rax on the stack. | ||
1400 | * returns in "no swapgs flag" in %ebx. | ||
1401 | */ | ||
1402 | ENTRY(error_entry) | ||
1403 | XCPT_FRAME | ||
1404 | CFI_ADJUST_CFA_OFFSET 15*8 | ||
1405 | /* oldrax contains error code */ | ||
1406 | cld | ||
1407 | movq_cfi rdi, RDI+8 | ||
1408 | movq_cfi rsi, RSI+8 | ||
1409 | movq_cfi rdx, RDX+8 | ||
1410 | movq_cfi rcx, RCX+8 | ||
1411 | movq_cfi rax, RAX+8 | ||
1412 | movq_cfi r8, R8+8 | ||
1413 | movq_cfi r9, R9+8 | ||
1414 | movq_cfi r10, R10+8 | ||
1415 | movq_cfi r11, R11+8 | ||
1416 | movq_cfi rbx, RBX+8 | ||
1417 | movq_cfi rbp, RBP+8 | ||
1418 | movq_cfi r12, R12+8 | ||
1419 | movq_cfi r13, R13+8 | ||
1420 | movq_cfi r14, R14+8 | ||
1421 | movq_cfi r15, R15+8 | ||
1422 | xorl %ebx,%ebx | ||
1423 | testl $3,CS+8(%rsp) | ||
1424 | je error_kernelspace | ||
1425 | error_swapgs: | ||
1426 | SWAPGS | ||
1427 | error_sti: | ||
1428 | TRACE_IRQS_OFF | ||
1429 | ret | ||
1430 | CFI_ENDPROC | ||
1431 | |||
1432 | /* | ||
1433 | * There are two places in the kernel that can potentially fault with | ||
1434 | * usergs. Handle them here. The exception handlers after iret run with | ||
1435 | * kernel gs again, so don't set the user space flag. B stepping K8s | ||
1436 | * sometimes report an truncated RIP for IRET exceptions returning to | ||
1437 | * compat mode. Check for these here too. | ||
1438 | */ | ||
1439 | error_kernelspace: | ||
1440 | incl %ebx | ||
1441 | leaq irq_return(%rip),%rcx | ||
1442 | cmpq %rcx,RIP+8(%rsp) | ||
1443 | je error_swapgs | ||
1444 | movl %ecx,%ecx /* zero extend */ | ||
1445 | cmpq %rcx,RIP+8(%rsp) | ||
1446 | je error_swapgs | ||
1447 | cmpq $gs_change,RIP+8(%rsp) | ||
1448 | je error_swapgs | ||
1449 | jmp error_sti | ||
1450 | END(error_entry) | ||
1451 | |||
1452 | |||
1453 | /* ebx: no swapgs flag (1: don't need swapgs, 0: need it) */ | ||
1454 | ENTRY(error_exit) | ||
1455 | DEFAULT_FRAME | ||
1456 | movl %ebx,%eax | ||
1457 | RESTORE_REST | ||
1458 | DISABLE_INTERRUPTS(CLBR_NONE) | ||
1459 | TRACE_IRQS_OFF | ||
1460 | GET_THREAD_INFO(%rcx) | ||
1461 | testl %eax,%eax | ||
1462 | jne retint_kernel | ||
1463 | LOCKDEP_SYS_EXIT_IRQ | ||
1464 | movl TI_flags(%rcx),%edx | ||
1465 | movl $_TIF_WORK_MASK,%edi | ||
1466 | andl %edi,%edx | ||
1467 | jnz retint_careful | ||
1468 | jmp retint_swapgs | ||
1469 | CFI_ENDPROC | ||
1470 | END(error_exit) | ||
1471 | |||
1472 | |||
1473 | /* runs on exception stack */ | ||
1474 | ENTRY(nmi) | ||
1475 | INTR_FRAME | ||
1476 | PARAVIRT_ADJUST_EXCEPTION_FRAME | ||
1477 | pushq_cfi $-1 | ||
1478 | subq $15*8, %rsp | ||
1479 | CFI_ADJUST_CFA_OFFSET 15*8 | ||
1480 | call save_paranoid | ||
1481 | DEFAULT_FRAME 0 | ||
1482 | /* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */ | ||
1483 | movq %rsp,%rdi | ||
1484 | movq $-1,%rsi | ||
1485 | call do_nmi | ||
1486 | #ifdef CONFIG_TRACE_IRQFLAGS | ||
1487 | /* paranoidexit; without TRACE_IRQS_OFF */ | ||
1488 | /* ebx: no swapgs flag */ | ||
1489 | DISABLE_INTERRUPTS(CLBR_NONE) | ||
1490 | testl %ebx,%ebx /* swapgs needed? */ | ||
1491 | jnz nmi_restore | ||
1492 | testl $3,CS(%rsp) | ||
1493 | jnz nmi_userspace | ||
1494 | nmi_swapgs: | ||
1495 | SWAPGS_UNSAFE_STACK | ||
1496 | nmi_restore: | ||
1497 | RESTORE_ALL 8 | ||
1498 | jmp irq_return | ||
1499 | nmi_userspace: | ||
1500 | GET_THREAD_INFO(%rcx) | ||
1501 | movl TI_flags(%rcx),%ebx | ||
1502 | andl $_TIF_WORK_MASK,%ebx | ||
1503 | jz nmi_swapgs | ||
1504 | movq %rsp,%rdi /* &pt_regs */ | ||
1505 | call sync_regs | ||
1506 | movq %rax,%rsp /* switch stack for scheduling */ | ||
1507 | testl $_TIF_NEED_RESCHED,%ebx | ||
1508 | jnz nmi_schedule | ||
1509 | movl %ebx,%edx /* arg3: thread flags */ | ||
1510 | ENABLE_INTERRUPTS(CLBR_NONE) | ||
1511 | xorl %esi,%esi /* arg2: oldset */ | ||
1512 | movq %rsp,%rdi /* arg1: &pt_regs */ | ||
1513 | call do_notify_resume | ||
1514 | DISABLE_INTERRUPTS(CLBR_NONE) | ||
1515 | jmp nmi_userspace | ||
1516 | nmi_schedule: | ||
1517 | ENABLE_INTERRUPTS(CLBR_ANY) | ||
1518 | call schedule | ||
1519 | DISABLE_INTERRUPTS(CLBR_ANY) | ||
1520 | jmp nmi_userspace | ||
1521 | CFI_ENDPROC | ||
1522 | #else | ||
1523 | jmp paranoid_exit | ||
1524 | CFI_ENDPROC | ||
1525 | #endif | ||
1526 | END(nmi) | ||
1527 | |||
1528 | ENTRY(ignore_sysret) | ||
1529 | CFI_STARTPROC | ||
1530 | mov $-ENOSYS,%eax | ||
1531 | sysret | ||
1532 | CFI_ENDPROC | ||
1533 | END(ignore_sysret) | ||
1534 | |||
1535 | /* | ||
1536 | * End of kprobes section | ||
1537 | */ | ||
1538 | .popsection | ||