From e8dd273d199f5bbe295a8e3d8b777c5505b6b2e1 Mon Sep 17 00:00:00 2001 From: Salah Triki Date: Thu, 17 Sep 2026 14:00:52 +0100 Subject: iio: proximity: isl29501: Fix return type of isl29501_register_write isl29501_register_write() was returning a u32 instead of an int. Since the function returns negative error codes (such as -ERANGE or return values from i2c_smbus_write_byte_data()), returning an unsigned integer type prevents callers from correctly checking for negative error conditions. Fix this by changing the function return type from u32 to int. This was found through manual code review. Fixes: 1c28799257bc ("iio: light: isl29501: Add support for the ISL29501 ToF sensor.") Signed-off-by: Salah Triki Reviewed-by: Joshua Crofts Cc: stable@vger.kernel.org Signed-off-by: Jonathan Cameron --- tools/lib/python/jobserver.py | 195 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 195 insertions(+) create mode 100755 tools/lib/python/jobserver.py (limited to 'tools/lib/python/jobserver.py') diff --git a/tools/lib/python/jobserver.py b/tools/lib/python/jobserver.py new file mode 100755 index 000000000..0b1ffdf9f --- /dev/null +++ b/tools/lib/python/jobserver.py @@ -0,0 +1,195 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0+ +# +# pylint: disable=C0103,C0209 +# +# + +""" +Interacts with the POSIX jobserver during the Kernel build time. + +A "normal" jobserver task, like the one initiated by a make subprocess would do: + + - open read/write file descriptors to communicate with the job server; + - ask for one slot by calling:: + + claim = os.read(reader, 1) + + - when the job finishes, call:: + + os.write(writer, b"+") # os.write(writer, claim) + +Here, the goal is different: This script aims to get the remaining number +of slots available, using all of them to run a command which handle tasks in +parallel. To to that, it has a loop that ends only after there are no +slots left. It then increments the number by one, in order to allow a +call equivalent to ``make -j$((claim+1))``, e.g. having a parent make creating +$claim child to do the actual work. + +The end goal here is to keep the total number of build tasks under the +limit established by the initial ``make -j$n_proc`` call. + +See: + https://www.gnu.org/software/make/manual/html_node/POSIX-Jobserver.html#POSIX-Jobserver +""" + +import errno +import os +import subprocess +import sys + +def warn(text, *args): + print(f'WARNING: {text}', *args, file = sys.stderr) + +class JobserverExec: + """ + Claim all slots from make using POSIX Jobserver. + + The main methods here are: + + - open(): reserves all slots; + - close(): method returns all used slots back to make; + - run(): executes a command setting PARALLELISM=. + """ + + def __init__(self): + """Initialize internal vars.""" + self.claim = 0 + self.jobs = b"" + self.reader = None + self.writer = None + self.is_open = False + + def open(self): + """Reserve all available slots to be claimed later on.""" + + if self.is_open: + return + self.is_open = True # We only try once + self.claim = None + # + # Check the make flags for "--jobserver=R,W" + # Note that GNU Make has used --jobserver-fds and --jobserver-auth + # so this handles all of them. + # + flags = os.environ.get('MAKEFLAGS', '') + opts = [x for x in flags.split(" ") if x.startswith("--jobserver")] + if not opts: + return + # + # Separate out the provided file descriptors + # + split_opt = opts[-1].split('=', 1) + if len(split_opt) != 2: + warn('unparseable option:', opts[-1]) + return + fds = split_opt[1] + # + # As of GNU Make 4.4, we'll be looking for a named pipe + # identified as fifo:path + # + if fds.startswith('fifo:'): + path = fds[len('fifo:'):] + try: + self.reader = os.open(path, os.O_RDONLY | os.O_NONBLOCK) + self.writer = os.open(path, os.O_WRONLY) + except (OSError, IOError): + warn('unable to open jobserver pipe', path) + return + # + # Otherwise look for integer file-descriptor numbers. + # + else: + split_fds = fds.split(',') + if len(split_fds) != 2: + warn('malformed jobserver file descriptors:', fds) + return + try: + self.reader = int(split_fds[0]) + self.writer = int(split_fds[1]) + except ValueError: + warn('non-integer jobserver file-descriptors:', fds) + return + try: + # + # Open a private copy of reader to avoid setting nonblocking + # on an unexpecting process with the same reader fd. + # + self.reader = os.open(f"/proc/self/fd/{self.reader}", + os.O_RDONLY | os.O_NONBLOCK) + except (IOError, OSError) as e: + warn('Unable to reopen jobserver read-side pipe:', repr(e)) + return + # + # OK, we have the channel to the job server; read out as many jobserver + # slots as possible. + # + while True: + try: + slot = os.read(self.reader, 8) + if not slot: + # + # Something went wrong. Clear self.jobs to avoid writing + # weirdness back to the jobserver and give up. + self.jobs = b"" + warn("unexpected empty token from jobserver;" + " possible invalid '--jobserver-auth=' setting") + self.claim = None + return + except (OSError, IOError) as e: + # + # If there is nothing more to read then we are done. + # + if e.errno == errno.EWOULDBLOCK: + break + # + # Anything else says that something went weird; give back + # the jobs and give up. + # + if self.jobs: + os.write(self.writer, self.jobs) + self.claim = None + warn('error reading from jobserver pipe', repr(e)) + return + self.jobs += slot + # + # Add a bump for our caller's reserveration, since we're just going + # to sit here blocked on our child. + # + self.claim = len(self.jobs) + 1 + + def close(self): + """Return all reserved slots to Jobserver.""" + + if not self.is_open: + return + + # Return all the reserved slots. + if len(self.jobs): + os.write(self.writer, self.jobs) + + self.is_open = False + + def __enter__(self): + self.open() + return self + + def __exit__(self, exc_type, exc_value, exc_traceback): + self.close() + + def run(self, cmd, *args, **pwargs): + """ + Run a command setting PARALLELISM env variable to the number of + available job slots (claim) + 1, e.g. it will reserve claim slots + to do the actual build work, plus one to monitor its children. + """ + self.open() # Ensure that self.claim is set + + # We can only claim parallelism if there was a jobserver (i.e. a + # top-level "-jN" argument) and there were no other failures. Otherwise + # leave out the environment variable and let the child figure out what + # is best. + if self.claim: + os.environ["PARALLELISM"] = str(self.claim) + + return subprocess.call(cmd, *args, **pwargs) -- cgit v1.3.1