* Re: [PATCH] powerpc/eeh_cache: Fix a possible debugfs deadlock
From: Oliver O'Halloran @ 2020-10-29 5:57 UTC (permalink / raw)
To: Qian Cai; +Cc: Linux Kernel Mailing List, Paul Mackerras, linuxppc-dev
In-Reply-To: <20201028152717.8967-1-cai@redhat.com>
On Thu, Oct 29, 2020 at 2:27 AM Qian Cai <cai@redhat.com> wrote:
>
> Lockdep complains that a possible deadlock below in
> eeh_addr_cache_show() because it is acquiring a lock with IRQ enabled,
> but eeh_addr_cache_insert_dev() needs to acquire the same lock with IRQ
> disabled. Let's just make eeh_addr_cache_show() acquire the lock with
> IRQ disabled as well.
>
> CPU0 CPU1
> ---- ----
> lock(&pci_io_addr_cache_root.piar_lock);
> local_irq_disable();
> lock(&tp->lock);
> lock(&pci_io_addr_cache_root.piar_lock);
> <Interrupt>
> lock(&tp->lock);
>
> *** DEADLOCK ***
>
> lock_acquire+0x140/0x5f0
> _raw_spin_lock_irqsave+0x64/0xb0
> eeh_addr_cache_insert_dev+0x48/0x390
> eeh_probe_device+0xb8/0x1a0
> pnv_pcibios_bus_add_device+0x3c/0x80
> pcibios_bus_add_device+0x118/0x290
> pci_bus_add_device+0x28/0xe0
> pci_bus_add_devices+0x54/0xb0
> pcibios_init+0xc4/0x124
> do_one_initcall+0xac/0x528
> kernel_init_freeable+0x35c/0x3fc
> kernel_init+0x24/0x148
> ret_from_kernel_thread+0x5c/0x80
>
> lock_acquire+0x140/0x5f0
> _raw_spin_lock+0x4c/0x70
> eeh_addr_cache_show+0x38/0x110
> seq_read+0x1a0/0x660
> vfs_read+0xc8/0x1f0
> ksys_read+0x74/0x130
> system_call_exception+0xf8/0x1d0
> system_call_common+0xe8/0x218
>
> Fixes: 5ca85ae6318d ("powerpc/eeh_cache: Add a way to dump the EEH address cache")
> Signed-off-by: Qian Cai <cai@redhat.com>
Good catch,
Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
^ permalink raw reply
* Re: [PATCH 0/4] Powerpc: Better preemption for shared processor
From: Srikar Dronamraju @ 2020-10-29 7:14 UTC (permalink / raw)
To: Waiman Long
Cc: Nathan Lynch, Gautham R Shenoy, Phil Auld, Juri Lelli,
Peter Zijlstra, LKML, Nicholas Piggin, linuxppc-dev,
Valentin Schneider
In-Reply-To: <da67d6ce-f120-f61a-19ff-0ae4f1f5dac0@redhat.com>
* Waiman Long <longman@redhat.com> [2020-10-28 20:01:30]:
> > Srikar Dronamraju (4):
> > powerpc: Refactor is_kvm_guest declaration to new header
> > powerpc: Rename is_kvm_guest to check_kvm_guest
> > powerpc: Reintroduce is_kvm_guest
> > powerpc/paravirt: Use is_kvm_guest in vcpu_is_preempted
> >
> > arch/powerpc/include/asm/firmware.h | 6 ------
> > arch/powerpc/include/asm/kvm_guest.h | 25 +++++++++++++++++++++++++
> > arch/powerpc/include/asm/kvm_para.h | 2 +-
> > arch/powerpc/include/asm/paravirt.h | 18 ++++++++++++++++++
> > arch/powerpc/kernel/firmware.c | 5 ++++-
> > arch/powerpc/platforms/pseries/smp.c | 3 ++-
> > 6 files changed, 50 insertions(+), 9 deletions(-)
> > create mode 100644 arch/powerpc/include/asm/kvm_guest.h
> >
> This patch series looks good to me and the performance is nice too.
>
> Acked-by: Waiman Long <longman@redhat.com>
Thank you.
>
> Just curious, is the performance mainly from the use of static_branch
> (patches 1 - 3) or from reducing call to yield_count_of().
Because of the reduced call to yield_count
>
> Cheers,
> Longman
>
--
Thanks and Regards
Srikar Dronamraju
^ permalink raw reply
* Re: [PATCH 2/4] PM: hibernate: improve robustness of mapping pages in the direct map
From: Mike Rapoport @ 2020-10-29 7:54 UTC (permalink / raw)
To: Edgecombe, Rick P
Cc: david@redhat.com, peterz@infradead.org, catalin.marinas@arm.com,
dave.hansen@linux.intel.com, linux-mm@kvack.org, paulus@samba.org,
pavel@ucw.cz, hpa@zytor.com, sparclinux@vger.kernel.org,
cl@linux.com, will@kernel.org, linux-riscv@lists.infradead.org,
linux-s390@vger.kernel.org, x86@kernel.org, rppt@linux.ibm.com,
borntraeger@de.ibm.com, mingo@redhat.com, rientjes@google.com,
Brown, Len, aou@eecs.berkeley.edu, gor@linux.ibm.com,
linux-pm@vger.kernel.org, hca@linux.ibm.com, bp@alien8.de,
luto@kernel.org, paul.walmsley@sifive.com, kirill@shutemov.name,
tglx@linutronix.de, akpm@linux-foundation.org,
linux-arm-kernel@lists.infradead.org, rjw@rjwysocki.net,
linux-kernel@vger.kernel.org, penberg@kernel.org,
palmer@dabbelt.com, iamjoonsoo.kim@lge.com,
linuxppc-dev@lists.ozlabs.org, davem@davemloft.net
In-Reply-To: <3b4b2b3559bd3dc68adcddf99415bae57152cb6b.camel@intel.com>
On Wed, Oct 28, 2020 at 09:15:38PM +0000, Edgecombe, Rick P wrote:
> On Sun, 2020-10-25 at 12:15 +0200, Mike Rapoport wrote:
> > + if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) {
> > + unsigned long addr = (unsigned
> > long)page_address(page);
> > + int ret;
> > +
> > + if (enable)
> > + ret = set_direct_map_default_noflush(page);
> > + else
> > + ret = set_direct_map_invalid_noflush(page);
> > +
> > + if (WARN_ON(ret))
> > + return;
> > +
> > + flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
> > + } else {
> > + debug_pagealloc_map_pages(page, 1, enable);
> > + }
>
> Looking at the arm side again, I think this might actually introduce a
> regression for the arm/hibernate/DEBUG_PAGEALLOC combo.
>
> Unlike __kernel_map_pages(), it looks like arm's cpa will always bail
> in the set_direct_map_() functions if rodata_full is false.
>
> So if rodata_full was disabled but debug page alloc is on, then this
> would now skip remapping the pages. I guess the significance depends
> on whether hibernate could actually try to save any DEBUG_PAGEALLOC
> unmapped pages. Looks like it to me though.
__kernel_map_pages() on arm64 will also bail out if rodata_full is
false:
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
if (!debug_pagealloc_enabled() && !rodata_full)
return;
set_memory_valid((unsigned long)page_address(page), numpages, enable);
}
So using set_direct_map() to map back pages removed from the direct map
with __kernel_map_pages() seems safe to me.
--
Sincerely yours,
Mike.
^ permalink raw reply
* Re: [PATCH 5/9] kprobes/ftrace: Add recursion protection to the ftrace callback
From: Masami Hiramatsu @ 2020-10-29 7:58 UTC (permalink / raw)
To: Steven Rostedt
Cc: James E.J. Bottomley, Guo Ren, linux-csky, H. Peter Anvin,
linux-s390, Helge Deller, x86, Anil S Keshavamurthy,
Christian Borntraeger, Naveen N. Rao, Vasily Gorbik,
Heiko Carstens, Borislav Petkov, Thomas Gleixner, linux-parisc,
linux-kernel, Masami Hiramatsu, Paul Mackerras, Andrew Morton,
linuxppc-dev, David S. Miller
In-Reply-To: <20201028115613.140212174@goodmis.org>
Hi Steve,
On Wed, 28 Oct 2020 07:52:49 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
>
> If a ftrace callback does not supply its own recursion protection and
> does not set the RECURSION_SAFE flag in its ftrace_ops, then ftrace will
> make a helper trampoline to do so before calling the callback instead of
> just calling the callback directly.
So in that case the handlers will be called without preempt disabled?
> The default for ftrace_ops is going to assume recursion protection unless
> otherwise specified.
This seems to skip entier handler if ftrace finds recursion.
I would like to increment the missed counter even in that case.
[...]
e.g.
> diff --git a/arch/csky/kernel/probes/ftrace.c b/arch/csky/kernel/probes/ftrace.c
> index 5264763d05be..5eb2604fdf71 100644
> --- a/arch/csky/kernel/probes/ftrace.c
> +++ b/arch/csky/kernel/probes/ftrace.c
> @@ -13,16 +13,21 @@ int arch_check_ftrace_location(struct kprobe *p)
> void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
> struct ftrace_ops *ops, struct pt_regs *regs)
> {
> + int bit;
> bool lr_saver = false;
> struct kprobe *p;
> struct kprobe_ctlblk *kcb;
>
> - /* Preempt is disabled by ftrace */
> + bit = ftrace_test_recursion_trylock();
> +
> + preempt_disable_notrace();
> p = get_kprobe((kprobe_opcode_t *)ip);
> if (!p) {
> p = get_kprobe((kprobe_opcode_t *)(ip - MCOUNT_INSN_SIZE));
> if (unlikely(!p) || kprobe_disabled(p))
> - return;
> + goto out;
> lr_saver = true;
> }
if (bit < 0) {
kprobes_inc_nmissed_count(p);
goto out;
}
>
> @@ -56,6 +61,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
> */
> __this_cpu_write(current_kprobe, NULL);
> }
> +out:
> + preempt_enable_notrace();
if (bit >= 0)
ftrace_test_recursion_unlock(bit);
> }
> NOKPROBE_SYMBOL(kprobe_ftrace_handler);
>
Or, we can also introduce a support function,
static inline void kprobes_inc_nmissed_ip(unsigned long ip)
{
struct kprobe *p;
preempt_disable_notrace();
p = get_kprobe((kprobe_opcode_t *)ip);
if (p)
kprobes_inc_nmissed_count(p);
preempt_enable_notrace();
}
> diff --git a/arch/parisc/kernel/ftrace.c b/arch/parisc/kernel/ftrace.c
> index 4bab21c71055..5f7742b225a5 100644
> --- a/arch/parisc/kernel/ftrace.c
> +++ b/arch/parisc/kernel/ftrace.c
> @@ -208,13 +208,19 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
> {
> struct kprobe_ctlblk *kcb;
> struct kprobe *p = get_kprobe((kprobe_opcode_t *)ip);
(BTW, here is a bug... get_kprobe() must be called with preempt disabled.)
