linux-stable.git/arch/parisc/kernel/vmlinux.lds.S, branch linux-4.8.y Linux kernel stable tree parisc: Fix kernel memory layout regarding position of __gp 2016-10-28T07:45:20+00:00 Helge Deller deller@gmx.de 2016-10-09T09:12:34+00:00 5112972e37079b54fbee64d35015d70e28576474 commit f8850abb7ba68229838014b3409460e576751c6d upstream. Architecturally we need to keep __gp below 0x1000000. But because of ftrace and tracepoint support, the RO_DATA_SECTION now gets much bigger than it was before. By moving the linkage tables before RO_DATA_SECTION we can avoid that __gp gets positioned at a too high address. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f8850abb7ba68229838014b3409460e576751c6d upstream.

Architecturally we need to keep __gp below 0x1000000.

But because of ftrace and tracepoint support, the RO_DATA_SECTION now gets much
bigger than it was before. By moving the linkage tables before RO_DATA_SECTION
we can avoid that __gp gets positioned at a too high address.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections 2016-03-25T23:37:42+00:00 Alexander Potapenko glider@google.com 2016-03-25T21:22:05+00:00 be7635e7287e0e8013af3c89a6354a9e0182594c KASAN needs to know whether the allocation happens in an IRQ handler. This lets us strip everything below the IRQ entry point to reduce the number of unique stack traces needed to be stored. Move the definition of __irq_entry to <linux/interrupt.h> so that the users don't need to pull in <linux/ftrace.h>. Also introduce the __softirq_entry macro which is similar to __irq_entry, but puts the corresponding functions to the .softirqentry.text section. Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
KASAN needs to know whether the allocation happens in an IRQ handler.
This lets us strip everything below the IRQ entry point to reduce the
number of unique stack traces needed to be stored.

Move the definition of __irq_entry to <linux/interrupt.h> so that the
users don't need to pull in <linux/ftrace.h>.  Also introduce the
__softirq_entry macro which is similar to __irq_entry, but puts the
corresponding functions to the .softirqentry.text section.

Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
parisc: Map kernel text and data on huge pages 2015-11-22T11:23:19+00:00 Helge Deller deller@gmx.de 2015-11-21T23:07:44+00:00 41b85a1163386f8328ad570f383973cb3975d2fa Adjust the linker script and map_pages() to map kernel text and data on physical 1MB huge/large pages. Signed-off-by: Helge Deller <deller@gmx.de> 
Adjust the linker script and map_pages() to map kernel text and data on
physical 1MB huge/large pages.

Signed-off-by: Helge Deller <deller@gmx.de>
parisc: fix kernel memory layout in vmlinux.ld.S 2013-11-30T21:09:21+00:00 Helge Deller deller@gmx.de 2013-11-30T21:07:51+00:00 161bd3bf60ee2c5765455ad3e3da967d03449f4a When building a 64bit kernel sometimes functions in the .init section were not able to reach the standard kernel function. Main reason for this problem is, that the linkage tables (.plt, .opd, .dlt) tend to become pretty huge and thus the distance gets too big for short calls. One option to avoid this is to use the -mlong-calls compiler option, but this increases the binary size and introduces a performance penalty. Instead, with this patch we just lay out the binary differently. Init code is stored first, followed by text, R/O and finally R/W data. This means, that init and text code is now much closer to each other, which is sufficient to reach each other by short calls. Signed-off-by: Helge Deller <deller@gmx.de> 
When building a 64bit kernel sometimes functions in the .init section were not
able to reach the standard kernel function. Main reason for this problem is,
that the linkage tables (.plt, .opd, .dlt) tend to become pretty huge and thus
the distance gets too big for short calls.

One option to avoid this is to use the -mlong-calls compiler option, but this
increases the binary size and introduces a performance penalty.

Instead, with this patch we just lay out the binary differently.  Init code is
stored first, followed by text, R/O and finally R/W data. This means, that init
and text code is now much closer to each other, which is sufficient to reach
each other by short calls.

