Function tracing is currently broken for all 32 bit MIPS platforms.
When tracing is enabled, the kernel immediately hangs on boot.
This is a result of commit b732d439cb
that changes the kernel/trace/Kconfig file so that is no longer
forces FRAME_POINTER when FUNCTION_TRACING is enabled.
MIPS frame pointers are generally considered to be useless because
they cannot be used to unwind the stack. Unfortunately the MIPS
function tracing code has bugs that are masked by the use of frame
pointers. This commit fixes the bugs so that MIPS frame pointers
don't need to be enabled.
The bugs are a result of the odd calling sequence used to call the trace
routine. This calling sequence is inserted into every traceable function
when the tracing CONFIG option is enabled. This sequence is generated
for 32bit MIPS platforms by the compiler via the "-pg" flag.
Part of the sequence is "addiu sp,sp,-8" in the delay slot after every
call to the trace routine "_mcount" (some legacy thing where 2 arguments
used to be pushed on the stack). The _mcount routine is expected to
adjust the sp by +8 before returning. So when not disabled, the original
jalr and addiu will be there, so _mcount has to adjust sp.
The problem is that when tracing is disabled for a function, the
"jalr _mcount" instruction is replaced with a nop, but the
"addiu sp,sp,-8" is still executed and the stack pointer is left
trashed. When frame pointers are enabled the problem is masked
because any access to the stack is done through the frame
pointer and the stack pointer is restored from the frame pointer when
the function returns.
This patch writes two nops starting at the address of the "jalr _mcount"
instruction whenever tracing is disabled. This means that the
"addiu sp,sp.-8" will be converted to a nop along with the "jalr". When
disabled, there will be two nops.
This is SMP safe because the first time this happens is during
ftrace_init() which is before any other processor has been started.
Subsequent calls to enable/disable tracing when other CPUs ARE running
will still be safe because the enable will only change the first nop
to a "jalr" and the disable, while writing 2 nops, will only be changing
the "jalr". This patch also stops using stop_machine() to call the
tracer enable/disable routines and calls them directly because the
routines are SMP safe.
When the kernel first boots we have to be able to handle the gcc
generated jalr, addui sequence until ftrace_init gets a chance to run
and change the sequence. At this point mcount just adjusts the stack
and returns. When ftrace_init runs, we convert the jalr/addui to nops.
Then whenever tracing is enabled we convert the first nop to a "jalr
mcount+8". The mcount+8 entry point skips the stack adjust.
[ralf@linux-mips.org: Folded in Steven Rostedt's build fix.]
Signed-off-by: Al Cooper <alcooperx@gmail.com>
Cc: rostedt@goodmis.org
Cc: ddaney.cavm@gmail.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/4806/
Patchwork: https://patchwork.linux-mips.org/patch/4841/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
In the printk, the variable t euqals to NULL, so there is no t->index.
Use v->tc->index instead.
[ralf@linux-mips.org: Use opportunity of changing this line anyway to make
this line whitespacely correct.]
Signed-off-by: Cong Ding <dinggnu@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/4792/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Pull MIPS fixes from Ralf Baechle:
"Various fixes across the tree. The modpost error due to
virt_addr_valid() not being usable from modules required a number of
preparatory cleanups so a clean fix was possible."
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: 64-bit: Fix build if !CONFIG_MODULES
MIPS: Wire up finit_module syscall.
MIPS: Fix modpost error in modules attepting to use virt_addr_valid().
MIPS: page.h: Remove now unnecessary #ifndef __ASSEMBLY__ wrapper.
MIPS: Switch remaining assembler PAGE_SIZE users to <asm/asm-offsets.h>.
MIPS: Include PAGE_S{IZE,HIFT} in <asm/offset.h>.
MIPS: Don't include <asm/page.h> unnecessarily.
MIPS: Fix comment.
Revert "MIPS: Optimise TLB handlers for MIPS32/64 R2 cores."
MIPS: perf: Fix build failure in XLP perf support.
MIPS: Alchemy: Make 32kHz and r4k timer coexist peacefully
CONFIG_HOTPLUG is going away as an option. As a result, the __dev*
markings need to be removed.
This change removes the use of __devinit, __devexit_p, __devinitdata,
and __devexit from these drivers.
Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.
Cc: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
So far we're jumping through hoops to keep the file usable from assembler
source but it's getting just too painful. Turns out that many uses of
<asm/page.h> are unnecessary anyway, so just remove those.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Commit 4be3d2f396 ("MIPS: perf: Add XLP
support for hardware perf.") added UNSUPPORTED_PERF_EVENT_ID which was
removed a while back.