> + int bit;
>
> - if (unlikely(!p) || kprobe_disabled(p))
> + bit = ftrace_test_recursion_trylock();
if (bit < 0) {
kprobes_inc_nmissed_ip(ip);
> return;
}
This may easier for you ?
Thank you,
>
> + preempt_disable_notrace();
> + if (unlikely(!p) || kprobe_disabled(p))
> + goto out;
> +
> if (kprobe_running()) {
> kprobes_inc_nmissed_count(p);
> - return;
> + goto out;
> }
>
> __this_cpu_write(current_kprobe, p);
> @@ -235,6 +241,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
> }
> }
> __this_cpu_write(current_kprobe, NULL);
> +out:
> + preempt_enable_notrace();
> + ftrace_test_recursion_unlock(bit);
> }
> NOKPROBE_SYMBOL(kprobe_ftrace_handler);
>
> diff --git a/arch/powerpc/kernel/kprobes-ftrace.c b/arch/powerpc/kernel/kprobes-ftrace.c
> index 972cb28174b2..5df8d50c65ae 100644
> --- a/arch/powerpc/kernel/kprobes-ftrace.c
> +++ b/arch/powerpc/kernel/kprobes-ftrace.c
> @@ -18,10 +18,16 @@ void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip,
> {
> struct kprobe *p;
> struct kprobe_ctlblk *kcb;
> + int bit;
>
> + bit = ftrace_test_recursion_trylock();
> + if (bit < 0)
> + return;
> +
> + preempt_disable_notrace();
> p = get_kprobe((kprobe_opcode_t *)nip);
> if (unlikely(!p) || kprobe_disabled(p))
> - return;
> + goto out;
>
> kcb = get_kprobe_ctlblk();
> if (kprobe_running()) {
> @@ -52,6 +58,9 @@ void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip,
> */
> __this_cpu_write(current_kprobe, NULL);
> }
> +out:
> + preempt_enable_notrace();
> + ftrace_test_recursion_unlock(bit);
> }
> NOKPROBE_SYMBOL(kprobe_ftrace_handler);
>
> diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
> index b388e87a08bf..88466d7fb6b2 100644
> --- a/arch/s390/kernel/ftrace.c
> +++ b/arch/s390/kernel/ftrace.c
> @@ -202,13 +202,19 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
> {
> struct kprobe_ctlblk *kcb;
> struct kprobe *p = get_kprobe((kprobe_opcode_t *)ip);
> + int bit;
>
> - if (unlikely(!p) || kprobe_disabled(p))
> + bit = ftrace_test_recursion_trylock();
> + if (bit < 0)
> return;
>
> + preempt_disable_notrace();
> + if (unlikely(!p) || kprobe_disabled(p))
> + goto out;
> +
> if (kprobe_running()) {
> kprobes_inc_nmissed_count(p);
> - return;
> + goto out;
> }
>
> __this_cpu_write(current_kprobe, p);
> @@ -228,6 +234,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
> }
> }
> __this_cpu_write(current_kprobe, NULL);
> +out:
> + preempt_enable_notrace();
> + ftrace_test_recursion_unlock(bit);
> }
> NOKPROBE_SYMBOL(kprobe_ftrace_handler);
>
> diff --git a/arch/x86/kernel/kprobes/ftrace.c b/arch/x86/kernel/kprobes/ftrace.c
> index 681a4b36e9bb..a40a6cdfcca3 100644
> --- a/arch/x86/kernel/kprobes/ftrace.c
> +++ b/arch/x86/kernel/kprobes/ftrace.c
> @@ -18,11 +18,16 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
> {
> struct kprobe *p;
> struct kprobe_ctlblk *kcb;
> + int bit;
>
> - /* Preempt is disabled by ftrace */
> + bit = ftrace_test_recursion_trylock();
> + if (bit < 0)
> + return;
> +
> + preempt_disable_notrace();
> p = get_kprobe((kprobe_opcode_t *)ip);
> if (unlikely(!p) || kprobe_disabled(p))
> - return;
> + goto out;
>
> kcb = get_kprobe_ctlblk();
> if (kprobe_running()) {
> @@ -52,6 +57,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
> */
> __this_cpu_write(current_kprobe, NULL);
> }
> +out:
> + preempt_enable_notrace();
> + ftrace_test_recursion_unlock(bit);
> }
> NOKPROBE_SYMBOL(kprobe_ftrace_handler);
>
> --
> 2.28.0
>
>
--
Masami Hiramatsu <mhiramat@kernel.org>
^ permalink raw reply
* Re: [PATCH 20/33] docs: ABI: testing: make the files compatible with ReST output
From: Mauro Carvalho Chehab @ 2020-10-29 7:21 UTC (permalink / raw)
To: Richard Cochran
Cc: Gautham R. Shenoy, Jason A. Donenfeld, Heikki Krogerus,
Peter Meerwald-Stadler, Petr Mladek, Linux Doc Mailing List,
Alexander Shishkin, Nayna Jain, Alexandre Belloni, Mimi Zohar,
Sebastian Reichel, Guenter Roeck, Bruno Meneguele, Vishal Verma,
Pavel Machek, Hanjun Guo, Mauro Carvalho Chehab, netdev,
Oleh Kravchenko, Dan Williams, Andrew Donnellan,
Javier González, Fabrice Gasnier, Stefano Stabellini,
linux-acpi, Jonathan Corbet, Chunyan Zhang, Mario Limonciello,
linux-stm32, Lakshmi Ramasubramanian, Ludovic Desroches,
Pawan Gupta, linux-arm-kernel, Frederic Barrat, Niklas Cassel,
Len Brown, Juergen Gross, Mika Westerberg, Alexandre Torgue,
linux-pm, linux-kernel, linuxppc-dev, Baolin Wang,
Lars-Peter Clausen, Dan Murphy, Orson Zhai, Philippe Bergheaud,
xen-devel, Boris Ostrovsky, Andy Shevchenko, Benson Leung,
Konstantin Khlebnikov, Jens Axboe, Felipe Balbi, Kranthi Kuntala,
Martin K. Petersen, linux-mm, Greg Kroah-Hartman, linux-usb,
Rafael J. Wysocki, Nicolas Ferre, linux-iio, Thinh Nguyen,
Sergey Senozhatsky, Thomas Gleixner, Leonid Maksymchuk,
Maxime Coquelin, Johannes Thumshirn, Enric Balletbo i Serra,
Vineela Tummalapalli, Peter Rosin, Jonathan Cameron, Mike Kravetz
In-Reply-To: <20201028174427.GE9364@hoboy.vegasvil.org>
Hi Richard,
Em Wed, 28 Oct 2020 10:44:27 -0700
Richard Cochran <richardcochran@gmail.com> escreveu:
> On Wed, Oct 28, 2020 at 03:23:18PM +0100, Mauro Carvalho Chehab wrote:
>
> > diff --git a/Documentation/ABI/testing/sysfs-uevent b/Documentation/ABI/testing/sysfs-uevent
> > index aa39f8d7bcdf..d0893dad3f38 100644
> > --- a/Documentation/ABI/testing/sysfs-uevent
> > +++ b/Documentation/ABI/testing/sysfs-uevent
> > @@ -19,7 +19,8 @@ Description:
> > a transaction identifier so it's possible to use the same UUID
> > value for one or more synthetic uevents in which case we
> > logically group these uevents together for any userspace
> > - listeners. The UUID value appears in uevent as
> > + listeners. The UUID value appears in uevent as:
>
> I know almost nothing about Sphinx, but why have one colon here ^^^ and ...
Good point. After re-reading the text, this ":" doesn't belong here.
>
> > +
> > "SYNTH_UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" environment
> > variable.
> >
> > @@ -30,18 +31,19 @@ Description:
> > It's possible to define zero or more pairs - each pair is then
> > delimited by a space character ' '. Each pair appears in
> > synthetic uevent as "SYNTH_ARG_KEY=VALUE". That means the KEY
> > - name gains "SYNTH_ARG_" prefix to avoid possible collisions
> > + name gains `SYNTH_ARG_` prefix to avoid possible collisions
> > with existing variables.
> >
> > - Example of valid sequence written to the uevent file:
> > + Example of valid sequence written to the uevent file::
>
> ... two here?
The main issue that this patch wants to solve is here:
This generates synthetic uevent including these variables::
ACTION=add
SYNTH_ARG_A=1
SYNTH_ARG_B=abc
SYNTH_UUID=fe4d7c9d-b8c6-4a70-9ef1-3d8a58d18eed
On Sphinx, consecutive lines with the same indent belongs to the same
paragraph. So, without "::", the above will be displayed on a single line,
which is undesired.
using "::" tells Sphinx to display as-is. It will also place it into a a
box (colored for html output) and using a monospaced font.
The change at the "uevent file:" line was done just for coherency
purposes.
Yet, after re-reading the text, there are other things that are not
coherent. So, I guess the enclosed patch will work better for sys-uevent.
