linux-toradex.git/arch/parisc/include, branch v4.1.26 Linux kernel for Apalis and Colibri modules parisc: Unbreak handling exceptions from kernel modules 2016-04-20T05:08:54+00:00 Helge Deller deller@gmx.de 2016-04-08T16:32:52+00:00 e213cce42b7107f64521eb1434e9dd5637ad777b [ Upstream commit 2ef4dfd9d9f288943e249b78365a69e3ea3ec072 ] Handling exceptions from modules never worked on parisc. It was just masked by the fact that exceptions from modules don't happen during normal use. When a module triggers an exception in get_user() we need to load the main kernel dp value before accessing the exception_data structure, and afterwards restore the original dp value of the module on exit. Noticed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin <sasha.levin@oracle.com> 
[ Upstream commit 2ef4dfd9d9f288943e249b78365a69e3ea3ec072 ]

Handling exceptions from modules never worked on parisc.
It was just masked by the fact that exceptions from modules
don't happen during normal use.

When a module triggers an exception in get_user() we need to load the
main kernel dp value before accessing the exception_data structure, and
afterwards restore the original dp value of the module on exit.

Noticed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
parisc: Fix __ARCH_SI_PREAMBLE_SIZE 2016-02-03T20:31:09+00:00 Helge Deller deller@gmx.de 2016-01-10T08:30:42+00:00 35a317f44dbf18460282a9c4d0d74480f5c3f7b2 [ Upstream commit e60fc5aa608eb38b47ba4ee058f306f739eb70a0 ] On a 64bit kernel build the compiler aligns the _sifields union in the struct siginfo_t on a 64bit address. The __ARCH_SI_PREAMBLE_SIZE define compensates for this alignment and thus fixes the wait testcase of the strace package. The symptoms of a wrong __ARCH_SI_PREAMBLE_SIZE value is that _sigchld.si_stime variable is missed to be copied and thus after a copy_siginfo() will have uninitialized values. Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin <sasha.levin@oracle.com> 
[ Upstream commit e60fc5aa608eb38b47ba4ee058f306f739eb70a0 ]

On a 64bit kernel build the compiler aligns the _sifields union in the
struct siginfo_t on a 64bit address. The __ARCH_SI_PREAMBLE_SIZE define
compensates for this alignment and thus fixes the wait testcase of the
strace package.

The symptoms of a wrong __ARCH_SI_PREAMBLE_SIZE value is that
_sigchld.si_stime variable is missed to be copied and thus after a
copy_siginfo() will have uninitialized values.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
parisc: mm: Fix a memory leak related to pmd not attached to the pgd 2015-08-10T19:21:50+00:00 Christophe Jaillet christophe.jaillet@wanadoo.fr 2015-07-13T09:32:43+00:00 0ab58712e54f3a3258072feb15ab14bfbc42fa02 commit 4c4ac9a48ac512c6b5a6cca06cfad2ad96e8caaa upstream. Commit 0e0da48dee8d ("parisc: mm: don't count preallocated pmds") introduced a memory leak. After this commit, the 'return' statement in pmd_free is executed in all cases. Even for pmd that are not attached to the pgd. So 'free_pages' can never be called anymore, leading to a memory leak. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Helge Deller <deller@gmx.de> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4c4ac9a48ac512c6b5a6cca06cfad2ad96e8caaa upstream.

Commit 0e0da48dee8d ("parisc: mm: don't count preallocated pmds")
introduced a memory leak.

