In commit c8c3735997 ("parisc: Enhance detection of synchronous cr16
clocksources") I assumed that CPUs on the same physical core are syncronous.
While booting up the kernel on two different C8000 machines, one with a
dual-core PA8800 and one with a dual-core PA8900 CPU, this turned out to be
wrong. The symptom was that I saw a jump in the internal clocks printed to the
syslog and strange overall behaviour. On machines which have 4 cores (2
dual-cores) the problem isn't visible, because the current logic already marked
the cr16 clocksource unstable in this case.
This patch now marks the cr16 interval timers unstable if we have more than one
CPU in the system, and it fixes this issue.
Fixes: c8c3735997 ("parisc: Enhance detection of synchronous cr16 clocksources")
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v5.15+
This reverts commit 279917e27e.
With the CONFIG_HARDENED_USERCOPY option enabled, this patch triggers
kernel bugs at runtime:
usercopy: Kernel memory overwrite attempt detected to kernel text (offset 2084839, size 6)!
kernel BUG at mm/usercopy.c:99!
Backtrace:
IAOQ[0]: usercopy_abort+0xc4/0xe8
[<00000000406ed1c8>] __check_object_size+0x174/0x238
[<00000000407086d4>] copy_strings.isra.0+0x3e8/0x708
[<0000000040709a20>] do_execveat_common.isra.0+0x1bc/0x328
[<000000004070b760>] compat_sys_execve+0x7c/0xb8
[<0000000040303eb8>] syscall_exit+0x0/0x14
The problem is, that we have an init section of at least 2MB size which
starts at _stext and is freed after bootup.
If then later some kernel data is (temporarily) stored in this free
memory, check_kernel_text_object() will trigger a bug since the data
appears to be inside the kernel text (>=_stext) area:
if (overlaps(ptr, len, _stext, _etext))
usercopy_abort("kernel text");
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@kernel.org # 5.4+
The extru instruction leaves the most significant 32 bits of the target
register in an undefined state on PA 2.0 systems. If any of these bits
are nonzero, this will break the calculation of the lock pointer.
Fix by using extrd,u instruction via extru_safe macro on 64-bit kernels.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
commit 8779e05ba8 ("parisc: Fix ptrace check on syscall return")
fixed testing of TI_FLAGS. This uncovered a bug in the test mask.
syscall_restore_rfi is only used when the kernel needs to exit to
usespace with single or block stepping and the recovery counter
enabled. The test however used _TIF_SYSCALL_TRACE_MASK, which
includes a lot of bits that shouldn't be tested here.
Fix this by using TIF_SINGLESTEP and TIF_BLOCKSTEP directly.
I encountered this bug by enabling syscall tracepoints. Both in qemu and
on real hardware. As soon as i enabled the tracepoint (sys_exit_read,
but i guess it doesn't really matter which one), i got random page
faults in userspace almost immediately.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
For years, there have been random segmentation faults in userspace on
SMP PA-RISC machines. It occurred to me that this might be a problem in
set_pte_at(). MIPS and some other architectures do cache flushes when
installing PTEs with the present bit set.
Here I have adapted the code in update_mmu_cache() to flush the kernel
mapping when the kernel flush is deferred, or when the kernel mapping
may alias with the user mapping. This simplifies calls to
update_mmu_cache().
I also changed the barrier in set_pte() from a compiler barrier to a
full memory barrier. I know this change is not sufficient to fix the
problem. It might not be needed.
I have had a few days of operation with 5.14.16 to 5.15.1 and haven't
seen any random segmentation faults on rp3440 or c8000 so far.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@kernel.org # 5.12+
I noticed that sometimes at kernel startup the backtraces did not
included the function names of init functions. Their address were not
resolved to function names and instead only the address was printed.
Debugging shows that the culprit is is_ksym_addr() which is called
by the backtrace functions to check if an address belongs to a function in
the kernel. The problem occurs only for CONFIG_KALLSYMS_ALL=y.
When looking at is_ksym_addr() one can see that for CONFIG_KALLSYMS_ALL=y
the function only tries to resolve the address via is_kernel() function,
which checks like this:
if (addr >= _stext && addr <= _end)
return 1;
On parisc the init functions are located before _stext, so this check fails.
Other platforms seem to have all functions (including init functions)
behind _stext.
The following patch moves the _stext symbol at the beginning of the
kernel and thus includes the init section. This fixes the check and does
not seem to have any negative side effects on where the kernel mapping
happens in the map_pages() function in arch/parisc/mm/init.c.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@kernel.org # 5.4+
In commit 2214c0e772 ("parisc: Move thread_info into task struct")
PA-RISC gained support for THREAD_INFO_IN_TASK while changes were
already underway to keep the CPU field in thread_info rather than move
it into task_struct when THREAD_INFO_IN_TASK is enabled. The result is a
broken build for all PA-RISC configs that enable SMP.
