diff options
| -rw-r--r-- | debuggerd/crasher.c | 6 | ||||
| -rwxr-xr-x | debuggerd/tombstone.cpp | 34 |
2 files changed, 25 insertions, 15 deletions
diff --git a/debuggerd/crasher.c b/debuggerd/crasher.c index e11d9af..9df3c64 100644 --- a/debuggerd/crasher.c +++ b/debuggerd/crasher.c @@ -7,6 +7,7 @@ #include <stdlib.h> #include <string.h> #include <sys/cdefs.h> +#include <sys/mman.h> #include <sys/ptrace.h> #include <sys/socket.h> #include <sys/wait.h> @@ -156,6 +157,10 @@ static int do_action(const char* arg) return EXIT_SUCCESS; } else if (!strcmp(arg, "heap-usage")) { abuse_heap(); + } else if (!strcmp(arg, "SIGSEGV-unmapped")) { + char* map = mmap(NULL, sizeof(int), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); + munmap(map, sizeof(int)); + map[0] = '8'; } fprintf(stderr, "%s OP\n", __progname); @@ -175,6 +180,7 @@ static int do_action(const char* arg) fprintf(stderr, " SIGPIPE cause a SIGPIPE\n"); fprintf(stderr, " SIGSEGV cause a SIGSEGV at address 0x0 (synonym: crash)\n"); fprintf(stderr, " SIGSEGV-non-null cause a SIGSEGV at a non-zero address\n"); + fprintf(stderr, " SIGSEGV-unmapped mmap/munmap a region of memory and then attempt to access it\n"); fprintf(stderr, " SIGTRAP cause a SIGTRAP\n"); fprintf(stderr, "prefix any of the above with 'thread-' to not run\n"); fprintf(stderr, "on the process' main thread.\n"); diff --git a/debuggerd/tombstone.cpp b/debuggerd/tombstone.cpp index dea016d..2bb9efd 100755 --- a/debuggerd/tombstone.cpp +++ b/debuggerd/tombstone.cpp @@ -329,10 +329,11 @@ static void dump_backtrace_and_stack(Backtrace* backtrace, log_t* log) { } static void dump_map(log_t* log, const backtrace_map_t* map, bool fault_addr) { - _LOG(log, logtype::MAPS, "%s%" PRIPTR "-%" PRIPTR " %c%c%c %s\n", - (fault_addr? "--->" : " "), map->start, map->end, + _LOG(log, logtype::MAPS, "%s%" PRIPTR "-%" PRIPTR " %c%c%c %7d %s\n", + (fault_addr? "--->" : " "), map->start, map->end - 1, (map->flags & PROT_READ) ? 'r' : '-', (map->flags & PROT_WRITE) ? 'w' : '-', - (map->flags & PROT_EXEC) ? 'x' : '-', map->name.c_str()); + (map->flags & PROT_EXEC) ? 'x' : '-', + (map->end - map->start), map->name.c_str()); } static void dump_nearby_maps(BacktraceMap* map, log_t* log, pid_t tid) { @@ -342,28 +343,31 @@ static void dump_nearby_maps(BacktraceMap* map, log_t* log, pid_t tid) { _LOG(log, logtype::MAPS, "cannot get siginfo for %d: %s\n", tid, strerror(errno)); return; } - if (!signal_has_si_addr(si.si_signo)) { - return; - } + bool is_running = (si.si_code == SI_USER); uintptr_t addr = reinterpret_cast<uintptr_t>(si.si_addr); addr &= ~0xfff; // round to 4K page boundary - if (addr == 0) { // null-pointer deref + if (!is_running && addr == 0) { // null-pointer deref return; } - _LOG(log, logtype::MAPS, "\nmemory map: (fault address prefixed with --->)\n"); + _LOG(log, logtype::MAPS, "\nmemory map: %s\n", is_running? "" : "(fault address prefixed with --->)"); + + if(!is_running && (addr < map->begin()->start)) { + _LOG(log, logtype::MAPS, "--->Fault address falls at %" PRIPTR " before any mapped regions\n", addr); + } - bool found_map = false; + BacktraceMap::const_iterator prev = map->begin(); for (BacktraceMap::const_iterator it = map->begin(); it != map->end(); ++it) { - bool in_map = addr >= (*it).start && addr < (*it).end; - dump_map(log, &*it, in_map); - if(in_map) { - found_map = true; + if (addr >= (*prev).end && addr < (*it).start) { + _LOG(log, logtype::MAPS, "--->Fault address falls at %" PRIPTR " between mapped regions\n", addr); } + prev = it; + bool in_map = !is_running && (addr >= (*it).start) && (addr < (*it).end); + dump_map(log, &*it, in_map); } - if(!found_map) { - _LOG(log, logtype::ERROR, "\nFault address was not in any map!"); + if (!is_running && (addr >= (*prev).end)) { + _LOG(log, logtype::MAPS, "--->Fault address falls at %" PRIPTR " after any mapped regions\n", addr); } } |