After this commit, the 'return' statement in pmd_free is executed in all
cases. Even for pmd that are not attached to the pgd.  So 'free_pages'
can never be called anymore, leading to a memory leak.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
parisc: Fix some PTE/TLB race conditions and optimize __flush_tlb_range based on timing results 2015-08-10T19:21:50+00:00 John David Anglin dave.anglin@bell.net 2015-07-01T21:18:37+00:00 78eb5efb6f79ca8fbd03cd0082e6bb22ca37fb48 commit 01ab60570427caa24b9debc369e452e86cd9beb4 upstream. The increased use of pdtlb/pitlb instructions seemed to increase the frequency of random segmentation faults building packages. Further, we had a number of cases where TLB inserts would repeatedly fail and all forward progress would stop. The Haskell ghc package caused a lot of trouble in this area. The final indication of a race in pte handling was this syslog entry on sibaris (C8000): swap_free: Unused swap offset entry 00000004 BUG: Bad page map in process mysqld pte:00000100 pmd:019bbec5 addr:00000000ec464000 vm_flags:00100073 anon_vma:0000000221023828 mapping: (null) index:ec464 CPU: 1 PID: 9176 Comm: mysqld Not tainted 4.0.0-2-parisc64-smp #1 Debian 4.0.5-1 Backtrace: [<0000000040173eb0>] show_stack+0x20/0x38 [<0000000040444424>] dump_stack+0x9c/0x110 [<00000000402a0d38>] print_bad_pte+0x1a8/0x278 [<00000000402a28b8>] unmap_single_vma+0x3d8/0x770 [<00000000402a4090>] zap_page_range+0xf0/0x198 [<00000000402ba2a4>] SyS_madvise+0x404/0x8c0 Note that the pte value is 0 except for the accessed bit 0x100. This bit shouldn't be set without the present bit. It should be noted that the madvise system call is probably a trigger for many of the random segmentation faults. In looking at the kernel code, I found the following problems: 1) The pte_clear define didn't take TLB lock when clearing a pte. 2) We didn't test pte present bit inside lock in exception support. 3) The pte and tlb locks needed to merged in order to ensure consistency between page table and TLB. This also has the effect of serializing TLB broadcasts on SMP systems. The attached change implements the above and a few other tweaks to try to improve performance. Based on the timing code, TLB purges are very slow (e.g., ~ 209 cycles per page on rp3440). Thus, I think it beneficial to test the split_tlb variable to avoid duplicate purges. Probably, all PA 2.0 machines have combined TLBs. I dropped using __flush_tlb_range in flush_tlb_mm as I realized all applications and most threads have a stack size that is too large to make this useful. I added some comments to this effect. Since implementing 1 through 3, I haven't had any random segmentation faults on mx3210 (rp3440) in about one week of building code and running as a Debian buildd. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 01ab60570427caa24b9debc369e452e86cd9beb4 upstream.

The increased use of pdtlb/pitlb instructions seemed to increase the
frequency of random segmentation faults building packages. Further, we
had a number of cases where TLB inserts would repeatedly fail and all
forward progress would stop. The Haskell ghc package caused a lot of
trouble in this area. The final indication of a race in pte handling was
this syslog entry on sibaris (C8000):

 swap_free: Unused swap offset entry 00000004
 BUG: Bad page map in process mysqld  pte:00000100 pmd:019bbec5
 addr:00000000ec464000 vm_flags:00100073 anon_vma:0000000221023828 mapping: (null) index:ec464
 CPU: 1 PID: 9176 Comm: mysqld Not tainted 4.0.0-2-parisc64-smp #1 Debian 4.0.5-1
 Backtrace:
  [<0000000040173eb0>] show_stack+0x20/0x38
  [<0000000040444424>] dump_stack+0x9c/0x110
  [<00000000402a0d38>] print_bad_pte+0x1a8/0x278
  [<00000000402a28b8>] unmap_single_vma+0x3d8/0x770
  [<00000000402a4090>] zap_page_range+0xf0/0x198
  [<00000000402ba2a4>] SyS_madvise+0x404/0x8c0

Note that the pte value is 0 except for the accessed bit 0x100. This bit
shouldn't be set without the present bit.

It should be noted that the madvise system call is probably a trigger for many
of the random segmentation faults.

In looking at the kernel code, I found the following problems:

1) The pte_clear define didn't take TLB lock when clearing a pte.
2) We didn't test pte present bit inside lock in exception support.
3) The pte and tlb locks needed to merged in order to ensure consistency
between page table and TLB. This also has the effect of serializing TLB
broadcasts on SMP systems.

The attached change implements the above and a few other tweaks to try
to improve performance. Based on the timing code, TLB purges are very
slow (e.g., ~ 209 cycles per page on rp3440). Thus, I think it
beneficial to test the split_tlb variable to avoid duplicate purges.
Probably, all PA 2.0 machines have combined TLBs.

I dropped using __flush_tlb_range in flush_tlb_mm as I realized all
applications and most threads have a stack size that is too large to
make this useful. I added some comments to this effect.

