The current mainline codes of ARCH_S5PC100 cannot support
suspend to ram. So needs this for preventing build error.
Cc: Russell King <rmk+kernel at arm.linux.org.uk>
Signed-off-by: Kukjin Kim <kgene.kim at samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Since mandatory barriers may be used (explicitly or implicitly via readl
etc.) to ensure the ordering between Device and Normal memory accesses,
a DMB is not enough. This patch converts it to a DSB.
Cc: Colin Cross <ccross@android.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
GDB's interrupt.exp test cases currenly fail on ARM. The problem is how do_signal
handled restarting interrupted system calls:
The entry.S assembler code determines that we come from a system call; and that
information is passed as "syscall" parameter to do_signal. That routine then
calls get_signal_to_deliver [*] and if a signal is to be delivered, calls into
handle_signal. If a system call is to be restarted either after the signal
handler returns, or if no handler is to be called in the first place, the PC
is updated after the get_signal_to_deliver call, either in handle_signal (if
we have a handler) or at the end of do_signal (otherwise).
Now the problem is that during [*], the call to get_signal_to_deliver, a ptrace
intercept may happen. During this intercept, the debugger may change registers,
including the PC. This is done by GDB if it wants to execute an "inferior call",
i.e. the execution of some code in the debugged program triggered by GDB.
To this purpose, GDB will save all registers, allocate a stack frame, set up
PC and arguments as appropriate for the call, and point the link register to
a dummy breakpoint instruction. Once the process is restarted, it will execute
the call and then trap back to the debugger, at which point GDB will restore
all registers and continue original execution.
This generally works fine. However, now consider what happens when GDB attempts
to do exactly that while the process was interrupted during execution of a to-be-
restarted system call: do_signal is called with the syscall flag set; it calls
get_signal_to_deliver, at which point the debugger takes over and changes the PC
to point to a completely different place. Now get_signal_to_deliver returns
without a signal to deliver; but now do_signal decides it should be restarting
a system call, and decrements the PC by 2 or 4 -- so it now points to 2 or 4
bytes before the function GDB wants to call -- which leads to a subsequent crash.
To fix this problem, two things need to be supported:
- do_signal must be able to recognize that get_signal_to_deliver changed the PC
to a different location, and skip the restart-syscall sequence
- once the debugger has restored all registers at the end of the inferior call
sequence, do_signal must recognize that *now* it needs to restart the pending
system call, even though it was now entered from a breakpoint instead of an
actual svc instruction
This set of issues is solved on other platforms, usually by one of two
mechanisms:
- The status information "do_signal is handling a system call that may need
restarting" is itself carried in some register that can be accessed via
ptrace. This is e.g. on Intel the "orig_eax" register; on Sparc the kernel
defines a magic extra bit in the flags register for this purpose.
This allows GDB to manage that state: reset it when doing an inferior call,
and restore it after the call is finished.
- On s390, do_signal transparently handles this problem without requiring
GDB interaction, by performing system call restarting in the following
way: first, adjust the PC as necessary for restarting the call. Then,
call get_signal_to_deliver; and finally just continue execution at the
PC. This way, if GDB does not change the PC, everything is as before.
If GDB *does* change the PC, execution will simply continue there --
and once GDB restores the PC it saved at that point, it will automatically
point to the *restarted* system call. (There is the minor twist how to
handle system calls that do *not* need restarting -- do_signal will undo
the PC change in this case, after get_signal_to_deliver has returned, and
only if ptrace did not change the PC during that call.)
Because there does not appear to be any obvious register to carry the
syscall-restart information on ARM, we'd either have to introduce a new
artificial ptrace register just for that purpose, or else handle the issue
transparently like on s390. The patch below implements the second option;
using this patch makes the interrupt.exp test cases pass on ARM, with no
regression in the GDB test suite otherwise.
Cc: patches@linaro.org
Signed-off-by: Ulrich Weigand <ulrich.weigand@linaro.org>
Signed-off-by: Arnd Bergmann <arnd.bergmann@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The SPARSEMEM code allocates memmap entries only for sections which are
present (i.e. those which contain some valid memory). The membank checks
in free_unused_memmap do not take this into account and can incorrectly
attempt to free memory which is not allocated, resulting in a BUG() in
the bootmem code.
However, if memory is configured as follows:
|<----section---->|<----hole---->|<----section---->|
+--------+--------+--------------+--------+--------+
| bank 0 | unused | | bank 1 | unused |
+--------+--------+--------------+--------+--------+
where a bank only occupies part of a section, the memmap allocated for
the remainder of the section *can* be freed.
This patch modifies the checks in free_unused_memmap so that only valid
memmap entries are considered for removal.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
For correctness, the initial page table located right before the
decompressed kernel should be considered when determining if relocation
is required.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Tony Lindgren <tony@atomide.com>
If the zImage load address is slightly below the relocation address,
there is a risk for the copied data to overwrite the copy loop or
cache flush code that the relocation process requires. Always
bump the relocation address by the size of that code to avoid this
issue.
