commit c78e710c1c9fbeff43dddc0aa3d0ff458e70b0cc upstream. The attached change interchanges the order of purging the TLB and setting the corresponding page table entry. TLB purges are strongly ordered. It occurred to me one night that setting the PTE first might have subtle ordering issues on SMP machines and cause random memory corruption. A TLB lock guards the insertion of user TLB entries. So after the TLB is purged, a new entry can't be inserted until the lock is released. This ensures that the new PTE value is used when the lock is released. Since making this change, no random segmentation faults have been observed on the Debian hppa buildd servers. 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 65bf34f59594c11f13d371c5334a6a0a385cd7ae upstream. Increase the initial kernel default page mapping size for 64-bit kernels to 64 MB and for 32-bit kernels to 32 MB. Due to the additional support of ftrace, tracepoint and huge pages the kernel size can exceed the sizes we used up to now. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 690d097c00c88fa9d93d198591e184164b1d8c20 upstream. Increase the initial kernel default page mapping size for SMP kernels to 32MB and add a runtime check which panics early if the kernel is bigger than the initial mapping size. This fixes boot crashes of 32bit SMP kernels. Due to the introduction of huge page support in kernel 4.4 and it's required initial kernel layout in memory, a 32bit SMP kernel usually got bigger (in layout, not size) than 16MB. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull uaccess fixes from Al Viro: "Fixes for broken uaccess primitives - mostly lack of proper zeroing in copy_from_user()/get_user()/__get_user(), but for several architectures there's more (broken clear_user() on frv and strncpy_from_user() on hexagon)" * 'uaccess-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits) avr32: fix copy_from_user() microblaze: fix __get_user() microblaze: fix copy_from_user() m32r: fix __get_user() blackfin: fix copy_from_user() sparc32: fix copy_from_user() sh: fix copy_from_user() sh64: failing __get_user() should zero score: fix copy_from_user() and friends score: fix __get_user/get_user s390: get_user() should zero on failure ppc32: fix copy_from_user() parisc: fix copy_from_user() openrisc: fix copy_from_user() nios2: fix __get_user() nios2: copy_from_user() should zero the tail of destination mn10300: copy_from_user() should zero on access_ok() failure... mn10300: failing __get_user() and get_user() should zero mips: copy_from_user() must zero the destination on access_ok() failure ARC: uaccess: get_user to zero out dest in cause of fault ...
Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
There are three usercopy warnings which are currently being silenced for
gcc 4.6 and newer:
1) "copy_from_user() buffer size is too small" compile warning/error
This is a static warning which happens when object size and copy size
are both const, and copy size > object size. I didn't see any false
positives for this one. So the function warning attribute seems to
be working fine here.
Note this scenario is always a bug and so I think it should be
changed to *always* be an error, regardless of
CONFIG_DEBUG_STRICT_USER_COPY_CHECKS.
2) "copy_from_user() buffer size is not provably correct" compile warning
This is another static warning which happens when I enable
__compiletime_object_size() for new compilers (and
CONFIG_DEBUG_STRICT_USER_COPY_CHECKS). It happens when object size
is const, but copy size is *not*. In this case there's no way to
compare the two at build time, so it gives the warning. (Note the
warning is a byproduct of the fact that gcc has no way of knowing
whether the overflow function will be called, so the call isn't dead
code and the warning attribute is activated.)
So this warning seems to only indicate "this is an unusual pattern,
maybe you should check it out" rather than "this is a bug".
I get 102(!) of these warnings with allyesconfig and the
__compiletime_object_size() gcc check removed. I don't know if there
are any real bugs hiding in there, but from looking at a small
sample, I didn't see any. According to Kees, it does sometimes find
real bugs. But the false positive rate seems high.
3) "Buffer overflow detected" runtime warning
This is a runtime warning where object size is const, and copy size >
object size.
All three warnings (both static and runtime) were completely disabled
for gcc 4.6 with the following commit:
2fb0815c9ee6 ("gcc4: disable __compiletime_object_size for GCC 4.6+")
That commit mistakenly assumed that the false positives were caused by a
gcc bug in __compiletime_object_size(). But in fact,
__compiletime_object_size() seems to be working fine. The false
positives were instead triggered by #2 above. (Though I don't have an
explanation for why the warnings supposedly only started showing up in
gcc 4.6.)