Cc: Zi Shen Lim <zlim@netlogicmicro.com>
Cc: Jayachandran C <jchandra@broadcom.com>
Cc: Linux-MIPS <linux-mips@linux-mips.org>
Cc: John Crispin <blogic@openwrt.org>
Cc: Zi Shen Lim <zlim@netlogicmicro.com>
Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Acked-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: https://patchwork.linux-mips.org/patch/4730/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Pull MIPS updates from Ralf Baechle:
"The MIPS bits for 3.8. This also includes a bunch fixes that were
sitting in the linux-mips.org git tree for a long time. This pull
request contains updates to several OCTEON drivers and the board
support code for BCM47XX, BCM63XX, XLP, XLR, XLS, lantiq, Loongson1B,
updates to the SSB bus support, MIPS kexec code and adds support for
kdump.
When pulling this, there are two expected merge conflicts in
include/linux/bcma/bcma_driver_chipcommon.h which are trivial to
resolve, just remove the conflict markers and keep both alternatives."
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (90 commits)
MIPS: PMC-Sierra Yosemite: Remove support.
VIDEO: Newport Fix console crashes
MIPS: wrppmc: Fix build of PCI code.
MIPS: IP22/IP28: Fix build of EISA code.
MIPS: RB532: Fix build of prom code.
MIPS: PowerTV: Fix build.
MIPS: IP27: Correct fucked grammar in ops-bridge.c
MIPS: Highmem: Fix build error if CONFIG_DEBUG_HIGHMEM is disabled
MIPS: Fix potencial corruption
MIPS: Fix for warning from FPU emulation code
MIPS: Handle COP3 Unusable exception as COP1X for FP emulation
MIPS: Fix poweroff failure when HOTPLUG_CPU configured.
MIPS: MT: Fix build with CONFIG_UIDGID_STRICT_TYPE_CHECKS=y
MIPS: Remove unused smvp.h
MIPS/EDAC: Improve OCTEON EDAC support.
MIPS: OCTEON: Add definitions for OCTEON memory contoller registers.
MIPS: OCTEON: Add OCTEON family definitions to octeon-model.h
ata: pata_octeon_cf: Use correct byte order for DMA in when built little-endian.
MIPS/OCTEON/ata: Convert pata_octeon_cf.c to use device tree.
MIPS: Remove usage of CEVT_R4K_LIB config option.
...
Our FP emulator is hardcoded for the MIPS IV FP instruction set and does
not match the FP ISA with the general ISA. However for the few MIPS IV FP
instructions that use the COP1X major opcode it relies on the Coprocessor
Unusable exception to be delivered as a COP1 rather than COP3 exception.
This includes indexed transfer (LDXC1, etc.) and FP multiply-accumulate
(MADD.D, etc.) instructions.
All the MIPS I, II, III and IV processors and some newer chips that do not
implement the FPU use the COP3 exception however. Therefore I believe the
kernel should follow and redirect any COP3 Unusable traps to the emulator
unless an actual FPU part or core is present.
This is a change that implements it. Any minor opcode encodings that are
not recognised as valid FP instructions are rejected by the emulator and
will result in a SIGILL signal being delivered as they currently do. We
do not support vendor-specific coprocessor 3 implementations supported
with MIPS I and MIPS II ISA processors; we never set CP0.Status.CU3.
[Ralf: On MIPS IV processors the kernel always enables the XX bit which
replaces the CU3 bit off earlier architecture revisions.]
If matching between the CPU and the FPU ISA is considered required one
day, this can still be done in the emulator itself. I think the CpU
exception dispatcher is not the right place to do this anyway, as there
are further differences between MIPS I, MIPS II, MIPS III, MIPS IV and
MIPS32 FP ISAs.
Corresponding explanation of this implementation is included within the
change itself.
Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/project/linux-mips/list/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When poweroff machine, kernel_power_off() call disable_nonboot_cpus().
And if we have HOTPLUG_CPU configured, disable_nonboot_cpus() is not an
empty function but attempt to actually disable the nonboot cpus. Since
system state is SYSTEM_POWER_OFF, play_dead() won't be called and thus
disable_nonboot_cpus() hangs. Therefore, we make this patch to avoid
poweroff failure.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Hongliang Tao <taohl@lemote.com>
Signed-off-by: Hua Yan <yanh@lemote.com>
Cc: Yong Zhang <yong.zhang@windriver.com>
Cc: stable@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/4211/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When CONFIG_UIDGID_STRICT_TYPE_CHECKS is enabled, plain integer checking
between different uids/gids is explicitely turned into a build failure
by making the k{uid,gid}_t types a structure containing a value:
arch/mips/kernel/mips-mt-fpaff.c: In function 'check_same_owner':
arch/mips/kernel/mips-mt-fpaff.c:53:22: error: invalid operands to
binary == (have 'kuid_t' and 'kuid_t')
arch/mips/kernel/mips-mt-fpaff.c:54:15: error: invalid operands to
binary == (have 'kuid_t' and 'kuid_t')
In order to ensure proper comparison between uids, using the helper
function uid_eq() which performs the right thing whenever this config
option is turned on or off.
