| Age | Commit message (Collapse) | Author |
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David reports that:
<quote>
Perf has this hack where it uses the kernel symbol map as a backup when
a symbol can't be found in the user's symbol table(s).
This causes problems because the tests driving this code path use
machine__kernel_ip(), and that is completely meaningless on Sparc. On
sparc64 the kernel and user live in physically separate virtual address
spaces, rather than a shared one. And the kernel lives at a virtual
address that overlaps common userspace addresses. So this test passes
almost all the time when a user symbol lookup fails.
The consequence of this is that, if the unfound user virtual address in
the sample doesn't match up to a kernel symbol either, we trigger things
like this code in builtin-top.c:
if (al.sym == NULL && al.map != NULL) {
const char *msg = "Kernel samples will not be resolved.\n";
/*
* As we do lazy loading of symtabs we only will know if the
* specified vmlinux file is invalid when we actually have a
* hit in kernel space and then try to load it. So if we get
* here and there are _no_ symbols in the DSO backing the
* kernel map, bail out.
*
* We may never get here, for instance, if we use -K/
* --hide-kernel-symbols, even if the user specifies an
* invalid --vmlinux ;-)
*/
if (!machine->kptr_restrict_warned && !top->vmlinux_warned &&
__map__is_kernel(al.map) && map__has_symbols(al.map)) {
if (symbol_conf.vmlinux_name) {
char serr[256];
dso__strerror_load(al.map->dso, serr, sizeof(serr));
ui__warning("The %s file can't be used: %s\n%s",
symbol_conf.vmlinux_name, serr, msg);
} else {
ui__warning("A vmlinux file was not found.\n%s",
msg);
}
if (use_browser <= 0)
sleep(5);
top->vmlinux_warned = true;
}
}
When I fire up a compilation on sparc, this triggers immediately.
I'm trying to figure out what the "backup to kernel map" code is
accomplishing.
I see some language in the current code and in the changes that have
happened in this area talking about vdso. Does that really happen?
The vdso is mapped into userspace virtual addresses, not kernel ones.
More history. This didn't cause problems on sparc some time ago,
because the kernel IP check used to be "ip < 0" :-) Sparc kernel
addresses are not negative. But now with machine__kernel_ip(), which
works using the symbol table determined kernel address range, it does
trigger.
What it all boils down to is that on architectures like sparc,
machine__kernel_ip() should always return false in this scenerio, and
therefore this kind of logic:
if (cpumode == PERF_RECORD_MISC_USER && machine &&
mg != &machine->kmaps &&
machine__kernel_ip(machine, al->addr)) {
is basically invalid. PERF_RECORD_MISC_USER implies no kernel address
can possibly match for the sample/event in question (no matter how
hard you try!) :-)
</>
So, I thought something had changed and in the past we would somehow
find that address in the kallsyms, but I couldn't find anything to back
that up, the patch introducing this is over a decade old, lots of things
changed, so I was just thinking I was missing something.
I tried a gtod busy loop to generate vdso activity and added a 'perf
probe' at that branch, on x86_64 to see if it ever gets hit:
Made thread__find_map() noinline, as 'perf probe' in lines of inline
functions seems to not be working, only at function start. (Masami?)
# perf probe -x ~/bin/perf -L thread__find_map:57
<thread__find_map@/home/acme/git/perf/tools/perf/util/event.c:57>
57 if (cpumode == PERF_RECORD_MISC_USER && machine &&
58 mg != &machine->kmaps &&
59 machine__kernel_ip(machine, al->addr)) {
60 mg = &machine->kmaps;
61 load_map = true;
62 goto try_again;
}
} else {
/*
* Kernel maps might be changed when loading
* symbols so loading
* must be done prior to using kernel maps.