Thanks,
Mauro
docs: ABI: sysfs-uevent: make it compatible with ReST output
- Replace " by ``, in order to use monospaced fonts;
- mark literal blocks as such.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
diff --git a/Documentation/ABI/testing/sysfs-uevent b/Documentation/ABI/testing/sysfs-uevent
index aa39f8d7bcdf..0b6227706b35 100644
--- a/Documentation/ABI/testing/sysfs-uevent
+++ b/Documentation/ABI/testing/sysfs-uevent
@@ -6,42 +6,46 @@ Description:
Enable passing additional variables for synthetic uevents that
are generated by writing /sys/.../uevent file.
- Recognized extended format is ACTION [UUID [KEY=VALUE ...].
+ Recognized extended format is::
- The ACTION is compulsory - it is the name of the uevent action
- ("add", "change", "remove"). There is no change compared to
- previous functionality here. The rest of the extended format
- is optional.
+ ACTION [UUID [KEY=VALUE ...]
+
+ The ACTION is compulsory - it is the name of the uevent
+ action (``add``, ``change``, ``remove``). There is no change
+ compared to previous functionality here. The rest of the
+ extended format is optional.
You need to pass UUID first before any KEY=VALUE pairs.
- The UUID must be in "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
+ The UUID must be in ``xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx``
format where 'x' is a hex digit. The UUID is considered to be
a transaction identifier so it's possible to use the same UUID
value for one or more synthetic uevents in which case we
logically group these uevents together for any userspace
listeners. The UUID value appears in uevent as
- "SYNTH_UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" environment
+ ``SYNTH_UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx`` environment
variable.
If UUID is not passed in, the generated synthetic uevent gains
- "SYNTH_UUID=0" environment variable automatically.
+ ``SYNTH_UUID=0`` environment variable automatically.
The KEY=VALUE pairs can contain alphanumeric characters only.
+
It's possible to define zero or more pairs - each pair is then
delimited by a space character ' '. Each pair appears in
- synthetic uevent as "SYNTH_ARG_KEY=VALUE". That means the KEY
- name gains "SYNTH_ARG_" prefix to avoid possible collisions
+ synthetic uevent as ``SYNTH_ARG_KEY=VALUE``. That means the KEY
+ name gains ``SYNTH_ARG_`` prefix to avoid possible collisions
with existing variables.
- Example of valid sequence written to the uevent file:
+ Example of valid sequence written to the uevent file::
add fe4d7c9d-b8c6-4a70-9ef1-3d8a58d18eed A=1 B=abc
- This generates synthetic uevent including these variables:
+ This generates synthetic uevent including these variables::
ACTION=add
SYNTH_ARG_A=1
SYNTH_ARG_B=abc
SYNTH_UUID=fe4d7c9d-b8c6-4a70-9ef1-3d8a58d18eed
+
Users:
udev, userspace tools generating synthetic uevents
^ permalink raw reply related
* [PATCH 02/25] ASoC: fsl: fsl_ssi: remove unnecessary CONFIG_PM_SLEEP
From: Coiby Xu @ 2020-10-29 7:42 UTC (permalink / raw)
To: Jaroslav Kysela, Takashi Iwai
Cc: moderated list:FREESCALE SOC SOUND DRIVERS, Timur Tabi, Xiubo Li,
Fabio Estevam, open list:FREESCALE SOC SOUND DRIVERS,
Liam Girdwood, open list, Nicolin Chen, Mark Brown, Shengjiu Wang
In-Reply-To: <20201029074301.226644-1-coiby.xu@gmail.com>
SET_SYSTEM_SLEEP_PM_OPS has already took good care of CONFIG_PM_CONFIG.
Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
---
sound/soc/fsl/fsl_ssi.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index 404be27c15fe..065500a4cbc1 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -1669,7 +1669,6 @@ static int fsl_ssi_remove(struct platform_device *pdev)
return 0;
}
-#ifdef CONFIG_PM_SLEEP
static int fsl_ssi_suspend(struct device *dev)
{
struct fsl_ssi *ssi = dev_get_drvdata(dev);
@@ -1699,7 +1698,6 @@ static int fsl_ssi_resume(struct device *dev)
return regcache_sync(regs);
}
-#endif /* CONFIG_PM_SLEEP */
static const struct dev_pm_ops fsl_ssi_pm = {
SET_SYSTEM_SLEEP_PM_OPS(fsl_ssi_suspend, fsl_ssi_resume)
--
2.28.0
^ permalink raw reply related
* [PATCH 03/25] ASoC: fsl: remove unnecessary CONFIG_PM_SLEEP
From: Coiby Xu @ 2020-10-29 7:42 UTC (permalink / raw)
To: Jaroslav Kysela, Takashi Iwai
Cc: moderated list:FREESCALE SOC SOUND DRIVERS, Timur Tabi, Xiubo Li,
Fabio Estevam, Sascha Hauer,
open list:FREESCALE SOC SOUND DRIVERS, Liam Girdwood, open list,
Nicolin Chen, Mark Brown, NXP Linux Team, Pengutronix Kernel Team,
Shawn Guo, Shengjiu Wang,
moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE
In-Reply-To: <20201029074301.226644-1-coiby.xu@gmail.com>
SET_SYSTEM_SLEEP_PM_OPS has already took good care of CONFIG_PM_CONFIG.
Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
---
sound/soc/fsl/imx-audmux.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/sound/soc/fsl/imx-audmux.c b/sound/soc/fsl/imx-audmux.c
index 25c18b9e348f..6d77188a4eab 100644
--- a/sound/soc/fsl/imx-audmux.c
+++ b/sound/soc/fsl/imx-audmux.c
@@ -349,7 +349,6 @@ static int imx_audmux_remove(struct platform_device *pdev)
return 0;
}
-#ifdef CONFIG_PM_SLEEP
static int imx_audmux_suspend(struct device *dev)
{
int i;
@@ -377,7 +376,6 @@ static int imx_audmux_resume(struct device *dev)
return 0;
}
-#endif /* CONFIG_PM_SLEEP */
static const struct dev_pm_ops imx_audmux_pm = {
SET_SYSTEM_SLEEP_PM_OPS(imx_audmux_suspend, imx_audmux_resume)
--
2.28.0
^ permalink raw reply related
* [PATCH 25/25] ALSA: aoa: remove unnecessary CONFIG_PM_SLEEP
From: Coiby Xu @ 2020-10-29 7:43 UTC (permalink / raw)
To: Jaroslav Kysela, Takashi Iwai
Cc: Johannes Berg, open list:AOA Apple Onboard Audio ALSA DRIVER,
moderated list:AOA Apple Onboard Audio ALSA DRIVER, open list
In-Reply-To: <20201029074301.226644-1-coiby.xu@gmail.com>
SIMPLE_DEV_PM_OPS has already took good care of CONFIG_PM_CONFIG.
Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
---
sound/aoa/fabrics/layout.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/sound/aoa/fabrics/layout.c b/sound/aoa/fabrics/layout.c
index d2e85b83f7ed..197d13f23141 100644
--- a/sound/aoa/fabrics/layout.c
+++ b/sound/aoa/fabrics/layout.c
@@ -1126,7 +1126,6 @@ static int aoa_fabric_layout_remove(struct soundbus_dev *sdev)
return 0;
}
-#ifdef CONFIG_PM_SLEEP
static int aoa_fabric_layout_suspend(struct device *dev)
{
struct layout_dev *ldev = dev_get_drvdata(dev);
@@ -1150,7 +1149,6 @@ static int aoa_fabric_layout_resume(struct device *dev)
static SIMPLE_DEV_PM_OPS(aoa_fabric_layout_pm_ops,
aoa_fabric_layout_suspend, aoa_fabric_layout_resume);
-#endif
static struct soundbus_driver aoa_soundbus_driver = {
.name = "snd_aoa_soundbus_drv",
@@ -1159,9 +1157,7 @@ static struct soundbus_driver aoa_soundbus_driver = {
.remove = aoa_fabric_layout_remove,
.driver = {
.owner = THIS_MODULE,
-#ifdef CONFIG_PM_SLEEP
.pm = &aoa_fabric_layout_pm_ops,
-#endif
}
};
--
2.28.0
^ permalink raw reply related
* Re: [PATCH 0/4] arch, mm: improve robustness of direct map manipulation
From: Mike Rapoport @ 2020-10-29 8:12 UTC (permalink / raw)
To: Edgecombe, Rick P
Cc: david@redhat.com, peterz@infradead.org, catalin.marinas@arm.com,
dave.hansen@linux.intel.com, linux-mm@kvack.org, paulus@samba.org,
pavel@ucw.cz, hpa@zytor.com, sparclinux@vger.kernel.org,
cl@linux.com, will@kernel.org, linux-riscv@lists.infradead.org,
linux-s390@vger.kernel.org, x86@kernel.org, rppt@linux.ibm.com,
borntraeger@de.ibm.com, mingo@redhat.com, rientjes@google.com,
Brown, Len, aou@eecs.berkeley.edu, gor@linux.ibm.com,
linux-pm@vger.kernel.org, hca@linux.ibm.com, bp@alien8.de,
luto@kernel.org, paul.walmsley@sifive.com, kirill@shutemov.name,
tglx@linutronix.de, iamjoonsoo.kim@lge.com,
linux-arm-kernel@lists.infradead.org, rjw@rjwysocki.net,
linux-kernel@vger.kernel.org, penberg@kernel.org,
palmer@dabbelt.com, akpm@linux-foundation.org,
linuxppc-dev@lists.ozlabs.org, davem@davemloft.net
In-Reply-To: <9e77d0a939eda3029d6ae89bd14d7f1465b0559d.camel@intel.com>
On Wed, Oct 28, 2020 at 09:03:31PM +0000, Edgecombe, Rick P wrote:
> > On Wed, Oct 28, 2020 at 11:20:12AM +0000, Will Deacon wrote:
> > > On Tue, Oct 27, 2020 at 10:38:16AM +0200, Mike Rapoport wrote:
> > > >
> > > > This is a theoretical bug, but it is still not nice :)
> > > >
> > >
> > > Just to clarify: this patch series fixes this problem, right?