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Patchwork: https://patchwork.linux-mips.org/patch/4717/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Manuel Lauss <manuel.lauss@gmail.com> writes:
I introduced it as a fallback because early revisions of Alchemy hardware
we shipped had a non-functional 32kHz timer and had to rely on the r4k
timer instead. Previously the r4k timer was initialized regardless, but
it's useless with the "wait" instruction.
So long story short: I need either the on-chip 32kHz timer OR the r4k
timer if the 32kHz one is unusable, but not both, and r4k timer is useless
when au1k_idle is in use.
The current in-kernel Alchemy boards all work with the 32kHz timer, so I'm
not against removing R4K_LIB symbols.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Manuel Lauss <manuel.lauss@gmail.com> writes:
I introduced it as a fallback because early revisions of Alchemy hardware
we shipped had a non-functional 32kHz timer and had to rely on the r4k
timer instead. Previously the r4k timer was initialized regardless, but
it's useless with the "wait" instruction.
So long story short: I need either the on-chip 32kHz timer OR the r4k
timer if the 32kHz one is unusable, but not both, and r4k timer is useless
when au1k_idle is in use.
The current in-kernel Alchemy boards all work with the 32kHz timer, so I'm
not against removing R4K_LIB symbols.
Signed-off-by: Steven J. Hill <sjhill@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Pull big execve/kernel_thread/fork unification series from Al Viro:
"All architectures are converted to new model. Quite a bit of that
stuff is actually shared with architecture trees; in such cases it's
literally shared branch pulled by both, not a cherry-pick.
A lot of ugliness and black magic is gone (-3KLoC total in this one):
- kernel_thread()/kernel_execve()/sys_execve() redesign.
We don't do syscalls from kernel anymore for either kernel_thread()
or kernel_execve():
kernel_thread() is essentially clone(2) with callback run before we
return to userland, the callbacks either never return or do
successful do_execve() before returning.
kernel_execve() is a wrapper for do_execve() - it doesn't need to
do transition to user mode anymore.
As a result kernel_thread() and kernel_execve() are
arch-independent now - they live in kernel/fork.c and fs/exec.c
resp. sys_execve() is also in fs/exec.c and it's completely
architecture-independent.
- daemonize() is gone, along with its parts in fs/*.c
- struct pt_regs * is no longer passed to do_fork/copy_process/
copy_thread/do_execve/search_binary_handler/->load_binary/do_coredump.
- sys_fork()/sys_vfork()/sys_clone() unified; some architectures
still need wrappers (ones with callee-saved registers not saved in
pt_regs on syscall entry), but the main part of those suckers is in
kernel/fork.c now."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (113 commits)
do_coredump(): get rid of pt_regs argument
print_fatal_signal(): get rid of pt_regs argument
ptrace_signal(): get rid of unused arguments
get rid of ptrace_signal_deliver() arguments
new helper: signal_pt_regs()
unify default ptrace_signal_deliver
flagday: kill pt_regs argument of do_fork()
death to idle_regs()
don't pass regs to copy_process()
flagday: don't pass regs to copy_thread()
bfin: switch to generic vfork, get rid of pointless wrappers
xtensa: switch to generic clone()
openrisc: switch to use of generic fork and clone
unicore32: switch to generic clone(2)
score: switch to generic fork/vfork/clone
c6x: sanitize copy_thread(), get rid of clone(2) wrapper, switch to generic clone()
take sys_fork/sys_vfork/sys_clone prototypes to linux/syscalls.h
mn10300: switch to generic fork/vfork/clone
h8300: switch to generic fork/vfork/clone
tile: switch to generic clone()
...
Conflicts:
arch/microblaze/include/asm/Kbuild
The actual bug is a missing else statement - but really this should be
expressed using a switch() statement.
Found by Al Viro who writes "the funny thing is, it *does* work only
because r2 is syscall number and syscall number around 512 => return
value being ENOSYS and not one of ERESTART... so we really can't hit
the first if and emerge from it with ERESTART_RESTARTBLOCK. still
wrong to write it that way..."