Since implementing 1 through 3, I haven't had any random segmentation
faults on mx3210 (rp3440) in about one week of building code and running
as a Debian buildd.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
parisc,metag: Fix crashes due to stack randomization on stack-grows-upwards architectures 2015-05-12T20:03:44+00:00 Helge Deller deller@gmx.de 2015-05-11T20:01:27+00:00 d045c77c1a69703143a36169c224429c48b9eecd On architectures where the stack grows upwards (CONFIG_STACK_GROWSUP=y, currently parisc and metag only) stack randomization sometimes leads to crashes when the stack ulimit is set to lower values than STACK_RND_MASK (which is 8 MB by default if not defined in arch-specific headers). The problem is, that when the stack vm_area_struct is set up in fs/exec.c, the additional space needed for the stack randomization (as defined by the value of STACK_RND_MASK) was not taken into account yet and as such, when the stack randomization code added a random offset to the stack start, the stack effectively got smaller than what the user defined via rlimit_max(RLIMIT_STACK) which then sometimes leads to out-of-stack situations and crashes. This patch fixes it by adding the maximum possible amount of memory (based on STACK_RND_MASK) which theoretically could be added by the stack randomization code to the initial stack size. That way, the user-defined stack size is always guaranteed to be at minimum what is defined via rlimit_max(RLIMIT_STACK). This bug is currently not visible on the metag architecture, because on metag STACK_RND_MASK is defined to 0 which effectively disables stack randomization. The changes to fs/exec.c are inside an "#ifdef CONFIG_STACK_GROWSUP" section, so it does not affect other platformws beside those where the stack grows upwards (parisc and metag). Signed-off-by: Helge Deller <deller@gmx.de> Cc: linux-parisc@vger.kernel.org Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-metag@vger.kernel.org Cc: stable@vger.kernel.org # v3.16+ 
On architectures where the stack grows upwards (CONFIG_STACK_GROWSUP=y,
currently parisc and metag only) stack randomization sometimes leads to crashes
when the stack ulimit is set to lower values than STACK_RND_MASK (which is 8 MB
by default if not defined in arch-specific headers).

The problem is, that when the stack vm_area_struct is set up in fs/exec.c, the
additional space needed for the stack randomization (as defined by the value of
STACK_RND_MASK) was not taken into account yet and as such, when the stack
randomization code added a random offset to the stack start, the stack
effectively got smaller than what the user defined via rlimit_max(RLIMIT_STACK)
which then sometimes leads to out-of-stack situations and crashes.

This patch fixes it by adding the maximum possible amount of memory (based on
STACK_RND_MASK) which theoretically could be added by the stack randomization
code to the initial stack size. That way, the user-defined stack size is always
guaranteed to be at minimum what is defined via rlimit_max(RLIMIT_STACK).

This bug is currently not visible on the metag architecture, because on metag
STACK_RND_MASK is defined to 0 which effectively disables stack randomization.

The changes to fs/exec.c are inside an "#ifdef CONFIG_STACK_GROWSUP"
section, so it does not affect other platformws beside those where the
stack grows upwards (parisc and metag).

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-metag@vger.kernel.org
Cc: stable@vger.kernel.org # v3.16+
parisc: Replace PT_NLEVELS with CONFIG_PGTABLE_LEVELS 2015-04-21T20:04:03+00:00 Guenter Roeck linux@roeck-us.net 2015-04-15T20:34:28+00:00 c19edb6946d250db6d4a3dbd6146f7b23bf3468b The following warning is seen when compiling parisc images ./arch/parisc/include/asm/pgalloc.h: In function 'pgd_alloc': ./arch/parisc/include/asm/pgalloc.h:29:5: warning: "PT_NLEVELS" is not defined Some definitions of PT_NLEVELS were missed with the conversion to CONFIG_PGTABLE_LEVELS. Fixes: f24ffde43237 ("parisc: expose number of page table levels on Kconfig level") Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Helge Deller <deller@gmx.de> 
The following warning is seen when compiling parisc images

./arch/parisc/include/asm/pgalloc.h: In function 'pgd_alloc':
./arch/parisc/include/asm/pgalloc.h:29:5: warning: "PT_NLEVELS" is not defined

Some definitions of PT_NLEVELS were missed with the conversion to
CONFIG_PGTABLE_LEVELS.