*/
69 if (load_map)
70 map__load(al->map);
71 al->addr = al->map->map_ip(al->map, al->addr);
# perf probe -x ~/bin/perf thread__find_map:60
Added new event:
probe_perf:thread__find_map (on thread__find_map:60 in /home/acme/bin/perf)
You can now use it in all perf tools, such as:
perf record -e probe_perf:thread__find_map -aR sleep 1
#
Then used this to see if, system wide, those probe points were being hit:
# perf trace -e *perf:thread*/max-stack=8/
^C[root@jouet ~]#
No hits when running 'perf top' and:
# cat gtod.c
#include <sys/time.h>
int main(void)
{
struct timeval tv;
while (1)
gettimeofday(&tv, 0);
return 0;
}
[root@jouet c]# ./gtod
^C
Pressed 'P' in 'perf top' and the [vdso] samples are there:
62.84% [vdso] [.] __vdso_gettimeofday
8.13% gtod [.] main
7.51% [vdso] [.] 0x0000000000000914
5.78% [vdso] [.] 0x0000000000000917
5.43% gtod [.] _init
2.71% [vdso] [.] 0x000000000000092d
0.35% [kernel] [k] native_io_delay
0.33% libc-2.26.so [.] __memmove_avx_unaligned_erms
0.20% [vdso] [.] 0x000000000000091d
0.17% [i2c_i801] [k] i801_access
0.06% firefox [.] free
0.06% libglib-2.0.so.0.5400.3 [.] g_source_iter_next
0.05% [vdso] [.] 0x0000000000000919
0.05% libpthread-2.26.so [.] __pthread_mutex_lock
0.05% libpixman-1.so.0.34.0 [.] 0x000000000006d3a7
0.04% [kernel] [k] entry_SYSCALL_64_trampoline
0.04% libxul.so [.] style::dom_apis::query_selector_slow
0.04% [kernel] [k] module_get_kallsym
0.04% firefox [.] malloc
0.04% [vdso] [.] 0x0000000000000910
I added a 'perf probe' to thread__find_map:69, and that surely got tons
of hits, i.e. for every map found, just to make sure the 'perf probe'
command was really working.
In the process I noticed a bug, we're only have records for '[vdso]' for
pre-existing commands, i.e. ones that are running when we start 'perf top',
when we will generate the PERF_RECORD_MMAP by looking at /perf/PID/maps.
I.e. like this, for preexisting processes with a vdso map, again,
tracing for all the system, only pre-existing processes get a [vdso] map
(when having one):
[root@jouet ~]# perf probe -x ~/bin/perf __machine__addnew_vdso
Added new event:
probe_perf:__machine__addnew_vdso (on __machine__addnew_vdso in /home/acme/bin/perf)
You can now use it in all perf tools, such as:
perf record -e probe_perf:__machine__addnew_vdso -aR sleep 1
[root@jouet ~]# perf trace -e probe_perf:__machine__addnew_vdso/max-stack=8/
0.000 probe_perf:__machine__addnew_vdso:(568eb3)
__machine__addnew_vdso (/home/acme/bin/perf)
map__new (/home/acme/bin/perf)
machine__process_mmap2_event (/home/acme/bin/perf)
machine__process_event (/home/acme/bin/perf)
perf_event__process (/home/acme/bin/perf)
perf_tool__process_synth_event (/home/acme/bin/perf)
perf_event__synthesize_mmap_events (/home/acme/bin/perf)
__event__synthesize_thread (/home/acme/bin/perf)
The kernel is generating a PERF_RECORD_MMAP for vDSOs, but somehow
'perf top' is not getting those records while 'perf record' is:
# perf record ~acme/c/gtod
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.076 MB perf.data (1499 samples) ]
# perf report -D | grep PERF_RECORD_MMAP2
71293612401913 0x11b48 [0x70]: PERF_RECORD_MMAP2 25484/25484: [0x400000(0x1000) @ 0 fd:02 1137 541179306]: r-xp /home/acme/c/gtod
71293612419012 0x11be0 [0x70]: PERF_RECORD_MMAP2 25484/25484: [0x7fa4a2783000(0x227000) @ 0 fd:00 3146370 854107250]: r-xp /usr/lib64/ld-2.26.so
71293612432110 0x11c50 [0x60]: PERF_RECORD_MMAP2 25484/25484: [0x7ffcdb53a000(0x2000) @ 0 00:00 0 0]: r-xp [vdso]
71293612509944 0x11cb0 [0x70]: PERF_RECORD_MMAP2 25484/25484: [0x7fa4a23cd000(0x3b6000) @ 0 fd:00 3149723 262067164]: r-xp /usr/lib64/libc-2.26.so
#
# perf script | grep vdso | head
gtod 25484 71293.612768: 2485554 cycles:ppp: 7ffcdb53a914 [unknown] ([vdso])
gtod 25484 71293.613576: 2149343 cycles:ppp: 7ffcdb53a917 [unknown] ([vdso])
gtod 25484 71293.614274: 1814652 cycles:ppp: 7ffcdb53aca8 __vdso_gettimeofday+0x98 ([vdso])
gtod 25484 71293.614862: 1669070 cycles:ppp: 7ffcdb53acc5 __vdso_gettimeofday+0xb5 ([vdso])
gtod 25484 71293.615404: 1451589 cycles:ppp: 7ffcdb53acc5 __vdso_gettimeofday+0xb5 ([vdso])
gtod 25484 71293.615999: 1269941 cycles:ppp: 7ffcdb53ace6 __vdso_gettimeofday+0xd6 ([vdso])
gtod 25484 71293.616405: 1177946 cycles:ppp: 7ffcdb53a914 [unknown] ([vdso])
gtod 25484 71293.616775: 1121290 cycles:ppp: 7ffcdb53ac47 __vdso_gettimeofday+0x37 ([vdso])
gtod 25484 71293.617150: 1037721 cycles:ppp: 7ffcdb53ace6 __vdso_gettimeofday+0xd6 ([vdso])
gtod 25484 71293.617478: 994526 cycles:ppp: 7ffcdb53ace6 __vdso_gettimeofday+0xd6 ([vdso])
#
The patch is the obvious one and with it we also continue to resolve
vdso symbols for pre-existing processes in 'perf top' and for all
processes in 'perf record' + 'perf report/script'.