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2957c9e61e (kernel.org) rsp.
b934da913f236bca00c41d9e386e980586000461 (lmo) [[MIPS] IRIX: Goodbye and
thanks for all the fish] left two fields in struct thread_struct which
were only being used for the IRIX compat code. Remove them.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The problem occurs [1] when a kernel-mode task returns from a system
call with a pending signal.
A real-life scenario is a child of 'khelper' returning from a failed
kernel_execve() in ____call_usermodehelper() [ kernel/kmod.c ].
kernel_execve() fails due to a pending SIGKILL, which is the result of
"kill -9 -1" (at least, busybox's init does it upon reboot).
The loop is as follows:
* syscall_exit_work:
- work_pending: // start_of_the_loop
- work_notifysig:
- do_notify_resume()
- do_signal()
- if (!user_mode(regs)) return;
- resume_userspace // TIF_SIGPENDING is still set
- work_pending // so we call work_pending => goto
// start_of_the_loop
More information can be found in another LKML thread:
http://www.serverphorums.com/read.php?12,457826
[1] The problem was also reproduced on !CONFIG_VM86 x86, and the
following fix was accepted.
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=29a2e2836ff9ea65a603c89df217f4198973a74f
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3571/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Broken since e05ea74fc56f347f872ef9946d27c53e8bf20864 (lmo) rsp.
cea7e2dfde (kernel.org) [MIPS: Sort out CPU
type to name translation.] These CPUs are no longer very popular to say
the least ...
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Reported-by: Murphy McCauley <murphy.mccauley@gmail.com>
This needs to use the compat entry point or it's going to fail on big
endian systems.
Noticed by Al Viro.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
By using the native syscall entry point the kernel was also expecting
64-bit iovec structures.
This is broken since ddd9e91b71 [preadv/
pwritev: MIPS: Add preadv(2) and pwritev(2) syscalls.] which originally
added these two syscalls. I walked through piles of code, including
libc and couldn't find anything that would have worked around the issue
so this change the API to what it should always have been.
Noticed and patch suggested by Al Viro.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Without this, we may end up with something like this in /proc/iomem:
01100000-014fffff : System RAM
01100000-013bf48f : Kernel code
013bf490-0149e01f : Kernel data
01500000-0c0fffff : System RAM
but the two System RAM ranges should be one single range. This particular
case will result in kexec failure on Octeon systems if the kernel being
loaded by kexec is bigger than the already running kernel.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add support for XLP performance counters register in perf. Update
mips/Kconfig so that perf events can be selected for XLP.
Signed-off-by: Zi Shen Lim <zlim@netlogicmicro.com>
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Patchwork: http://patchwork.linux-mips.org/patch/4457
Signed-off-by: John Crispin <blogic@openwrt.org>
The CPUNum Field in EBase register is 10bit wide, so after 1 bit right
shift, the mask value should be 0x1ff.
Signed-off-by: jerin jacob <jerinjacobk@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/4420/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This version contains a few updates by David Daney, in particular it's
now using __builtin_frame_address() instead of asm() which depending
on personal taste, is slightly more appealing.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Pull MIPS update from Ralf Baechle:
"Cleanups and fixes for breakage that occured earlier during this merge
phase. Also a few patches that didn't make the first pull request.
Of those is the Alchemy work that merges code for many of the SOCs and
evaluation boards thus among other code shrinkage, reduces the number
of MIPS defconfigs by 5."
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (22 commits)
MIPS: SNI: Switch RM400 serial to SCCNXP driver
MIPS: Remove unused empty_bad_pmd_table[] declaration.
MIPS: MT: Remove kspd.
MIPS: Malta: Fix section mismatch.
MIPS: asm-offset.c: Delete unused irq_cpustat_t struct offsets.
MIPS: Alchemy: Merge PB1100/1500 support into DB1000 code.
MIPS: Alchemy: merge PB1550 support into DB1550 code
MIPS: Alchemy: Single kernel for DB1200/1300/1550
MIPS: Optimize TLB refill for RI/XI configurations.
MIPS: proc: Cleanup printing of ASEs.
MIPS: Hardwire detection of DSP ASE Rev 2 for systems, as required.
MIPS: Add detection of DSP ASE Revision 2.
MIPS: Optimize pgd_init and pmd_init
MIPS: perf: Add perf functionality for BMIPS5000
MIPS: perf: Split the Kconfig option CONFIG_MIPS_MT_SMP
MIPS: perf: Remove unnecessary #ifdef
MIPS: perf: Add cpu feature bit for PCI (performance counter interrupt)
MIPS: perf: Change the "mips_perf_event" table unsupported indicator.