So let's partially revert that commit, and get rid of the ugly hack to
get at the offset of task_struct::cpu without having to include
linux/sched.h, and put the CPU field back where it was before.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Fixes: bcf9033e54 ("sched: move CPU field back into thread_info if THREAD_INFO_IN_TASK=y")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Helge Deller <deller@gmx.de>
I no longer think interrupts can be disabled in the futex and cmpxchg
operations because of COW breaks. This not ideal but I suspect it's the
best we can do.
For the cmpxchg operations in syscall.S, we rely on the code to not
schedule off the gateway page. For the futex, I added code to disable
preemption.
So far, I haven't seen the warnings with the attached change but the
change is only lightly tested.
Signed-off-by: Dave Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
If the previous context had interrupts disabled, we should better
keep them disabled. This was noticed in the unwinding code where
a copy_from_kernel_nofault() triggered a page fault, and after
the fixup by the page fault handler interrupts where suddenly
enabled.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Pull audit updates from Paul Moore:
"Add some additional audit logging to capture the openat2() syscall
open_how struct info.
Previous variations of the open()/openat() syscalls allowed audit
admins to inspect the syscall args to get the information contained in
the new open_how struct used in openat2()"
* tag 'audit-pr-20211101' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
audit: return early if the filter rule has a lower priority
audit: add OPENAT2 record to list "how" info
audit: add support for the openat2 syscall
audit: replace magic audit syscall class numbers with macros
lsm_audit: avoid overloading the "key" audit field
audit: Convert to SPDX identifier
audit: rename struct node to struct audit_node to prevent future name collisions
Pull tracing updates from Steven Rostedt:
- kprobes: Restructured stack unwinder to show properly on x86 when a
stack dump happens from a kretprobe callback.
- Fix to bootconfig parsing
- Have tracefs allow owner and group permissions by default (only
denying others). There's been pressure to allow non root to tracefs
in a controlled fashion, and using groups is probably the safest.
- Bootconfig memory managament updates.
- Bootconfig clean up to have the tools directory be less dependent on
changes in the kernel tree.
- Allow perf to be traced by function tracer.
- Rewrite of function graph tracer to be a callback from the function
tracer instead of having its own trampoline (this change will happen
on an arch by arch basis, and currently only x86_64 implements it).
- Allow multiple direct trampolines (bpf hooks to functions) be batched
together in one synchronization.
- Allow histogram triggers to add variables that can perform
calculations against the event's fields.
- Use the linker to determine architecture callbacks from the ftrace
trampoline to allow for proper parameter prototypes and prevent
warnings from the compiler.
- Extend histogram triggers to key off of variables.
- Have trace recursion use bit magic to determine preempt context over
if branches.
- Have trace recursion disable preemption as all use cases do anyway.
- Added testing for verification of tracing utilities.
- Various small clean ups and fixes.
* tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (101 commits)
tracing/histogram: Fix semicolon.cocci warnings
tracing/histogram: Fix documentation inline emphasis warning
tracing: Increase PERF_MAX_TRACE_SIZE to handle Sentinel1 and docker together
tracing: Show size of requested perf buffer
bootconfig: Initialize ret in xbc_parse_tree()
ftrace: do CPU checking after preemption disabled
ftrace: disable preemption when recursion locked
tracing/histogram: Document expression arithmetic and constants
tracing/histogram: Optimize division by a power of 2
tracing/histogram: Covert expr to const if both operands are constants
tracing/histogram: Simplify handling of .sym-offset in expressions
tracing: Fix operator precedence for hist triggers expression
tracing: Add division and multiplication support for hist triggers
tracing: Add support for creating hist trigger variables from literal
selftests/ftrace: Stop tracing while reading the trace file by default
MAINTAINERS: Update KPROBES and TRACING entries
test_kprobes: Move it from kernel/ to lib/
docs, kprobes: Remove invalid URL and add new reference
samples/kretprobes: Fix return value if register_kretprobe() failed
lib/bootconfig: Fix the xbc_get_info kerneldoc
...