> >
> > Yes.
> >
>
> Well, now I'm confused again.
>
> As David pointed, __vunmap() should not be executing simultaneously
> with the hibernate operation because hibernate can't snapshot while
> data it needs to save is still updating. If a thread was paused when a
> page was in an "invalid" state, it should be remapped by hibernate
> before the copy.
>
> To level set, before reading this mail, my takeaways from the
> discussions on potential hibernate/debug page alloc problems were:
>
> Potential RISC-V issue:
> Doesn't have hibernate support
>
> Potential ARM issue:
> The logic around when it's cpa determines pages might be unmapped looks
> correct for current callers.
>
> Potential x86 page break issue:
> Seems to be ok for now, but a new set_memory_np() caller could violate
> assumptions in hibernate.
>
> Non-obvious thorny logic:
> General agreement it would be good to separate dependencies.
>
> Behavior of V1 of this patchset:
> No functional change other than addition of a warn in hibernate.
There is a change that adds explicit use of set_direct_map() to
hibernate. Currently, in case of arm64 with DEBUG_PAGEALLOC=n if a
thread was paused when a page was in an "invalid" state hibernate will
access an unmapped data because __kernel_map_pages() will bail out.
After the change set_direct_map_default_noflush() would be used and the
page will get mapped before copy.
> So "does this fix the problem", "yes" leaves me a bit confused... Not
> saying there couldn't be any problems, especially due to the thorniness
> and cross arch stride, but what is it exactly and how does this series
> fix it?
This series goal was primarily to separate dependincies and make it
clearer what DEBUG_PAGEALLOC and what SET_DIRECT_MAP are. As it turned
out, there is also some lack of consistency between architectures that
implement either of this so I tried to improve this as well.
Honestly, I don't know if a thread can be paused at the time __vunmap()
left invalid pages, but it could, there is an issue on arm64 with
DEBUG_PAGEALLOC=n and this set fixes it.
__vunmap()
vm_remove_mappings()
set_direct_map_invalid()
/* thread is frozen */
safe_copy_page()
__kernel_map_pages()
if (!debug_pagealloc())
return
do_copy_page() -> fault
--
Sincerely yours,
Mike.
^ permalink raw reply
* Re: [PATCH 0/4] arch, mm: improve robustness of direct map manipulation
From: David Hildenbrand @ 2020-10-29 8:15 UTC (permalink / raw)
To: Mike Rapoport, Andrew Morton
Cc: Peter Zijlstra, Dave Hansen, linux-mm, Paul Mackerras,
Pavel Machek, H. Peter Anvin, sparclinux, Christoph Lameter,
Will Deacon, linux-riscv, linux-s390, x86, Mike Rapoport,
Christian Borntraeger, Ingo Molnar, Catalin Marinas, Len Brown,
Albert Ou, Vasily Gorbik, linux-pm, Heiko Carstens,
David Rientjes, Borislav Petkov, Andy Lutomirski, Paul Walmsley,
Kirill A. Shutemov, Thomas Gleixner, linux-arm-kernel,
Rafael J. Wysocki, linux-kernel, Pekka Enberg, Palmer Dabbelt,
Joonsoo Kim, Edgecombe, Rick P, linuxppc-dev, David S. Miller
In-Reply-To: <20201025101555.3057-1-rppt@kernel.org>
On 25.10.20 11:15, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@linux.ibm.com>
>
> Hi,
>
> During recent discussion about KVM protected memory, David raised a concern
> about usage of __kernel_map_pages() outside of DEBUG_PAGEALLOC scope [1].
>
> Indeed, for architectures that define CONFIG_ARCH_HAS_SET_DIRECT_MAP it is
> possible that __kernel_map_pages() would fail, but since this function is
> void, the failure will go unnoticed.
>
> Moreover, there's lack of consistency of __kernel_map_pages() semantics
> across architectures as some guard this function with
> #ifdef DEBUG_PAGEALLOC, some refuse to update the direct map if page
> allocation debugging is disabled at run time and some allow modifying the
> direct map regardless of DEBUG_PAGEALLOC settings.
>
> This set straightens this out by restoring dependency of
> __kernel_map_pages() on DEBUG_PAGEALLOC and updating the call sites
> accordingly.
>
So, I was primarily wondering if we really have to touch direct mappings
in hibernation code, or if we can avoid doing that. I was wondering if
we cannot simply do something like kmap() when trying to access a
!mapped page. Similar to reading old-os memory after kexec when in
kdump. Just a thought.
--
Thanks,
David / dhildenb
^ permalink raw reply
* Re: [PATCH kernel v3 2/2] powerpc/dma: Fallback to dma_ops when persistent memory present
From: Michael Ellerman @ 2020-10-29 9:55 UTC (permalink / raw)
To: Alexey Kardashevskiy, linuxppc-dev; +Cc: iommu, Christoph Hellwig, linux-kernel
In-Reply-To: <2f285412-9e19-7888-1102-f50658c43b9d@ozlabs.ru>
Alexey Kardashevskiy <aik@ozlabs.ru> writes:
> On 29/10/2020 11:40, Michael Ellerman wrote:
>> Alexey Kardashevskiy <aik@ozlabs.ru> writes:
>>> @@ -1126,7 +1129,7 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
>>>
>>> mutex_lock(&direct_window_init_mutex);
>>>
>>> - dma_addr = find_existing_ddw(pdn);
>>> + dma_addr = find_existing_ddw(pdn, &len);
>>
>> I don't see len used anywhere?
>>
>>> if (dma_addr != 0)
>>> goto out_unlock;
>>>
>>> @@ -1212,14 +1215,26 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
>>> }
>>> /* verify the window * number of ptes will map the partition */
>>> /* check largest block * page size > max memory hotplug addr */
>>> - max_addr = ddw_memory_hotplug_max();
>>> - if (query.largest_available_block < (max_addr >> page_shift)) {
>>> - dev_dbg(&dev->dev, "can't map partition max 0x%llx with %llu "
>>> - "%llu-sized pages\n", max_addr, query.largest_available_block,
>>> - 1ULL << page_shift);
>>> + /*
>>> + * The "ibm,pmemory" can appear anywhere in the address space.
>>> + * Assuming it is still backed by page structs, try MAX_PHYSMEM_BITS
>>> + * for the upper limit and fallback to max RAM otherwise but this
>>> + * disables device::dma_ops_bypass.
>>> + */
>>> + len = max_ram_len;
>>
>> Here you override whatever find_existing_ddw() wrote to len?
>
> Not always, there is a bunch of gotos before this line to the end of the
> function and one (which returns the existing window) is legit. Thanks,
Ah yep I see it.
Gotos considered confusing ;)
cheers
^ permalink raw reply
* Re: [PATCH kernel v4 2/2] powerpc/dma: Fallback to dma_ops when persistent memory present
From: Michael Ellerman @ 2020-10-29 9:56 UTC (permalink / raw)
To: Alexey Kardashevskiy, linuxppc-dev
Cc: Alexey Kardashevskiy, iommu, Christoph Hellwig, linux-kernel
In-Reply-To: <20201029015241.73920-3-aik@ozlabs.ru>
Alexey Kardashevskiy <aik@ozlabs.ru> writes:
> So far we have been using huge DMA windows to map all the RAM available.
> The RAM is normally mapped to the VM address space contiguously, and
> there is always a reasonable upper limit for possible future hot plugged
> RAM which makes it easy to map all RAM via IOMMU.
>
> Now there is persistent memory ("ibm,pmemory" in the FDT) which (unlike
> normal RAM) can map anywhere in the VM space beyond the maximum RAM size
> and since it can be used for DMA, it requires extending the huge window
> up to MAX_PHYSMEM_BITS which requires hypervisor support for:
> 1. huge TCE tables;
> 2. multilevel TCE tables;
> 3. huge IOMMU pages.
>
> Certain hypervisors cannot do either so the only option left is
> restricting the huge DMA window to include only RAM and fallback to
> the default DMA window for persistent memory.
>
> This defines arch_dma_map_direct/etc to allow generic DMA code perform
> additional checks on whether direct DMA is still possible.
>
> This checks if the system has persistent memory. If it does not,
> the DMA bypass mode is selected, i.e.
> * dev->bus_dma_limit = 0
> * dev->dma_ops_bypass = true <- this avoid calling dma_ops for mapping.
>
> If there is such memory, this creates identity mapping only for RAM and
> sets the dev->bus_dma_limit to let the generic code decide whether to
> call into the direct DMA or the indirect DMA ops.
>
> This should not change the existing behaviour when no persistent memory
> as dev->dma_ops_bypass is expected to be set.
>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
cheers
^ permalink raw reply
* [PATCH kernel v2] irq: Add reference counting to IRQ mappings
From: Alexey Kardashevskiy @ 2020-10-29 11:01 UTC (permalink / raw)
To: linuxppc-dev
Cc: Rob Herring, Alexey Kardashevskiy, Marc Zyngier, linux-kernel,
Qian Cai, Cédric Le Goater, Frederic Barrat, Thomas Gleixner,
Michal Suchánek, David Gibson
PCI devices share 4 legacy INTx interrupts from the same PCI host bridge.
Device drivers map/unmap hardware interrupts via irq_create_mapping()/
irq_dispose_mapping(). The problem with that these interrupts are
shared and when performing hot unplug, we need to unmap the interrupt
only when the last device is released.
This reuses already existing irq_desc::kobj for this purpose.
The refcounter is naturally 1 when the descriptor is allocated already;
this adds kobject_get() in places where already existing mapped virq
is returned.
This reorganizes irq_dispose_mapping() to release the kobj and let
the release callback do the cleanup.
Quick grep shows no sign of irq reference counting in drivers. Drivers
typically request mapping when probing and dispose it when removing;
platforms tend to dispose only if setup failed and the rest seems
calling one dispose per one mapping. Except (at least) PPC/pseries
which needs https://lkml.org/lkml/2020/10/27/259
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
What is the easiest way to get irq-hierarchical hardware?