Signed-off-by: Helge Deller <deller@gmx.de>
parisc: add kernel stack overflow check 2013-05-07T19:34:07+00:00 Helge Deller deller@gmx.de 2013-05-07T19:28:52+00:00 9372450cc22d185f708e5cc3557cf991be4b7dc5 Add the CONFIG_DEBUG_STACKOVERFLOW config option to enable checks to detect kernel stack overflows. Stack overflows can not be detected reliable since we do not want to introduce too much overhead. Instead, during irq processing in do_cpu_irq_mask() we check kernel stack usage of the interrupted kernel process. Kernel threads can be easily detected by checking the value of space register 7 (sr7) which is zero when running inside the kernel. Since THREAD_SIZE is 16k and PAGE_SIZE is 4k, reduce the alignment of the init thread to the lower value (PAGE_SIZE) in the kernel vmlinux.ld.S linker script. Signed-off-by: Helge Deller <deller@gmx.de> 
Add the CONFIG_DEBUG_STACKOVERFLOW config option to enable checks to
detect kernel stack overflows.

Stack overflows can not be detected reliable since we do not want to
introduce too much overhead.

Instead, during irq processing in do_cpu_irq_mask() we check kernel
stack usage of the interrupted kernel process. Kernel threads can be
easily detected by checking the value of space register 7 (sr7) which
is zero when running inside the kernel.

Since THREAD_SIZE is 16k and PAGE_SIZE is 4k, reduce the alignment of
the init thread to the lower value (PAGE_SIZE) in the kernel
vmlinux.ld.S linker script.

Signed-off-by: Helge Deller <deller@gmx.de>
[PARISC] fix boot failure on 32-bit systems caused by branch stubs placed before .text 2012-05-25T09:52:17+00:00 John David Anglin dave.anglin@bell.net 2012-05-17T14:34:34+00:00 ed5fb2471b7060767957fb964eb1aaec71533ab1 In certain configurations, the resulting kernel becomes too large to boot because the linker places the long branch stubs for the merged .text section at the very start of the image. As a result, the initial transfer of control jumps to an unexpected location. Fix this by placing the head text in a separate section so the stubs for .text are not at the start of the image. Signed-off-by: John David Anglin <dave.anglin@bell.net> Cc: stable@vger.kernel.org Signed-off-by: James Bottomley <JBottomley@Parallels.com> 
In certain configurations, the resulting kernel becomes too large to boot
because the linker places the long branch stubs for the merged .text section
at the very start of the image.  As a result, the initial transfer of control
jumps to an unexpected location.  Fix this by placing the head text in a
separate section so the stubs for .text are not at the start of the image.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Merge branch 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-05-24T18:53:42+00:00 Linus Torvalds torvalds@linux-foundation.org 2011-05-24T18:53:42+00:00 5129df03d0c44b2d5a5f9d7d52f3b079706b9a8f * 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu: Unify input section names percpu: Avoid extra NOP in percpu_cmpxchg16b_double percpu: Cast away printk format warning percpu: Always align percpu output section to PAGE_SIZE Fix up fairly trivial conflict in arch/x86/include/asm/percpu.h as per Tejun 
* 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: Unify input section names
  percpu: Avoid extra NOP in percpu_cmpxchg16b_double
  percpu: Cast away printk format warning
  percpu: Always align percpu output section to PAGE_SIZE