Suggested-by: David Miller <davem@davemloft.net>
Acked-by: David Miller <davem@davemloft.net>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-cs7skq9pp0kjypiju6o7trse@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Pull single NVMe fix from Christoph.
* 'nvme-4.19' of git://git.infradead.org/nvme:
nvme: remove ns sibling before clearing path
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The DAC960 driver has been obsoleted by the myrb/myrs drivers,
so it can be dropped.
Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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This patch adds the necessary code to patch a running kernel at runtime
to improve performance.
The current implementation offers a few optimizations variants:
- When running a SMP kernel on a single UP processor, unwanted assembler
statements like locking functions are overwritten with NOPs. When
multiple instructions shall be skipped, one branch instruction is used
instead of multiple nop instructions.
- In the UP case, some pdtlb and pitlb instructions are patched to
become pdtlb,l and pitlb,l which only flushes the CPU-local tlb
entries instead of broadcasting the flush to other CPUs in the system
and thus may improve performance.
- fic and fdc instructions are skipped if no I- or D-caches are
installed. This should speed up qemu emulation and cacheless systems.
- If no cache coherence is needed for IO operations, the relevant fdc
and sync instructions in the sba and ccio drivers are replaced by
nops.
- On systems which share I- and D-TLBs and thus don't have a seperate
instruction TLB, the pitlb instruction is replaced by a nop.
Live-patching is done early in the boot process, just after having run
the system inventory. No drivers are running and thus no external
interrupts should arrive. So the hope is that no TLB exceptions will
occur during the patching. If this turns out to be wrong we will
probably need to do the patching in real-mode.
Signed-off-by: Helge Deller <deller@gmx.de>
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git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Helge writes:
"parisc fix:
Fix an unitialized variable usage in the parisc unwind code."
* 'parisc-4.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Fix uninitialized variable usage in unwind.c
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git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Stephen writes:
"clk fixes for v4.19-rc8
One fix for the Allwinner A10 SoC's audio PLL that wasn't properly
set and generating noise."
* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
clk: sunxi-ng: sun4i: Set VCO and PLL bias current to lowest setting
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switch if there is an FPU
Booting an i486 with "no387 nofxsr" ends with with the following crash:
math_emulate: 0060:c101987d
Kernel panic - not syncing: Math emulation needed in kernel
on the first context switch in user land.
The reason is that copy_fpregs_to_fpstate() tries FNSAVE which does not work
as the FPU is turned off.
This bug was introduced in:
f1c8cd0176078 ("x86/fpu: Change fpu->fpregs_active users to fpu->fpstate_active")
Add a check for X86_FEATURE_FPU before trying to save FPU registers (we
have such a check in switch_fpu_finish() already).
