1. For VM_EXEC based delayed dcache/icache flush, reduces the number of
flushes.
2. Makes this security feature ON by default rather than OFF before.
3. Applications can use mprotect() to selectively override this.
4. ELF binaries have a GNU_STACK segment which can easily override the
kernel default permissions.
For nested-functions/trampolines, gcc already auto-enables executable
stack in elf. Others needing this can use -Wl,-z,execstack option.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Non-congruent SRC page in copy_user_page() is dcache clean in the end -
so record that fact, to avoid a subsequent extraneous flush.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* Number of (i|d)cache ways can be retrieved from BCRs and hence no need
to cross check with with built-in constants
* Use of IS_ENABLED() to check for a Kconfig option
* is_not_cache_aligned() not used anymore
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* Move the various sub-system defines/types into relevant files/functions
(reduces compilation time)
* move CPU specific stuff out of asm/tlb.h into asm/mmu.h
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This fixes the following:
- CONFIG_ARC_SERIAL_BAUD is only defined when CONFIG_SERIAL_ARC is defined.
Make sure that it isn't referenced otherwise.
- There is no use for initializing arc_uart_info[] when CONFIG_SERIAL_ARC is
not defined.
[vgupta: tweaked changelog title, used IS_ENABLED() kconfig helper]
Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Pull ARM SoC fixes from Olof Johansson:
"These are a little later than I planned on since I got caught up with
handling merges for 3.11 most of the week.
Another week, another batch of fixes for arm-soc platforms.
Again, nothing controversial. A few more than would be ideal, but all
are valid fixes. In particular the prima2 panic patch is critical
since it fixes a problem where multiplatform kernels panic on all but
prima2 hardware."
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
ARM: SAMSUNG: pm: Adjust for pinctrl- and DT-enabled platforms
ARM: prima2: fix incorrect panic usage
arm: mvebu: armada-xp-{gp,openblocks-ax3-4}: specify PCIe range
ARM: Kirkwood: handle mv88f6282 cpu in __kirkwood_variant().
ARM: omap3: clock: fix wrong container_of in clock36xx.c
ARM: dts: OMAP5: Fix missing PWM capability to timer nodes
ARM: dts: omap4-panda|sdp: Fix mux for twl6030 IRQ pin and msecure line
ARM: dts: AM33xx: Fix properties on gpmc node
arm: omap2: fix AM33xx hwmod infos for UART2
ARM: OMAP3: Fix iva2_pwrdm settings for 3703
Pull powerpc fixes from Benjamin Herrenschmidt:
"So here are 3 fixes still for 3.10. Fixes are simple, bugs are nasty
(though not recent regressions, nasty enough) and all targeted at
stable"
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc: Fix missing/delayed calls to irq_work
powerpc: Fix emulation of illegal instructions on PowerNV platform
powerpc: Fix stack overflow crash in resume_kernel when ftracing
When replaying interrupts (as a result of the interrupt occurring
while soft-disabled), in the case of the decrementer, we are exclusively
testing for a pending timer target. However we also use decrementer
interrupts to trigger the new "irq_work", which in this case would
be missed.
This change the logic to force a replay in both cases of a timer
boundary reached and a decrementer interrupt having actually occurred
while disabled. The former test is still useful to catch cases where
a CPU having been hard-disabled for a long time completely misses the
interrupt due to a decrementer rollover.
CC: <stable@vger.kernel.org> [v3.4+]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Normally, the kernel emulates a few instructions that are unimplemented
on some processors (e.g. the old dcba instruction), or privileged (e.g.
mfpvr). The emulation of unimplemented instructions is currently not
working on the PowerNV platform. The reason is that on these machines,
unimplemented and illegal instructions cause a hypervisor emulation
assist interrupt, rather than a program interrupt as on older CPUs.
Our vector for the emulation assist interrupt just calls
program_check_exception() directly, without setting the bit in SRR1
that indicates an illegal instruction interrupt. This fixes it by
making the emulation assist interrupt set that bit before calling
program_check_interrupt(). With this, old programs that use no-longer
implemented instructions such as dcba now work again.
CC: <stable@vger.kernel.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
It's possible for us to crash when running with ftrace enabled, eg:
Bad kernel stack pointer bffffd12 at c00000000000a454
cpu 0x3: Vector: 300 (Data Access) at [c00000000ffe3d40]
pc: c00000000000a454: resume_kernel+0x34/0x60
lr: c00000000000335c: performance_monitor_common+0x15c/0x180
sp: bffffd12
msr: 8000000000001032
dar: bffffd12
dsisr: 42000000
If we look at current's stack (paca->__current->stack) we see it is
equal to c0000002ecab0000. Our stack is 16K, and comparing to
paca->kstack (c0000002ecab3e30) we can see that we have overflowed our
kernel stack. This leads to us writing over our struct thread_info, and
in this case we have corrupted thread_info->flags and set
_TIF_EMULATE_STACK_STORE.
