michael@0: // Copyright (c) 2007, Google Inc.
michael@0: // All rights reserved.
michael@0: //
michael@0: // Redistribution and use in source and binary forms, with or without
michael@0: // modification, are permitted provided that the following conditions are
michael@0: // met:
michael@0: //
michael@0: //     * Redistributions of source code must retain the above copyright
michael@0: // notice, this list of conditions and the following disclaimer.
michael@0: //     * Redistributions in binary form must reproduce the above
michael@0: // copyright notice, this list of conditions and the following disclaimer
michael@0: // in the documentation and/or other materials provided with the
michael@0: // distribution.
michael@0: //     * Neither the name of Google Inc. nor the names of its
michael@0: // contributors may be used to endorse or promote products derived from
michael@0: // this software without specific prior written permission.
michael@0: //
michael@0: // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
michael@0: // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
michael@0: // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
michael@0: // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
michael@0: // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
michael@0: // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
michael@0: // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
michael@0: // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
michael@0: // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
michael@0: // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
michael@0: // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0: 
michael@0: // Author: Alfred Peng
michael@0: 
michael@0: #include <dirent.h>
michael@0: #include <elf.h>
michael@0: #include <errno.h>
michael@0: #include <fcntl.h>
michael@0: #include <limits.h>
michael@0: #include <sys/frame.h>
michael@0: #include <sys/stat.h>
michael@0: #include <sys/types.h>
michael@0: #include <sys/wait.h>
michael@0: #include <unistd.h>
michael@0: 
michael@0: #include <algorithm>
michael@0: #include <cassert>
michael@0: #include <cstdio>
michael@0: #include <cstdlib>
michael@0: #include <functional>
michael@0: 
michael@0: #include "client/solaris/handler/solaris_lwp.h"
michael@0: #include "common/solaris/message_output.h"
michael@0: 
michael@0: using namespace google_breakpad;
michael@0: 
michael@0: // This unamed namespace contains helper function.
michael@0: namespace {
michael@0: 
michael@0: uintptr_t stack_base_address = 0;
michael@0: static const int HEADER_MAX = 2000;
michael@0: static const int MAP_MAX = 1000;
michael@0: 
michael@0: // Context information for the callbacks when validating address by listing
michael@0: // modules.
michael@0: struct AddressValidatingContext {
michael@0:   uintptr_t address;
michael@0:   bool is_mapped;
michael@0: 
michael@0:   AddressValidatingContext() : address(0UL), is_mapped(false) {
michael@0:   }
michael@0: };
michael@0: 
michael@0: // Convert from string to int.
michael@0: static bool LocalAtoi(char *s, int *r) {
michael@0:   assert(s != NULL);
michael@0:   assert(r != NULL);
michael@0:   char *endptr = NULL;
michael@0:   int ret = strtol(s, &endptr, 10);
michael@0:   if (endptr == s)
michael@0:     return false;
michael@0:   *r = ret;
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: // Callback invoked for each mapped module.
michael@0: // It uses the module's adderss range to validate the address.
michael@0: static bool AddressNotInModuleCallback(const ModuleInfo &module_info,
michael@0:                                        void *context) {
michael@0:   AddressValidatingContext *addr =
michael@0:     reinterpret_cast<AddressValidatingContext *>(context);
michael@0:   if (addr->is_mapped = ((module_info.start_addr > 0) &&
michael@0:                          (addr->address >= module_info.start_addr) &&
michael@0:                          (addr->address <= module_info.start_addr +
michael@0:                           module_info.size))) {
michael@0:     stack_base_address = module_info.start_addr + module_info.size;
michael@0:   }
michael@0: 
michael@0:   return !addr->is_mapped;
michael@0: }
michael@0: 
michael@0: static int IterateLwpAll(int pid,
michael@0:                          CallbackParam<LwpidCallback> *callback_param) {
michael@0:   char lwp_path[40];
michael@0:   DIR *dir;
michael@0:   int count = 0;
michael@0: 
michael@0:   snprintf(lwp_path, sizeof (lwp_path), "/proc/%d/lwp", (int)pid);
michael@0:   if ((dir = opendir(lwp_path)) == NULL)
michael@0:     return -1;
michael@0: 
michael@0:   struct dirent *entry = NULL;
michael@0:   while ((entry = readdir(dir)) != NULL) {
michael@0:     if ((strcmp(entry->d_name, ".") != 0) &&
michael@0:         (strcmp(entry->d_name, "..") != 0)) {
michael@0:       int lwpid = 0;
michael@0:       int last_pid = 0;
michael@0:       if (LocalAtoi(entry->d_name, &lwpid) && last_pid != lwpid) {
