Pull SMP cross-CPU function-call updates from Ingo Molnar:
- Remove diagnostics and adjust config for CSD lock diagnostics
- Add a generic IPI-sending tracepoint, as currently there's no easy
way to instrument IPI origins: it's arch dependent and for some major
architectures it's not even consistently available.
* tag 'smp-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
trace,smp: Trace all smp_function_call*() invocations
trace: Add trace_ipi_send_cpu()
sched, smp: Trace smp callback causing an IPI
smp: reword smp call IPI comment
treewide: Trace IPIs sent via smp_send_reschedule()
irq_work: Trace self-IPIs sent via arch_irq_work_raise()
smp: Trace IPIs sent via arch_send_call_function_ipi_mask()
sched, smp: Trace IPIs sent via send_call_function_single_ipi()
trace: Add trace_ipi_send_cpumask()
kernel/smp: Make csdlock_debug= resettable
locking/csd_lock: Remove per-CPU data indirection from CSD lock debugging
locking/csd_lock: Remove added data from CSD lock debugging
locking/csd_lock: Add Kconfig option for csd_debug default
Pull objtool updates from Ingo Molnar:
- Mark arch_cpu_idle_dead() __noreturn, make all architectures &
drivers that did this inconsistently follow this new, common
convention, and fix all the fallout that objtool can now detect
statically
- Fix/improve the ORC unwinder becoming unreliable due to
UNWIND_HINT_EMPTY ambiguity, split it into UNWIND_HINT_END_OF_STACK
and UNWIND_HINT_UNDEFINED to resolve it
- Fix noinstr violations in the KCSAN code and the lkdtm/stackleak code
- Generate ORC data for __pfx code
- Add more __noreturn annotations to various kernel startup/shutdown
and panic functions
- Misc improvements & fixes
* tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
x86/hyperv: Mark hv_ghcb_terminate() as noreturn
scsi: message: fusion: Mark mpt_halt_firmware() __noreturn
x86/cpu: Mark {hlt,resume}_play_dead() __noreturn
btrfs: Mark btrfs_assertfail() __noreturn
objtool: Include weak functions in global_noreturns check
cpu: Mark nmi_panic_self_stop() __noreturn
cpu: Mark panic_smp_self_stop() __noreturn
arm64/cpu: Mark cpu_park_loop() and friends __noreturn
x86/head: Mark *_start_kernel() __noreturn
init: Mark start_kernel() __noreturn
init: Mark [arch_call_]rest_init() __noreturn
objtool: Generate ORC data for __pfx code
x86/linkage: Fix padding for typed functions
objtool: Separate prefix code from stack validation code
objtool: Remove superfluous dead_end_function() check
objtool: Add symbol iteration helpers
objtool: Add WARN_INSN()
scripts/objdump-func: Support multiple functions
context_tracking: Fix KCSAN noinstr violation
objtool: Add stackleak instrumentation to uaccess safe list
...
To be able to trace invocations of smp_send_reschedule(), rename the
arch-specific definitions of it to arch_smp_send_reschedule() and wrap it
into an smp_send_reschedule() that contains a tracepoint.
Changes to include the declaration of the tracepoint were driven by the
following coccinelle script:
@func_use@
@@
smp_send_reschedule(...);
@include@
@@
#include <trace/events/ipi.h>
@no_include depends on func_use && !include@
@@
#include <...>
+
+ #include <trace/events/ipi.h>
[csky bits]
[riscv bits]
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Guo Ren <guoren@kernel.org>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20230307143558.294354-6-vschneid@redhat.com
Before commit 076cbf5d2163 ("x86/xen: don't let xen_pv_play_dead()
return"), in Xen, when a previously offlined CPU was brought back
online, it unexpectedly resumed execution where it left off in the
middle of the idle loop.
There were some hacks to make that work, but the behavior was surprising
as do_idle() doesn't expect an offlined CPU to return from the dead (in
arch_cpu_idle_dead()).
Now that Xen has been fixed, and the arch-specific implementations of
arch_cpu_idle_dead() also don't return, give it a __noreturn attribute.
This will cause the compiler to complain if an arch-specific
implementation might return. It also improves code generation for both
caller and callee.