I have a bunch of powerpc boxes (no good) but also a raspberry pi,
a bunch of 32/64bit orange pi's, an "armada" arm box,
thinkpads - is any of this good for the task?
---
Changes:
v2:
* added more get/put, including irq_domain_associate/irq_domain_disassociate
---
kernel/irq/irqdesc.c | 36 ++++++++++++++++++++-----------
kernel/irq/irqdomain.c | 49 +++++++++++++++++++++++++++++-------------
2 files changed, 58 insertions(+), 27 deletions(-)
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 1a7723604399..bc8f62157ffa 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -419,20 +419,40 @@ static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
return NULL;
}
+static void delayed_free_desc(struct rcu_head *rhp);
static void irq_kobj_release(struct kobject *kobj)
{
struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
+#ifdef CONFIG_IRQ_DOMAIN
+ struct irq_domain *domain;
+ unsigned int virq = desc->irq_data.irq;
- free_masks(desc);
- free_percpu(desc->kstat_irqs);
- kfree(desc);
+ domain = desc->irq_data.domain;
+ if (domain) {
+ if (irq_domain_is_hierarchy(domain)) {
+ irq_domain_free_irqs(virq, 1);
+ } else {
+ irq_domain_disassociate(domain, virq);
+ irq_free_desc(virq);
+ }
+ }
+#endif
+ /*
+ * We free the descriptor, masks and stat fields via RCU. That
+ * allows demultiplex interrupts to do rcu based management of
+ * the child interrupts.
+ * This also allows us to use rcu in kstat_irqs_usr().
+ */
+ call_rcu(&desc->rcu, delayed_free_desc);
}
static void delayed_free_desc(struct rcu_head *rhp)
{
struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
- kobject_put(&desc->kobj);
+ free_masks(desc);
+ free_percpu(desc->kstat_irqs);
+ kfree(desc);
}
static void free_desc(unsigned int irq)
@@ -453,14 +473,6 @@ static void free_desc(unsigned int irq)
*/
irq_sysfs_del(desc);
delete_irq_desc(irq);
-
- /*
- * We free the descriptor, masks and stat fields via RCU. That
- * allows demultiplex interrupts to do rcu based management of
- * the child interrupts.
- * This also allows us to use rcu in kstat_irqs_usr().
- */
- call_rcu(&desc->rcu, delayed_free_desc);
}
static int alloc_descs(unsigned int start, unsigned int cnt, int node,
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index cf8b374b892d..5fb060e077e3 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -487,6 +487,7 @@ static void irq_domain_set_mapping(struct irq_domain *domain,
void irq_domain_disassociate(struct irq_domain *domain, unsigned int irq)
{
+ struct irq_desc *desc = irq_to_desc(irq);
struct irq_data *irq_data = irq_get_irq_data(irq);
irq_hw_number_t hwirq;
@@ -514,11 +515,14 @@ void irq_domain_disassociate(struct irq_domain *domain, unsigned int irq)
/* Clear reverse map for this hwirq */
irq_domain_clear_mapping(domain, hwirq);
+
+ kobject_put(&desc->kobj);
}
int irq_domain_associate(struct irq_domain *domain, unsigned int virq,
irq_hw_number_t hwirq)
{
+ struct irq_desc *desc = irq_to_desc(virq);
struct irq_data *irq_data = irq_get_irq_data(virq);
int ret;
@@ -530,6 +534,8 @@ int irq_domain_associate(struct irq_domain *domain, unsigned int virq,
if (WARN(irq_data->domain, "error: virq%i is already associated", virq))
return -EINVAL;
+ kobject_get(&desc->kobj);
+
mutex_lock(&irq_domain_mutex);
irq_data->hwirq = hwirq;
irq_data->domain = domain;
@@ -548,6 +554,7 @@ int irq_domain_associate(struct irq_domain *domain, unsigned int virq,
irq_data->domain = NULL;
irq_data->hwirq = 0;
mutex_unlock(&irq_domain_mutex);
+ kobject_put(&desc->kobj);
return ret;
}
@@ -638,6 +645,7 @@ unsigned int irq_create_mapping(struct irq_domain *domain,
{
struct device_node *of_node;
int virq;
+ struct irq_desc *desc;
pr_debug("irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq);
@@ -655,7 +663,9 @@ unsigned int irq_create_mapping(struct irq_domain *domain,
/* Check if mapping already exists */
virq = irq_find_mapping(domain, hwirq);
if (virq) {
+ desc = irq_to_desc(virq);
pr_debug("-> existing mapping on virq %d\n", virq);
+ kobject_get(&desc->kobj);
return virq;
}
@@ -674,6 +684,7 @@ unsigned int irq_create_mapping(struct irq_domain *domain,
pr_debug("irq %lu on domain %s mapped to virtual irq %u\n",
hwirq, of_node_full_name(of_node), virq);
+ desc = irq_to_desc(virq);
return virq;
}
EXPORT_SYMBOL_GPL(irq_create_mapping);
@@ -751,6 +762,7 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
irq_hw_number_t hwirq;
unsigned int type = IRQ_TYPE_NONE;
int virq;
+ struct irq_desc *desc;
if (fwspec->fwnode) {
domain = irq_find_matching_fwspec(fwspec, DOMAIN_BUS_WIRED);
@@ -787,8 +799,15 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
* current trigger type then we are done so return the
* interrupt number.
*/
- if (type == IRQ_TYPE_NONE || type == irq_get_trigger_type(virq))
+ if (type == IRQ_TYPE_NONE || type == irq_get_trigger_type(virq)) {
+ desc = irq_to_desc(virq);
+ kobject_get(&desc->kobj);
+
+ pr_err("___K___ (%u) %s %u: virq %d counter %d\n",
+ smp_processor_id(),
+ __func__, __LINE__, virq, kref_read(&desc->kobj.kref));
return virq;
+ }
/*
* If the trigger type has not been set yet, then set
@@ -800,6 +819,8 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
return 0;
irqd_set_trigger_type(irq_data, type);
+ desc = irq_to_desc(virq);
+ kobject_get(&desc->kobj);
return virq;
}
@@ -852,22 +873,12 @@ EXPORT_SYMBOL_GPL(irq_create_of_mapping);
*/
void irq_dispose_mapping(unsigned int virq)
{
- struct irq_data *irq_data = irq_get_irq_data(virq);
- struct irq_domain *domain;
+ struct irq_desc *desc = irq_to_desc(virq);
- if (!virq || !irq_data)
+ if (!virq || !desc)
return;
- domain = irq_data->domain;
- if (WARN_ON(domain == NULL))
- return;
-
- if (irq_domain_is_hierarchy(domain)) {
- irq_domain_free_irqs(virq, 1);
- } else {
- irq_domain_disassociate(domain, virq);
- irq_free_desc(virq);
- }
+ kobject_put(&desc->kobj);
}
EXPORT_SYMBOL_GPL(irq_dispose_mapping);
@@ -1413,6 +1424,7 @@ int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base,
bool realloc, const struct irq_affinity_desc *affinity)
{
int i, ret, virq;
+ bool get_ref = false;
if (domain == NULL) {
domain = irq_default_domain;
@@ -1422,6 +1434,7 @@ int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base,
if (realloc && irq_base >= 0) {
virq = irq_base;
+ get_ref = true;
} else {
virq = irq_domain_alloc_descs(irq_base, nr_irqs, 0, node,
affinity);
@@ -1453,8 +1466,14 @@ int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base,
}
}
- for (i = 0; i < nr_irqs; i++)
+ for (i = 0; i < nr_irqs; i++) {
irq_domain_insert_irq(virq + i);
+ if (get_ref) {
+ struct irq_desc *desc = irq_to_desc(virq + i);
+
+ kobject_get(&desc->kobj);
+ }
+ }
mutex_unlock(&irq_domain_mutex);
return virq;
--
2.17.1
^ permalink raw reply related
* Re: [PATCH] powerpc: avoid broken GCC __attribute__((optimize))
From: Michael Ellerman @ 2020-10-29 11:35 UTC (permalink / raw)
To: Ard Biesheuvel, Linux Kernel Mailing List
Cc: Kees Cook, Daniel Borkmann, Peter Zijlstra, Randy Dunlap,
Nick Desaulniers, Alexei Starovoitov, Arvind Sankar,
Paul Mackerras, Josh Poimboeuf, Geert Uytterhoeven,
Thomas Gleixner, open list:LINUX FOR POWERPC (32-BIT AND 64-BIT)
In-Reply-To: <CAMj1kXHFS7BonvRaSYCn+1rTXKsT8qfQocRaYovj-BTNZw_qng@mail.gmail.com>
Ard Biesheuvel <ardb@kernel.org> writes:
> On Wed, 28 Oct 2020 at 09:04, Ard Biesheuvel <ardb@kernel.org> wrote:
>>
>> Commit 7053f80d9696 ("powerpc/64: Prevent stack protection in early boot")
>> introduced a couple of uses of __attribute__((optimize)) with function
>> scope, to disable the stack protector in some early boot code.
>>
>> Unfortunately, and this is documented in the GCC man pages [0], overriding
>> function attributes for optimization is broken, and is only supported for
>> debug scenarios, not for production: the problem appears to be that
>> setting GCC -f flags using this method will cause it to forget about some
>> or all other optimization settings that have been applied.
>>
>> So the only safe way to disable the stack protector is to disable it for
>> the entire source file.
