Maneesh Soni [Tue, 8 Nov 2011 11:38:26 +0000 (17:08 +0530)]
MIPS Kprobes: Support branch instructions probing
This patch provides support for kprobes on branch instructions. The branch
instruction at the probed address is actually emulated and not executed
out-of-line like other normal instructions. Instead the delay-slot instruction
is copied and single stepped out of line.
At the time of probe hit, the original branch instruction is evaluated
and the target cp0_epc is computed similar to compute_retrun_epc(). It
is also checked if the delay slot instruction can be skipped, which is
true if there is a NOP in delay slot or branch is taken in case of
branch likely instructions. Once the delay slot instruction is single
stepped the normal execution resume with the cp0_epc updated the earlier
computed cp0_epc as per the branch instructions.
Signed-off-by: Maneesh Soni <manesoni@cisco.com> Signed-off-by: Victor Kamensky <kamensky@cisco.com> Cc: David Daney <david.daney@cavium.com> Cc: ananth@in.ibm.com Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2914/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Maneesh Soni [Tue, 8 Nov 2011 11:37:11 +0000 (17:07 +0530)]
MIPS Kprobes: Refactor branch emulation
This patch refactors MIPS branch emulation code so as to allow skipping
delay slot instruction in case of branch likely instructions when branch is
not taken. This is useful for keeping the code common for use cases like
kprobes where one would like to handle the branch instructions keeping the
delay slot instuction also in picture for branch likely instructions. Also
allow emulation when instruction to be decoded is not at pt_regs->cp0_epc
as in case of kprobes where pt_regs->cp0_epc points to the breakpoint
instruction.
The patch also exports the function for modules.
Signed-off-by: Maneesh Soni <manesoni@cisco.com> Signed-off-by: Victor Kamensky <kamensky@cisco.com> Cc: David Daney <david.daney@cavium.com> Cc: ananth@in.ibm.com Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2913/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Maneesh Soni [Tue, 8 Nov 2011 11:34:54 +0000 (17:04 +0530)]
MIPS Kprobes: Fix OOPS in arch_prepare_kprobe()
This patch fixes the arch_prepare_kprobe() on MIPS when it tries to find the
instruction at the previous address to the probed address. The oops happens
when the probed address is the first address in a kernel module and there is
no previous address. The patch uses probe_kernel_read() to safely read the
previous instruction.
Gabor Juhos [Thu, 17 Nov 2011 22:13:46 +0000 (23:13 +0100)]
MIPS: ath79: Rename ATH79_DEV_AR913X_WMAC option to ATH79_DEV_WMAC
The ATH79_DEV_AR913X_WMAC option was used to select the AR913x specific
wireless MAC registration code. The registration code now supports the
AR933X SoCs as well. Rename the option to reflect the changes.
Gabor Juhos [Thu, 17 Nov 2011 22:13:44 +0000 (23:13 +0100)]
MIPS: ath79: Separate AR913x SoC specific WMAC setup code
The device registration code can be shared between the different SoCs, but
the required setup code varies Move AR913x specific setup code into a
separate function in order to make adding support for another SoCs easier.
Gabor Juhos [Thu, 17 Nov 2011 22:13:43 +0000 (23:13 +0100)]
MIPS: ath79: Remove 'ar913x' from common variable and function names
The wireless MAC specific variables and the registration code can be shared
between multiple SoCs. Remove the 'ar913x' part from the function and
variable names to avoid confusions.
Gabor Juhos [Thu, 17 Nov 2011 22:13:42 +0000 (23:13 +0100)]
MIPS: ath79: Store the SoC revision in a global variable
Knowing the exact revision of the SoC is required to make runtime decisions
in various code paths. We have determined the SoC revision already, so we
only need to store that in a global variable.
Shubhrajyoti D [Wed, 16 Nov 2011 05:18:00 +0000 (10:48 +0530)]
mtd: nand: Making MTD_NAND_OMAP2 depend on ARCH_OMAP2PLUS
Making MTD_NAND_OMAP2 depend on ARCH_OMAP2PLUS instead of
oring with ARCH2/3/4.
Reported-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@intel.com>
Eric Dumazet [Thu, 17 Nov 2011 03:13:26 +0000 (03:13 +0000)]
net: use jump_label to shortcut RPS if not setup
Most machines dont use RPS/RFS, and pay a fair amount of instructions in
netif_receive_skb() / netif_rx() / get_rps_cpu() just to discover
RPS/RFS is not setup.
Add a jump_label named rps_needed.
If no device rps_map or global rps_sock_flow_table is setup,
netif_receive_skb() / netif_rx() do a single instruction instead of many
ones, including conditional jumps.
jmp +0 (if CONFIG_JUMP_LABEL=y)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Aaron Sierra [Tue, 15 Nov 2011 00:44:34 +0000 (18:44 -0600)]
mtd: cfi: Allow per-mapping CFI device endianness
This patch allows each CFI device map to use its own endianness. The
globally defined CFI endianness (CONFIG_MTD_CFI_NOSWAP,
CONFIG_MTD_CFI_BE_BYTE_SWAP or CONFIG_MTD_CFI_LE_BYTE_SWAP) becomes the
default value which can be overridden by a driver for a particular device.
Signed-off-by: Aaron Sierra <asierra@xes-inc.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@intel.com>
But on these error paths, the block device's `dev->open' count is
already incremented before we check for errors. This meant that, while
the error path was handled correctly on the first time through
blktrans_open(), the device is erroneously considered already open on
the second time through.
This problem can be seen, for instance, when a UBI volume is
simultaneously mounted as a UBIFS partition and read through its
corresponding gluebi mtdblockX device. This results in blktrans_open()
passing its error checks (with `dev->open > 0') without actually having
a handle on the device. Here's a summarized log of the actions and
results with nandsim:
projects / karo-tx-linux.git / log