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: f1c8cd0176078 ("x86/fpu: Change fpu->fpregs_active users to fpu->fpstate_active")
Link: http://lkml.kernel.org/r/20181016202525.29437-4-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Commit:
c5bedc6847c3b ("x86/fpu: Get rid of PF_USED_MATH usage, convert it to fpu->fpstate_active")
introduced the 'fpu' variable at top of __restore_xstate_sig(),
which now shadows the other definition:
arch/x86/kernel/fpu/signal.c:318:28: warning: symbol 'fpu' shadows an earlier one
arch/x86/kernel/fpu/signal.c:271:20: originally declared here
Remove the shadowed definition of 'fpu', as the two definitions are the same.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: c5bedc6847c3b ("x86/fpu: Get rid of PF_USED_MATH usage, convert it to fpu->fpstate_active")
Link: http://lkml.kernel.org/r/20181016202525.29437-3-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Commit:
16561f27f94e ("x86/entry: Add some paranoid entry/exit CR3 handling comments")
... added some comments. This improves them a bit:
- When I first read the new comments, it was unclear to me whether
they were referring to the case where paranoid_entry interrupted
other entry code or where paranoid_entry was itself interrupted.
Clarify it.
- Remove the EBX comment. We no longer use EBX as a SWAPGS
indicator.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/c47daa1888dc2298e7e1d3f82bd76b776ea33393.1539542111.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Even if not on an entry stack, the CS's high bits must be
initialized because they are unconditionally evaluated in
PARANOID_EXIT_TO_KERNEL_MODE.
Failing to do so broke the boot on Galileo Gen2 and IOT2000 boards.
[ bp: Make the commit message tone passive and impartial. ]
Fixes: b92a165df17e ("x86/entry/32: Handle Entry from Kernel-Mode on Entry-Stack")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andrea Arcangeli <aarcange@redhat.com>
CC: Andy Lutomirski <luto@kernel.org>
CC: Boris Ostrovsky <boris.ostrovsky@oracle.com>
CC: Brian Gerst <brgerst@gmail.com>
CC: Dave Hansen <dave.hansen@intel.com>
CC: David Laight <David.Laight@aculab.com>
CC: Denys Vlasenko <dvlasenk@redhat.com>
CC: Eduardo Valentin <eduval@amazon.com>
CC: Greg KH <gregkh@linuxfoundation.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Jiri Kosina <jkosina@suse.cz>
CC: Josh Poimboeuf <jpoimboe@redhat.com>
CC: Juergen Gross <jgross@suse.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Will Deacon <will.deacon@arm.com>
CC: aliguori@amazon.com
CC: daniel.gruss@iaik.tugraz.at
CC: hughd@google.com
CC: keescook@google.com
CC: linux-mm <linux-mm@kvack.org>
CC: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/f271c747-1714-5a5b-a71f-ae189a093b8d@siemens.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The DMA API does its own zone decisions based on the coherent_dma_mask.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
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The DMA API does its own zone decisions based on the coherent_dma_mask.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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A removal waits for the reset_work to complete. If a surprise removal
occurs around the same time as an error triggered controller reset, and
reset work happened to dispatch a command to the removed controller, the
command won't be recovered since the timeout work doesn't do anything
during error recovery. We wouldn't want to wait for timeout handling
anyway, so this patch fixes this by disabling the controller and killing
admin queues prior to syncing with the reset_work.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Building with W=1 enables the compiler warning -Wimplicit-fallthrough=3. That
option does not recognize the fall-through comment in the fcloop driver. Add
a fall-through comment that is recognized for -Wimplicit-fallthrough=3. This
patch avoids that the compiler reports the following warning when building
with W=1:
drivers/nvme/target/fcloop.c:647:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (op == NVMET_FCOP_READDATA)
^
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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The nvme_user_io.slba field is 64 bits wide. That value is copied into the
32-bit bio_integrity_payload.bip_iter.bi_sector field. Make that truncation
explicit to avoid that Coverity complains about implicit truncation. See
also Coverity ID 1056486 on http://scan.coverity.com/projects/linux.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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This patch avoids that the kernel-doc tool complains about two function
headers when building with W=1.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Instead of setting and then clearing the first_sgl pointer for AEN requests,
leave that pointer zero. This patch does not change how requests are
initialized but avoids that Coverity reports the following complaint for
nvme_fc_init_aen_ops():
CID 1418400 (#1 of 1): Out-of-bounds access (OVERRUN)
4. overrun-buffer-val: Overrunning buffer pointed to by aen_op of 312 bytes by passing it to a function which accesses it at byte offset 312.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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This patch does not change any functionality but makes the intent of the
code more clear.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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This patch avoids that the kernel-doc tool complains about several
multiple function headers when building with W=1.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Although I'm not sure whether it is a good idea to support large discard
commands, I think integer overflow for discard ranges larger than 4 GB
should be avoided. This patch avoids that smatch reports the following:
drivers/nvme/target/io-cmd-file.c:249:1 nvmet_file_execute_discard() warn: should '((range.nlb)) << req->ns->blksize_shift' be a 64 bit type?