michael@0:         last_pid = lwpid;
michael@0:         ++count;
michael@0:         if (callback_param &&
michael@0:             !(callback_param->call_back)(lwpid, callback_param->context)) {
michael@0:           break;
michael@0:         }
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   closedir(dir);
michael@0:   return count;
michael@0: }
michael@0: 
michael@0: #if defined(__i386) && !defined(NO_FRAME_POINTER)
michael@0: void *GetNextFrame(void **last_ebp) {
michael@0:   void *sp = *last_ebp;
michael@0:   if ((unsigned long)sp == (unsigned long)last_ebp)
michael@0:     return NULL;
michael@0:   if ((unsigned long)sp & (sizeof(void *) - 1))
michael@0:     return NULL;
michael@0:   if ((unsigned long)sp - (unsigned long)last_ebp > 100000)
michael@0:     return NULL;
michael@0:   return sp;
michael@0: }
michael@0: #elif defined(__sparc)
michael@0: void *GetNextFrame(void *last_ebp) {
michael@0:   return reinterpret_cast<struct frame *>(last_ebp)->fr_savfp;
michael@0: }
michael@0: #else
michael@0: void *GetNextFrame(void **last_ebp) {
michael@0:   return reinterpret_cast<void*>(last_ebp);
michael@0: }
michael@0: #endif
michael@0: 
michael@0: 
michael@0: class AutoCloser {
michael@0:  public:
michael@0:   AutoCloser(int fd) : fd_(fd) {}
michael@0:   ~AutoCloser() { if (fd_) close(fd_); }
michael@0:  private:
michael@0:   int fd_;
michael@0: };
michael@0: 
michael@0: // Control the execution of the lwp.
michael@0: // Suspend/Resume lwp based on the value of context.
michael@0: static bool ControlLwp(int lwpid, void *context) {
michael@0:   // The current thread is the one to handle the crash. Ignore it.
michael@0:   if (lwpid != pthread_self()) {
michael@0:     int ctlfd;
michael@0:     char procname[PATH_MAX];
michael@0:     bool suspend = *(bool *)context;
michael@0: 
michael@0:     // Open the /proc/$pid/lwp/$lwpid/lwpctl files
michael@0:     snprintf(procname, sizeof (procname), "/proc/self/lwp/%d/lwpctl", lwpid);
michael@0: 
michael@0:     if ((ctlfd = open(procname, O_WRONLY|O_EXCL)) < 0) {
michael@0:       print_message2(2, "failed to open %s in ControlLwp\n", procname);
michael@0:       return false;
michael@0:     }
michael@0: 
michael@0:     AutoCloser autocloser(ctlfd);
michael@0: 
michael@0:     long ctl[2];
michael@0:     ctl[0] = suspend ? PCSTOP : PCRUN;
michael@0:     ctl[1] = 0;
michael@0:     if (write(ctlfd, ctl, sizeof (ctl)) != sizeof (ctl)) {
michael@0:       print_message2(2, "failed in lwp %d\n", lwpid);
michael@0:       return false;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * Utility function to read the contents of a file that contains a
michael@0:  * prheader_t at the start (/proc/$pid/lstatus or /proc/$pid/lpsinfo).
michael@0:  * Return true on success.
michael@0:  */
michael@0: static bool read_lfile(int pid, const char *lname, prheader_t *lhp) {
michael@0:   char lpath[PATH_MAX];
michael@0:   struct stat statb;
michael@0:   int fd;
michael@0:   size_t size;
michael@0: 
michael@0:   snprintf(lpath, sizeof (lpath), "/proc/%d/%s", pid, lname);
michael@0:   if ((fd = open(lpath, O_RDONLY)) < 0) {
michael@0:     print_message2(2, "failed to open %s in read_lfile\n", lpath);
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   AutoCloser autocloser(fd);
michael@0: 
michael@0:   if (fstat(fd, &statb) != 0)
michael@0:     return false;
michael@0: 
michael@0:   size = statb.st_size;
michael@0:   if ((size / sizeof (prheader_t)) + 32 > HEADER_MAX) {
michael@0:     print_message1(2, "map size overflow\n");
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   if (pread(fd, lhp, size, 0) <= sizeof (prheader_t))
michael@0:     return false;
michael@0: 
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: }  // namespace
michael@0: 
michael@0: namespace google_breakpad {
michael@0: 
michael@0: SolarisLwp::SolarisLwp(int pid) : pid_(pid) {
michael@0: }
michael@0: 
michael@0: SolarisLwp::~SolarisLwp() {
michael@0: }
michael@0: 
michael@0: int SolarisLwp::ControlAllLwps(bool suspend) {
michael@0:   CallbackParam<LwpidCallback> callback_param(ControlLwp, &suspend);
michael@0:   return IterateLwpAll(pid_, &callback_param);
michael@0: }
michael@0: 
michael@0: int SolarisLwp::GetLwpCount() const {
michael@0:   return IterateLwpAll(pid_, NULL);
michael@0: }
michael@0: 
michael@0: int SolarisLwp::Lwp_iter_all(int pid,
michael@0:                              CallbackParam<LwpCallback> *callback_param) const {
michael@0:   lwpstatus_t *Lsp;
michael@0:   lwpstatus_t *sp;
michael@0:   prheader_t lphp[HEADER_MAX];
michael@0:   prheader_t lhp[HEADER_MAX];
michael@0:   prheader_t *Lphp = lphp;
michael@0:   prheader_t *Lhp = lhp;
michael@0:   lwpsinfo_t *Lpsp;
michael@0:   long nstat;
michael@0:   long ninfo;
michael@0:   int rv = 0;
michael@0: 
michael@0:   /*
michael@0:    * The /proc/pid/lstatus file has the array of lwpstatus_t's and the
michael@0:    * /proc/pid/lpsinfo file has the array of lwpsinfo_t's.
