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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 9325 | Boppan | 1 | #include |
| 2 | #include |
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| 3 | #include |
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| 4 | #include |
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| 5 | #include |
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| 6 | #include |
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| 7 | #include |
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| 8 | #include |
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| 9 | #include "umka.h" |
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| 10 | |||
| 11 | #define MSR_IA32_DEBUGCTLMSR 0x1d9 |
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| 12 | #define MSR_IA32_LASTBRANCHFROMIP 0x1db |
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| 13 | #define MSR_IA32_LASTBRANCHTOIP 0x1dc |
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| 14 | |||
| 15 | int covfd, msrfd; |
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| 16 | |||
| 17 | uint64_t rdmsr(uint32_t reg) |
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| 18 | { |
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| 19 | uint64_t data; |
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| 20 | |||
| 21 | if (pread(msrfd, &data, sizeof data, reg) != sizeof data) { |
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| 22 | perror("rdmsr: pread"); |
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| 23 | exit(1); |
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| 24 | } |
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| 25 | |||
| 26 | return data; |
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| 27 | } |
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| 28 | |||
| 29 | void wrmsr(uint32_t reg, uint64_t data) |
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| 30 | { |
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| 31 | int fd; |
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| 32 | fd = open("/dev/cpu/0/msr", O_WRONLY); |
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| 33 | if (fd < 0) { |
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| 34 | perror("wrmsr: open"); |
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| 35 | exit(1); |
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| 36 | } |
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| 37 | |||
| 38 | if (pwrite(fd, &data, sizeof data, reg) != sizeof data) { |
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| 39 | perror("wrmsr: pwrite"); |
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| 40 | exit(1); |
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| 41 | } |
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| 42 | |||
| 43 | close(fd); |
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| 44 | return; |
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| 45 | } |
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| 46 | |||
| 47 | void handle_sigtrap() { |
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| 48 | uint64_t from = rdmsr(MSR_IA32_LASTBRANCHFROMIP); |
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| 49 | uint64_t to = rdmsr(MSR_IA32_LASTBRANCHTOIP); |
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| 50 | |||
| 51 | if ((from >= (uintptr_t)coverage_begin && from < (uintptr_t)coverage_end) || |
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| 52 | (to >= (uintptr_t)coverage_begin && to < (uintptr_t)coverage_end)) { |
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| 53 | write(covfd, &from, 4); |
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| 54 | write(covfd, &to, 4); |
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| 55 | } |
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| 56 | |||
| 57 | wrmsr(MSR_IA32_DEBUGCTLMSR, 3); |
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| 58 | } |
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| 59 | |||
| 60 | uint32_t set_eflags_tf(uint32_t tf) { |
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| 61 | uint32_t prev; |
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| 62 | __asm__ __inline__ __volatile__ ( |
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| 63 | "pushfd;" |
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| 64 | "pop eax;" |
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| 65 | "ror eax, 8;" |
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| 66 | "mov edx, eax;" |
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| 67 | "and edx, 1;" |
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| 68 | "and eax, ~1;" |
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| 69 | "or eax, ecx;" |
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| 70 | "rol eax, 8;" |
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| 71 | "push eax;" |
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| 72 | "popfd" |
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| 73 | : "=d"(prev) |
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| 74 | : "c"(tf) |
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| 75 | : "eax", "memory"); |
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| 76 | return prev; |
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| 77 | } |
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| 78 | |||
| 79 | void trace_lbr_begin() { |
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| 80 | struct sigaction action; |
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| 81 | action.sa_sigaction = &handle_sigtrap; |
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| 82 | action.sa_flags = SA_SIGINFO; |
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| 83 | sigaction(SIGTRAP, &action, NULL); |
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| 84 | |||
| 85 | wrmsr(MSR_IA32_DEBUGCTLMSR, 3); |
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| 86 | msrfd = open("/dev/cpu/0/msr", O_RDONLY); |
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| 87 | if (msrfd < 0) { |
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| 88 | perror("rdmsr: open"); |
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| 89 | exit(1); |
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| 90 | } |
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| 91 | char coverage_filename[32]; |
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| 92 | sprintf(coverage_filename, "coverage.%i", getpid()); |
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| 93 | covfd = open(coverage_filename, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH | S_IWOTH); |
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| 94 | void *coverage_begin_addr = coverage_begin; |
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| 95 | void *coverage_end_addr = coverage_end; |
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| 96 | write(covfd, &coverage_begin_addr, 4); |
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| 97 | write(covfd, &coverage_end_addr, 4); |
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| 98 | } |
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| 99 | |||
| 100 | void trace_lbr_end() { |
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| 101 | wrmsr(MSR_IA32_DEBUGCTLMSR, 0); |
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| 102 | close(msrfd); |
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| 103 | close(covfd); |
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| 104 | } |
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| 105 | |||
| 106 | uint32_t trace_lbr_pause(void) { |
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| 107 | return set_eflags_tf(0u); |
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| 108 | } |
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| 109 | |||
| 110 | void trace_lbr_resume(uint32_t value) { |
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| 111 | set_eflags_tf(value); |
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| 112 | } |