Fixes: d5eff33ee6f8 ("nvmet: add simple file backed ns support")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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This patch avoids that sparse complains about missing declarations.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Although the code modified by this patch looks fine to me, this patch avoids
that Coverity reports the following complaint (ID 1364971 and ID 1364973):
"You might overrun the 256-character fixed-size string id->subnqn".
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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This patch avoids that the kernel-doc tool complains about the
nvme_suspend_queue() function header when building with W=1.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Although it is easy to see that the code in nvme_init_subnqn() guarantees that
the subsys->nqn string is '\0'-terminated, apparently Coverity is not smart
enough to see this. Make it easier for Coverity to analyze this code by changing
the strncpy() call into a strlcpy() call. This patch does not change the
behavior of the code but fixes Coveritiy ID 1423720.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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This patch avoids that sparse complains about missing declarations.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Check whether queue->cm_error holds a value before reading it. This patch
addresses Coverity ID 1373774: unchecked return value.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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strncmp() stops comparing when either the end of one of the first two arguments
is reached or when 'n' characters have been compared, whichever comes first.
That means that strncmp(s1, s2, n) is equivalent to strcmp(s1, s2) if n exceeds
the length of s1 or the length of s2. Since that is the case in
nvmet_find_get_subsys(), change strncmp() into strcmp(). This patch avoids that
the following warning is reported by smatch:
drivers/nvme/target/core.c:940:1 nvmet_find_get_subsys() error: strncmp() '"nqn.2014-08.org.nvmexpress.discovery"' too small (37 vs 223)
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Get rid of the unreachable code in the nvmet_parse_discovery_cmd().
Keep the error message identical to the admin-cmd.c and io-cmd*.c
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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The nvme namespace paths were being updated only when the current path
was not set or nonoptimized. If a new path comes online that is a better
path for its NUMA node, the multipath selector may continue using the
previously set path on a potentially further node.
This patch re-runs the path assignment after successfully adding a new
optimized path.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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'default n' is the default value for any bool or tristate Kconfig
setting so there is no need to write it explicitly.
Also, since commit:
f467c5640c29 ("kconfig: only write '# CONFIG_FOO is not set' for visible symbols")
... the Kconfig behavior is the same regardless of 'default n' being present or not:
...
One side effect of (and the main motivation for) this change is making
the following two definitions behave exactly the same:
config FOO
bool
config FOO
bool
default n
With this change, neither of these will generate a
'# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied).
That might make it clearer to people that a bare 'default n' is
redundant.
...
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Juergen Gross <jgross@suse.co>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20181016134217eucas1p2102984488b89178a865162553369025b%7EeGpI5NlJo0851008510eucas1p2D@eucas1p2.samsung.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The qspinlock code supports up to 4 levels of slowpath nesting using
four per-CPU mcs_spinlock structures. For 64-bit architectures, they
fit nicely in one 64-byte cacheline.
For para-virtualized (PV) qspinlocks it needs to store more information
in the per-CPU node structure than there is space for. It uses a trick
to use a second cacheline to hold the extra information that it needs.
So PV qspinlock needs to access two extra cachelines for its information
whereas the native qspinlock code only needs one extra cacheline.
Freshly added counter profiling of the qspinlock code, however, revealed
that it was very rare to use more than two levels of slowpath nesting.
So it doesn't make sense to penalize PV qspinlock code in order to have
four mcs_spinlock structures in the same cacheline to optimize for a case
in the native qspinlock code that rarely happens.
Extend the per-CPU node structure to have two more long words when PV
qspinlock locks are configured to hold the extra data that it needs.
As a result, the PV qspinlock code will enjoy the same benefit of using
just one extra cacheline like the native counterpart, for most cases.
[ mingo: Minor changelog edits. ]
Signed-off-by: Waiman Long <longman@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/1539697507-28084-2-git-send-email-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Queued spinlock supports up to 4 levels of lock slowpath nesting -
user context, soft IRQ, hard IRQ and NMI. However, we are not sure how
often the nesting happens.
So add 3 more per-CPU stat counters to track the number of instances where
nesting index goes to 1, 2 and 3 respectively.