michael@0:    */
michael@0:   if (read_lfile(pid, "lstatus", Lhp) == NULL)
michael@0:     return -1;
michael@0:   if (read_lfile(pid, "lpsinfo", Lphp) == NULL) {
michael@0:     return -1;
michael@0:   }
michael@0: 
michael@0:   Lsp = (lwpstatus_t *)(uintptr_t)(Lhp + 1);
michael@0:   Lpsp = (lwpsinfo_t *)(uintptr_t)(Lphp + 1);
michael@0: 
michael@0:   for (ninfo = Lphp->pr_nent; ninfo != 0; --ninfo) {
michael@0:     if (Lpsp->pr_sname != 'Z') {
michael@0:       sp = Lsp;
michael@0:       Lsp = (lwpstatus_t *)((uintptr_t)Lsp + Lhp->pr_entsize);
michael@0:     } else {
michael@0:       sp = NULL;
michael@0:     }
michael@0:     if (callback_param &&
michael@0:         !(callback_param->call_back)(sp, callback_param->context))
michael@0:       break;
michael@0:     ++rv;
michael@0:     Lpsp = (lwpsinfo_t *)((uintptr_t)Lpsp + Lphp->pr_entsize);
michael@0:   }
michael@0: 
michael@0:   return rv;
michael@0: }
michael@0: 
michael@0: uintptr_t SolarisLwp::GetLwpStackBottom(uintptr_t current_esp) const {
michael@0:   AddressValidatingContext addr;
michael@0:   addr.address = current_esp;
michael@0:   CallbackParam<ModuleCallback> callback_param(AddressNotInModuleCallback,
michael@0:                                                &addr);
michael@0:   ListModules(&callback_param);
michael@0:   return stack_base_address;
michael@0: }
michael@0: 
michael@0: int SolarisLwp::GetModuleCount() const {
michael@0:   return ListModules(NULL);
michael@0: }
michael@0: 
michael@0: int SolarisLwp::ListModules(
michael@0:     CallbackParam<ModuleCallback> *callback_param) const {
michael@0:   const char *maps_path = "/proc/self/map";
michael@0:   struct stat status;
michael@0:   int fd = 0, num;
michael@0:   prmap_t map_array[MAP_MAX];
michael@0:   prmap_t *maps = map_array;
michael@0:   size_t size;
michael@0: 
michael@0:   if ((fd = open(maps_path, O_RDONLY)) == -1) {
michael@0:     print_message2(2, "failed to open %s in ListModules\n", maps_path);
michael@0:     return -1;
michael@0:   }
michael@0: 
michael@0:   AutoCloser autocloser(fd);
michael@0: 
michael@0:   if (fstat(fd, &status))
michael@0:     return -1;
michael@0: 
michael@0:   /*
michael@0:    * Determine number of mappings, this value must be 
michael@0:    * larger than the actual module count
michael@0:    */
michael@0:   size = status.st_size;
michael@0:   if ((num = (int)(size / sizeof (prmap_t))) > MAP_MAX) {
michael@0:     print_message1(2, "map size overflow\n");
michael@0:     return -1;
michael@0:   }
michael@0: 
michael@0:   if (read(fd, (void *)maps, size) < 0) {
michael@0:     print_message2(2, "failed to read %d\n", fd);
michael@0:     return -1;
michael@0:   }
michael@0: 
michael@0:   prmap_t *_maps;
michael@0:   int _num;
michael@0:   int module_count = 0;
michael@0:   
michael@0:   /*
michael@0:    * Scan each mapping - note it is assummed that the mappings are
michael@0:    * presented in order.  We fill holes between mappings.  On intel
michael@0:    * the last mapping is usually the data segment of ld.so.1, after
michael@0:    * this comes a red zone into which non-fixed mapping won't get
michael@0:    * place.  Thus we can simply bail from the loop after seeing the
michael@0:    * last mapping.