MIPS: Align swapper_pg_dir to 64K for better TLB Refill code.
vmlinux.lds.h: Allow architectures to add sections to the front of .bss
...
Pull module signing support from Rusty Russell:
"module signing is the highlight, but it's an all-over David Howells frenzy..."
Hmm "Magrathea: Glacier signing key". Somebody has been reading too much HHGTTG.
* 'modules-next' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (37 commits)
X.509: Fix indefinite length element skip error handling
X.509: Convert some printk calls to pr_devel
asymmetric keys: fix printk format warning
MODSIGN: Fix 32-bit overflow in X.509 certificate validity date checking
MODSIGN: Make mrproper should remove generated files.
MODSIGN: Use utf8 strings in signer's name in autogenerated X.509 certs
MODSIGN: Use the same digest for the autogen key sig as for the module sig
MODSIGN: Sign modules during the build process
MODSIGN: Provide a script for generating a key ID from an X.509 cert
MODSIGN: Implement module signature checking
MODSIGN: Provide module signing public keys to the kernel
MODSIGN: Automatically generate module signing keys if missing
MODSIGN: Provide Kconfig options
MODSIGN: Provide gitignore and make clean rules for extra files
MODSIGN: Add FIPS policy
module: signature checking hook
X.509: Add a crypto key parser for binary (DER) X.509 certificates
MPILIB: Provide a function to read raw data into an MPI
X.509: Add an ASN.1 decoder
X.509: Add simple ASN.1 grammar compiler
...
Cleanups
Clean up compile warnings in kgdboc.c and x86/kernel/kgdb.c
Add module event hooks for simplified debugging with gdb
Fixes
Fix kdb to stop paging with 'q' on bta and dmesg
Fix for data that scrolls off the vga console due to line wrapping
when using the kdb pager
New
The debug core registers for kernel module events which allows a
kernel aware gdb to automatically load symbols and break on entry
to a kernel module
Allow kgdboc=kdb to setup kdb on the vga console
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)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=uf0L
-----END PGP SIGNATURE-----
Merge tag 'for_linus-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb
Pull KGDB/KDB fixes and cleanups from Jason Wessel:
"Cleanups
- Clean up compile warnings in kgdboc.c and x86/kernel/kgdb.c
- Add module event hooks for simplified debugging with gdb
Fixes
- Fix kdb to stop paging with 'q' on bta and dmesg
- Fix for data that scrolls off the vga console due to line wrapping
when using the kdb pager
New
- The debug core registers for kernel module events which allows a
kernel aware gdb to automatically load symbols and break on entry
to a kernel module
- Allow kgdboc=kdb to setup kdb on the vga console"
* tag 'for_linus-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
tty/console: fix warnings in drivers/tty/serial/kgdboc.c
kdb,vt_console: Fix missed data due to pager overruns
kdb: Fix dmesg/bta scroll to quit with 'q'
kgdboc: Accept either kbd or kdb to activate the vga + keyboard kdb shell
kgdb,x86: fix warning about unused variable
mips,kgdb: fix recursive page fault with CONFIG_KPROBES
kgdb: Add module event hooks
getname() is intended to copy pathname strings from userspace into a
kernel buffer. The result is just a string in kernel space. It would
however be quite helpful to be able to attach some ancillary info to
the string.
For instance, we could attach some audit-related info to reduce the
amount of audit-related processing needed. When auditing is enabled,
we could also call getname() on the string more than once and not
need to recopy it from userspace.
This patchset converts the getname()/putname() interfaces to return
a struct instead of a string. For now, the struct just tracks the
string in kernel space and the original userland pointer for it.
Later, we'll add other information to the struct as it becomes
convenient.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This fault was detected using the kgdb test suite on boot and it
crashes recursively due to the fact that CONFIG_KPROBES on mips adds
an extra die notifier in the page fault handler. The crash signature
looks like this:
kgdbts:RUN bad memory access test
KGDB: re-enter exception: ALL breakpoints killed
Call Trace:
[<807b7548>] dump_stack+0x20/0x54
[<807b7548>] dump_stack+0x20/0x54
The fix for now is to have kgdb return immediately if the fault type
is DIE_PAGE_FAULT and allow the kprobe code to decide what is supposed
to happen.
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Originally added in 05b541489c48e7fbeec19a92acf8683230750d0a [Merge with
Linux 2.5.5.] over 10 years ago but never been used.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
[ralf@linux-mips.org: This patch really only detects the ASE and passes its
existence on to userland via /proc/cpuinfo. The DSP ASE Rev 2. adds new
resources but no resources that would need management by the kernel.]
Signed-off-by: Steven J. Hill <sjhill@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/4165/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Steven J. Hill