Noticed by Tony Lindgren <tony@atomide.com>.
While at it, let's start the copy from the restart symbol which makes
the above code size computation possible by the assembler directly
(same sections), given that we don't need to preserve the code before
that point anyway. And therefore we don't need to carry the _start
pointer in r5 anymore.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Otherwise cache_clean_flush can overwrite some of the relocated
area depending on where the kernel image gets loaded. This fixes
booting on n900 after commit 6d7d0ae515
(ARM: 6750/1: improvements to compressed/head.S).
Thanks to Aaro Koskinen <aaro.koskinen@nokia.com> for debugging
the address of the relocated area that gets corrupted, and to
Nicolas Pitre <nicolas.pitre@linaro.org> for the other uncompress
related fixes.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
With ARMv5+ and EABI, the compiler expects a 64-bit aligned stack so
instructions like STRD and LDRD can be used. Without this, mysterious
boot failures were seen semi randomly with the LZMA decompressor.
While at it, let's align .bss as well.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Tony Lindgren <tony@atomide.com>
CC: stable@kernel.org
* 'fixes' of master.kernel.org:/home/rmk/linux-2.6-arm: (47 commits)
CLKDEV: Fix clkdev return value for NULL clk case
ARM: 6891/1: prevent heap corruption in OABI semtimedop
ARM: kprobes: Tidy-up kprobes-decode.c
ARM: kprobes: Add emulation of hint instructions like NOP and WFI
ARM: kprobes: Add emulation of SBFX, UBFX, BFI and BFC instructions
ARM: kprobes: Add emulation of MOVW and MOVT instructions
ARM: kprobes: Reject probing of undefined data processing instructions
ARM: kprobes: Remove redundant code in space_1111
ARM: kprobes: Fix emulation of PLD instructions
ARM: kprobes: Reject probing of SETEND instructions
ARM: kprobes: Consolidate stub decoding functions
ARM: kprobes: Reject probing of all coprocessor instructions
ARM: kprobes: Fix emulation of USAD8 instructions
ARM: kprobes: Fix emulation of SMUAD, SMUSD and SMMUL instructions
ARM: kprobes: Fix emulation of SXTB16, SXTB, SXTH, UXTB16, UXTB and UXTH instructions
ARM: kprobes: Reject probing of undefined media instructions
ARM: kprobes: Add emulation of RBIT instruction
ARM: kprobes: Reject probing of LDRB instructions which load PC
ARM: kprobes: Fix emulation of LDRD and STRD instructions
ARM: kprobes: Reject probing of LDR/STR instructions which update PC unpredictably
...
* 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6:
OMAP3+: voltage: remove initial voltage
OMAP4: Intialize IVA Device in addition to DSP device.
omap: rx51: mark reserved memory earlier
OMAP3: l3: fix for "irq 10: nobody cared" message
arm: omap2: enable smc instruction for sleep34xx
OMAP2/3: hwmod: fix gpio-reset timeouts seen during bootup.
OMAP3: PM: Do not rely on ROM code to restore CM_AUTOIDLE_PLL.AUTO_PERIPH_DPLL
OMAP2+: PM: Fix the saving of CM_AUTOIDLE_PLL register on scratchpad area
OMAP4: clock data: Change DSS clock aliases
OMAP2+: hwmod data: Fix wrong dma_system end address
When CONFIG_OABI_COMPAT is set, the wrapper for semtimedop does not
bound the nsops argument. A sufficiently large value will cause an
integer overflow in allocation size, followed by copying too much data
into the allocated buffer. Fix this by restricting nsops to SEMOPM.
Untested.
Cc: stable@kernel.org
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
- Remove coding standard violations reported by checkpatch.pl
- Delete comment about handling of conditional branches which is no
longer true.
- Delete comment at end of file which lists all ARM instructions. This
duplicates data available in the ARM ARM and seems like an
unnecessary maintenance burden to keep this up to date and accurate.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Being able to probe NOP instructions is useful for hard-coding probeable
locations and is used by the kprobes test code.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
These bit field manipulation instructions occur several thousand
times in an ARMv7 kernel.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The MOVW and MOVT instructions account for approximately 7% of all
instructions in a ARMv7 kernel as GCC uses them instead of a literal
pool.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The instruction decoding in space_cccc_000x needs to reject probing of
instructions with undefined patterns as they may in future become
defined and then emulated faultily - as has already happened with the
SMC instruction.
This fix is achieved by testing for the instruction patterns we want to
probe and making the the default fall-through paths reject probes. This
also allows us to remove some explicit tests for instructions that we
wish to reject, as that is now the default action.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The tests to explicitly reject probing CPS, RFE and SRS instructions
are redundant as the default case is now to reject undecoded patterns.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The PLD instructions wasn't being decoded correctly and the emulation
code wasn't adjusting PC correctly.