>>
>> [0] https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html
>>
>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>> Cc: Paul Mackerras <paulus@samba.org>
>> Cc: Nick Desaulniers <ndesaulniers@google.com>
>> Cc: Arvind Sankar <nivedita@alum.mit.edu>
>> Cc: Randy Dunlap <rdunlap@infradead.org>
>> Cc: Josh Poimboeuf <jpoimboe@redhat.com>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: Alexei Starovoitov <ast@kernel.org>
>> Cc: Daniel Borkmann <daniel@iogearbox.net>
>> Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
>> Cc: Geert Uytterhoeven <geert@linux-m68k.org>
>> Cc: Kees Cook <keescook@chromium.org>
>> Fixes: 7053f80d9696 ("powerpc/64: Prevent stack protection in early boot")
>> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
>> ---
>> Related discussion here:
>> https://lore.kernel.org/lkml/CAMuHMdUg0WJHEcq6to0-eODpXPOywLot6UD2=GFHpzoj_hCoBQ@mail.gmail.com/
>>
>> TL;DR using __attribute__((optimize("-fno-gcse"))) in the BPF interpreter
>> causes the compiler to forget about -fno-asynchronous-unwind-tables passed
>> on the command line, resulting in unexpected .eh_frame sections in vmlinux.
>>
>> arch/powerpc/kernel/Makefile | 3 +++
>> arch/powerpc/kernel/paca.c | 2 +-
>> arch/powerpc/kernel/setup.h | 6 ------
>> arch/powerpc/kernel/setup_64.c | 2 +-
>> 4 files changed, 5 insertions(+), 8 deletions(-)
Thanks for the patch.
> FYI i was notified by one of the robots that I missed one occurrence
> of __nostackprotector in arch/powerpc/kernel/paca.c
>
> Let me know if I need to resend.
That's fine I'll fix it up when applying.
With the existing code, with STACKPROTECTOR_STRONG=y, I see two
functions in setup_64.c that are triggering stack protection. One is
__init, and the other takes no parameters and is not easily reachable
from userspace, so I don't think losing the stack canary on either of
those is a concern.
I don't see anything in paca.c triggering stack protection.
I don't think there's any evidence this is causing a bug for us, so I'll
plan to put this in next for v5.11.
cheers
^ permalink raw reply
* Re: [PATCH] powerpc/smp: Move rcu_cpu_starting() earlier
From: Qian Cai @ 2020-10-29 12:17 UTC (permalink / raw)
To: Michael Ellerman, Paul E . McKenney
Cc: Peter Zijlstra, Paul Mackerras, linuxppc-dev, linux-kernel
In-Reply-To: <87lffpx598.fsf@mpe.ellerman.id.au>
On Thu, 2020-10-29 at 11:09 +1100, Michael Ellerman wrote:
> Qian Cai <cai@redhat.com> writes:
> > The call to rcu_cpu_starting() in start_secondary() is not early enough
> > in the CPU-hotplug onlining process, which results in lockdep splats as
> > follows:
>
> Since when?
For me, it is since the commit in the link which looks now merged into
v5.10-rc1. Then, it needs CONFIG_PROVE_RCU_LIST=y.
> What kernel version?
>
> I haven't seen this running CPU hotplug tests with PROVE_LOCKING=y on
> v5.10-rc1. Am I missing a CONFIG?
>
> cheers
>
>
> > WARNING: suspicious RCU usage
> > -----------------------------
> > kernel/locking/lockdep.c:3497 RCU-list traversed in non-reader section!!
> >
> > other info that might help us debug this:
> >
> > RCU used illegally from offline CPU!
> > rcu_scheduler_active = 1, debug_locks = 1
> > no locks held by swapper/1/0.
> >
> > Call Trace:
> > dump_stack+0xec/0x144 (unreliable)
> > lockdep_rcu_suspicious+0x128/0x14c
> > __lock_acquire+0x1060/0x1c60
> > lock_acquire+0x140/0x5f0
> > _raw_spin_lock_irqsave+0x64/0xb0
> > clockevents_register_device+0x74/0x270
> > register_decrementer_clockevent+0x94/0x110
> > start_secondary+0x134/0x800
> > start_secondary_prolog+0x10/0x14
> >
> > This is avoided by moving the call to rcu_cpu_starting up near the
> > beginning of the start_secondary() function. Note that the
> > raw_smp_processor_id() is required in order to avoid calling into
> > lockdep before RCU has declared the CPU to be watched for readers.
> >
> > Link:
> > https://lore.kernel.org/lkml/160223032121.7002.1269740091547117869.tip-bot2@tip-bot2/
> > Signed-off-by: Qian Cai <cai@redhat.com>
> > ---
> > arch/powerpc/kernel/smp.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
> > index 3c6b9822f978..8c2857cbd960 100644
> > --- a/arch/powerpc/kernel/smp.c
> > +++ b/arch/powerpc/kernel/smp.c
> > @@ -1393,13 +1393,14 @@ static void add_cpu_to_masks(int cpu)
> > /* Activate a secondary processor. */
> > void start_secondary(void *unused)
> > {
> > - unsigned int cpu = smp_processor_id();
> > + unsigned int cpu = raw_smp_processor_id();
> >
> > mmgrab(&init_mm);
> > current->active_mm = &init_mm;
> >
> > smp_store_cpu_info(cpu);
> > set_dec(tb_ticks_per_jiffy);
> > + rcu_cpu_starting(cpu);
> > preempt_disable();
> > cpu_callin_map[cpu] = 1;
> >
> > --
> > 2.28.0
^ permalink raw reply
* Re: [PATCH 01/13] PCI: dwc/imx6: Drop setting PCI_MSI_FLAGS_ENABLE
From: Rob Herring @ 2020-10-29 13:01 UTC (permalink / raw)
To: Michael Ellerman
Cc: Kunihiko Hayashi, Neil Armstrong, PCI, Binghui Wang,
Bjorn Andersson, Minghuan Lian, Thierry Reding,
Krzysztof Kozlowski, Thomas Petazzoni, Jonathan Chocron,
Jonathan Hunter, Fabio Estevam, Jerome Brunet, Jesper Nilsson,
Lorenzo Pieralisi, Kevin Hilman, Pratyush Anand, linux-arm-kernel,
Kishon Vijay Abraham I, Kukjin Kim, NXP Linux Team, Xiaowei Song,
Richard Zhu, Martin Blumenstingl, linux-arm-msm, Sascha Hauer,
linuxppc-dev, Yue Wang, linux-samsung-soc, Murali Karicheri,
linux-tegra, open list:ARM/Amlogic Meson..., linux-omap,
Mingkai Hu, Roy Zang, Bjorn Helgaas, Masahiro Yamada, Jingoo Han,
Andy Gross, Stanimir Varbanov, Pengutronix Kernel Team,
Gustavo Pimentel, Shawn Guo, Lucas Stach
In-Reply-To: <87h7qdx4oz.fsf@mpe.ellerman.id.au>
On Wed, Oct 28, 2020 at 7:21 PM Michael Ellerman <mpe@ellerman.id.au> wrote:
>
> Rob Herring <robh@kernel.org> writes:
> > No other host driver sets the PCI_MSI_FLAGS_ENABLE bit, so it must not
> > be necessary. If it is, a comment is needed.
>
> Yeah, but git blame directly points to:
>
> 75cb8d20c112 ("PCI: imx: Enable MSI from downstream components")
I think I did read this at some point and then forgot about it when I
made the change later...
> Which has a pretty long explanation. The relevant bit probably being:
>
> ... on i.MX6, the MSI Enable bit controls delivery of MSI interrupts
> from components below the Root Port.
The thing is that all seems not i.MX6 specific but DWC specific given
MSI handling is contained within the DWC block. So I don't see how
this could be an integration difference.
So maybe everyone else is still just setting CONFIG_PCIEPORTBUS
typically and haven't noticed? Is it correct for the host driver to
set MSI enable?
Rob
^ permalink raw reply
* Re: [PATCH 5/9] kprobes/ftrace: Add recursion protection to the ftrace callback
From: Steven Rostedt @ 2020-10-29 13:40 UTC (permalink / raw)
To: Masami Hiramatsu
Cc: James E.J. Bottomley, Guo Ren, linux-csky, H. Peter Anvin,
linux-s390, Helge Deller, x86, Anil S Keshavamurthy,
Christian Borntraeger, Naveen N. Rao, Vasily Gorbik,
Heiko Carstens, Borislav Petkov, Thomas Gleixner, linux-parisc,
linux-kernel, Paul Mackerras, Andrew Morton, linuxppc-dev,
David S. Miller
In-Reply-To: <20201029165803.5f6b401e5bccca4e57c70181@kernel.org>
On Thu, 29 Oct 2020 16:58:03 +0900
Masami Hiramatsu <mhiramat@kernel.org> wrote:
> Hi Steve,
>
> On Wed, 28 Oct 2020 07:52:49 -0400
> Steven Rostedt <rostedt@goodmis.org> wrote:
>
> > From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
> >
> > If a ftrace callback does not supply its own recursion protection and
> > does not set the RECURSION_SAFE flag in its ftrace_ops, then ftrace will
> > make a helper trampoline to do so before calling the callback instead of
> > just calling the callback directly.
>
> So in that case the handlers will be called without preempt disabled?
>
>
> > The default for ftrace_ops is going to assume recursion protection unless
> > otherwise specified.
>
> This seems to skip entier handler if ftrace finds recursion.
> I would like to increment the missed counter even in that case.
Note, this code does not change the functionality at this point, because
without having the FL_RECURSION flag set (which kprobes does not even in
this patch), it always gets called from the helper function that does this:
bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
if (bit < 0)
return;
preempt_disable_notrace();
op->func(ip, parent_ip, op, regs);
preempt_enable_notrace();
trace_clear_recursion(bit);
Where this function gets called by op->func().
In other words, you don't get that count anyway, and I don't think you want
it. Because it means you traced something that your callback calls.
That bit check is basically a nop, because the last patch in this series
will make the default that everything has recursion protection, but at this
patch the test does this:
/* A previous recursion check was made */
if ((val & TRACE_CONTEXT_MASK) > max)
return 0;
Which would always return true, because this function is called via the
helper that already did the trace_test_and_set_recursion() which, if it
made it this far, the val would always be greater than max.
>
> [...]
> e.g.
