litmus-rt.git/arch/parisc/include/asm, branch test The LITMUS^RT kernel. 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>
arch: Remove exec_domain from remaining archs 2015-04-12T19:03:30+00:00 Richard Weinberger richard@nod.at 2015-03-30T05:30:38+00:00 fa41b1c7dfa0453931afb32c9988af67a2ee28ae Signed-off-by: Richard Weinberger <richard@nod.at> 
Signed-off-by: Richard Weinberger <richard@nod.at>
parisc: Fix pmd code to depend on PT_NLEVELS value, not on CONFIG_64BIT 2015-03-23T11:28:16+00:00 Helge Deller deller@gmx.de 2015-03-16T20:17:50+00:00 2e3f0ab2bb4853694570b9610b1fcfbfa8fd295b Make the code which sets up the pmd depend on PT_NLEVELS == 3, not on CONFIG_64BIT. The reason is, that a 64bit kernel with a page size greater than 4k doesn't need the pmd and thus has PT_NLEVELS = 2. Signed-off-by: Helge Deller <deller@gmx.de> 
Make the code which sets up the pmd depend on PT_NLEVELS == 3, not on
CONFIG_64BIT. The reason is, that a 64bit kernel with a page size
greater than 4k doesn't need the pmd and thus has PT_NLEVELS = 2.

Signed-off-by: Helge Deller <deller@gmx.de>
parisc: mm: don't count preallocated pmds 2015-03-23T11:28:15+00:00 Mikulas Patocka mpatocka@redhat.com 2015-03-18T17:42:38+00:00 0e0da48dee8dfbcc0df4b8e2ff4efc7a2c89ba6b The patch dc6c9a35b66b520cf67e05d8ca60ebecad3b0479 that counts pmds allocated for a process introduced a bug on 64-bit PA-RISC kernels. The PA-RISC architecture preallocates one pmd with each pgd. This preallocated pmd can never be freed - pmd_free does nothing when it is called with this pmd. When the kernel attempts to free this preallocated pmd, it decreases the count of allocated pmds. The result is that the counter underflows and this error is reported. This patch fixes the bug by artifically incrementing the counter in pmd_free when the kernel tries to free the preallocated pmd. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Helge Deller <deller@gmx.de> 
The patch dc6c9a35b66b520cf67e05d8ca60ebecad3b0479 that counts pmds
allocated for a process introduced a bug on 64-bit PA-RISC kernels.

The PA-RISC architecture preallocates one pmd with each pgd. This
preallocated pmd can never be freed - pmd_free does nothing when it is
called with this pmd. When the kernel attempts to free this preallocated
pmd, it decreases the count of allocated pmds. The result is that the
counter underflows and this error is reported.

This patch fixes the bug by artifically incrementing the counter in
pmd_free when the kernel tries to free the preallocated pmd.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Helge Deller <deller@gmx.de>
mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines 2015-02-28T17:57:51+00:00 Kirill A. Shutemov kirill.shutemov@linux.intel.com 2015-02-27T23:52:12+00:00 c07af4f1ce413d009ea76ee69099f06f73ce75b2 Core mm expects __PAGETABLE_{PUD,PMD}_FOLDED to be defined if these page table levels folded. Usually, these defines are provided by <asm-generic/pgtable-nopmd.h> and <asm-generic/pgtable-nopud.h>. But some architectures fold page table levels in a custom way. They need to define these macros themself. This patch adds missing defines. The patch fixes mm->nr_pmds underflow and eliminates dead __pmd_alloc() and __pud_alloc() on architectures without these page table levels. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Aaro Koskinen <aaro.koskinen@iki.fi> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Core mm expects __PAGETABLE_{PUD,PMD}_FOLDED to be defined if these page
table levels folded.  Usually, these defines are provided by
<asm-generic/pgtable-nopmd.h> and <asm-generic/pgtable-nopud.h>.

But some architectures fold page table levels in a custom way.  They
need to define these macros themself.  This patch adds missing defines.

The patch fixes mm->nr_pmds underflow and eliminates dead __pmd_alloc()
and __pud_alloc() on architectures without these page table levels.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>