(#1307) Init version of snapshot logic

- replace `SCOPE_ERROR_SIGNAL_HANDLER` with snapshot

Closes: #1307

docs/Snapshot.md

@@ -0,0 +1,14 @@
+# Snapshot information
+
+TODO describe idea
+TODO describe what information in which format files contain
+TODO this is an interface description between CLI and library
+
+Snapshot file details
+```
+/tmp/appscope/<PID>
+│   info          <mandatory>
+│   cfg           <mandatory>
+│   coredump      <optional>
+|   backtrace     <optional>    
+```

os/linux/aarch64.mk

@@ -6,7 +6,7 @@ ARCH_OBJ=$(ARCH)
 LD_FLAGS=$(MUSL_AR) $(UNWIND_AR) $(COREDUMPER_AR) $(PCRE2_AR) $(LS_HPACK_AR) $(YAML_AR) $(JSON_AR) -ldl -lpthread -lrt -lresolv -Lcontrib/build/funchook -lfunchook -Lcontrib/build/funchook/capstone_src-prefix/src/capstone_src-build -lcapstone -z noexecstack
 INCLUDES=-I./contrib/libyaml/include -I./contrib/cJSON -I./os/$(OS) -I./contrib/pcre2/src -I./contrib/build/pcre2 -I./contrib/funchook/capstone_src/include/ -I./contrib/jni -I./contrib/jni/linux/ -I./contrib/openssl/include -I./contrib/build/openssl/include -I./contrib/build/libunwind/include -I./contrib/libunwind/include/ -I./contrib/coredumper/src
 
-$(LIBSCOPE): src/wrap.c src/state.c src/httpstate.c src/metriccapture.c src/report.c src/httpagg.c src/plattime.c src/fn.c os/$(OS)/os.c src/cfgutils.c src/cfg.c src/transport.c src/backoff.c src/log.c src/mtc.c src/circbuf.c src/linklist.c src/evtformat.c src/ctl.c src/mtcformat.c src/com.c src/scopestdlib.c src/dbg.c src/search.c src/wrap_go.c src/sysexec.c src/gocontext_arm.S src/scopeelf.c src/utils.c src/strset.c src/javabci.c src/javaagent.c src/ipc.c src/ipc_resp.c src/signalhandler.c src/coredump.c
+$(LIBSCOPE): src/wrap.c src/state.c src/httpstate.c src/metriccapture.c src/report.c src/httpagg.c src/plattime.c src/fn.c os/$(OS)/os.c src/cfgutils.c src/cfg.c src/transport.c src/backoff.c src/log.c src/mtc.c src/circbuf.c src/linklist.c src/evtformat.c src/ctl.c src/mtcformat.c src/com.c src/scopestdlib.c src/dbg.c src/search.c src/wrap_go.c src/sysexec.c src/gocontext_arm.S src/scopeelf.c src/utils.c src/strset.c src/javabci.c src/javaagent.c src/ipc.c src/ipc_resp.c src/snapshot.c src/coredump.c
 	@$(MAKE) -C contrib funchook pcre2 openssl ls-hpack musl libyaml libunwind cJSON coredumper
 	@echo "$${CI:+::group::}Building $@"
 	$(CC) $(LIBRARY_CFLAGS) $(ARCH_CFLAGS) \

os/linux/x86_64.mk

@@ -11,7 +11,7 @@ INCLUDES=-I./contrib/libyaml/include -I./contrib/cJSON -I./os/$(OS) -I./contrib/
 #	objcopy -I binary -O elf64-x86-64 -B i386 ./lib/$(OS)/libscope.so ./lib/$(OS)/libscope.o && \
 #	rm -f ./lib/$(OS)/libscope.so
 
