deps: V8: backport a4545db

Original commit message: FreeBSD update of process library mapping listing. Not best to rely on /proc presence basically when the linux compatibily layer is enabled so going through more programmatically. Change-Id: Ida4973f9da6dec6e9caa6e419f3612ec5ef95048 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1710664 Reviewed-by: Ulan Degenbaev <[email protected]> Commit-Queue: Ulan Degenbaev <[email protected]> Cr-Commit-Position: refs/heads/master@{#65442} PR-URL: #31127 Refs: v8/v8@a4545db Reviewed-By: Jiawen Geng <[email protected]> Reviewed-By: Ruben Bridgewater <[email protected]> Reviewed-By: Colin Ihrig <[email protected]>

Author: devnexen

common.gypi

@@ -38,7 +38,7 @@
 
 # Reset this number to 0 on major V8 upgrades.
 # Increment by one for each non-official patch applied to deps/v8.
-'v8_embedder_string': '-node.26',
+'v8_embedder_string': '-node.27',
 
 ##### V8 defaults for Node.js #####
 

deps/v8/src/base/platform/platform-freebsd.cc

@@ -13,10 +13,12 @@
 #include<sys/time.h>
 #include<sys/types.h>
 #include<sys/ucontext.h>
+#include<sys/user.h>
 
 #include<sys/fcntl.h>// open
 #include<sys/mman.h>// mmap & munmap
 #include<sys/stat.h>// open
+#include<sys/sysctl.h>
 #include<unistd.h>// getpagesize
 // If you don't have execinfo.h then you need devel/libexecinfo from ports.
 #include<errno.h>
@@ -46,41 +48,47 @@ static unsigned StringToLong(char* buffer){
 
 std::vector<OS::SharedLibraryAddress> OS::GetSharedLibraryAddresses(){
  std::vector<SharedLibraryAddress> result;
-staticconstint MAP_LENGTH = 1024;
-int fd = open("/proc/self/maps", O_RDONLY);
-if (fd < 0) return result;
-while (true){
-char addr_buffer[11];
- addr_buffer[0] = '0';
- addr_buffer[1] = 'x';
- addr_buffer[10] = 0;
-ssize_t bytes_read = read(fd, addr_buffer + 2, 8);
-if (bytes_read < 8) break;
-unsigned start = StringToLong(addr_buffer);
- bytes_read = read(fd, addr_buffer + 2, 1);
-if (bytes_read < 1) break;
-if (addr_buffer[2] != '-') break;
- bytes_read = read(fd, addr_buffer + 2, 8);
-if (bytes_read < 8) break;
-unsigned end = StringToLong(addr_buffer);
-char buffer[MAP_LENGTH];
- bytes_read = -1;
-do{
- bytes_read++;
-if (bytes_read >= MAP_LENGTH - 1) break;
- bytes_read = read(fd, buffer + bytes_read, 1);
-if (bytes_read < 1) break;
- } while (buffer[bytes_read] != '\n');
- buffer[bytes_read] = 0;
-// Ignore mappings that are not executable.
-if (buffer[3] != 'x') continue;
-char* start_of_path = index(buffer, '/');
-// There may be no filename in this line. Skip to next.
-if (start_of_path == nullptr) continue;
- buffer[bytes_read] = 0;
- result.push_back(SharedLibraryAddress(start_of_path, start, end));
+int mib[4] ={CTL_KERN, KERN_PROC, KERN_PROC_VMMAP, getpid()};
+size_t miblen = sizeof(mib) / sizeof(mib[0]);
+size_t buffer_size;
+if (sysctl(mib, miblen, nullptr, &buffer_size, nullptr, 0) == 0){
+// Overallocate the buffer by 1/3 to account for concurrent
+// kinfo_vmentry change. 1/3 is an arbitrary constant that
+// works in practice.
+ buffer_size = buffer_size * 4 / 3;
+ std::vector<char> buffer(buffer_size);
+int ret = sysctl(mib, miblen, buffer.data(), &buffer_size, nullptr, 0);
+
+if (ret == 0 || (ret == -1 && errno == ENOMEM)){
+char* start = buffer.data();
+char* end = start + buffer_size;
+
+while (start < end){
+structkinfo_vmentry* map =
+reinterpret_cast<structkinfo_vmentry*>(start);
+constsize_t ssize = map->kve_structsize;
+char* path = map->kve_path;
+
+CHECK_NE(0, ssize);
+
+if ((map->kve_protection & KVME_PROT_READ) != 0 &&
+ (map->kve_protection & KVME_PROT_EXEC) != 0 && path[0] != '\0'){
+char* sep = strrchr(path, '/');
+ std::string lib_name;
+if (sep != nullptr){
+ lib_name = std::string(++sep);
+ } else{
+ lib_name = std::string(path);
+ }
+ result.push_back(SharedLibraryAddress(
+ lib_name, reinterpret_cast<uintptr_t>(map->kve_start),
+reinterpret_cast<uintptr_t>(map->kve_end)));
+ }
+
+ start += ssize;
+ }
+ }
  }
-close(fd);
 return result;
 }