As the PLD instruction is only a performance hint we emulate it as a
simple nop, and we can broaden the instruction decoding to take into
account newer PLI and PLDW instructions.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The emulation of SETEND was broken as it changed the endianess for
the running kprobes handling code. Rather than adding a new simulation
routine to fix this we'll just reject probing of SETEND as these should
be very rare in the kernel.
Note, the function emulate_none is now unused but it is left in the
source code as future patches will use it.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Following the change to remove support for coprocessor instructions
we are left with three stub functions which can be consolidated.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The kernel doesn't currently support VFP or Neon code, and probing of
code with CP15 operations is fraught with bad consequences. Therefore we
don't need the ability to probe coprocessor instructions and the code to
support this can be removed.
The removed code also had at least two bugs:
- MRC into R15 should set CPSR not trash PC
- LDC and STC which use PC as base register needed the address offset by 8
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The USAD8 instruction wasn't being explicitly decoded leading
to the incorrect emulation routine being called. It can be correctly
decoded in the same way as the signed multiply instructions so we move
the decoding there.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The signed multiply instructions were being decoded incorrectly.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
These sign extension instructions are encoded as extend-and-add
instructions where the register to add is specified as r15. The decoding
routines weren't checking for this and were using the incorrect
emulation code, giving incorrect results.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The instructions space for media instructions contains some undefined
patterns. We need to reject probing of these because they may in future
become defined and the kprobes code may then emulate them faultily.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The v6T2 RBIT instruction was accidentally being emulated correctly,
this patch adds correct decoding for the instruction.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
These instructions are specified as UNPREDICTABLE.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The decoding of these instructions got the register indexed and
immediate indexed forms the wrong way around, causing incorrect
emulation.
Instructions like "LDRD Rx, [Rx]" were corrupting Rx because the base
register writeback was being performed unconditionally, overwriting the
value just loaded from memory. The fix is to only writeback the base
register when that form of the instruction is used. Note, now that we
reject probing writeback with PC the emulation code doesn't need the
check rn!=15.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Using PC as an base register with writeback is UNPREDICTABLE, as is non
word-sized loads or stores of PC. (We only really care about preventing
loads to PC but it keeps the code simpler if we also exclude stores.)
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The decoding of these instructions got the register indexed and
immediate indexed forms the wrong way around, causing incorrect
emulation.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The emulation code for STREX and LDREX instructions is faulty, however,
rather than attempting to fix this we reject probes of these
instructions. We do this because they can never succeed in gaining
exclusive access as the exception framework clears the exclusivity
monitor when a probes breakpoint is hit. (This is a general problem
when probing all instructions executing between a LDREX and its
corresponding STREX and can lead to infinite retry loops.)
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The instructions space for 'Multiply and multiply-accumulate'
instructions contains some undefined patterns. We need to reject
probing of these because they may in future become defined and the
kprobes code may then emulate them faultily.
This has already happened with the new MLS instruction which this patch
also adds correct decoding for as well as tightening up other decoding
tests. (Before this patch the wrong emulation routine was being called
for MLS though it still produced correct results.)
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The MRS instruction should set mode and interrupt bits in the read value
so it is simpler to use a new simulation routine (simulate_mrs) rather
than some modified emulation.
prep_emulate_rd12 is now unused and removed.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
We need to reject probing of instructions which read SPSR because
we can't handle this as the value in SPSR is lost when the exception
handler for the probe breakpoint first runs.
This patch also fixes the bitmask for MRS instructions decoding to
include checking bits 5-7.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Emulation of instructions like "ADD rd, rn, #<const>" would result in a
corrupted value for rd.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Probing these instructions was corrupting R0 because the emulation code
didn't account for the fact that they don't write a result to a
register.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Now we have the framework code handling conditionally executed
instructions we can remove redundant checks in individual simulation
routines.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
When a kprobe is placed onto conditionally executed ARM instructions,
many of the emulation routines used to single step them produce corrupt
register results. Rather than fix all of these cases we modify the
framework which calls them to test the relevant condition flags and, if
the test fails, skip calling the emulation code.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Currently emulate_ldrd and emulate_strd don't even have the adjustment
of the PC value, so in case of Rn == PC, it will not update the PC
incorrectly but instead load/store from the wrong address. Let's add
both the adjustment of the PC value and the check for PC == PC.
Signed-off-by: Viktor Rosendahl <viktor.rosendahl@nokia.com>
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
gas used to accept (and ignore?) .size directives which referred to
undefined symbols, as this does. In binutils 2.21 these are treated
as fatal errors.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
This function is only called by percpu_timer_setup() which is
also __cpuinit marked. Thus it's safe to mark this function as
__cpuinit as well.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The ARM user backtrace code can get into an infinite loop if it
runs into an invalid stack frame which points back to itself.
This situation has been observed in practice. Fix it by capping
the number of entries in the backtrace. This is also what other
architectures do in their backtrace code.
Signed-off-by: Sonny Rao <sonnyrao@chromium.org>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
