[PATCH] mm: remove the newlines, which are added for unknown reasons and interfere with bug analysis
Looking at the source code links for mm/memory.c in the sample reports in the syzbot report links [1].
it looks like the line numbers are designated as lines that have been increased by 1. This may seem like a problem with syzkaller or the addr2line program that assigns the line numbers, but there is no problem with either of them.
In the previous commit d61ea1cb0095 ("userfaultfd: UFFD_FEATURE_WP_ASYNC"), when modifying mm/memory.c, an unknown line break is added to the very first line of the file. However, the git.kernel.org site displays the source code with the added line break removed, so even though addr2line has assigned the correct line number, it looks like the line number has increased by 1.
This may seem like a trivial thing, but I think it would be appropriate to remove all the newline characters added to the upstream and stable versions, as they are not only incorrect in terms of code style but also hinder bug analysis.
[1]
https://syzkaller.appspot.com/bug?extid=4145b11cdf925264bff4 https://syzkaller.appspot.com/bug?extid=fa43f1b63e3aa6f66329 https://syzkaller.appspot.com/bug?extid=890a1df7294175947697
Fixes: d61ea1cb0095 ("userfaultfd: UFFD_FEATURE_WP_ASYNC") Cc: stable@vger.kernel.org Signed-off-by: Jeongjun Park aha310510@gmail.com --- mm/memory.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/mm/memory.c b/mm/memory.c index 2366578015ad..7dffe8749014 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1,4 +1,3 @@ - // SPDX-License-Identifier: GPL-2.0-only /* * linux/mm/memory.c --
On Mon, Oct 07, 2024 at 03:53:07PM +0900, Jeongjun Park wrote:
Looking at the source code links for mm/memory.c in the sample reports in the syzbot report links [1].
it looks like the line numbers are designated as lines that have been increased by 1. This may seem like a problem with syzkaller or the addr2line program that assigns the line numbers, but there is no problem with either of them.
In the previous commit d61ea1cb0095 ("userfaultfd: UFFD_FEATURE_WP_ASYNC"), when modifying mm/memory.c, an unknown line break is added to the very first line of the file. However, the git.kernel.org site displays the source code with the added line break removed, so even though addr2line has assigned the correct line number, it looks like the line number has increased by 1.
This may seem like a trivial thing, but I think it would be appropriate to remove all the newline characters added to the upstream and stable versions, as they are not only incorrect in terms of code style but also hinder bug analysis.
[1]
https://syzkaller.appspot.com/bug?extid=4145b11cdf925264bff4 https://syzkaller.appspot.com/bug?extid=fa43f1b63e3aa6f66329 https://syzkaller.appspot.com/bug?extid=890a1df7294175947697
Fixes: d61ea1cb0095 ("userfaultfd: UFFD_FEATURE_WP_ASYNC") Cc: stable@vger.kernel.org Signed-off-by: Jeongjun Park aha310510@gmail.com
mm/memory.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/mm/memory.c b/mm/memory.c index 2366578015ad..7dffe8749014 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1,4 +1,3 @@
This sounds like you have broken tools that can not handle an empty line in a file.
Why not fix those?
Also, your changelog text has trailing whitespace, ironic for a patch that does a whitespace cleanup :)
thanks,
greg k-h
Greg KH gregkh@linuxfoundation.org wrote:
On Mon, Oct 07, 2024 at 03:53:07PM +0900, Jeongjun Park wrote:
Looking at the source code links for mm/memory.c in the sample reports in the syzbot report links [1].
it looks like the line numbers are designated as lines that have been increased by 1. This may seem like a problem with syzkaller or the addr2line program that assigns the line numbers, but there is no problem with either of them.
In the previous commit d61ea1cb0095 ("userfaultfd: UFFD_FEATURE_WP_ASYNC"), when modifying mm/memory.c, an unknown line break is added to the very first line of the file. However, the git.kernel.org site displays the source code with the added line break removed, so even though addr2line has assigned the correct line number, it looks like the line number has increased by 1.