Fixes: f24ffde43237 ("parisc: expose number of page table levels
	on Kconfig level")
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Helge Deller <deller@gmx.de>
parisc: Eliminate sg_virt_addr() and private scatterlist.h 2015-04-21T20:02:43+00:00 Matthew Wilcox willy@linux.intel.com 2015-03-20T17:37:59+00:00 8bf8a1d1c13c687eda599c827d713eb70764a79f The only reason to keep parisc's private asm/scatterlist.h was that it had the macro sg_virt_addr(). Convert all callers to use something else (sometimes just sg->offset was enough, others should use sg_virt()), and we can just use the asm-generic scatterlist.h instead. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Dave Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> 
The only reason to keep parisc's private asm/scatterlist.h was that it
had the macro sg_virt_addr().  Convert all callers to use something else
(sometimes just sg->offset was enough, others should use sg_virt()), and
we can just use the asm-generic scatterlist.h instead.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Dave Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
parisc: switch to using asm-generic for seccomp.h 2015-04-17T13:04:10+00:00 Kees Cook keescook@chromium.org 2015-04-16T19:48:55+00:00 cf7a71b602fe2255b5b42162fa39a3090a1ea2c7 Switch to using the newly created asm-generic/seccomp.h for the seccomp strict mode syscall definitions. Definitions were identical. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Switch to using the newly created asm-generic/seccomp.h for the seccomp
strict mode syscall definitions. Definitions were identical.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge branch 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc 2015-04-15T20:53:55+00:00 Linus Torvalds torvalds@linux-foundation.org 2015-04-15T20:53:55+00:00 fa2e5c073a355465a2a8c9a2fbecf404f9857c3a Pull exec domain removal from Richard Weinberger: "This series removes execution domain support from Linux. The idea behind exec domains was to support different ABIs. The feature was never complete nor stable. Let's rip it out and make the kernel signal handling code less complicated" * 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc: (27 commits) arm64: Removed unused variable sparc: Fix execution domain removal Remove rest of exec domains. arch: Remove exec_domain from remaining archs arc: Remove signal translation and exec_domain xtensa: Remove signal translation and exec_domain xtensa: Autogenerate offsets in struct thread_info x86: Remove signal translation and exec_domain unicore32: Remove signal translation and exec_domain um: Remove signal translation and exec_domain tile: Remove signal translation and exec_domain sparc: Remove signal translation and exec_domain sh: Remove signal translation and exec_domain s390: Remove signal translation and exec_domain mn10300: Remove signal translation and exec_domain microblaze: Remove signal translation and exec_domain m68k: Remove signal translation and exec_domain m32r: Remove signal translation and exec_domain m32r: Autogenerate offsets in struct thread_info frv: Remove signal translation and exec_domain ... 
Pull exec domain removal from Richard Weinberger:
 "This series removes execution domain support from Linux.

  The idea behind exec domains was to support different ABIs.  The
  feature was never complete nor stable.  Let's rip it out and make the
  kernel signal handling code less complicated"

* 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc: (27 commits)
  arm64: Removed unused variable
  sparc: Fix execution domain removal
  Remove rest of exec domains.
  arch: Remove exec_domain from remaining archs
  arc: Remove signal translation and exec_domain
  xtensa: Remove signal translation and exec_domain
  xtensa: Autogenerate offsets in struct thread_info
  x86: Remove signal translation and exec_domain
  unicore32: Remove signal translation and exec_domain
  um: Remove signal translation and exec_domain
  tile: Remove signal translation and exec_domain
  sparc: Remove signal translation and exec_domain
  sh: Remove signal translation and exec_domain
  s390: Remove signal translation and exec_domain
  mn10300: Remove signal translation and exec_domain
  microblaze: Remove signal translation and exec_domain
  m68k: Remove signal translation and exec_domain
  m32r: Remove signal translation and exec_domain
  m32r: Autogenerate offsets in struct thread_info
  frv: Remove signal translation and exec_domain
  ...
parisc: expose number of page table levels on Kconfig level 2015-04-14T23:49:02+00:00 Kirill A. Shutemov kirill.shutemov@linux.intel.com 2015-04-14T22:45:54+00:00 f24ffde43237755b290c46306a3dd2deb1428700 We would want to use number of page table level to define mm_struct. Let's expose it as CONFIG_PGTABLE_LEVELS. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
We would want to use number of page table level to define mm_struct.
Let's expose it as CONFIG_PGTABLE_LEVELS.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>