-$(LIBSCOPE): src/wrap.c src/state.c src/httpstate.c src/metriccapture.c src/report.c src/httpagg.c src/plattime.c src/fn.c os/$(OS)/os.c src/cfgutils.c src/cfg.c src/transport.c src/backoff.c src/log.c src/mtc.c src/circbuf.c src/linklist.c src/evtformat.c src/ctl.c src/mtcformat.c src/com.c src/scopestdlib.c src/dbg.c src/search.c src/sysexec.c src/gocontext.S src/scopeelf.c src/wrap_go.c src/utils.c src/strset.c src/javabci.c src/javaagent.c src/ipc.c src/ipc_resp.c src/signalhandler.c src/coredump.c
+$(LIBSCOPE): src/wrap.c src/state.c src/httpstate.c src/metriccapture.c src/report.c src/httpagg.c src/plattime.c src/fn.c os/$(OS)/os.c src/cfgutils.c src/cfg.c src/transport.c src/backoff.c src/log.c src/mtc.c src/circbuf.c src/linklist.c src/evtformat.c src/ctl.c src/mtcformat.c src/com.c src/scopestdlib.c src/dbg.c src/search.c src/sysexec.c src/gocontext.S src/scopeelf.c src/wrap_go.c src/utils.c src/strset.c src/javabci.c src/javaagent.c src/ipc.c src/ipc_resp.c src/snapshot.c src/coredump.c
 	@$(MAKE) -C contrib funchook pcre2 openssl ls-hpack musl libyaml cJSON libunwind coredumper
 	@echo "$${CI:+::group::}Building $@"
 	$(CC) $(LIBRARY_CFLAGS) $(ARCH_CFLAGS) \

src/coredump.c

@@ -5,25 +5,17 @@
 #include "utils.h"
 #include "google/coredumper.h"
 
-
 /*
- * Generates core dump in location based on <pathPrefix><pid>
+ * Generates core dump in location specifed by path
+ *
+ * Developer note: `WriteCoreDump` internally used PTRACE_ATTACH.
+ * If You try to observe behavior of `WriteCoreDump` function
+ * using GDB You will receive different result than in normal run.
+ * Ref: Schrödinger's cat
+ * 
  * Return status of operation
  */
 bool
-coreDumpGenerate(const char *pathPrefix, size_t pathPrefixSize, pid_t pid) {
-    char path[PATH_MAX] = {0};
-    if (pathPrefixSize > PATH_MAX) {
-        return FALSE;
-    }
-    scope_memcpy(path, pathPrefix, pathPrefixSize);
-    char pidBuf[32] = {0};
-    int msgLen = 0;
-    sigSafeUtoa(pid, pidBuf, 10, &msgLen);
-    if (pathPrefixSize + msgLen > PATH_MAX) {
-        return FALSE;
-    }
-    scope_memcpy(path + pathPrefixSize, pidBuf, msgLen);
-
+coreDumpGenerate(const char *path) {
     return (WriteCoreDump(path) == 0);
 }

src/coredump.h

@@ -3,6 +3,6 @@
 
 #include "scopetypes.h"
 
-bool coreDumpGenerate(const char *, size_t, pid_t);
+bool coreDumpGenerate(const char *);
 
 #endif // __COREDUMP_H__

src/log.c

@@ -47,15 +47,6 @@ logSend(log_t* log, const char* msg, cfg_log_level_t mlevel)
     return transportSend(log->transport, msg, scope_strlen(msg));
 }
 
-int
-logSigSafeSendWithLen(log_t *log, const char *msg, size_t msgLen, cfg_log_level_t mlevel) {
-    if (!log || !msg) return -1;
-
-    if ((log->level == CFG_LOG_NONE) || (log->level > mlevel)) return 0;
-
-    return transportSigSafeSend(log->transport, msg, msgLen);
-}
-
 cfg_log_level_t
 logLevel(log_t* log)
 {

src/log.h

@@ -11,7 +11,6 @@ void                logDestroy(log_t **);
 
 // Accessors
 int                 logSend(log_t *, const char *, cfg_log_level_t);
-int                 logSigSafeSendWithLen(log_t *, const char *, size_t, cfg_log_level_t);
 cfg_log_level_t     logLevel(log_t *);
 void                logFlush(log_t *);
 transport_status_t  logConnectionStatus(log_t *);

src/scopetypes.h

@@ -207,10 +207,6 @@ typedef struct
 //    SCOPE_PAYLOAD_HEADER           write payload headers to files
 //    SCOPE_PAYLOAD_TO_DISK          if payloads are enabled, "true" forces writes to payload->dir
 //    SCOPE_ALLOW_CONSTRUCT_DBG      allows debug inside the constructor
-//    SCOPE_ERROR_SIGNAL_HANDLER     allows to register signal error handler for following signals: SIGSEGV, SIGBUS, SIGILL and SIGFPE
-//                                   "log" - log the backtrace
-//                                   "coredump" - generate coredump file as "/tmp/scope_core.<pid>"
-//                                   "full" - includes "log" and "coredump" functionality
 //    SCOPE_QUEUE_LENGTH             override default circular buffer sizes
 //    SCOPE_START_NOPROFILE          cause the start command to ignore updates to /etc/profile.d
 //    SCOPE_START_FORCE_PROFILE      force the start command to update profile.d with a dev version