On a dual-socket 64-core 128-thread Zen server, the following were the
new stat counter values under different circumstances:
State slowpath index1 index2 index3
----- -------- ------ ------ -------
After bootup 1,012,150 82 0 0
After parallel build + perf-top 125,195,009 82 0 0
So the chance of having more than 2 levels of nesting is extremely low.
[ mingo: Minor changelog edits. ]
Signed-off-by: Waiman Long <longman@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/1539697507-28084-1-git-send-email-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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completions
To prevent dynamic completion objects from being de-allocated while still
in use, add a recommendation to embed them in long lived data structures.
Also add a note for the on-stack case that emphasizes the dangers of
the limited scope, and recommends dynamic allocation if scope limitations
are not clearly understood.
[ mingo: Minor touch-ups of the text, expanded it a bit to make the
warnings Nicholas added more prominent. ]
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john.garry@huawei.com
Link: http://lkml.kernel.org/r/1539697539-24055-1-git-send-email-hofrat@osadl.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Change the parisc vmlinuz boot code to include and process the real
compressed vmlinux.gz ELF file instead of a compressed memory dump.
This brings parisc in sync on how it's done on x86_64.
The benefit of this change is that, e.g. for debugging purposes, one can
then extract the vmlinux file out of the vmlinuz which was booted which
wasn't possible before. This can be archieved with the existing
scripts/extract-vmlinux script, which just needs a small tweak to prefer
to extract a compressed file before trying the existing given binary.
The downside of this approach is that due to the extra round of
decompression/ELF processing we need more physical memory installed to
be able to boot a kernel.
Signed-off-by: Helge Deller <deller@gmx.de>
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As on x86-64 and other architectures, the boot kernel on parisc (vmlinuz
and bzImage) contains a full compressed copy of the final kernel
executable (vmlinux.bin.gz), which one should be able to extract with
the extract-vmlinux script.
But on parisc extracting the kernel with extract-vmlinux fails.
Currently the script first checks if the given file is an ELF file
(which is true on parisc) and if so returns it. Thus on parisc we
unexpectedly get back the vmlinuz boot file instead of the uncompressed
vmlinux image.
This patch fixes this issue by reverting the logic. It now first tries
to find a compression signature in the given file and if that fails it
checks the file itself as fallback.
Signed-off-by: Helge Deller <deller@gmx.de>
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Helge noticed that the address of the os_hpmc handler was not being
correctly calculated in the hpmc macro. As a result, PDCE_CHECK would
fail to call os_hpmc:
<Cpu2> e800009802e00000 0000000000000000 CC_ERR_CHECK_HPMC
<Cpu2> 37000f7302e00000 8040004000000000 CC_ERR_CPU_CHECK_SUMMARY
<Cpu2> f600105e02e00000 fffffff0f0c00000 CC_MC_HPMC_MONARCH_SELECTED
<Cpu2> 140003b202e00000 000000000000000b CC_ERR_HPMC_STATE_ENTRY
<Cpu2> 5600100b02e00000 00000000000001a0 CC_MC_OS_HPMC_LEN_ERR
<Cpu2> 5600106402e00000 fffffff0f0438e70 CC_MC_BR_TO_OS_HPMC_FAILED
<Cpu2> e800009802e00000 0000000000000000 CC_ERR_CHECK_HPMC
<Cpu2> 37000f7302e00000 8040004000000000 CC_ERR_CPU_CHECK_SUMMARY
<Cpu2> 4000109f02e00000 0000000000000000 CC_MC_HPMC_INITIATED
<Cpu2> 4000101902e00000 0000000000000000 CC_MC_MULTIPLE_HPMCS
<Cpu2> 030010d502e00000 0000000000000000 CC_CPU_STOP
The address problem can be seen by dumping the fault vector:
0000000040159000 <fault_vector_20>:
40159000: 63 6f 77 73 stb r15,-2447(dp)
40159004: 20 63 61 6e ldil L%b747000,r3
40159008: 20 66 6c 79 ldil L%-1c3b3000,r3
...
