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libc: always set argv and envp to valid arrays

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The arrays passed to main(…) must always be valid null-terminated arrays.

Fix #3955
This commit is contained in:
Emery Hemingway 2020-11-26 12:47:30 +01:00 committed by Norman Feske
parent 063e4bd072
commit 306466fc60
1 changed files with 14 additions and 4 deletions
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18
repos/libports/include/libc/args.h
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@ -40,12 +40,20 @@ static void populate_args_and_env(Libc::Env &env, int &argc, char **&argv, char
++envc;
});
if (argc == 0 && envc == 0)
if (argc == 0 && envc == 0) {
/*
* If argc is zero then argv is still a NULL-terminated array.
*/
static char const *args[] = { nullptr, nullptr };
argc = 0;
argv = (char**)&args;
envp = &argv[1];
return; /* from lambda */
}
/* arguments and environment are a contiguous array (but don't count on it) */
argv = (char**)malloc((argc + envc + 1) * sizeof(char*));
envp = &argv[argc];
/* arguments and environment are arranged System V style (but don't count on it) */
argv = (char**)malloc((argc + envc + 2) * sizeof(char*));
envp = &argv[argc+1];
/* read the arguments */
int arg_i = 0;
@ -123,6 +131,8 @@ static void populate_args_and_env(Libc::Env &env, int &argc, char **&argv, char
catch (Xml_node::Nonexistent_attribute) { }
});
/* argv and envp are both NULL terminated */
argv[arg_i] = NULL;
envp[env_i] = NULL;
});
}