This may seem like a trivial thing, but I think it would be appropriate to remove all the newline characters added to the upstream and stable versions, as they are not only incorrect in terms of code style but also hinder bug analysis.
[1]
https://syzkaller.appspot.com/bug?extid=4145b11cdf925264bff4 https://syzkaller.appspot.com/bug?extid=fa43f1b63e3aa6f66329 https://syzkaller.appspot.com/bug?extid=890a1df7294175947697
Fixes: d61ea1cb0095 ("userfaultfd: UFFD_FEATURE_WP_ASYNC") Cc: stable@vger.kernel.org Signed-off-by: Jeongjun Park aha310510@gmail.com
mm/memory.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/mm/memory.c b/mm/memory.c index 2366578015ad..7dffe8749014 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1,4 +1,3 @@
This sounds like you have broken tools that can not handle an empty line in a file.
Why not fix those?
As I mentioned above, there is no problem with addr2line's ability to parse the code line that called the function in the calltrace of the crash report.
However, when the source code of mm/memory.c is printed on the screen on the git.kernel.org site, the line break character that exists in the first line of the file is deleted and printed, so as a result, all code lines in the mm/memory.c file are located at line numbers that are -1 less than the actual line.
You can understand it easily if you compare the source code of mm/memory.c on github and git.kernel.org.
https://github.com/torvalds/linux/blob/master/mm/memory.c https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/mm/m...
Since I cannot modify the source code printing function of the git.kernel.org site, the best solution I can suggest is to remove the unnecessary line break character that exists in all versions.
Also, your changelog text has trailing whitespace, ironic for a patch that does a whitespace cleanup :)
Oops, I forgot to remove the trailing space in the patch description. If you absolutely must remove the space, I'll write a v2 patch and send it to you.
Regards, Jeongjun Park
thanks,
greg k-h
On Mon, Oct 07, 2024 at 05:57:18PM +0900, Jeongjun Park wrote:
Greg KH gregkh@linuxfoundation.org wrote:
On Mon, Oct 07, 2024 at 03:53:07PM +0900, Jeongjun Park wrote:
Looking at the source code links for mm/memory.c in the sample reports in the syzbot report links [1].
it looks like the line numbers are designated as lines that have been increased by 1. This may seem like a problem with syzkaller or the addr2line program that assigns the line numbers, but there is no problem with either of them.
In the previous commit d61ea1cb0095 ("userfaultfd: UFFD_FEATURE_WP_ASYNC"), when modifying mm/memory.c, an unknown line break is added to the very first line of the file. However, the git.kernel.org site displays the source code with the added line break removed, so even though addr2line has assigned the correct line number, it looks like the line number has increased by 1.
This may seem like a trivial thing, but I think it would be appropriate to remove all the newline characters added to the upstream and stable versions, as they are not only incorrect in terms of code style but also hinder bug analysis.
[1]
https://syzkaller.appspot.com/bug?extid=4145b11cdf925264bff4 https://syzkaller.appspot.com/bug?extid=fa43f1b63e3aa6f66329 https://syzkaller.appspot.com/bug?extid=890a1df7294175947697
Fixes: d61ea1cb0095 ("userfaultfd: UFFD_FEATURE_WP_ASYNC") Cc: stable@vger.kernel.org Signed-off-by: Jeongjun Park aha310510@gmail.com
mm/memory.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/mm/memory.c b/mm/memory.c index 2366578015ad..7dffe8749014 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1,4 +1,3 @@
This sounds like you have broken tools that can not handle an empty line in a file.
Why not fix those?
As I mentioned above, there is no problem with addr2line's ability to parse the code line that called the function in the calltrace of the crash report.
However, when the source code of mm/memory.c is printed on the screen on the git.kernel.org site, the line break character that exists in the first line of the file is deleted and printed, so as a result, all code lines in the mm/memory.c file are located at line numbers that are -1 less than the actual line.
You can understand it easily if you compare the source code of mm/memory.c on github and git.kernel.org.
https://github.com/torvalds/linux/blob/master/mm/memory.c https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/mm/m...
