We are not working with values from MSR that's why
we can discard it and use r11 for different purpose without
saving/restoring.
Signed-off-by: Michal Simek <monstr@monstr.eu>
Remove set_vms because UMS is cleared and VMS is already setup.
Optimize function calling which save one additional instruction.
Signed-off-by: Michal Simek <monstr@monstr.eu>
VMS is always setup because VM mode was before
exception/syscall/interrupt. Kernel continues in kernel mode
that's why we have to clear UMS bit if kernel comes from
user space.
Signed-off-by: Michal Simek <monstr@monstr.eu>
PT_MODE stores information if kernel comes from user
or kernel space. If come from user space, PT_MODE
contains 0. If come from kernel store, PT_MODE contains
non zero value. We don't need to save value 1. I am using
r1 register which contains non zero value.
This change save one additional instruction.
Signed-off-by: Michal Simek <monstr@monstr.eu>
Keep together all arguments for send_sig function.
Move returning address to delay slot which is executed.
Remove additional send_sig loading. I am using IMM part of
rtbd instruction with r0.
old solution:
addik r11, r0, send_sig
rtbd r11, 0
nop
new solution:
rtbd r0, send_sig
nop
There is one instruction saving.
Signed-off-by: Michal Simek <monstr@monstr.eu>
It is necessary to setup BIP and EE and clear EIP
only for unaligned exception handler. The rest of
hw exception handlers don't require it.
HW exception occured and we are not in virtual mode.
That's why we can do operations protected by EIP.
Interrupt, next hw exception or syscall can't occur.
EIP is cleared by rted.
This change speedup page_fault hw exception handler
which is critical path.
There is also necessary to save R11 content before
flag setup for unaligned exception.
Signed-off-by: Michal Simek <monstr@monstr.eu>
SAVE_STATE macro is used in hw exceptions high level handling
functions. Hw exception doesn't disable IRQ that's why we don't
need to reenable it.
Signed-off-by: Michal Simek <monstr@monstr.eu>
We don't need to protect by BIP whole ret_from_trap/ret_from_exc code.
Only restoring from user/hw exception should be covered.
If BIP is setup, IRQ can't occur.
Signed-off-by: Michal Simek <monstr@monstr.eu>
There is a way howto remove Kernel Mode variable. It is easier
to parse UMS bit in MSR to find out if I come from kernel or user
space. Loading MSR content should be in one cycle and loading
PER_CPU variable depends on memory state.
Signed-off-by: Michal Simek <monstr@monstr.eu>
Save and restore R3/R4 registers in macros. This change
help to cleanup entry.S.
In ret_from_trap function we are saving returning value from
syscall to pt_regs on stack that's why we don't need to save and
restore these values before kernel functions (schedule, do_signal).
Signed-off-by: Michal Simek <monstr@monstr.eu>
_start symbol stores physical address where kernel is.
Gdb uses this symbol for their purpose that's why
we have to rename it.
Signed-off-by: Michal Simek <monstr@monstr.eu>
Lower shifting values ensure that shifted 32bit counter
value doesn't exceed 64bit cycle variable too fast.
Signed-off-by: Michal Simek <monstr@monstr.eu>
Microblaze has support for early printk. The second serial
driver (uart16550/8250) has no microblaze support for early
printk.
Signed-off-by: Michal Simek <monstr@monstr.eu>
HAVE_ARCH_PCI_SET_DMA_MASK was removed in 2.6.34 (no architecture has
the own implementation of pci_set_dma_mask).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Michal Simek <monstr@monstr.eu>
Implement intelligent backtracing by searching for stack frame creation,
and emitting only return addresses. Use print_hex_dump() to display the
entire binary kernel stack.
Limitation: MMU kernels are not currently able to trace beyond a system trap
(interrupt, syscall, etc.). It is the intent of this patch to provide
infrastructure that can be extended to add this capability later.
Changes from V1:
* Removed checks in find_frame_creation() that prevented location of the frame
creation instruction in heavily optimized code
* Various formatting/commenting/file location tweaks per review comments
* Dropped Kconfig option to enable STACKTRACE as something logically separate
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Allow developer to configure memory page size at compile time.
Larger pages can improve performance on some workloads.
Based on PowerPC code.
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
sys_clone syscall ignored args which this patch mapped to args
which are passing from glibc.
Here is the origin problem description.
"I ran the static libgcc tests (very few of them are there, they are
mostly dynamically linked) and some of them fail with an assertion in
fork() system call (tid != pid), I looked at the microblaze/entry.S
file and it looks suspicious (ignores arguments 3-5)"
Arg mapping should be:
glibc ARCH_FORK(...) -> do_fork(...)
r5 -> r5 (clone_flags)
r6 -> r6 (stack_start, use parent->stack if NULL)
pt_regs -> r7 (pt_regs)
r7 -> r8 (stack_size)
r8 -> r9 (parent_tidptr)
r9 -> r10 (child_tidptr)
Signed-off-by: John Williams <john.williams@petalogix.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
copy_to_user_page macro is used in mm/memory.c:access_process_vm
function. This function is called from ptrace code (POKETEXT, POKEDATA)
which write data to memory. Microblaze handle physical address for
caches that's why there is virt_to_phys conversion.
