When preempt debugging is enabled, smp_processor_id() may utilize the
"current" structure. This may not be safe to access under all exceptions
due to it being in dynamically allocated memory. So in exception code,
make sure we use raw_smp_processor_id() instead to get at the real value
directly.
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Since the exception handler cannot cause exceptions, we cannot trace it
without easily causing double faults and crashing the system.
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Since the hardware only provides reporting for the last exception handled,
and the values are valid only when executing the exception handler, we
need to save the context for reporting at a later point. While we do this
for one exception, it doesn't work properly when handling a second one as
the original exception is clobbered by the double fault. So when double
fault debugging is enabled, create a dedicated shadow of these values and
save/restore out of there. Now the crash report properly displays the
first exception as well as the second one.
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The protect_page() function was incorrectly setting up the hardware tables
based on possible access capabilities rather than the actual requested
values. This means we would grant more access to mmap-ed pages than we
should have. Once we fix this, we need to tweak the signal generated by
such accesses to aline ourselves with other ports. This allows the LTP
mmap0{5,6,7} cases to run properly.
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The end of the stack may not be valid (and that could be OK), so do not
attempt to parse it. If we do, we might use a bad pointer in kernel space
which makes things panic().
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Unify the address display to shrink the code, and add missing decoding of
a few special Blackfin-specific regions (L1 ROM and MMRs).
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
We handle many exceptions at EVT5 (hardware error level) so that we can
catch exceptions in our exception handling code. Today - if the global
interrupt enable bit (IPEND[4]) is set (interrupts disabled) our trap
handling code goes into a infinite loop, since we need interrupts to be
on to defer things to EVT5.
Normal kernel code should not trigger this for any reason as IPEND[4] gets
cleared early (when doing an interrupt context save) and the kernel stack
there should be sane (or something much worse is happening in the system).
But there have been a few times where this has happened, so this change
makes sure we dump a proper crash message even when things have gone south.
Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Similar to anomaly 05000281 but not as bad, we cannot return to the
instruction causing a fault otherwise we'll trigger a second false
exception. The system can still recover, but it isn't correct.
Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Previous unification code put the exception banner behind the "is oops"
logic when it should have been printed all the time.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Add missing anomaly workaround for anomaly 05000281 - we can't return to
instructions which cause hardware errors otherwise we trigger the error
again which means we go into an infinite loop of handling, returning, and
retriggering. This work around confuses gdb when the error occurs as the
PC will seemed to have moved, so a better long term fix will need to be
figured out, but for now this is better than an infinite crash loop.
Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Commit 5fd29d6ccb ("printk: clean up
handling of log-levels and newlines") changed printk semantics. printk
lines with multiple KERN_<level> prefixes are no longer emitted as
before the patch.
<level> is now included in the output on each additional use.
Remove all uses of multiple KERN_<level>s in formats.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kgdb (in multiple places) and traps code developed pretty much
identical checks for how to access different regions of the Blackfin
memory map, but each wasn't 100%, so unify them to avoid duplication,
bitrot, and bugs with edge cases.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Rather than maintain a duplicate list of valid exceptions we can take in
the kernel both in the first if() check and the switch() check, delay the
oops check to after the switch(). All valid exceptions will have returned
by this point leaving only the invalid ones.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The trap_c() code pushes the hardware trace status onto the stack, but
doesn't always restore it when returning from some trap code paths. So
unify the exit code paths to all head to the end of the function.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
We have some test code that runs in userspace that exercises the exception
handling of the Blackfin pretty thoroughly. Part of the validation process
is checking the exact exception triggered, so export the last one seen to
userspace via debugfs when debugging is enabled for the test code to check.
Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
People often copy & paste crash messages without surrounding context, so
include common useful information like system/processor stats in the crash
summary. This should smooth over the report/test cycle a bit more.
Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Returning too fast with a bad RETI can trigger false errors.
Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
When displaying a crash dump, make sure accessing the stack is safe so
we don't crash at the same time.
Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Make sure we don't accidently re-enable interrupts if we are being
called in atomic context
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Make VMAs per mm_struct as for MMU-mode linux. This solves two problems:
(1) In SYSV SHM where nattch for a segment does not reflect the number of
shmat's (and forks) done.