40159020: 08 00 02 40 nop
40159024: 20 6e 60 02 ldil L%15d000,r3
40159028: 34 63 00 00 ldo 0(r3),r3
4015902c: e8 60 c0 02 bv,n r0(r3)
40159030: 08 00 02 40 nop
40159034: 00 00 00 00 break 0,0
40159038: c0 00 70 00 bb,*< r0,sar,40159840 <fault_vector_20+0x840>
4015903c: 00 00 00 00 break 0,0
Location 40159038 should contain the physical address of os_hpmc:
000000004015d000 <os_hpmc>:
4015d000: 08 1a 02 43 copy r26,r3
4015d004: 01 c0 08 a4 mfctl iva,r4
4015d008: 48 85 00 68 ldw 34(r4),r5
This patch moves the address setup into initialize_ivt to resolve the
above problem. I tested the change by dumping the HPMC entry after setup:
0000000040209020: 8000240
0000000040209024: 206a2004
0000000040209028: 34630ac0
000000004020902c: e860c002
0000000040209030: 8000240
0000000040209034: 1bdddce6
0000000040209038: 15d000
000000004020903c: 1a0
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Helge Deller <deller@gmx.de>
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In the C-code we need to put the physical address of the hpmc handler in
the interrupt vector table (IVA) in order to get HPMCs working. Since
on parisc64 function pointers are indirect (in fact they are function
descriptors) we instead export the address as variable and not as
function.
This reverts a small part of commit f39cce654f9a ("parisc: Add
cfi_startproc and cfi_endproc to assembly code").
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> [4.9+]
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Fix a long-existing small nasty bug in the map_pages() implementation which
leads to overwriting already written pte entries with zero, *if* map_pages() is
called a second time with an end address which isn't aligned on a pmd boundry.
This happens for example if we want to remap only the text segment read/write
in order to run alternative patching on the code. Exiting the loop when we
reach the end address fixes this.
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
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accessed flag in TLB handler
This patch may resolve some races in TLB handling. Hopefully, TLB
inserts are accesses and protected by spin lock.
If not, we may need to IPI calls and do local purges on PA 2.0.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
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This patch updates the spin unlock code to use an ordered store with
release semanatics. All prior accesses are guaranteed to be performed
before an ordered store is performed.
Using an ordered store is significantly faster than using the sync
memory barrier.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
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While playing with qemu with an emulated RT8139cp NIC, I faced lots of
the following warnings:
Dino 0x00810000: stuck interrupt 2
This patch ratelimits this warning and reports back that the IRQ was
handled.
Signed-off-by: Helge Deller <deller@gmx.de>
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Signed-off-by: Helge Deller <deller@gmx.de>
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On kernel crash, this is the current output:
Kernel Fault: Code=26 (Data memory access rights trap) regs=(ptrval) (Addr=00000004)
Drop the address of regs, it's of no use for debugging, and show the
faulty address without parenthesis.
Signed-off-by: Helge Deller <deller@gmx.de>
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Signed-off-by: Helge Deller <deller@gmx.de>
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This change removes the PTE load and present check from the L2_ptep
macro. The load and check for kernel pages is now done in the tlb_lock
macro. This avoids a double load and check for user pages. The load
and check for user pages is now done inside the lock so the fault
handler can't be called while the entry is being updated. This version
uses an ordered store to release the lock when the page table entry
isn't present. It also corrects the check in the non SMP case.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
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On boot (mostly reboot), my c8000 sometimes crashes after it prints the
TLB flush threshold. The lockup is hard. The front LED flashes red and
the box must be unplugged to reset the error.
I noticed that when the crash occurs the TLB flush threshold is about
one quarter what it is on a successful boot. If I disabled the
calculation, the crash didn't occur. There also seemed to be a timing
dependency affecting the crash. I finally realized that the
flush_tlb_all() timing test runs just after the secondary CPUs are
started. There seems to be a problem with running flush_tlb_all() too
soon after the CPUs are started.
The timing for the range test always seemed okay. So, I reversed the
order of the two timing tests and I haven't had a crash at this point so
far.
I added a couple of information messages which I have left to help with
diagnosis if the problem should appear on another machine.
This version reduces the minimum TLB flush threshold to 16 KiB.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
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This driver has never been wired up due to the life of the Linux
git tree, and has severely bitrotted.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Helge Deller <deller@gmx.de>
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Commit cafa0010cd51 ("Raise the minimum required gcc version to 4.6")
bumped the minimum GCC version to 4.6 for all architectures.
The version check in arch/parisc/Makefile is obsolete now.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Helge Deller <deller@gmx.de>
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Fixes: 5b00ca0b8035 ("parisc: Restore possibility to execute 64-bit applications")
Signed-off-by: Helge Deller <deller@gmx.de>
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Add an entry for the Broadcom SPI controller in the MAINTAINERS file.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
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