[PATCH AUTOSEL 5.15 1/3] scripts: handle BrokenPipeError for python scripts

[PATCH AUTOSEL 5.15 1/3] scripts: handle BrokenPipeError for python scripts

[Sasha Levin]

From: Masahiro Yamada <masahiroy@kernel.org>

[ Upstream commit 87c7ee67deb7fce9951a5f9d80641138694aad17 ]

In the follow-up of commit fb3041d61f68 ("kbuild: fix SIGPIPE error
message for AR=gcc-ar and AR=llvm-ar"), Kees Cook pointed out that
tools should _not_ catch their own SIGPIPEs [1] [2].

Based on his feedback, LLVM was fixed [3].

However, Python's default behavior is to show noisy bracktrace when
SIGPIPE is sent. So, scripts written in Python are basically in the
same situation as the buggy llvm tools.

Example:

  $ make -s allnoconfig
  $ make -s allmodconfig
  $ scripts/diffconfig .config.old .config | head -n1
  -ALIX n
  Traceback (most recent call last):
    File "/home/masahiro/linux/scripts/diffconfig", line 132, in <module>
      main()
    File "/home/masahiro/linux/scripts/diffconfig", line 130, in main
      print_config("+", config, None, b[config])
    File "/home/masahiro/linux/scripts/diffconfig", line 64, in print_config
      print("+%s %s" % (config, new_value))
  BrokenPipeError: [Errno 32] Broken pipe

Python documentation [4] notes how to make scripts die immediately and
silently:

  """
  Piping output of your program to tools like head(1) will cause a
  SIGPIPE signal to be sent to your process when the receiver of its
  standard output closes early. This results in an exception like
  BrokenPipeError: [Errno 32] Broken pipe. To handle this case,
  wrap your entry point to catch this exception as follows:

    import os
    import sys

    def main():
        try:
            # simulate large output (your code replaces this loop)
            for x in range(10000):
                print("y")
            # flush output here to force SIGPIPE to be triggered
            # while inside this try block.
            sys.stdout.flush()
        except BrokenPipeError:
            # Python flushes standard streams on exit; redirect remaining output
            # to devnull to avoid another BrokenPipeError at shutdown
            devnull = os.open(os.devnull, os.O_WRONLY)
            os.dup2(devnull, sys.stdout.fileno())
            sys.exit(1)  # Python exits with error code 1 on EPIPE

    if __name__ == '__main__':
        main()

  Do not set SIGPIPE’s disposition to SIG_DFL in order to avoid
  BrokenPipeError. Doing that would cause your program to exit
  unexpectedly whenever any socket connection is interrupted while
  your program is still writing to it.
  """

Currently, tools/perf/scripts/python/intel-pt-events.py seems to be the
only script that fixes the issue that way.

tools/perf/scripts/python/compaction-times.py uses another approach
signal.signal(signal.SIGPIPE, signal.SIG_DFL) but the Python
documentation clearly says "Don't do it".

I cannot fix all Python scripts since there are so many.
I fixed some in the scripts/ directory.

[1]: https://lore.kernel.org/all/202211161056.1B9611A@keescook/
[2]: https://github.com/llvm/llvm-project/issues/59037
[3]: https://github.com/llvm/llvm-project/commit/4787efa38066adb51e2c049499d25b3610c0877b
[4]: https://docs.python.org/3/library/signal.html#note-on-sigpipe

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 scripts/checkkconfigsymbols.py         | 13 ++++++++++++-
 scripts/clang-tools/run-clang-tools.py | 21 ++++++++++++++-------
 scripts/diffconfig                     | 16 ++++++++++++++--
 3 files changed, 40 insertions(+), 10 deletions(-)

diff --git a/scripts/checkkconfigsymbols.py b/scripts/checkkconfigsymbols.py
index 217d21abc86e8..36c920e713137 100755
--- a/scripts/checkkconfigsymbols.py
+++ b/scripts/checkkconfigsymbols.py
@@ -115,7 +115,7 @@ def parse_options():
     return args
 
 
-def main():
+def print_undefined_symbols():
     """Main function of this module."""
     args = parse_options()
 
@@ -467,5 +467,16 @@ def parse_kconfig_file(kfile):
     return defined, references
 