Fix up fairly trivial conflict in arch/x86/include/asm/percpu.h as per Tejun
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/parisc-2.6 2011-05-22T19:38:40+00:00 Linus Torvalds torvalds@linux-foundation.org 2011-05-22T19:38:40+00:00 17238005f377888b9d4583835205c77e3d781bb8 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/parisc-2.6: [PARISC] wire up syncfs syscall [PARISC] wire up the fhandle syscalls [PARISC] wire up clock_adjtime syscall [PARISC] wire up fanotify syscalls [PARISC] prevent speculative re-read on cache flush [PARISC] only make executable areas executable [PARISC] fix pacache .size with new binutils 
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/parisc-2.6:
  [PARISC] wire up syncfs syscall
  [PARISC] wire up the fhandle syscalls
  [PARISC] wire up clock_adjtime syscall
  [PARISC] wire up fanotify syscalls
  [PARISC] prevent speculative re-read on cache flush
  [PARISC] only make executable areas executable
  [PARISC] fix pacache .size with new binutils
extable, core_kernel_data(): Make sure all archs define _sdata 2011-05-20T06:56:56+00:00 Steven Rostedt rostedt@goodmis.org 2011-05-20T01:34:58+00:00 a2d063ac216c1618bfc2b4d40b7176adffa63511 A new utility function (core_kernel_data()) is used to determine if a passed in address is part of core kernel data or not. It may or may not return true for RO data, but this utility must work for RW data. Thus both _sdata and _edata must be defined and continuous, without .init sections that may later be freed and replaced by volatile memory (memory that can be freed). This utility function is used to determine if data is safe from ever being freed. Thus it should return true for all RW global data that is not in a module or has been allocated, or false otherwise. Also change core_kernel_data() back to the more precise _sdata condition and document the function. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Ralf Baechle <ralf@linux-mips.org> Acked-by: Hirokazu Takata <takata@linux-m32r.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: linux-m68k@lists.linux-m68k.org Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Helge Deller <deller@gmx.de> Cc: JamesE.J.Bottomley <jejb@parisc-linux.org> Link: http://lkml.kernel.org/r/1305855298.1465.19.camel@gandalf.stny.rr.com Signed-off-by: Ingo Molnar <mingo@elte.hu> ---- arch/alpha/kernel/vmlinux.lds.S | 1 + arch/m32r/kernel/vmlinux.lds.S | 1 + arch/m68k/kernel/vmlinux-std.lds | 2 ++ arch/m68k/kernel/vmlinux-sun3.lds | 1 + arch/mips/kernel/vmlinux.lds.S | 1 + arch/parisc/kernel/vmlinux.lds.S | 3 +++ kernel/extable.c | 12 +++++++++++- 7 files changed, 20 insertions(+), 1 deletion(-) 
A new utility function (core_kernel_data()) is used to determine if a
passed in address is part of core kernel data or not. It may or may not
return true for RO data, but this utility must work for RW data.

Thus both _sdata and _edata must be defined and continuous,
without .init sections that may later be freed and replaced by
volatile memory (memory that can be freed).

This utility function is used to determine if data is safe from
ever being freed. Thus it should return true for all RW global
data that is not in a module or has been allocated, or false
otherwise.

Also change core_kernel_data() back to the more precise _sdata condition
and document the function.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Hirokazu Takata <takata@linux-m32r.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: linux-m68k@lists.linux-m68k.org
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Cc: JamesE.J.Bottomley <jejb@parisc-linux.org>
Link: http://lkml.kernel.org/r/1305855298.1465.19.camel@gandalf.stny.rr.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
----
 arch/alpha/kernel/vmlinux.lds.S   |    1 +
 arch/m32r/kernel/vmlinux.lds.S    |    1 +
 arch/m68k/kernel/vmlinux-std.lds  |    2 ++
 arch/m68k/kernel/vmlinux-sun3.lds |    1 +
 arch/mips/kernel/vmlinux.lds.S    |    1 +
 arch/parisc/kernel/vmlinux.lds.S  |    3 +++
 kernel/extable.c                  |   12 +++++++++++-
 7 files changed, 20 insertions(+), 1 deletion(-)
[PARISC] only make executable areas executable 2011-04-15T17:55:18+00:00 James Bottomley James.Bottomley@HansenPartnership.com 2011-04-14T23:25:21+00:00 d7dd2ff11b7fcd425aca5a875983c862d19a67ae Currently parisc has the whole kernel marked as RWX, meaning any kernel page at all is eligible to be executed. This can cause a theoretical problem on systems with combined I/D TLB because the act of referencing a page causes a TLB insertion with an executable bit. This TLB entry may be used by the CPU as the basis for speculating the page into the I-Cache. If this speculated page is subsequently used for a user process, there is the possibility we will get a stale I-cache line picked up as the binary executes. As a point of good practise, only mark actual kernel text pages as executable. The same has to be done for init_text pages, but they're converted to data pages (and the I-Cache flushed) when the init memory is released. Signed-off-by: James Bottomley <James.Bottomley@suse.de> 
Currently parisc has the whole kernel marked as RWX, meaning any
kernel page at all is eligible to be executed.  This can cause a
theoretical problem on systems with combined I/D TLB because the act
of referencing a page causes a TLB insertion with an executable bit.
This TLB entry may be used by the CPU as the basis for speculating the
page into the I-Cache.  If this speculated page is subsequently used
for a user process, there is the possibility we will get a stale
I-cache line picked up as the binary executes.

As a point of good practise, only mark actual kernel text pages as
executable.  The same has to be done for init_text pages, but they're
converted to data pages (and the I-Cache flushed) when the init memory
is released.

Signed-off-by: James Bottomley <James.Bottomley@suse.de>