Hi Chen, On Sat, Jan 25, 2025 at 05:46:05PM +0800, Chen Linxuan wrote: > `mkdir` and `mkdirat` might set errno to EOVERFLOW when UID or GID > mapping has not been configured. See > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=036d523641c66bef713042894a17f4335f199e49 > > This is a small program in the commit message that shows this behavior: Please add the necessary includes. I can't compile the program. You'll need to indent the program, so that the '#' are not interpreted as comments by git(1). Have a lovely day! Alex > > static int childFunc(void *_) > { > if (mount("tmpfs", "/tmp", "tmpfs", 0, NULL)) { > err(EXIT_FAILURE, "mount"); > } > if (mkdir("/tmp/test", 0755) == -1) { > err(EXIT_FAILURE, "mkdir"); > } > return 0; > } > > int main(int argc, char *argv[]) > { > char *stack; /* Start of stack buffer */ > char *stackTop; /* End of stack buffer */ > pid_t pid; > > stack = mmap(NULL, STACK_SIZE, PROT_READ | PROT_WRITE, > MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0); > if (stack == MAP_FAILED) > err(EXIT_FAILURE, "mmap"); > > stackTop = stack + STACK_SIZE; > > pid = clone(childFunc, stackTop, CLONE_NEWUSER | CLONE_NEWNS | SIGCHLD, > NULL); > if (munmap(stack, STACK_SIZE) == -1) > err(EXIT_FAILURE, "munmap"); > if (pid == -1) > err(EXIT_FAILURE, "clone"); > > if (waitpid(pid, NULL, 0) == -1) > err(EXIT_FAILURE, "waitpid"); > > exit(EXIT_SUCCESS); > } > > Signed-off-by: Chen Linxuan <chenlinxuan@xxxxxxxxxxxxx> > --- > man/man2/mkdir.2 | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/man/man2/mkdir.2 b/man/man2/mkdir.2 > index d84dbc27e..2af618d68 100644 > --- a/man/man2/mkdir.2 > +++ b/man/man2/mkdir.2 > @@ -203,6 +203,10 @@ does not support the creation of directories. > .B EROFS > .I pathname > refers to a file on a read-only filesystem. > +.B EOVERFLOW > +UID or GID mappings (see > +.BR user_namespaces (7)) > +has not been configured. > .SH VERSIONS > Under Linux, apart from the permission bits, the > .B S_ISVTX > -- > 2.43.0 > -- <https://www.alejandro-colomar.es/>
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