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authorRon Yorston <rmy@pobox.com>2021-11-12 13:56:22 +0000
committerRon Yorston <rmy@pobox.com>2021-11-12 13:56:22 +0000
commit3d660bd84208ffc797f9d41423a8951123b3e46e (patch)
tree549b46d79633b4e03822a9f91dd00bae62533b3a
parent9e12622a8706a0d23a3ff8792773e73b0d6108b4 (diff)
downloadbusybox-w32-ucrt_hack.tar.gz
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busybox-w32-ucrt_hack.zip
win32: another attempt at a UCRT hackucrt_hack
The problem with UCRT seems to be that if a process has been started with a non-NULL environment block passed to CreateProcess() any subsequent call to spawnve() with a non-NULL environment pointer fails. Commit 5b48ca53b (win32: pass NULL to spawnve, not environ) fixed the problem in busybox-w32 for those cases where a NULL environment pointer was sufficient. It didn't handle the case where the shell passes a modified environment to its child. All calls to spawnve() in the shell occur in a process which will terminate whether or not the call succeeds. It therefore doesn't matter if we mess with the environment of this process such that spawnve() can be passed a NULL environment pointer. (I think.)
-rw-r--r--shell/ash.c10
-rw-r--r--win32/process.c8
2 files changed, 10 insertions, 8 deletions
diff --git a/shell/ash.c b/shell/ash.c
index ad1e5ba7e..6d7066a1b 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -8898,9 +8898,11 @@ tryexec(IF_FEATURE_SH_STANDALONE(int applet_no,) const char *cmd, char **argv, c
8898# else 8898# else
8899 if (APPLET_IS_NOEXEC(applet_no)) { 8899 if (APPLET_IS_NOEXEC(applet_no)) {
8900# endif 8900# endif
8901#if !defined(_UCRT)
8901 clearenv(); 8902 clearenv();
8902 while (*envp) 8903 while (*envp)
8903 putenv(*envp++); 8904 putenv(*envp++);
8905#endif
8904 popredir(/*drop:*/ 1); 8906 popredir(/*drop:*/ 1);
8905 run_noexec_applet_and_exit(applet_no, cmd, argv); 8907 run_noexec_applet_and_exit(applet_no, cmd, argv);
8906 } 8908 }
@@ -8973,6 +8975,14 @@ static void shellexec(char *prog, char **argv, const char *path, int idx)
8973#if !ENABLE_PLATFORM_MINGW32 8975#if !ENABLE_PLATFORM_MINGW32
8974 if (strchr(prog, '/') != NULL 8976 if (strchr(prog, '/') != NULL
8975#else 8977#else
8978#if defined(_UCRT)
8979 /* Avoid UCRT bug by updating parent's environment and passing a
8980 * NULL environment pointer to execve(). */
8981 clearenv();
8982 while (*envp)
8983 putenv(*envp++);
8984 envp = NULL;
8985#endif
8976 if (has_path(prog) 8986 if (has_path(prog)
8977#endif 8987#endif
8978#if ENABLE_FEATURE_SH_STANDALONE 8988#if ENABLE_FEATURE_SH_STANDALONE
diff --git a/win32/process.c b/win32/process.c
index 137cb6a39..812e259f4 100644
--- a/win32/process.c
+++ b/win32/process.c
@@ -268,14 +268,6 @@ spawnveq(int mode, const char *path, char *const *argv, char *const *env)
268 new_path = xasprintf("%s.", path); 268 new_path = xasprintf("%s.", path);
269 } 269 }
270 270
271#if defined(_UCRT)
272 if (env) {
273 char buffer[64];
274
275 sprintf(buffer, "BB_HELLO_%d", getpid());
276 SetEnvironmentVariable(buffer, "1");
277 }
278#endif
279 errno = 0; 271 errno = 0;
280 ret = spawnve(mode, new_path ? new_path : path, new_argv, env); 272 ret = spawnve(mode, new_path ? new_path : path, new_argv, env);
281 273