michael@0:    */
michael@0:   for (_num = 0, _maps = maps; _num < num; ++_num, ++_maps) {
michael@0:     ModuleInfo module;
michael@0:     char *name = _maps->pr_mapname;
michael@0: 
michael@0:     memset(&module, 0, sizeof (module));
michael@0:     module.start_addr = _maps->pr_vaddr;
michael@0:     module.size = _maps->pr_size;
michael@0:     if (strlen(name) > 0) {
michael@0:       int objectfd = 0;
michael@0:       char path[PATH_MAX];
michael@0:       char buf[SELFMAG];
michael@0: 
michael@0:       snprintf(path, sizeof (path), "/proc/self/object/%s", name);
michael@0:       if ((objectfd = open(path, O_RDONLY)) < 0) {
michael@0:         print_message1(2, "can't open module file\n");
michael@0:         continue;
michael@0:       }
michael@0: 
michael@0:       AutoCloser autocloser(objectfd);
michael@0: 
michael@0:       if (read(objectfd, buf, SELFMAG) != SELFMAG) {
michael@0:         print_message1(2, "can't read module file\n");
michael@0:         continue;
michael@0:       }
michael@0:       if (buf[0] != ELFMAG0 || buf[1] != ELFMAG1 ||
michael@0:           buf[2] != ELFMAG2 || buf[3] != ELFMAG3) {
michael@0:         continue;
michael@0:       }
michael@0: 
michael@0:       strncpy(module.name, name, sizeof (module.name) - 1);
michael@0:       ++module_count;
michael@0:     }
michael@0:     if (callback_param &&
michael@0:         (!callback_param->call_back(module, callback_param->context))) {
michael@0:       break;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   return module_count;
michael@0: }
michael@0: 
michael@0: // Check if the address is a valid virtual address.
michael@0: // If the address is in any of the mapped modules, we take it as valid.
michael@0: // Otherwise it is invalid.
michael@0: bool SolarisLwp::IsAddressMapped(uintptr_t address) const {
michael@0:   AddressValidatingContext addr;
michael@0:   addr.address = address;
michael@0:   CallbackParam<ModuleCallback> callback_param(AddressNotInModuleCallback,
michael@0:                                                &addr);
michael@0:   ListModules(&callback_param);
michael@0:   return addr.is_mapped;
michael@0: }
michael@0: 
michael@0: // We're looking for a ucontext_t as the second parameter
michael@0: // to a signal handler function call.  Luckily, the ucontext_t
michael@0: // has an ebp(fp on SPARC) member which should match the ebp(fp)
michael@0: // pointed to by the ebp(fp) of the signal handler frame.
michael@0: // The Solaris stack looks like this:
michael@0: // http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/lib/libproc/common/Pstack.c#81
michael@0: bool SolarisLwp::FindSigContext(uintptr_t sighandler_ebp,
michael@0:                                 ucontext_t **sig_ctx) {
michael@0:   uintptr_t previous_ebp;
michael@0:   uintptr_t sig_ebp;
michael@0:   const int MAX_STACK_DEPTH = 50;
michael@0:   int depth_counter = 0;
michael@0: 
michael@0:   do {
michael@0: #if TARGET_CPU_SPARC
michael@0:     previous_ebp = reinterpret_cast<uintptr_t>(GetNextFrame(
michael@0:                                   reinterpret_cast<void*>(sighandler_ebp)));
michael@0:     *sig_ctx = reinterpret_cast<ucontext_t*>(sighandler_ebp + sizeof (struct frame));
michael@0:     uintptr_t sig_esp = (*sig_ctx)->uc_mcontext.gregs[REG_O6];
michael@0:     if (sig_esp < previous_ebp && sig_esp > sighandler_ebp)
michael@0:       sig_ebp = (uintptr_t)(((struct frame *)sig_esp)->fr_savfp);
michael@0: 
michael@0: #elif TARGET_CPU_X86
michael@0:     previous_ebp = reinterpret_cast<uintptr_t>(GetNextFrame(
michael@0:                                   reinterpret_cast<void**>(sighandler_ebp)));
michael@0:     *sig_ctx = reinterpret_cast<ucontext_t*>(sighandler_ebp + sizeof (struct frame) +
michael@0:                                              3 * sizeof(uintptr_t));
michael@0:     sig_ebp = (*sig_ctx)->uc_mcontext.gregs[EBP];
michael@0: #endif
michael@0:     sighandler_ebp = previous_ebp;
michael@0:     depth_counter++;
michael@0:   } while(previous_ebp != sig_ebp && sighandler_ebp != 0 &&
michael@0:           IsAddressMapped(sighandler_ebp) && depth_counter < MAX_STACK_DEPTH);
michael@0: 
michael@0:   return previous_ebp == sig_ebp && previous_ebp != 0;
michael@0: }
michael@0: 
michael@0: }  // namespace google_breakpad