<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/fs/binfmt_elf.c, branch v4.12</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.12</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.12'/>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/'/>
<updated>2017-03-02T07:42:39Z</updated>
<entry>
<title>sched/headers: Prepare to move cputime functionality from &lt;linux/sched.h&gt; into &lt;linux/sched/cputime.h&gt;</title>
<updated>2017-03-02T07:42:39Z</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2017-02-05T10:48:36Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=32ef5517c298042ed58408545f475df43afe1f24'/>
<id>urn:sha1:32ef5517c298042ed58408545f475df43afe1f24</id>
<content type='text'>
Introduce a trivial, mostly empty &lt;linux/sched/cputime.h&gt; header
to prepare for the moving of cputime functionality out of sched.h.

Update all code that relies on these facilities.

Acked-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
<entry>
<title>sched/headers: Prepare for new header dependencies before moving code to &lt;linux/sched/task_stack.h&gt;</title>
<updated>2017-03-02T07:42:36Z</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2017-02-08T17:51:37Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=68db0cf10678630d286f4bbbbdfa102951a35faa'/>
<id>urn:sha1:68db0cf10678630d286f4bbbbdfa102951a35faa</id>
<content type='text'>
We are going to split &lt;linux/sched/task_stack.h&gt; out of &lt;linux/sched.h&gt;, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder &lt;linux/sched/task_stack.h&gt; file that just
maps to &lt;linux/sched.h&gt; to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
<entry>
<title>sched/headers: Prepare to remove &lt;linux/cred.h&gt; inclusion from &lt;linux/sched.h&gt;</title>
<updated>2017-03-02T07:42:31Z</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2017-02-02T16:54:15Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=5b825c3af1d8a0af4deb4a5eb349d0d0050c62e5'/>
<id>urn:sha1:5b825c3af1d8a0af4deb4a5eb349d0d0050c62e5</id>
<content type='text'>
Add #include &lt;linux/cred.h&gt; dependencies to all .c files rely on sched.h
doing that for them.

Note that even if the count where we need to add extra headers seems high,
it's still a net win, because &lt;linux/sched.h&gt; is included in over
2,200 files ...

Acked-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
<entry>
<title>sched/headers: Prepare for new header dependencies before moving code to &lt;linux/sched/coredump.h&gt;</title>
<updated>2017-03-02T07:42:28Z</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2017-02-08T17:51:30Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=f7ccbae45c5e2c1077654b0e857e7efb1aa31c92'/>
<id>urn:sha1:f7ccbae45c5e2c1077654b0e857e7efb1aa31c92</id>
<content type='text'>
We are going to split &lt;linux/sched/coredump.h&gt; out of &lt;linux/sched.h&gt;, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder &lt;linux/sched/coredump.h&gt; file that just
maps to &lt;linux/sched.h&gt; to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
<entry>
<title>powerpc: do not make the entire heap executable</title>
<updated>2017-02-23T00:41:29Z</updated>
<author>
<name>Denys Vlasenko</name>
<email>dvlasenk@redhat.com</email>
</author>
<published>2017-02-22T23:45:16Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=16e72e9b30986ee15f17fbb68189ca842c32af58'/>
<id>urn:sha1:16e72e9b30986ee15f17fbb68189ca842c32af58</id>
<content type='text'>
On 32-bit powerpc the ELF PLT sections of binaries (built with
--bss-plt, or with a toolchain which defaults to it) look like this:

  [17] .sbss             NOBITS          0002aff8 01aff8 000014 00  WA  0   0  4
  [18] .plt              NOBITS          0002b00c 01aff8 000084 00 WAX  0   0  4
  [19] .bss              NOBITS          0002b090 01aff8 0000a4 00  WA  0   0  4

Which results in an ELF load header:

  Type           Offset   VirtAddr   PhysAddr   FileSiz MemSiz  Flg Align
  LOAD           0x019c70 0x00029c70 0x00029c70 0x01388 0x014c4 RWE 0x10000

This is all correct, the load region containing the PLT is marked as
executable.  Note that the PLT starts at 0002b00c but the file mapping
ends at 0002aff8, so the PLT falls in the 0 fill section described by
the load header, and after a page boundary.

