Commit Graph

7 Commits

Author SHA1 Message Date
Giacomo Tesio e70feee4a3 libc: introduce "jehanne_" namespace
With this commit all functions declared in libc.h have been renamed
with the "jehanne_" prefix. This is done for several reason:

- it removes conflicts during symbol resolution when linking
  standard C libraries like newlib or musl
- it allows programs depending on a standard C library to directly
  link to a library depending on our non standard libc (eg libsec).

To ease transiction two files are provided:

- sys/include/lib9.h that can be included instead of <libc.h> to use
  the old names (via a simple set of macros)
- sys/src/lib/c/lib9.c that can be compiled with a program where the
  macro provided by lib9.h are too dumb (see for example rc or grep).

In the kernel port/lib.h has been modified accordingly and some of
the functions it directly provides has been renamed too (eg malloc
in qmalloc.c and print in devcons.c).
2017-04-19 23:48:21 +02:00
Giacomo Tesio 65cdad4317 libc: rewrite putenv and getenv.
These new implementations

- do several validity check on input parameters
- allow a bit larger variable names (127 bytes, aka sizeof(Proc.genbuf)-1)
- preserve nulls in the content (the original version used to replace
  '\0' with ' '). I can't see why they did, actually.
  See also http://marc.info/?l=9fans&m=148475801229908&w=2

Should also fix CID 155718
2017-01-19 00:58:43 +01:00
Giacomo Tesio 01562d4ddb qa: rfork(RFNAMEG) on tests that are going to rfork(RFNOMNT) later 2017-01-06 23:04:04 +01:00
Giacomo Tesio 4676c65a3d kernel: move nsec to libc 2017-01-06 00:56:22 +01:00
Giacomo Tesio b862596737 kernel&all: create() syscall only sends Tcreate
In Plan9 the create syscall fallback on a open(OTRUNC) if the
path provided already exists. This is actually a common requirement
as most programs (editors, cat...) simply requires that a file is
there and is empty, and doesn't care overwriting existing contents
(note that this is particularily sensible with something like fossil).

In Jehanne the application is responsible of actually handle this
"file exists" error but libc provides ocreate() to mimic the Plan9
behaviour. Note that ocreate introduce a subtle race too: the path
is walked several times if the file exists, thus it could misbehave
on concurrent namespace changes. However I guess this is not going to
happen often enough to care now.

NOTE we will probably address this rare race too, with a more drammatic change
to syscalls: a new walk() syscall that will provide an unopen fd.
2016-12-24 21:25:20 +01:00
Giacomo Tesio 99855d60d6 kernel: move chdir to libc using devself/devproc
Added wdir to devself and devproc:

- read '#0/wdir' to get the working directory of the calling process
  NOTE that a read(fd, nil, -1) will return the negated length
  of the working directory, just in case you want to
  allocate the memory required

- read '/proc/n/wdir' to know the working directory of process n
  (read(fd, nil, -1) still returns the negated length)

- write '#0/wdir' to change the working directory of the calling process
  NOTE: no offset is allowed and the provided string must
  be null terminated

- write '/proc/n/wdir' to change the working directory of process n
  NOTE: no offset is allowed and the provided string must
  be null terminated; moreover if another process change the working
  directory change during the write, the current process will
  receive an error.

In libc updated getwd() and chdir().
Also modified pwd to get advantage of the new file.

To test, run /arch/amd64/qa/kern/wdir.rc or simply try

	% pwd
	/usr/glenda
	% echo -n /tmp > /proc/$pid/wdir
        % pwd
        /tmp
        % cat '#0/wdir' && echo
        /tmp

The expected use cases for wdir in devproc are rio and acme.

Also, note that we could theoretically remove the cd builtin
from rc and simply implement it as a rc function.
We don't do that to preserve rc portability to other OS.
2016-12-15 22:42:01 +01:00
Giacomo Tesio 38aca7a581 first usable version of kernel and commands
After an year of hard work, this is a first "usable" version of Jehanne.
2016-11-26 03:49:29 +01:00