>
> > diff --git a/arch/csky/kernel/probes/ftrace.c b/arch/csky/kernel/probes/ftrace.c
> > index 5264763d05be..5eb2604fdf71 100644
> > --- a/arch/csky/kernel/probes/ftrace.c
> > +++ b/arch/csky/kernel/probes/ftrace.c
> > @@ -13,16 +13,21 @@ int arch_check_ftrace_location(struct kprobe *p)
> > void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
> > struct ftrace_ops *ops, struct pt_regs *regs)
> > {
> > + int bit;
> > bool lr_saver = false;
> > struct kprobe *p;
> > struct kprobe_ctlblk *kcb;
> >
> > - /* Preempt is disabled by ftrace */
> > + bit = ftrace_test_recursion_trylock();
>
> > +
> > + preempt_disable_notrace();
> > p = get_kprobe((kprobe_opcode_t *)ip);
> > if (!p) {
> > p = get_kprobe((kprobe_opcode_t *)(ip - MCOUNT_INSN_SIZE));
> > if (unlikely(!p) || kprobe_disabled(p))
> > - return;
> > + goto out;
> > lr_saver = true;
> > }
>
> if (bit < 0) {
> kprobes_inc_nmissed_count(p);
> goto out;
> }
If anything called in get_kprobe() or kprobes_inc_nmissed_count() gets
traced here, you have zero recursion protection, and this will crash the
machine with a likely reboot (triple fault).
Note, the recursion handles interrupts and wont stop them. bit < 0 only
happens if you recurse because this function called something that ends up
calling itself. Really, why would you care about missing a kprobe on the
same kprobe?
-- Steve
^ permalink raw reply
* Re: [PATCH] powerpc/smp: Move rcu_cpu_starting() earlier
From: Qian Cai @ 2020-10-29 13:48 UTC (permalink / raw)
To: paulmck, Michael Ellerman
Cc: Peter Zijlstra, Paul Mackerras, linuxppc-dev, linux-kernel
In-Reply-To: <20201029003127.GJ3249@paulmck-ThinkPad-P72>
On Wed, 2020-10-28 at 17:31 -0700, Paul E. McKenney wrote:
> On Thu, Oct 29, 2020 at 11:09:07AM +1100, Michael Ellerman wrote:
> > Qian Cai <cai@redhat.com> writes:
> > > The call to rcu_cpu_starting() in start_secondary() is not early enough
> > > in the CPU-hotplug onlining process, which results in lockdep splats as
> > > follows:
> >
> > Since when?
> > What kernel version?
> >
> > I haven't seen this running CPU hotplug tests with PROVE_LOCKING=y on
> > v5.10-rc1. Am I missing a CONFIG?
>
> My guess would be that adding CONFIG_PROVE_RAW_LOCK_NESTING=y will
> get you some splats.
Well, I don't have that set, so it should be CONFIG_PROVE_RCU_LIST=y. Anyway,
this is .config to reproduce on Power9 NV:
https://cailca.coding.net/public/linux/mm/git/files/master/powerpc.config
^ permalink raw reply
* Re: [PATCH v2 1/2] ASoC: dt-bindings: fsl_aud2htx: Add binding doc for aud2htx module
From: Rob Herring @ 2020-10-29 15:27 UTC (permalink / raw)
To: Shengjiu Wang
Cc: devicetree, alsa-devel, linuxppc-dev, timur, Xiubo.Lee, lgirdwood,
broonie, tiwai, linux-kernel, perex, nicoleotsuka, robh+dt,
festevam
In-Reply-To: <1603877930-10553-1-git-send-email-shengjiu.wang@nxp.com>
On Wed, 28 Oct 2020 17:38:49 +0800, Shengjiu Wang wrote:
> AUD2HTX (Audio Subsystem TO HDMI TX Subsystem) is a new
> IP module found on i.MX8MP.
>
> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> ---
> changes in v2:
> - fix indentation issue
> - remove nodename
>
> .../bindings/sound/fsl,aud2htx.yaml | 64 +++++++++++++++++++
> 1 file changed, 64 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/sound/fsl,aud2htx.yaml
>
My bot found errors running 'make dt_binding_check' on your patch:
yamllint warnings/errors:
dtschema/dtc warnings/errors:
/builds/robherring/linux-dt-review/Documentation/devicetree/bindings/sound/fsl,aud2htx.yaml: 'additionalProperties' is a required property
/builds/robherring/linux-dt-review/Documentation/devicetree/bindings/sound/fsl,aud2htx.yaml: ignoring, error in schema:
warning: no schema found in file: ./Documentation/devicetree/bindings/sound/fsl,aud2htx.yaml
See https://patchwork.ozlabs.org/patch/1389813
The base for the patch is generally the last rc1. Any dependencies
should be noted.
If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:
pip3 install dtschema --upgrade
Please check and re-submit.
^ permalink raw reply
* [PATCH v2 0/4] arch, mm: improve robustness of direct map manipulation
From: Mike Rapoport @ 2020-10-29 16:18 UTC (permalink / raw)
To: Andrew Morton
Cc: David Hildenbrand, Peter Zijlstra, Dave Hansen, linux-mm,
Paul Mackerras, Pavel Machek, H. Peter Anvin, sparclinux,
Christoph Lameter, Will Deacon, linux-riscv, linux-s390, x86,
Mike Rapoport, Christian Borntraeger, Ingo Molnar,
Catalin Marinas, Len Brown, Albert Ou, Vasily Gorbik, linux-pm,
Heiko Carstens, David Rientjes, Borislav Petkov, Andy Lutomirski,
Paul Walmsley, Kirill A. Shutemov, Thomas Gleixner,
linux-arm-kernel, Rafael J. Wysocki, linux-kernel, Pekka Enberg,
Palmer Dabbelt, Joonsoo Kim, Edgecombe, Rick P, linuxppc-dev,
David S. Miller, Mike Rapoport
From: Mike Rapoport <rppt@linux.ibm.com>
Hi,
During recent discussion about KVM protected memory, David raised a concern
about usage of __kernel_map_pages() outside of DEBUG_PAGEALLOC scope [1].
Indeed, for architectures that define CONFIG_ARCH_HAS_SET_DIRECT_MAP it is
possible that __kernel_map_pages() would fail, but since this function is
void, the failure will go unnoticed.
Moreover, there's lack of consistency of __kernel_map_pages() semantics
across architectures as some guard this function with
#ifdef DEBUG_PAGEALLOC, some refuse to update the direct map if page
allocation debugging is disabled at run time and some allow modifying the
direct map regardless of DEBUG_PAGEALLOC settings.
This set straightens this out by restoring dependency of
__kernel_map_pages() on DEBUG_PAGEALLOC and updating the call sites
accordingly.
Since currently the only user of __kernel_map_pages() outside
DEBUG_PAGEALLOC, it is updated to make direct map accesses there more
explicit.
[1] https://lore.kernel.org/lkml/2759b4bf-e1e3-d006-7d86-78a40348269d@redhat.com
v2 changes:
* Rephrase patch 2 changelog to better describe the change intentions and
implications
* Move removal of kernel_map_pages() from patch 1 to patch 2, per David
v1:
https://lore.kernel.org/lkml/20201025101555.3057-1-rppt@kernel.org
Mike Rapoport (4):
mm: introduce debug_pagealloc_map_pages() helper
PM: hibernate: make direct map manipulations more explicit
arch, mm: restore dependency of __kernel_map_pages() of DEBUG_PAGEALLOC
arch, mm: make kernel_page_present() always available
arch/Kconfig | 3 +++
arch/arm64/Kconfig | 4 +---
arch/arm64/include/asm/cacheflush.h | 1 +
arch/arm64/mm/pageattr.c | 6 +++--
arch/powerpc/Kconfig | 5 +----
arch/riscv/Kconfig | 4 +---
arch/riscv/include/asm/pgtable.h | 2 --
arch/riscv/include/asm/set_memory.h | 1 +
arch/riscv/mm/pageattr.c | 31 +++++++++++++++++++++++++
arch/s390/Kconfig | 4 +---
arch/sparc/Kconfig | 4 +---
arch/x86/Kconfig | 4 +---
arch/x86/include/asm/set_memory.h | 1 +
arch/x86/mm/pat/set_memory.c | 4 ++--
include/linux/mm.h | 35 +++++++++++++----------------
include/linux/set_memory.h | 5 +++++
kernel/power/snapshot.c | 30 +++++++++++++++++++++++--
mm/memory_hotplug.c | 3 +--
mm/page_alloc.c | 6 ++---
mm/slab.c | 8 +++----
20 files changed, 103 insertions(+), 58 deletions(-)
--
2.28.0
^ permalink raw reply
* [PATCH v2 1/4] mm: introduce debug_pagealloc_map_pages() helper
From: Mike Rapoport @ 2020-10-29 16:18 UTC (permalink / raw)
To: Andrew Morton
Cc: David Hildenbrand, Peter Zijlstra, Dave Hansen, linux-mm,
Paul Mackerras, Pavel Machek, H. Peter Anvin, sparclinux,
Christoph Lameter, Will Deacon, linux-riscv, linux-s390, x86,
Mike Rapoport, Christian Borntraeger, Ingo Molnar,
Catalin Marinas, Len Brown, Albert Ou, Vasily Gorbik, linux-pm,
Heiko Carstens, David Rientjes, Borislav Petkov, Andy Lutomirski,
Paul Walmsley, Kirill A. Shutemov, Thomas Gleixner,
linux-arm-kernel, Rafael J. Wysocki, linux-kernel, Pekka Enberg,
Palmer Dabbelt, Joonsoo Kim, Edgecombe, Rick P, linuxppc-dev,
David S. Miller, Mike Rapoport
In-Reply-To: <20201029161902.19272-1-rppt@kernel.org>
From: Mike Rapoport <rppt@linux.ibm.com>
When CONFIG_DEBUG_PAGEALLOC is enabled, it unmaps pages from the kernel
direct mapping after free_pages(). The pages than need to be mapped back
before they could be used. Theese mapping operations use
__kernel_map_pages() guarded with with debug_pagealloc_enabled().
The only place that calls __kernel_map_pages() without checking whether
DEBUG_PAGEALLOC is enabled is the hibernation code that presumes
availability of this function when ARCH_HAS_SET_DIRECT_MAP is set.
