March 2017 - kernelnewbies@kernelnewbies.org - Kernelnewbies Mailing Lists

return codes
by Tobin C. Harding March 14, 2017

March 14, 2017

On investigating call sites for 'return' in drivers/staging/ks7010/ it can be seen that a number of functions us *custom* (positive) integers to indicate error. Notwithstanding that they are positive, is this ok for code in the kernel (i.e in order to get out of staging does this need to be changed)? Functions in question have internal linkage and the error code is used for debug messages. Should these be A) left alone B) made negative C) changed to use standard error codes (i.e -ENOMEM etc) thanks, Tobin.

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MS_BIND flag on / folder not working
by Prabhunath G March 13, 2017

March 13, 2017

Hi All, Binding / folder onto someother folder say /opt/lxc is not working but otherway round is working. Can I get some help on this. The following code snippet is executed after cloning After executing the following code snippet the contents of / is visible in /opt/lxc ret = mount("/", "/opt/lxc", NULL, MS_BIND, NULL); if (ret) { perror("mount bind / on /opt/lxc"); exit(1); } But after executing the following code snippet the contents of /opt/lxc is not visible in / ret = mount("/opt/lxc", "/", NULL, MS_BIND, NULL); if (ret) { perror("mount bind /opt/lxc on /"); exit(1); } The code is executing successfully, but the result is not as expected. Regards, Prabhu

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Re: cannot insmod sculld in ldd3
by Ali Aminian March 13, 2017

March 13, 2017

Hello, Freeman Zhang. copying 'Module.symvers' to sculld folder solved the problem. Thank you, man. Now I wonder what is the proper way to export "Module.symvers" information to the outside so that modules that use it do not have to copy that file into their directory. for example, what do pci and usb buses do in this case?

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diff
by Tobin C. Harding March 13, 2017

March 13, 2017

On occasions diff output does not render the same as it does when editing a file. For example, while removing checkpatch tab warning the following diff was generated -#define KS_WLAN_SET_WPS_ENABLE SIOCIWFIRSTPRIV + 4 -#define KS_WLAN_GET_WPS_ENABLE SIOCIWFIRSTPRIV + 5 +#define KS_WLAN_SET_WPS_ENABLE SIOCIWFIRSTPRIV + 4 +#define KS_WLAN_GET_WPS_ENABLE SIOCIWFIRSTPRIV + 5 However when editing the file the alignment was not changed, just tabs were inserted instead of spaces. I had the same thing happen a few days ago (reproduced here from memory) -static void foo(struct bar *barp, struct baz *bazp) +static void foo(struct bar *barp, + struct baz *bazp) { ... When editing the file the two s's in struct were aligned but not in the diff output. I reapplied this patch to a clean tree and it applied correctly. How do maintainers visually parse this if the output is not identical in the diff and the file once applied? thanks, Tobin.

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RapidIO (SRIO) support in Linux - generic driver or device dependent ?
by Ran Shalit March 13, 2017

March 13, 2017

Hello, I find in documentation mention of rapidIO: https://www.kernel.org/doc/Documentation/rapidio/rapidio.txt Yet, in source code it seems that only few devices are supported with rapidIO: http://lxr.free-electrons.com/source/drivers/rapidio/ http://lxr.free-electrons.com/source/drivers/rapidio/devices But now I am not sure if it means that it is actually a generic driver for all devices, ot that my specific device (Arria V - Altera) does not have RapioIO driver support. Thank for any idea, Ran

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cannot insmod sculld in ldd3
by Ali Aminian March 12, 2017

March 12, 2017

Hello when i try to insmod sculld insmod prints this error message: insmod: ERROR: could not insert module ./sculld.ko: Invalid parameters i checked dmsg and it says: [12073.858764] sculld: no symbol version for unregister_ldd_driver [12073.858767] sculld: Unknown symbol unregister_ldd_driver (err -22) [12073.858780] sculld: no symbol version for register_ldd_device [12073.858781] sculld: Unknown symbol register_ldd_device (err -22) [12073.858789] sculld: no symbol version for unregister_ldd_device [12073.858790] sculld: Unknown symbol unregister_ldd_device (err -22) [12073.858794] sculld: no symbol version for register_ldd_driver [12073.858795] sculld: Unknown symbol register_ldd_driver (err -22) these functions are defined in lddbus and i have insmod lddbus. can anyone tell me what is wrong. thank you.

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Re: cannot insmod sculld in ldd3
by Ali Aminian March 12, 2017

March 12, 2017

Hello Tobin C. Harding I used the source you provided and still receive the same error. also the output of "uname -a" is this. if that matters: Linux ali-Z97-D3H 4.4.0-62-generic #83-Ubuntu SMP Wed Jan 18 14:10:15 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

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cannot insmod sculld in ldd3
by Ali Aminian March 11, 2017

March 11, 2017

Hello I mean lddbus and sculld from the book "Linux Device Drivers, Third Edition". Here I attached the codes.

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why `send(2)' blocks even though I've turned up the related sock settings?
by Shiyao Ma March 11, 2017

March 11, 2017

Hi, The related settings are, sudo sysctl -w net.core.rmem_max=2147483647 sudo sysctl -w net.core.wmem_max=2147483647 sudo sysctl -w net.ipv4.tcp_rmem="10240 8738000 2147483647" sudo sysctl -w net.ipv4.tcp_wmem="10240 8738000 2147483647" sudo sysctl -w net.ipv4.tcp_limit_output_bytes=2147483647 They are insanely big. However, when executing `send' for a large buffer, it still blocks. I thought L4 (tcp) will accept that large buffer as long as it can copy those buffer into kernel. Turns out not. What could be the possible reason? Does the TCP check the `cwnd' setting or so even in the step of copying buffer from userspace to kernel? I didn't find the related code, though. Regards.

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quilt mail not threading
by Okash Khawaja March 10, 2017

March 10, 2017

Hi, I can send patchset using quilt mail alright but the emails don't appear threaded. Checking email headers, I couldn't see References header either, which is what it should be using according to the README.MAIL. Have I missed something? Thanks, Okash

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