(2) In mmap() where the VMA's vm_mm is set to point to the parent mm by an
exec'ing process when VM_EXECUTABLE is specified, regardless of the fact
that a VMA might be shared and already have its vm_mm assigned to another
process or a dead process.
A new struct (vm_region) is introduced to track a mapped region and to remember
the circumstances under which it may be shared and the vm_list_struct structure
is discarded as it's no longer required.
This patch makes the following additional changes:
(1) Regions are now allocated with alloc_pages() rather than kmalloc() and
with no recourse to __GFP_COMP, so the pages are not composite. Instead,
each page has a reference on it held by the region. Anything else that is
interested in such a page will have to get a reference on it to retain it.
When the pages are released due to unmapping, each page is passed to
put_page() and will be freed when the page usage count reaches zero.
(2) Excess pages are trimmed after an allocation as the allocation must be
made as a power-of-2 quantity of pages.
(3) VMAs are added to the parent MM's R/B tree and mmap lists. As an MM may
end up with overlapping VMAs within the tree, the VMA struct address is
appended to the sort key.
(4) Non-anonymous VMAs are now added to the backing inode's prio list.
(5) Holes may be punched in anonymous VMAs with munmap(), releasing parts of
the backing region. The VMA and region structs will be split if
necessary.
(6) sys_shmdt() only releases one attachment to a SYSV IPC shared memory
segment instead of all the attachments at that addresss. Multiple
shmat()'s return the same address under NOMMU-mode instead of different
virtual addresses as under MMU-mode.
(7) Core dumping for ELF-FDPIC requires fewer exceptions for NOMMU-mode.
(8) /proc/maps is now the global list of mapped regions, and may list bits
that aren't actually mapped anywhere.
(9) /proc/meminfo gains a line (tagged "MmapCopy") that indicates the amount
of RAM currently allocated by mmap to hold mappable regions that can't be
mapped directly. These are copies of the backing device or file if not
anonymous.
These changes make NOMMU mode more similar to MMU mode. The downside is that
NOMMU mode requires some extra memory to track things over NOMMU without this
patch (VMAs are no longer shared, and there are now region structs).
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Mike Frysinger <vapier.adi@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
[Mike Frysinger <vapier.adi@gmail.com>:
- handle bf531/bf532/bf534/bf536 variants in ipipe.h
- cleanup IPIPE logic for bfin_set_irq_handler()
- cleanup ipipe asm code a bit and add missing ENDPROC()
- simplify IPIPE code in trap_c
- unify some of the IPIPE code and fix style
- simplify DO_IRQ_L1 handling with ipipe code
- revert IRQ_SW_INT# addition from ipipe merge
- remove duplicate get_{c,s}clk() prototypes
]
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Blackfin dual core BF561 processor can support SMP like features.
https://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:smp-like
In this patch, we provide SMP extend to Blackfin kernel and memory management code
Singed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
d_path() can return an error. Most of its callers do something or other to
make up something sane in that case. Do similar for blackfin's
decode_address() call to d_path().
Signed-off-by: Tim Pepper <lnxninja@linux.vnet.ibm.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Add optional verbose debug - which when turned off, quiets down
userspace errors. Saves ~8k of code/data for production systems
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
The kernel does not properly clear the EBIU Error Master (EBIU_ERRMST) Register
on BF548, which causes the kernel to panic.
We need to make sure that we clear the EBIU_ERRMST (necessary on BF54x)
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Better error handling of unknown exceptions, allows userspace to do a
EXCPT n instruction for a not installed exception handler, and the
kernel doesn't crash (like it use to before this).
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
as pointed out by Michael McTernan in the forums, when expanding
the trace buffer, it does not print out the decoded instruction.
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
so that we always send the same signal and we handle the NULL ptr condition properly
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Remove the circular buffering mechanism for exceptions. Instead, point RETX
at a safe location from which to fetch three NOPs.
This safe location is now in the fixed code area, and also used for certain
anomaly workarounds, to ensure that user space can find a valid ICPLB when
things are built with CONFIG_MPU.
Also, save I/DCPLB_FAULT_ADDRESS when lowering to level 5, since the hardware
reg is valid only at exception level.
Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
grab locks when not atomic - this fixes the issues
sometimes seen when using magic sysrq.
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Sometimes when we crash, current is not valid, (has been written
over), so the existing code causes a invalid read during exception
context - which is a unrecoverable double fault. This fixes this.
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Yi Li