Since I cannot modify the source code printing function of the git.kernel.org site, the best solution I can suggest is to remove the unnecessary line break character that exists in all versions.
I would recommend fixing the git.kernel.org code, it is all open source and can be fixed up, as odds are other projects/repos would like to have it fixed as well.
thanks,
greg k-h
Greg KH gregkh@linuxfoundation.org wrote:
On Mon, Oct 07, 2024 at 05:57:18PM +0900, Jeongjun Park wrote:
Greg KH gregkh@linuxfoundation.org wrote:
On Mon, Oct 07, 2024 at 03:53:07PM +0900, Jeongjun Park wrote:
Looking at the source code links for mm/memory.c in the sample reports in the syzbot report links [1].
it looks like the line numbers are designated as lines that have been increased by 1. This may seem like a problem with syzkaller or the addr2line program that assigns the line numbers, but there is no problem with either of them.
In the previous commit d61ea1cb0095 ("userfaultfd: UFFD_FEATURE_WP_ASYNC"), when modifying mm/memory.c, an unknown line break is added to the very first line of the file. However, the git.kernel.org site displays the source code with the added line break removed, so even though addr2line has assigned the correct line number, it looks like the line number has increased by 1.
This may seem like a trivial thing, but I think it would be appropriate to remove all the newline characters added to the upstream and stable versions, as they are not only incorrect in terms of code style but also hinder bug analysis.
[1]
https://syzkaller.appspot.com/bug?extid=4145b11cdf925264bff4 https://syzkaller.appspot.com/bug?extid=fa43f1b63e3aa6f66329 https://syzkaller.appspot.com/bug?extid=890a1df7294175947697
Fixes: d61ea1cb0095 ("userfaultfd: UFFD_FEATURE_WP_ASYNC") Cc: stable@vger.kernel.org Signed-off-by: Jeongjun Park aha310510@gmail.com
mm/memory.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/mm/memory.c b/mm/memory.c index 2366578015ad..7dffe8749014 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1,4 +1,3 @@
This sounds like you have broken tools that can not handle an empty line in a file.
Why not fix those?
As I mentioned above, there is no problem with addr2line's ability to parse the code line that called the function in the calltrace of the crash report.
However, when the source code of mm/memory.c is printed on the screen on the git.kernel.org site, the line break character that exists in the first line of the file is deleted and printed, so as a result, all code lines in the mm/memory.c file are located at line numbers that are -1 less than the actual line.
You can understand it easily if you compare the source code of mm/memory.c on github and git.kernel.org.
https://github.com/torvalds/linux/blob/master/mm/memory.c https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/mm/m...
Since I cannot modify the source code printing function of the git.kernel.org site, the best solution I can suggest is to remove the unnecessary line break character that exists in all versions.
I would recommend fixing the git.kernel.org code, it is all open source and can be fixed up, as odds are other projects/repos would like to have it fixed as well.
Oh, I just realized that this website is open source and written in C.
This seems to be the correct git repository, so I'll commit here.
https://git.kernel.org/pub/scm/linux/kernel/git/zx2c4/cgit.git
Regards, Jeongjun Park
thanks,
greg k-h
On 10/7/24 4:24 PM, Jeongjun Park wrote:
Greg KH gregkh@linuxfoundation.org wrote:
On Mon, Oct 07, 2024 at 05:57:18PM +0900, Jeongjun Park wrote:
Greg KH gregkh@linuxfoundation.org wrote:
On Mon, Oct 07, 2024 at 03:53:07PM +0900, Jeongjun Park wrote:
Looking at the source code links for mm/memory.c in the sample reports in the syzbot report links [1].
it looks like the line numbers are designated as lines that have been increased by 1. This may seem like a problem with syzkaller or the addr2line program that assigns the line numbers, but there is no problem with either of them.
In the previous commit d61ea1cb0095 ("userfaultfd: UFFD_FEATURE_WP_ASYNC"), when modifying mm/memory.c, an unknown line break is added to the very first line of the file. However, the git.kernel.org site displays the source code with the added line break removed, so even though addr2line has assigned the correct line number, it looks like the line number has increased by 1.