Also fixes the following warning:
vmlinux.o: warning: objtool: do_idle+0x25f: unreachable instruction
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/60d527353da8c99d4cf13b6473131d46719ed16d.1676358308.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Pull alpha updates from Al Viro:
"Mostly small janitorial fixes but there's also more important ones: a
patch to fix loading large modules from Edward Humes, and some fixes
from Al Viro"
[ The fixes from Al mostly came in separately through Al's trees too and
are now duplicated.. - Linus ]
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha:
alpha: in_irq() cleanup
alpha: lazy FPU switching
alpha/boot/misc: trim unused declarations
alpha/boot/tools/objstrip: fix the check for ELF header
alpha/boot: fix the breakage from -isystem series...
alpha: fix FEN fault handling
alpha: Avoid comma separated statements
alpha: fixed a typo in core_cia.c
alpha: remove unused __SLOW_DOWN_IO and SLOW_DOWN_IO definitions
alpha: update config files
alpha: fix R_ALPHA_LITERAL reloc for large modules
alpha: Add some spaces to ensure format specification
alpha: replace NR_SYSCALLS by NR_syscalls
alpha: Remove redundant local asm header redirections
alpha: Implement "current_stack_pointer"
alpha: remove redundant err variable
alpha: osf_sys: reduce kernel log spamming on invalid osf_mount call typenr
Replace the obsolete and ambiguos macro in_irq() with new
macro in_hardirq().
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Matt Turner <mattst88@gmail.com>
On each context switch we save the FPU registers on stack
of old process and restore FPU registers from the stack of new one.
That allows us to avoid doing that each time we enter/leave the
kernel mode; however, that can get suboptimal in some cases.
For one thing, we don't need to bother saving anything
for kernel threads. For another, if between entering and leaving
the kernel a thread gives CPU up more than once, it will do
useless work, saving the same values every time, only to discard
the saved copy as soon as it returns from switch_to().
Alternative solution:
* move the array we save into from switch_stack to thread_info
* have a (thread-synchronous) flag set when we save them
* have another flag set when they should be restored on return to userland.
* do *NOT* save/restore them in do_switch_stack()/undo_switch_stack().
* restore on the exit to user mode if the restore flag had
been set. Clear both flags.
* on context switch, entry to fork/clone/vfork, before entry into do_signal()
and on entry into straced syscall save the registers and set the 'saved' flag
unless it had been already set.
* on context switch set the 'restore' flag as well.
* have copy_thread() set both flags for child, so the registers would be
restored once the child returns to userland.
* use the saved data in setup_sigcontext(); have restore_sigcontext() set both flags
and copy from sigframe to save area.
* teach ptrace to look for FPU registers in thread_info instead of
switch_stack.
* teach isolated accesses to FPU registers (rdfpcr, wrfpcr, etc.)
to check the 'saved' flag (under preempt_disable()) and work with the save area
if it's been set; if 'saved' flag is found upon write access, set 'restore' flag
as well.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Type 3 instruction fault (FPU insn with FPU disabled) is handled
by quietly enabling FPU and returning. Which is fine, except that
we need to do that both for fault in userland and in the kernel;
the latter *can* legitimately happen - all it takes is this:
.global _start
_start:
call_pal 0xae
lda $0, 0
ldq $0, 0($0)
- call_pal CLRFEN to clear "FPU enabled" flag and arrange for
a signal delivery (SIGSEGV in this case).
Fixed by moving the handling of type 3 into the common part of
do_entIF(), before we check for kernel vs. user mode.
Incidentally, check for kernel mode is unidiomatic; the normal
way to do that is !user_mode(regs). The difference is that
the open-coded variant treats any of bits 63..3 of regs->ps being
set as "it's user mode" while the normal approach is to check just
the bit 3. PS is a 4-bit register and regs->ps always will have
bits 63..4 clear, so the open-code variant here is actually equivalent
to !user_mode(regs). Harder to follow, though...
Reproducer above will crash any box where CLRFEN is not ignored by
PAL (== any actual hardware, AFAICS; PAL used in qemu doesn't
bother implementing that crap).
Cc: stable@vger.kernel.org # all way back...
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Pull alpha updates from Al Viro:
"FEN (floating-point enable) fault fix deals with a really old oopsable
braino, the rest is alpha/boot compile fixes and minor cleaning up"
* 'work.alpha' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
alpha/boot/misc: trim unused declarations
alpha/boot/tools/objstrip: fix the check for ELF header
alpha/boot: fix the breakage from -isystem series...
alpha: fix FEN fault handling
Pull non-MM updates from Andrew Morton:
"There is no particular theme here - mainly quick hits all over the
tree.