So remove warning #2 to get rid of all the false positives, and re-enable
warnings #1 and #3 by reverting the above commit.
Furthermore, since #1 is a real bug which is detected at compile time,
upgrade it to always be an error.
Having done all that, CONFIG_DEBUG_STRICT_USER_COPY_CHECKS is no longer
needed.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When building gccgo in userspace, errno.h gets parsed and the go include file sysinfo.go is generated. Since EREFUSED is defined to the same value as ECONNREFUSED, and ECONNREFUSED is defined later on in errno.h, this leads to go complaining that EREFUSED isn't defined yet. Fix this trivial problem by moving the define of EREFUSED down after ECONNREFUSED in errno.h (and clean up the indenting while touching this line). Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org
Pull RTC updates from Alexandre Belloni:
"RTC for 4.8
Cleanups:
- huge cleanup of rtc-generic and char/genrtc this allowed to cleanup
rtc-cmos, rtc-sh, rtc-m68k, rtc-powerpc and rtc-parisc
- move mn10300 to rtc-cmos
Subsystem:
- fix wakealarms after hibernate
- multiples fixes for rctest
- simplify implementations of .read_alarm
New drivers:
- Maxim MAX6916
Drivers:
- ds1307: fix weekday
- m41t80: add wakeup support
- pcf85063: add support for PCF85063A variant
- rv8803: extend i2c fix and other fixes
- s35390a: fix alarm reading, this fixes instant reboot after
shutdown for QNAP TS-41x
- s3c: clock fixes"
* tag 'rtc-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (65 commits)
rtc: rv8803: Clear V1F when setting the time
rtc: rv8803: Stop the clock while setting the time
rtc: rv8803: Always apply the I²C workaround
rtc: rv8803: Fix read day of week
rtc: rv8803: Remove the check for valid time
rtc: rv8803: Kconfig: Indicate rx8900 support
rtc: asm9260: remove .owner field for driver
rtc: at91sam9: Fix missing spin_lock_init()
rtc: m41t80: add suspend handlers for alarm IRQ
rtc: m41t80: make it a real error message
rtc: pcf85063: Add support for the PCF85063A device
rtc: pcf85063: fix year range
rtc: hym8563: in .read_alarm set .tm_sec to 0 to signal minute accuracy
rtc: explicitly set tm_sec = 0 for drivers with minute accurancy
rtc: s3c: Add s3c_rtc_{enable/disable}_clk in s3c_rtc_setfreq()
rtc: s3c: Remove unnecessary call to disable already disabled clock
rtc: abx80x: use devm_add_action_or_reset()
rtc: m41t80: use devm_add_action_or_reset()
rtc: fix a typo and reduce three empty lines to one
rtc: s35390a: improve two comments in .set_alarm
...
Pull parisc updates from Helge Deller: - added an optimized hash implementation for parisc (George Spelvin) - C99 style cleanups in iomap.c (Amitoj Kaur Chawla) - added breaks to switch statement in PDC function (noticed by Dan Carpenter) * 'parisc-4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Change structure intialisation to C99 style in iomap.c parisc: Add break statements to pdc_pat_io_pci_cfg_read() parisc: Add <asm/hash.h>
PA-RISC is interesting; integer multiplies are implemented in the FPU, so are painful in the kernel. But it tries to be friendly to shift-and-add sequences for constant multiplies. __hash_32 is implemented using the same shift-and-add sequence as Microblaze, just scheduled for the PA7100. (It's 2-way superscalar but in-order, like the Pentium.) hash_64 was tricky, but a suggestion from Jason Thong allowed a good solution by breaking up the multiplier. After a lot of manual optimization, I found a 19-instruction sequence for the multiply that can be executed in 10 cycles using only 4 temporaries. (The PA8xxx can issue 4 instructions per cycle, but 2 must be ALU ops and 2 must be loads/stores. And the final add can't be paired.) An alternative considered, but ultimately not used, was Thomas Wang's 64-to-32-bit integer hash. At 12 instructions, it's smaller, but they're all sequentially dependent, so it has longer latency. https://web.archive.org/web/2011/http://www.concentric.net/~Ttwang/tech/inthash.htm http://burtleburtle.net/bob/hash/integer.html Signed-off-by: George Spelvin <linux@sciencehorizons.net> Cc: Helge Deller <deller@gmx.de> Cc: linux-parisc@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de>