 
+def main():
+    try:
+        print_undefined_symbols()
+    except BrokenPipeError:
+        # Python flushes standard streams on exit; redirect remaining output
+        # to devnull to avoid another BrokenPipeError at shutdown
+        devnull = os.open(os.devnull, os.O_WRONLY)
+        os.dup2(devnull, sys.stdout.fileno())
+        sys.exit(1)  # Python exits with error code 1 on EPIPE
+
+
 if __name__ == "__main__":
     main()
diff --git a/scripts/clang-tools/run-clang-tools.py b/scripts/clang-tools/run-clang-tools.py
index f754415af398b..f42699134f1c0 100755
--- a/scripts/clang-tools/run-clang-tools.py
+++ b/scripts/clang-tools/run-clang-tools.py
@@ -60,14 +60,21 @@ def run_analysis(entry):
 
 
 def main():
-    args = parse_arguments()
+    try:
+        args = parse_arguments()
 
-    lock = multiprocessing.Lock()
-    pool = multiprocessing.Pool(initializer=init, initargs=(lock, args))
-    # Read JSON data into the datastore variable
-    with open(args.path, "r") as f:
-        datastore = json.load(f)
-        pool.map(run_analysis, datastore)
+        lock = multiprocessing.Lock()
+        pool = multiprocessing.Pool(initializer=init, initargs=(lock, args))
+        # Read JSON data into the datastore variable
+        with open(args.path, "r") as f:
+            datastore = json.load(f)
+            pool.map(run_analysis, datastore)
+    except BrokenPipeError:
+        # Python flushes standard streams on exit; redirect remaining output
+        # to devnull to avoid another BrokenPipeError at shutdown
+        devnull = os.open(os.devnull, os.O_WRONLY)
+        os.dup2(devnull, sys.stdout.fileno())
+        sys.exit(1)  # Python exits with error code 1 on EPIPE
 
 
 if __name__ == "__main__":
diff --git a/scripts/diffconfig b/scripts/diffconfig
index d5da5fa05d1d3..43f0f3d273ae7 100755
--- a/scripts/diffconfig
+++ b/scripts/diffconfig
@@ -65,7 +65,7 @@ def print_config(op, config, value, new_value):
         else:
             print(" %s %s -> %s" % (config, value, new_value))
 
-def main():
+def show_diff():
     global merge_style
 
     # parse command line args
@@ -129,4 +129,16 @@ def main():
     for config in new:
         print_config("+", config, None, b[config])
 
-main()
+def main():
+    try:
+        show_diff()
+    except BrokenPipeError:
+        # Python flushes standard streams on exit; redirect remaining output
+        # to devnull to avoid another BrokenPipeError at shutdown
+        devnull = os.open(os.devnull, os.O_WRONLY)
+        os.dup2(devnull, sys.stdout.fileno())
+        sys.exit(1)  # Python exits with error code 1 on EPIPE
+
+
+if __name__ == '__main__':
+    main()
-- 
2.39.2

[PATCH AUTOSEL 5.15 2/3] media: ov5640: Fix analogue gain control

[Sasha Levin]

From: Paul Elder <paul.elder@ideasonboard.com>

[ Upstream commit afa4805799c1d332980ad23339fdb07b5e0cf7e0 ]

Gain control is badly documented in publicly available (including
leaked) documentation.

There is an AGC pre-gain in register 0x3a13, expressed as a 6-bit value
(plus an enable bit in bit 6). The driver hardcodes it to 0x43, which
one application note states is equal to x1.047. The documentation also
states that 0x40 is equel to x1.000. The pre-gain thus seems to be
expressed as in 1/64 increments, and thus ranges from x1.00 to x1.984.
What the pre-gain does is however unspecified.

There is then an AGC gain limit, in registers 0x3a18 and 0x3a19,
expressed as a 10-bit "real gain format" value. One application note
sets it to 0x00f8 and states it is equal to x15.5, so it appears to be
expressed in 1/16 increments, up to x63.9375.

The manual gain is stored in registers 0x350a and 0x350b, also as a
10-bit "real gain format" value. It is documented in the application
note as a Q6.4 values, up to x63.9375.

One version of the datasheet indicates that the sensor supports a
digital gain:

  The OV5640 supports 1/2/4 digital gain. Normally, the gain is
  controlled automatically by the automatic gain control (AGC) block.

It isn't clear how that would be controlled manually.