Unfortunately the generic ELF loader ignores the X bit in the load
headers when it creates the 0 filled non-file backed mappings.  It
assumes all of these mappings are RW BSS sections, which is not the case
for PPC.

gcc/ld has an option (--secure-plt) to not do this, this is said to
incur a small performance penalty.

Currently, to support 32-bit binaries with PLT in BSS kernel maps
*entire brk area* with executable rights for all binaries, even
--secure-plt ones.

Stop doing that.

Teach the ELF loader to check the X bit in the relevant load header and
create 0 filled anonymous mappings that are executable if the load
header requests that.

Test program showing the difference in /proc/$PID/maps:

int main() {
	char buf[16*1024];
	char *p = malloc(123); /* make "[heap]" mapping appear */
	int fd = open("/proc/self/maps", O_RDONLY);
	int len = read(fd, buf, sizeof(buf));
	write(1, buf, len);
	printf("%p\n", p);
	return 0;
}

Compiled using: gcc -mbss-plt -m32 -Os test.c -otest

Unpatched ppc64 kernel:
00100000-00120000 r-xp 00000000 00:00 0                                  [vdso]
0fe10000-0ffd0000 r-xp 00000000 fd:00 67898094                           /usr/lib/libc-2.17.so
0ffd0000-0ffe0000 r--p 001b0000 fd:00 67898094                           /usr/lib/libc-2.17.so
0ffe0000-0fff0000 rw-p 001c0000 fd:00 67898094                           /usr/lib/libc-2.17.so
10000000-10010000 r-xp 00000000 fd:00 100674505                          /home/user/test
10010000-10020000 r--p 00000000 fd:00 100674505                          /home/user/test
10020000-10030000 rw-p 00010000 fd:00 100674505                          /home/user/test
10690000-106c0000 rwxp 00000000 00:00 0                                  [heap]
f7f70000-f7fa0000 r-xp 00000000 fd:00 67898089                           /usr/lib/ld-2.17.so
f7fa0000-f7fb0000 r--p 00020000 fd:00 67898089                           /usr/lib/ld-2.17.so
f7fb0000-f7fc0000 rw-p 00030000 fd:00 67898089                           /usr/lib/ld-2.17.so
ffa90000-ffac0000 rw-p 00000000 00:00 0                                  [stack]
0x10690008

Patched ppc64 kernel:
00100000-00120000 r-xp 00000000 00:00 0                                  [vdso]
0fe10000-0ffd0000 r-xp 00000000 fd:00 67898094                           /usr/lib/libc-2.17.so
0ffd0000-0ffe0000 r--p 001b0000 fd:00 67898094                           /usr/lib/libc-2.17.so
0ffe0000-0fff0000 rw-p 001c0000 fd:00 67898094                           /usr/lib/libc-2.17.so
10000000-10010000 r-xp 00000000 fd:00 100674505                          /home/user/test
10010000-10020000 r--p 00000000 fd:00 100674505                          /home/user/test
10020000-10030000 rw-p 00010000 fd:00 100674505                          /home/user/test
10180000-101b0000 rw-p 00000000 00:00 0                                  [heap]
                  ^^^^ this has changed
f7c60000-f7c90000 r-xp 00000000 fd:00 67898089                           /usr/lib/ld-2.17.so
f7c90000-f7ca0000 r--p 00020000 fd:00 67898089                           /usr/lib/ld-2.17.so
f7ca0000-f7cb0000 rw-p 00030000 fd:00 67898089                           /usr/lib/ld-2.17.so
ff860000-ff890000 rw-p 00000000 00:00 0                                  [stack]
0x10180008

The patch was originally posted in 2012 by Jason Gunthorpe
and apparently ignored:

https://lkml.org/lkml/2012/9/30/138

Lightly run-tested.

Link: http://lkml.kernel.org/r/20161215131950.23054-1-dvlasenk@redhat.com
Signed-off-by: Jason Gunthorpe &lt;jgunthorpe@obsidianresearch.com&gt;
Signed-off-by: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Tested-by: Jason Gunthorpe &lt;jgunthorpe@obsidianresearch.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: "Aneesh Kumar K.V" &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Florian Weimer &lt;fweimer@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>fs/binfmt: Convert obsolete cputime type to nsecs</title>
<updated>2017-02-01T08:13:51Z</updated>
<author>
<name>Frederic Weisbecker</name>
<email>fweisbec@gmail.com</email>
</author>
<published>2017-01-31T03:09:27Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=cd19c364b313c179410fcac8376330964cc9bfd9'/>
<id>urn:sha1:cd19c364b313c179410fcac8376330964cc9bfd9</id>
<content type='text'>
Use the new nsec based cputime accessors as part of the whole cputime
conversion from cputime_t to nsecs.

Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Rik van Riel &lt;riel@redhat.com&gt;
Cc: Stanislaw Gruszka &lt;sgruszka@redhat.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Wanpeng Li &lt;wanpeng.li@hotmail.com&gt;
Link: http://lkml.kernel.org/r/1485832191-26889-12-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
<entry>
<title>sched/cputime: Convert task/group cputime to nsecs</title>
<updated>2017-02-01T08:13:49Z</updated>
<author>
<name>Frederic Weisbecker</name>
<email>fweisbec@gmail.com</email>
</author>
<published>2017-01-31T03:09:23Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=5613fda9a503cd6137b120298902a34a1386b2c1'/>
<id>urn:sha1:5613fda9a503cd6137b120298902a34a1386b2c1</id>
<content type='text'>
Now that most cputime readers use the transition API which return the
task cputime in old style cputime_t, we can safely store the cputime in
nsecs. This will eventually make cputime statistics less opaque and more
granular. Back and forth convertions between cputime_t and nsecs in order
to deal with cputime_t random granularity won't be needed anymore.

Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Rik van Riel &lt;riel@redhat.com&gt;
Cc: Stanislaw Gruszka &lt;sgruszka@redhat.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Wanpeng Li &lt;wanpeng.li@hotmail.com&gt;
Link: http://lkml.kernel.org/r/1485832191-26889-8-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
<entry>
<title>sched/cputime: Introduce special task_cputime_t() API to return old-typed cputime</title>
<updated>2017-02-01T08:13:48Z</updated>
<author>
<name>Frederic Weisbecker</name>
<email>fweisbec@gmail.com</email>
</author>
<published>2017-01-31T03:09:22Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=a1cecf2ba78e0a6de00ff99df34b662728535aa5'/>
<id>urn:sha1:a1cecf2ba78e0a6de00ff99df34b662728535aa5</id>
<content type='text'>
This API returns a task's cputime in cputime_t in order to ease the
conversion of cputime internals to use nsecs units instead. Blindly
converting all cputime readers to use this API now will later let us
convert more smoothly and step by step all these places to use the
new nsec based cputime.

Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Rik van Riel &lt;riel@redhat.com&gt;
Cc: Stanislaw Gruszka &lt;sgruszka@redhat.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Wanpeng Li &lt;wanpeng.li@hotmail.com&gt;
Link: http://lkml.kernel.org/r/1485832191-26889-7-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
<entry>
<title>coredump: Ensure proper size of sparse core files</title>
<updated>2017-01-15T00:32:40Z</updated>
<author>
<name>Dave Kleikamp</name>
<email>dave.kleikamp@oracle.com</email>
</author>
<published>2017-01-11T19:25:00Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=4d22c75d4c7b5c5f4bd31054f09103ee490878fd'/>
<id>urn:sha1:4d22c75d4c7b5c5f4bd31054f09103ee490878fd</id>
<content type='text'>
If the last section of a core file ends with an unmapped or zero page,
the size of the file does not correspond with the last dump_skip() call.
gdb complains that the file is truncated and can be confusing to users.

After all of the vma sections are written, make sure that the file size
is no smaller than the current file position.

This problem can be demonstrated with gdb's bigcore testcase on the
sparc architecture.

Signed-off-by: Dave Kleikamp &lt;dave.kleikamp@oracle.com&gt;
Cc: Alexander Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
</entry>
<entry>
<title>Replace &lt;asm/uaccess.h&gt; with &lt;linux/uaccess.h&gt; globally</title>
<updated>2016-12-24T19:46:01Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-12-24T19:46:01Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=7c0f6ba682b9c7632072ffbedf8d328c8f3c42ba'/>
<id>urn:sha1:7c0f6ba682b9c7632072ffbedf8d328c8f3c42ba</id>
<content type='text'>
This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*&lt;asm/uaccess.h&gt;'
  sed -i -e "s!$PATT!#include &lt;linux/uaccess.h&gt;!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
</feed>