Pull parisc updates from Helge Deller:
"Lots of new features and fixes:
- Added TOC (table of content) support, which is a debugging feature
which is either initiated by pressing the TOC button or via command
in the BMC. If pressed the Linux built-in KDB/KGDB will be called
(Sven Schnelle)
- Fix CONFIG_PREEMPT (Sven)
- Fix unwinder on 64-bit kernels (Sven)
- Various kgdb fixes (Sven)
- Added KFENCE support (me)
- Switch to ARCH_STACKWALK implementation (me)
- Fix ptrace check on syscall return (me)
- Fix kernel crash with fixmaps on PA1.x machines (me)
- Move thread_info into task struct, aka CONFIG_THREAD_INFO_IN_TASK
(me)
- Updated defconfigs
- Smaller cleanups, including Makefile cleanups (Masahiro Yamada),
use kthread_run() macro (Cai Huoqing), use swap() macro (Yihao
Han)"
* tag 'for-5.16/parisc-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: (36 commits)
parisc: Fix set_fixmap() on PA1.x CPUs
parisc: Use swap() to swap values in setup_bootmem()
parisc: Update defconfigs
parisc: decompressor: clean up Makefile
parisc: decompressor: remove repeated depenency of misc.o
parisc: Remove unused constants from asm-offsets.c
parisc/ftrace: use static key to enable/disable function graph tracer
parisc/ftrace: set function trace function
parisc: Make use of the helper macro kthread_run()
parisc: mark xchg functions notrace
parisc: enhance warning regarding usage of O_NONBLOCK
parisc: Drop ifdef __KERNEL__ from non-uapi kernel headers
parisc: Use PRIV_USER and PRIV_KERNEL in ptrace.h
parisc: Use PRIV_USER in syscall.S
parisc/kgdb: add kgdb_roundup() to make kgdb work with idle polling
parisc: Move thread_info into task struct
parisc: add support for TOC (transfer of control)
parisc/firmware: add functions to retrieve TOC data
parisc: add PIM TOC data structures
parisc: move virt_map macro to assembly.h
...
This avoids using dereference_function_descriptor in the ftrace code
path, and it's also faster.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
With DYNAMIC_FTRACE, we need to implement ftrace_update_trace_func
and not call ftrace_trace_function() directly, as ftrace doesn't
expect calls to this function during code patching.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Replace kthread_create/wake_up_process() with kthread_run()
to simplify the code.
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Instead of showing only the very first application which needs
recompile, show all of them, but print them only once.
Includes typo fix noticed by Colin Ian King.
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
With idle polling, IPIs are not sent when a CPU idle, but queued
and run later from do_idle(). The default kgdb_call_nmi_hook()
implementation gets the pointer to struct pt_regs from get_irq_reqs(),
which doesn't work in that case because it was not called from the
IPI interrupt handler. Fix it by defining our own kgdb_roundup()
function which sents an IPI_ENTER_KGDB. When that IPI is received
on the target CPU kgdb_nmicallback() is called.
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
This implements the CONFIG_THREAD_INFO_IN_TASK option.
With this change:
- before thread_info was part of the stack and located at the beginning of the stack
- now the thread_info struct is moved and located inside the task_struct structure
- the stack is allocated and handled like the major other platforms
- drop the cpu field of thread_info and use instead the one in task_struct
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Almost all PA-RISC machines have either a button that
is labeled with 'TOC' or a BMC function to trigger a TOC.
TOC is a non-maskable interrupt that is sent to the processor.
This can be used for diagnostic purposes like obtaining a
stack trace/register dump or to enter KDB/KGDB.
As an example, on my c8000, TOC can be used with:
CONFIG_KGDB=y
CONFIG_KGDB_KDB=y
and the 'kgdboc=ttyS0,115200' appended to the command line.
Press ^[( on serial console, which will enter the BMC command line,
and enter 'TOC s':
root@(none):/# (
cli>TOC s
Sending TOC/INIT.
<Cpu3> 2800035d03e00000 0000000040c21ac8 CC_ERR_CHECK_TOC
<Cpu0> 2800035d00e00000 0000000040c21ad0 CC_ERR_CHECK_TOC
<Cpu2> 2800035d02e00000 0000000040c21ac8 CC_ERR_CHECK_TOC
<Cpu1> 2800035d01e00000 0000000040c21ad0 CC_ERR_CHECK_TOC
<Cpu3> 37000f7303e00000 2000000000000000 CC_ERR_CPU_CHECK_SUMMARY
<Cpu0> 37000f7300e00000 2000000000000000 CC_ERR_CPU_CHECK_SUMMARY
<Cpu2> 37000f7302e00000 2000000000000000 CC_ERR_CPU_CHECK_SUMMARY
<Cpu1> 37000f7301e00000 2000000000000000 CC_ERR_CPU_CHECK_SUMMARY
<Cpu3> 4300100803e00000 c0000000001d26cc CC_MC_BR_TO_OS_TOC
<Cpu0> 4300100800e00000 c0000000001d26cc CC_MC_BR_TO_OS_TOC
<Cpu2> 4300100802e00000 c0000000001d26cc CC_MC_BR_TO_OS_TOC
<Cpu1> 4300100801e00000 c0000000001d26cc CC_MC_BR_TO_OS_TOC
Entering kdb (current=0x00000000411cef80, pid 0) on processor 0 due to NonMaskable Interrupt @ 0x40c21ad0
[0]kdb>
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