There appears to be no indication regarding whether the gain controlled
through registers 0x350a and 0x350b is an analogue gain only or also
includes digital gain. The words "real gain" don't necessarily mean
"combined analogue and digital gains". Some OmniVision sensors (such as
the OV8858) are documented as supoprting different formats for the gain
values, selectable through a register bit, and they are called "real
gain format" and "sensor gain format". For that sensor, we have (one of)
the gain registers documented as

  0x3503[2]=0, gain[7:0] is real gain format, where low 4 bits are
  fraction bits, for example, 0x10 is 1x gain, 0x28 is 2.5x gain

  If 0x3503[2]=1, gain[7:0] is sensor gain format, gain[7:4] is coarse
  gain, 00000: 1x, 00001: 2x, 00011: 4x, 00111: 8x, gain[7] is 1,
  gain[3:0] is fine gain. For example, 0x10 is 1x gain, 0x30 is 2x gain,
  0x70 is 4x gain

(The second part of the text makes little sense)

"Real gain" may thus refer to the combination of the coarse and fine
analogue gains as a single value.

The OV5640 0x350a and 0x350b registers thus appear to control analogue
gain. The driver incorrectly uses V4L2_CID_GAIN as V4L2 has a specific
control for analogue gain, V4L2_CID_ANALOGUE_GAIN. Use it.

If registers 0x350a and 0x350b are later found to control digital gain
as well, the driver could then restrict the range of the analogue gain
control value to lower than x64 and add a separate digital gain control.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Jai Luthra <j-luthra@ti.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/media/i2c/ov5640.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c
index db5a19babe67d..a141552531f7e 100644
--- a/drivers/media/i2c/ov5640.c
+++ b/drivers/media/i2c/ov5640.c
@@ -2776,7 +2776,7 @@ static int ov5640_init_controls(struct ov5640_dev *sensor)
 	/* Auto/manual gain */
 	ctrls->auto_gain = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_AUTOGAIN,
 					     0, 1, 1, 1);
-	ctrls->gain = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_GAIN,
+	ctrls->gain = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_ANALOGUE_GAIN,
 					0, 1023, 1, 0);
 
 	ctrls->saturation = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_SATURATION,
-- 
2.39.2

[PATCH AUTOSEL 5.15 3/3] media: rc: gpio-ir-recv: add remove function

[Sasha Levin]

From: Li Jun <jun.li@nxp.com>

[ Upstream commit 30040818b338b8ebc956ce0ebd198f8d593586a6 ]

In case runtime PM is enabled, do runtime PM clean up to remove
cpu latency qos request, otherwise driver removal may have below
kernel dump:

[   19.463299] Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000048
[   19.472161] Mem abort info:
[   19.474985]   ESR = 0x0000000096000004
[   19.478754]   EC = 0x25: DABT (current EL), IL = 32 bits
[   19.484081]   SET = 0, FnV = 0
[   19.487149]   EA = 0, S1PTW = 0
[   19.490361]   FSC = 0x04: level 0 translation fault
[   19.495256] Data abort info:
[   19.498149]   ISV = 0, ISS = 0x00000004
[   19.501997]   CM = 0, WnR = 0
[   19.504977] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000049f81000
[   19.511432] [0000000000000048] pgd=0000000000000000,
p4d=0000000000000000
[   19.518245] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[   19.524520] Modules linked in: gpio_ir_recv(+) rc_core [last
unloaded: rc_core]
[   19.531845] CPU: 0 PID: 445 Comm: insmod Not tainted
6.2.0-rc1-00028-g2c397a46d47c #72
[   19.531854] Hardware name: FSL i.MX8MM EVK board (DT)
[   19.531859] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS
BTYPE=--)
[   19.551777] pc : cpu_latency_qos_remove_request+0x20/0x110
[   19.557277] lr : gpio_ir_recv_runtime_suspend+0x18/0x30
[gpio_ir_recv]
[   19.557294] sp : ffff800008ce3740
[   19.557297] x29: ffff800008ce3740 x28: 0000000000000000 x27:
ffff800008ce3d50
[   19.574270] x26: ffffc7e3e9cea100 x25: 00000000000f4240 x24:
ffffc7e3f9ef0e30
[   19.574284] x23: 0000000000000000 x22: ffff0061803820f4 x21:
0000000000000008
[   19.574296] x20: ffffc7e3fa75df30 x19: 0000000000000020 x18:
ffffffffffffffff
[   19.588570] x17: 0000000000000000 x16: ffffc7e3f9efab70 x15:
ffffffffffffffff
[   19.595712] x14: ffff800008ce37b8 x13: ffff800008ce37aa x12:
0000000000000001
[   19.602853] x11: 0000000000000001 x10: ffffcbe3ec0dff87 x9 :
0000000000000008
[   19.609991] x8 : 0101010101010101 x7 : 0000000000000000 x6 :
000000000f0bfe9f
[   19.624261] x5 : 00ffffffffffffff x4 : 0025ab8e00000000 x3 :
ffff006180382010
[   19.631405] x2 : ffffc7e3e9ce8030 x1 : ffffc7e3fc3eb810 x0 :
0000000000000020
[   19.638548] Call trace:
[   19.640995]  cpu_latency_qos_remove_request+0x20/0x110
[   19.646142]  gpio_ir_recv_runtime_suspend+0x18/0x30 [gpio_ir_recv]
[   19.652339]  pm_generic_runtime_suspend+0x2c/0x44
[   19.657055]  __rpm_callback+0x48/0x1dc
[   19.660807]  rpm_callback+0x6c/0x80
[   19.664301]  rpm_suspend+0x10c/0x640
[   19.667880]  rpm_idle+0x250/0x2d0
[   19.671198]  update_autosuspend+0x38/0xe0
[   19.675213]  pm_runtime_set_autosuspend_delay+0x40/0x60
[   19.680442]  gpio_ir_recv_probe+0x1b4/0x21c [gpio_ir_recv]
[   19.685941]  platform_probe+0x68/0xc0
[   19.689610]  really_probe+0xc0/0x3dc
[   19.693189]  __driver_probe_device+0x7c/0x190
[   19.697550]  driver_probe_device+0x3c/0x110
[   19.701739]  __driver_attach+0xf4/0x200
[   19.705578]  bus_for_each_dev+0x70/0xd0
[   19.709417]  driver_attach+0x24/0x30
[   19.712998]  bus_add_driver+0x17c/0x240
[   19.716834]  driver_register+0x78/0x130
[   19.720676]  __platform_driver_register+0x28/0x34
[   19.725386]  gpio_ir_recv_driver_init+0x20/0x1000 [gpio_ir_recv]
[   19.731404]  do_one_initcall+0x44/0x2ac
[   19.735243]  do_init_module+0x48/0x1d0
[   19.739003]  load_module+0x19fc/0x2034
[   19.742759]  __do_sys_finit_module+0xac/0x12c
[   19.747124]  __arm64_sys_finit_module+0x20/0x30
[   19.751664]  invoke_syscall+0x48/0x114
[   19.755420]  el0_svc_common.constprop.0+0xcc/0xec
[   19.760132]  do_el0_svc+0x38/0xb0
[   19.763456]  el0_svc+0x2c/0x84
[   19.766516]  el0t_64_sync_handler+0xf4/0x120
[   19.770789]  el0t_64_sync+0x190/0x194
[   19.774460] Code: 910003fd a90153f3 aa0003f3 91204021 (f9401400)
[   19.780556] ---[ end trace 0000000000000000 ]---

Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/media/rc/gpio-ir-recv.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/media/rc/gpio-ir-recv.c b/drivers/media/rc/gpio-ir-recv.c
index 22e524b69806a..a56c844d7f816 100644
--- a/drivers/media/rc/gpio-ir-recv.c
+++ b/drivers/media/rc/gpio-ir-recv.c
@@ -130,6 +130,23 @@ static int gpio_ir_recv_probe(struct platform_device *pdev)
 				"gpio-ir-recv-irq", gpio_dev);
 }
 
+static int gpio_ir_recv_remove(struct platform_device *pdev)
+{
+	struct gpio_rc_dev *gpio_dev = platform_get_drvdata(pdev);
+	struct device *pmdev = gpio_dev->pmdev;
+
+	if (pmdev) {
+		pm_runtime_get_sync(pmdev);
+		cpu_latency_qos_remove_request(&gpio_dev->qos);
+
+		pm_runtime_disable(pmdev);
+		pm_runtime_put_noidle(pmdev);
+		pm_runtime_set_suspended(pmdev);
+	}
+
+	return 0;
+}
+
 #ifdef CONFIG_PM
 static int gpio_ir_recv_suspend(struct device *dev)
 {
@@ -189,6 +206,7 @@ MODULE_DEVICE_TABLE(of, gpio_ir_recv_of_match);
 
 static struct platform_driver gpio_ir_recv_driver = {
 	.probe  = gpio_ir_recv_probe,
+	.remove = gpio_ir_recv_remove,
 	.driver = {
 		.name   = KBUILD_MODNAME,
 		.of_match_table = of_match_ptr(gpio_ir_recv_of_match),
-- 
2.39.2