liblttng-ust/compat.h

   1 /*
   2  * SPDX-License-Identifier: LGPL-2.1-only
   3  *
   4  * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   5  * Copyright (C) 2016 Raphaël Beamonte <raphael.beamonte@gmail.com>
   6  * Copyright (C) 2020 Michael Jeanson <mjeanson@efficios.com>
   7  */
   8
   9 #ifndef _UST_COMPAT_H
  10 #define _UST_COMPAT_H
  11
  12 #include <pthread.h>
  13 #include <errno.h>
  14 #include <string.h>
  15
  16 #include <lttng/ust-abi.h>
  17
  18 #define LTTNG_UST_PROCNAME_SUFFIX "-ust"
  19
  20
  21 #if defined(HAVE_PTHREAD_SETNAME_NP_WITH_TID)
  22 static inline
  23 int lttng_pthread_setname_np(const char *name)
  24 {
  25         /*
  26          * Some implementations don't error out, replicate this behavior for
  27          * consistency.
  28          */
  29         if (strnlen(name, LTTNG_UST_ABI_PROCNAME_LEN) >= LTTNG_UST_ABI_PROCNAME_LEN) {
  30                 return ERANGE;
  31         }
  32
  33         return pthread_setname_np(pthread_self(), name);
  34 }
  35
  36 static inline
  37 int lttng_pthread_getname_np(char *name, size_t len)
  38 {
  39         return pthread_getname_np(pthread_self(), name, len);
  40 }
  41 #elif defined(HAVE_PTHREAD_SETNAME_NP_WITHOUT_TID)
  42 static inline
  43 int lttng_pthread_setname_np(const char *name)
  44 {
  45         return pthread_setname_np(name);
  46 }
  47
  48 static inline
  49 int lttng_pthread_getname_np(char *name, size_t len)
  50 {
  51         return pthread_getname_np(name, len);
  52 }
  53 #elif defined(HAVE_PTHREAD_SET_NAME_NP_WITH_TID)
  54
  55 #include <pthread_np.h>
  56 static inline
  57 int lttng_pthread_setname_np(const char *name)
  58 {
  59         /* Replicate pthread_setname_np's behavior */
  60         if (strnlen(name, LTTNG_UST_ABI_PROCNAME_LEN) >= LTTNG_UST_ABI_PROCNAME_LEN) {
  61                 return ERANGE;
  62         }
  63
  64         pthread_set_name_np(pthread_self(), name);
  65         return 0;
  66 }
  67
  68 static inline
  69 int lttng_pthread_getname_np(char *name, size_t len)
  70 {
  71         pthread_get_name_np(pthread_self(), name, len);
  72         return 0;
  73 }
  74 #elif defined(__linux__)
  75
  76 /* Fallback on prtctl on Linux */
  77 #include <sys/prctl.h>
  78
  79 static inline
  80 int lttng_pthread_setname_np(const char *name)
  81 {
  82         /* Replicate pthread_setname_np's behavior */
  83         if (strnlen(name, LTTNG_UST_ABI_PROCNAME_LEN) >= LTTNG_UST_ABI_PROCNAME_LEN) {
  84                 return ERANGE;
  85         }
  86         return prctl(PR_SET_NAME, name, 0, 0, 0);
  87 }
  88
  89 static inline
  90 int lttng_pthread_getname_np(char *name, size_t len)
  91 {
  92         return prctl(PR_GET_NAME, name, 0, 0, 0);
  93 }
  94
  95 #else
  96 #error "Please add pthread name support for your OS."
  97 #endif
  98
  99 /*
 100  * If a pthread setname/set_name function is available, declare
 101  * the setustprocname() function that will add '-ust' to the end
 102  * of the current process name, while truncating it if needed.
 103  */
 104 static inline
 105 int lttng_ust_setustprocname(void)
 106 {
 107         int ret = 0, len;
 108         char name[LTTNG_UST_ABI_PROCNAME_LEN];
 109         int limit = LTTNG_UST_ABI_PROCNAME_LEN - strlen(LTTNG_UST_PROCNAME_SUFFIX) - 1;
 110
 111         /*
 112          * Get the current thread name.
 113          */
 114         ret = lttng_pthread_getname_np(name, LTTNG_UST_ABI_PROCNAME_LEN);
 115         if (ret) {
 116                 goto error;
 117         }
 118
 119         len = strlen(name);
 120         if (len > limit) {
 121                 len = limit;
 122         }
 123
 124         ret = sprintf(name + len, LTTNG_UST_PROCNAME_SUFFIX);
 125         if (ret != strlen(LTTNG_UST_PROCNAME_SUFFIX)) {
 126                 goto error;
 127         }
 128
 129         ret = lttng_pthread_setname_np(name);
 130
 131 error:
 132         return ret;
 133 }
 134
 135 #include <errno.h>
 136
 137 #ifndef ENODATA
 138 #define ENODATA ENOMSG
 139 #endif
 140
 141 #endif /* _UST_COMPAT_H */