This may seem like a trivial thing, but I think it would be appropriate to remove all the newline characters added to the upstream and stable versions, as they are not only incorrect in terms of code style but also hinder bug analysis.
[1]
https://syzkaller.appspot.com/bug?extid=4145b11cdf925264bff4 https://syzkaller.appspot.com/bug?extid=fa43f1b63e3aa6f66329 https://syzkaller.appspot.com/bug?extid=890a1df7294175947697
Fixes: d61ea1cb0095 ("userfaultfd: UFFD_FEATURE_WP_ASYNC") Cc: stable@vger.kernel.org Signed-off-by: Jeongjun Park aha310510@gmail.com
mm/memory.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/mm/memory.c b/mm/memory.c index 2366578015ad..7dffe8749014 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1,4 +1,3 @@
This sounds like you have broken tools that can not handle an empty line in a file.
Why not fix those?
As I mentioned above, there is no problem with addr2line's ability to parse the code line that called the function in the calltrace of the crash report.
However, when the source code of mm/memory.c is printed on the screen on the git.kernel.org site, the line break character that exists in the first line of the file is deleted and printed, so as a result, all code lines in the mm/memory.c file are located at line numbers that are -1 less than the actual line.
You can understand it easily if you compare the source code of mm/memory.c on github and git.kernel.org.
https://github.com/torvalds/linux/blob/master/mm/memory.c https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/mm/m...
Since I cannot modify the source code printing function of the git.kernel.org site, the best solution I can suggest is to remove the unnecessary line break character that exists in all versions.
I would recommend fixing the git.kernel.org code, it is all open source and can be fixed up, as odds are other projects/repos would like to have it fixed as well.
Oh, I just realized that this website is open source and written in C.
This seems to be the correct git repository, so I'll commit here.
https://git.kernel.org/pub/scm/linux/kernel/git/zx2c4/cgit.git
Get latest tag from https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/ instead.
https://kernelnewbies.org/FirstKernelPatch could be helpful in understanding some missing details.
Regards, Jeongjun Park
thanks,
greg k-h
On Mon, 7 Oct 2024 20:24:57 +0900 Jeongjun Park aha310510@gmail.com wrote:
Since I cannot modify the source code printing function of the git.kernel.org site, the best solution I can suggest is to remove the unnecessary line break character that exists in all versions.
I would recommend fixing the git.kernel.org code, it is all open source and can be fixed up, as odds are other projects/repos would like to have it fixed as well.
Oh, I just realized that this website is open source and written in C.
This seems to be the correct git repository, so I'll commit here.
https://git.kernel.org/pub/scm/linux/kernel/git/zx2c4/cgit.git
Still, we don't want that newline in there. I did this as a little cleanup. Please send a new (similar) patch if you're prefer.
From: Andrew Morton akpm@linux-foundation.org Subject: mm/memory.c: remove stray newline at top of file Date: Mon Oct 7 06:20:09 PM PDT 2024
Fixes: d61ea1cb0095 ("userfaultfd: UFFD_FEATURE_WP_ASYNC") Reported-by: Jeongjun Park aha310510@gmail.com Closes: https://lkml.kernel.org/r/20241007065307.4158-1-aha310510@gmail.com Cc: Muhammad Usama Anjum usama.anjum@collabora.com Cc: Peter Xu peterx@redhat.com Cc: Greg KH gregkh@linuxfoundation.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
mm/memory.c | 1 - 1 file changed, 1 deletion(-)
--- a/mm/memory.c~mm-memoryc-remove-stray-newline-at-top-of-file +++ a/mm/memory.c @@ -1,4 +1,3 @@ - // SPDX-License-Identifier: GPL-2.0-only /* * linux/mm/memory.c _
linux-stable-mirror@lists.linaro.org
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Andrew Morton -
Greg KH -
Jeongjun Park -
Muhammad Usama Anjum