Most notable is a set of zlib changes from Mikhail Zaslonko which
enhances and fixes zlib's use of S390 hardware support: 'lib/zlib: Set
of s390 DFLTCC related patches for kernel zlib'"
* tag 'mm-nonmm-stable-2023-02-20-15-29' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (55 commits)
Update CREDITS file entry for Jesper Juhl
sparc: allow PM configs for sparc32 COMPILE_TEST
hung_task: print message when hung_task_warnings gets down to zero.
arch/Kconfig: fix indentation
scripts/tags.sh: fix the Kconfig tags generation when using latest ctags
nilfs2: prevent WARNING in nilfs_dat_commit_end()
lib/zlib: remove redundation assignement of avail_in dfltcc_gdht()
lib/Kconfig.debug: do not enable DEBUG_PREEMPT by default
lib/zlib: DFLTCC always switch to software inflate for Z_PACKET_FLUSH option
lib/zlib: DFLTCC support inflate with small window
lib/zlib: Split deflate and inflate states for DFLTCC
lib/zlib: DFLTCC not writing header bits when avail_out == 0
lib/zlib: fix DFLTCC ignoring flush modes when avail_in == 0
lib/zlib: fix DFLTCC not flushing EOBS when creating raw streams
lib/zlib: implement switching between DFLTCC and software
lib/zlib: adjust offset calculation for dfltcc_state
nilfs2: replace WARN_ONs for invalid DAT metadata block requests
scripts/spelling.txt: add "exsits" pattern and fix typo instances
fs: gracefully handle ->get_block not mapping bh in __mpage_writepage
cramfs: Kconfig: fix spelling & punctuation
...
Previously, R_ALPHA_LITERAL relocations would overflow for large kernel
modules.
This was because the Alpha's apply_relocate_add was relying on the kernel's
module loader to have sorted the GOT towards the very end of the module as it
was mapped into memory in order to correctly assign the global pointer. While
this behavior would mostly work fine for small kernel modules, this approach
would overflow on kernel modules with large GOT's since the global pointer
would be very far away from the GOT, and thus, certain entries would be out of
range.
This patch fixes this by instead using the Tru64 behavior of assigning the
global pointer to be 32KB away from the start of the GOT. The change made
in this patch won't work for multi-GOT kernel modules as it makes the
assumption the module only has one GOT located at the beginning of .got,
although for the vast majority kernel modules, this should be fine. Of the
kernel modules that would previously result in a relocation error, none of
them, even modules like nouveau, have even come close to filling up a single
GOT, and they've all worked fine under this patch.
Signed-off-by: Edward Humes <aurxenon@lunos.org>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Calling the osf_mount system call with an invalid typenr value will
spam the kernel log with error messages. Reduce the spamming by making
it a ratelimited printk. Issue found when exercising with the stress-ng
enosys system call stressor.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Current arch_cpu_idle() is called with IRQs disabled, but will return
with IRQs enabled.
However, the very first thing the generic code does after calling
arch_cpu_idle() is raw_local_irq_disable(). This means that
architectures that can idle with IRQs disabled end up doing a
pointless 'enable-disable' dance.
Therefore, push this IRQ disabling into the idle function, meaning
that those architectures can avoid the pointless IRQ state flipping.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Acked-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Guo Ren <guoren@kernel.org>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195540.618076436@infradead.org
Type 3 instruction fault (FPU insn with FPU disabled) is handled
by quietly enabling FPU and returning. Which is fine, except that
we need to do that both for fault in userland and in the kernel;
the latter *can* legitimately happen - all it takes is this:
.global _start
_start:
call_pal 0xae
lda $0, 0
ldq $0, 0($0)
- call_pal CLRFEN to clear "FPU enabled" flag and arrange for
a signal delivery (SIGSEGV in this case).
Fixed by moving the handling of type 3 into the common part of
do_entIF(), before we check for kernel vs. user mode.
Incidentally, the check for kernel mode is unidiomatic; the normal
way to do that is !user_mode(regs). The difference is that
the open-coded variant treats any of bits 63..3 of regs->ps being
set as "it's user mode" while the normal approach is to check just
the bit 3. PS is a 4-bit register and regs->ps always will have
bits 63..4 clear, so the open-coded variant here is actually equivalent
to !user_mode(regs). Harder to follow, though...
Cc: stable@vger.kernel.org
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull alpha updates from Al Viro:
"Alpha architecture cleanups and fixes.
One thing *not* included is lazy FPU switching stuff - this pile is
just the straightforward stuff"
* tag 'pull-alpha' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
alpha: ret_from_fork can go straight to ret_to_user
alpha: syscall exit cleanup
alpha: fix handling of a3 on straced syscalls
alpha: fix syscall entry in !AUDUT_SYSCALL case
alpha: _TIF_ALLWORK_MASK is unused
alpha: fix TIF_NOTIFY_SIGNAL handling