Dumping the stack we see:
3:mon> t c0000002ecab0000
[c0000002ecab0000] c00000000002131c .performance_monitor_exception+0x5c/0x70
[c0000002ecab0080] c00000000000335c performance_monitor_common+0x15c/0x180
--- Exception: f01 (Performance Monitor) at c0000000000fb2ec .trace_hardirqs_off+0x1c/0x30
[c0000002ecab0370] c00000000016fdb0 .trace_graph_entry+0xb0/0x280 (unreliable)
[c0000002ecab0410] c00000000003d038 .prepare_ftrace_return+0x98/0x130
[c0000002ecab04b0] c00000000000a920 .ftrace_graph_caller+0x14/0x28
[c0000002ecab0520] c0000000000d6b58 .idle_cpu+0x18/0x90
[c0000002ecab05a0] c00000000000a934 .return_to_handler+0x0/0x34
[c0000002ecab0620] c00000000001e660 .timer_interrupt+0x160/0x300
[c0000002ecab06d0] c0000000000025dc decrementer_common+0x15c/0x180
--- Exception: 901 (Decrementer) at c0000000000104d4 .arch_local_irq_restore+0x74/0xa0
[c0000002ecab09c0] c0000000000fe044 .trace_hardirqs_on+0x14/0x30 (unreliable)
[c0000002ecab0fb0] c00000000016fe3c .trace_graph_entry+0x13c/0x280
[c0000002ecab1050] c00000000003d038 .prepare_ftrace_return+0x98/0x130
[c0000002ecab10f0] c00000000000a920 .ftrace_graph_caller+0x14/0x28
[c0000002ecab1160] c0000000000161f0 .__ppc64_runlatch_on+0x10/0x40
[c0000002ecab11d0] c00000000000a934 .return_to_handler+0x0/0x34
--- Exception: 901 (Decrementer) at c0000000000104d4 .arch_local_irq_restore+0x74/0xa0
... and so on
__ppc64_runlatch_on() is called from RUNLATCH_ON in the exception entry
path. At that point the irq state is not consistent, ie. interrupts are
hard disabled (by the exception entry), but the paca soft-enabled flag
may be out of sync.
This leads to the local_irq_restore() in trace_graph_entry() actually
enabling interrupts, which we do not want. Because we have not yet
reprogrammed the decrementer we immediately take another decrementer
exception, and recurse.
The fix is twofold. Firstly make sure we call DISABLE_INTS before
calling RUNLATCH_ON. The badly named DISABLE_INTS actually reconciles
the irq state in the paca with the hardware, making it safe again to
call local_irq_save/restore().
Although that should be sufficient to fix the bug, we also mark the
runlatch routines as notrace. They are called very early in the
exception entry and we are asking for trouble tracing them. They are
also fairly uninteresting and tracing them just adds unnecessary
overhead.
[ This regression was introduced by fe1952fc0a
"powerpc: Rework runlatch code" by myself --BenH
]
CC: <stable@vger.kernel.org> [v3.4+]
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Pull device tree bug fixes from Grant Likely:
"This branch contains the following bug fixes:
- Fix locking vs. interrupts. Bug caught by lockdep checks
- Fix parsing of cpp #line directive output by dtc
- Fix 'make clean' for dtc temporary files.
There is also a commit that regenerates the dtc lexer and parser files
with Bison 2.5. The only purpose of this commit is to separate the
functional change in the dtc bug fix from the code generation change
caused by a different Bison version"
* tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux:
dtc: ensure #line directives don't consume data from the next line
dtc: Update generated files to output from Bison 2.5
of: Fix locking vs. interrupts
kbuild: make sure we clean up DTB temporary files
The OF code uses irqsafe locks everywhere except in a handful of functions
for no obvious reasons. Since the conversion from the old rwlocks, this
now triggers lockdep warnings when used at interrupt time. At least one
driver (ibmvscsi) seems to be doing that from softirq context.
This converts the few non-irqsafe locks into irqsafe ones, making them
consistent with the rest of the code.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
Pull x86 fixes from Peter Anvin:
"Another set of fixes, the biggest bit of this is yet another tweak to
the UEFI anti-bricking code; apparently we finally got some feedback
from Samsung as to what makes at least their systems fail. This set
should actually fix the boot regressions that some other systems (e.g.
SGI) have exhibited.
Other than that, there is a patch to avoid a panic with particularly
unhappy memory layouts and two minor protocol fixes which may or may
not be manifest bugs"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Fix typo in kexec register clearing
x86, relocs: Move __vvar_page from S_ABS to S_REL
Modify UEFI anti-bricking code
x86: Fix adjust_range_size_mask calling position
Pull s390 fixes from Martin Schwidefsky:
"Three kvm related memory management fixes, a fix for show_trace, a fix
for early console output and a patch from Ben to help prevent compile
errors in regard to irq functions (or our lack thereof)"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/pci: Implement IRQ functions if !PCI
s390/sclp: fix new line detection
s390/pgtable: make pgste lock an explicit barrier
s390/pgtable: Save pgste during modify_prot_start/commit
s390/dumpstack: fix address ranges for asynchronous and panic stack
s390/pgtable: Fix guest overindication for change bit
* More tweaking to the EFI variable anti-bricking algorithm. Quite a
few users were reporting boot regressions in v3.9. This has now been
fixed with a more accurate "minimum storage requirement to avoid
bricking" value from Samsung (5K instead of 50%) and code to trigger
garbage collection when we near our limit - Matthew Garrett.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The __vvar_page relocation should actually be listed in S_REL instead
of S_ABS. Oddly, this didn't always cause things to break, presumably
because there are no users for relocation information on 64 bits yet.
[ hpa: Not for stable - new code in 3.10 ]
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/20130611185652.GA23674@www.outflux.net
Reported-by: Michael Davidson <md@google.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Vineet Gupta
Alexey Brodkin
Mischa Jonker
Linus Torvalds
Benjamin Herrenschmidt
Paul Mackerras
Michael Ellerman
H. Peter Anvin
Kees Cook