There is potential one location which can caused the problem on WB system.
The important is take a look at write PTRACEs requests
(POKE/TEXT, DATA, USR).
Note:
Majority of Microblaze PTRACE code is moved to generic location
in newer kernel version that's why this solution should work on
the newest kernel version too.
linux/io.h is in cacheflush because of mm/nommu.c
Tested on a WB system - hello world debugging.
Signed-off-by: Michal Simek <monstr@monstr.eu>
The label should be remove by
21e1c93631
Warning message:
arch/microblaze/mm/fault.c: In function 'do_page_fault':
arch/microblaze/mm/fault.c:229: warning: label 'survive' defined but not used
Signed-off-by: Michal Simek <monstr@monstr.eu>
__copy_to/from_user_inatomic should call __copy_to/from_user
because there is not necessary to check access because of kernel function.
might_sleep in copy_to/from_user macros is causing problems
in debug sessions too (CONFIG_DEBUG_SPINLOCK_SLEEP).
BUG: sleeping function called from invalid context at
.../arch/microblaze/include/asm/uaccess.h:388
in_atomic(): 1, irqs_disabled(): 0, pid: 1, name: swapper
1 lock held by swapper/1:
#0: (&p->cred_guard_mutex){......}, at: [<c00d4b90>] prepare_bprm_creds+0x2c/0x88
Kernel Stack:
...
Call Trace:
[<c0006bd4>] microblaze_unwind+0x7c/0x94
[<c0006684>] show_stack+0xf4/0x190
[<c0006730>] dump_stack+0x10/0x30
[<c00103a0>] __might_sleep+0x12c/0x160
[<c0090de4>] file_read_actor+0x1d8/0x2a8
[<c0091568>] generic_file_aio_read+0x6b4/0xa64
[<c00cd778>] do_sync_read+0xac/0x110
[<c00ce254>] vfs_read+0xc8/0x160
[<c00d585c>] kernel_read+0x38/0x64
[<c00d5984>] prepare_binprm+0xfc/0x130
[<c00d6430>] do_execve+0x228/0x370
[<c000614c>] microblaze_execve+0x58/0xa4
caused by file_read_actor (mm/filemap.c) which calls
__copy_to_user_inatomic.
Signed-off-by: Michal Simek <monstr@monstr.eu>
* master.kernel.org:/home/rmk/linux-2.6-arm:
cyber2000fb: fix console in truecolor modes
cyber2000fb: fix machine hang on module load
SA1111: Eliminate use after free
ARM: Fix Versatile/Realview/VExpress MMC card detection sense
ARM: 6279/1: highmem: fix SMP preemption bug in kmap_high_l1_vipt
ARM: Add barriers to io{read,write}{8,16,32} accessors as well
ARM: 6273/1: Add barriers to the I/O accessors if ARM_DMA_MEM_BUFFERABLE
ARM: 6272/1: Convert L2x0 to use the IO relaxed operations
ARM: 6271/1: Introduce *_relaxed() I/O accessors
ARM: 6275/1: ux500: don't use writeb() in uncompress.h
ARM: 6270/1: clean files in arch/arm/boot/compressed/
ARM: Fix csum_partial_copy_from_user()
__sa1111_remove always frees its argument, so the subsequent reference to
sachip->saved_state represents a use after free. __sa1111_remove does not
appear to use the saved_state field, so the patch simply frees it first.
A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@@
expression E,E2;
@@
__sa1111_remove(E)
...
(
E = E2
|
* E
)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The MMC card detection sense has become really confused with negations
at various levels, leading to some platforms not detecting inserted
cards. Fix this by converting everything to positive logic throughout,
thereby getting rid of these negations.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
smp_processor_id() must not be called from a preemptible context (this
is checked by CONFIG_DEBUG_PREEMPT). kmap_high_l1_vipt() was doing so.
This lead to a problem where the wrong per_cpu kmap_high_l1_vipt_depth
could be incremented, causing a BUG_ON(*depth <= 0); in
kunmap_high_l1_vipt().
The solution is to move the call to smp_processor_id() after the call
to preempt_disable().
Originally by: Andrew Howe <ahowe@nvidia.com>
Signed-off-by: Gary King <gking@nvidia.com>
Acked-by: Nicolas Pitre <nico.as.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The ioread/iowrite accessors also need barriers as they're used in
place of readl/writel et.al. in portable drivers. Create __iormb()
and __iowmb() which are conditionally defined to be barriers dependent
on ARM_DMA_MEM_BUFFERABLE, and always use these macros in the accessors.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