Still, on arm64, __kernel_map_pages() will bail out when DEBUG_PAGEALLOC is
not enabled but set_direct_map_invalid_noflush() may render some pages not
present in the direct map and hibernation code won't be able to save such
pages.
To make page allocation debugging and hibernation interaction more robust,
the dependency on DEBUG_PAGEALLOC or ARCH_HAS_SET_DIRECT_MAP has to be made
more explicit.
Start with combining the guard condition and the call to
__kernel_map_pages() into a single debug_pagealloc_map_pages() function to
emphasize that __kernel_map_pages() should not be called without
DEBUG_PAGEALLOC and use this new function to map/unmap pages when page
allocation debug is enabled.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
---
include/linux/mm.h | 10 ++++++++++
mm/memory_hotplug.c | 3 +--
mm/page_alloc.c | 6 ++----
mm/slab.c | 8 +++-----
4 files changed, 16 insertions(+), 11 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index ef360fe70aaf..1fc0609056dc 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2936,12 +2936,22 @@ kernel_map_pages(struct page *page, int numpages, int enable)
{
__kernel_map_pages(page, numpages, enable);
}
+
+static inline void debug_pagealloc_map_pages(struct page *page,
+ int numpages, int enable)
+{
+ if (debug_pagealloc_enabled_static())
+ __kernel_map_pages(page, numpages, enable);
+}
+
#ifdef CONFIG_HIBERNATION
extern bool kernel_page_present(struct page *page);
#endif /* CONFIG_HIBERNATION */
#else /* CONFIG_DEBUG_PAGEALLOC || CONFIG_ARCH_HAS_SET_DIRECT_MAP */
static inline void
kernel_map_pages(struct page *page, int numpages, int enable) {}
+static inline void debug_pagealloc_map_pages(struct page *page,
+ int numpages, int enable) {}
#ifdef CONFIG_HIBERNATION
static inline bool kernel_page_present(struct page *page) { return true; }
#endif /* CONFIG_HIBERNATION */
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index b44d4c7ba73b..e2b6043a4428 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -614,8 +614,7 @@ void generic_online_page(struct page *page, unsigned int order)
* so we should map it first. This is better than introducing a special
* case in page freeing fast path.
*/
- if (debug_pagealloc_enabled_static())
- kernel_map_pages(page, 1 << order, 1);
+ debug_pagealloc_map_pages(page, 1 << order, 1);
__free_pages_core(page, order);
totalram_pages_add(1UL << order);
#ifdef CONFIG_HIGHMEM
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 23f5066bd4a5..9a66a1ff9193 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1272,8 +1272,7 @@ static __always_inline bool free_pages_prepare(struct page *page,
*/
arch_free_page(page, order);
- if (debug_pagealloc_enabled_static())
- kernel_map_pages(page, 1 << order, 0);
+ debug_pagealloc_map_pages(page, 1 << order, 0);
kasan_free_nondeferred_pages(page, order);
@@ -2270,8 +2269,7 @@ inline void post_alloc_hook(struct page *page, unsigned int order,
set_page_refcounted(page);
arch_alloc_page(page, order);
- if (debug_pagealloc_enabled_static())
- kernel_map_pages(page, 1 << order, 1);
+ debug_pagealloc_map_pages(page, 1 << order, 1);
kasan_alloc_pages(page, order);
kernel_poison_pages(page, 1 << order, 1);
set_page_owner(page, order, gfp_flags);
diff --git a/mm/slab.c b/mm/slab.c
index b1113561b98b..340db0ce74c4 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1431,10 +1431,8 @@ static bool is_debug_pagealloc_cache(struct kmem_cache *cachep)
#ifdef CONFIG_DEBUG_PAGEALLOC
static void slab_kernel_map(struct kmem_cache *cachep, void *objp, int map)
{
- if (!is_debug_pagealloc_cache(cachep))
- return;
-
- kernel_map_pages(virt_to_page(objp), cachep->size / PAGE_SIZE, map);
+ debug_pagealloc_map_pages(virt_to_page(objp),
+ cachep->size / PAGE_SIZE, map);
}
#else
@@ -2062,7 +2060,7 @@ int __kmem_cache_create(struct kmem_cache *cachep, slab_flags_t flags)
#if DEBUG
/*
- * If we're going to use the generic kernel_map_pages()
+ * If we're going to use the generic debug_pagealloc_map_pages()
* poisoning, then it's going to smash the contents of
* the redzone and userword anyhow, so switch them off.
*/
--
2.28.0
^ permalink raw reply related
* [PATCH v2 2/4] PM: hibernate: make direct map manipulations more explicit
From: Mike Rapoport @ 2020-10-29 16:19 UTC (permalink / raw)
To: Andrew Morton
Cc: David Hildenbrand, Peter Zijlstra, Dave Hansen, linux-mm,
Paul Mackerras, Pavel Machek, H. Peter Anvin, sparclinux,
Christoph Lameter, Will Deacon, linux-riscv, linux-s390, x86,
Mike Rapoport, Christian Borntraeger, Ingo Molnar,
Catalin Marinas, Len Brown, Albert Ou, Vasily Gorbik, linux-pm,
Heiko Carstens, David Rientjes, Borislav Petkov, Andy Lutomirski,
Paul Walmsley, Kirill A. Shutemov, Thomas Gleixner,
linux-arm-kernel, Rafael J. Wysocki, linux-kernel, Pekka Enberg,
Palmer Dabbelt, Joonsoo Kim, Edgecombe, Rick P, linuxppc-dev,
David S. Miller, Mike Rapoport
In-Reply-To: <20201029161902.19272-1-rppt@kernel.org>
From: Mike Rapoport <rppt@linux.ibm.com>
When DEBUG_PAGEALLOC or ARCH_HAS_SET_DIRECT_MAP is enabled a page may be
not present in the direct map and has to be explicitly mapped before it
could be copied.
On arm64 it is possible that a page would be removed from the direct map
using set_direct_map_invalid_noflush() but __kernel_map_pages() will refuse
to map this page back if DEBUG_PAGEALLOC is disabled.
Introduce hibernate_map_page() that will explicitly use
set_direct_map_{default,invalid}_noflush() for ARCH_HAS_SET_DIRECT_MAP case
and debug_pagealloc_map_pages() for DEBUG_PAGEALLOC case.
The remapping of the pages in safe_copy_page() presumes that it only
changes protection bits in an existing PTE and so it is safe to ignore
return value of set_direct_map_{default,invalid}_noflush().
Still, add a WARN_ON() so that future changes in set_memory APIs will not
silently break hibernation.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
include/linux/mm.h | 12 ------------
kernel/power/snapshot.c | 30 ++++++++++++++++++++++++++++--
2 files changed, 28 insertions(+), 14 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1fc0609056dc..14e397f3752c 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2927,16 +2927,6 @@ static inline bool debug_pagealloc_enabled_static(void)
#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP)
extern void __kernel_map_pages(struct page *page, int numpages, int enable);
-/*
- * When called in DEBUG_PAGEALLOC context, the call should most likely be
- * guarded by debug_pagealloc_enabled() or debug_pagealloc_enabled_static()
- */
-static inline void
-kernel_map_pages(struct page *page, int numpages, int enable)
-{
- __kernel_map_pages(page, numpages, enable);
-}
-
static inline void debug_pagealloc_map_pages(struct page *page,
int numpages, int enable)
{
@@ -2948,8 +2938,6 @@ static inline void debug_pagealloc_map_pages(struct page *page,
extern bool kernel_page_present(struct page *page);
#endif /* CONFIG_HIBERNATION */
#else /* CONFIG_DEBUG_PAGEALLOC || CONFIG_ARCH_HAS_SET_DIRECT_MAP */
-static inline void
-kernel_map_pages(struct page *page, int numpages, int enable) {}
static inline void debug_pagealloc_map_pages(struct page *page,
int numpages, int enable) {}
#ifdef CONFIG_HIBERNATION
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 46b1804c1ddf..054c8cce4236 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -76,6 +76,32 @@ static inline void hibernate_restore_protect_page(void *page_address) {}
static inline void hibernate_restore_unprotect_page(void *page_address) {}
#endif /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */
+static inline void hibernate_map_page(struct page *page, int enable)
+{
+ if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) {
+ unsigned long addr = (unsigned long)page_address(page);
+ int ret;
+
+ /*
+ * This should not fail because remapping a page here means
+ * that we only update protection bits in an existing PTE.
+ * It is still worth to have WARN_ON() here if something
+ * changes and this will no longer be the case.
+ */
+ if (enable)
+ ret = set_direct_map_default_noflush(page);
+ else
+ ret = set_direct_map_invalid_noflush(page);
+
+ if (WARN_ON(ret))
+ return;
+
+ flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
+ } else {
+ debug_pagealloc_map_pages(page, 1, enable);
+ }
+}
+
static int swsusp_page_is_free(struct page *);
static void swsusp_set_page_forbidden(struct page *);
static void swsusp_unset_page_forbidden(struct page *);
@@ -1355,9 +1381,9 @@ static void safe_copy_page(void *dst, struct page *s_page)
if (kernel_page_present(s_page)) {
do_copy_page(dst, page_address(s_page));
} else {
- kernel_map_pages(s_page, 1, 1);
+ hibernate_map_page(s_page, 1);
do_copy_page(dst, page_address(s_page));
- kernel_map_pages(s_page, 1, 0);
+ hibernate_map_page(s_page, 0);
}
}
--
2.28.0
^ permalink raw reply related
* [PATCH] powerpc: add support for TIF_NOTIFY_SIGNAL
From: Jens Axboe @ 2020-10-29 16:19 UTC (permalink / raw)
To: linuxppc-dev
Wire up TIF_NOTIFY_SIGNAL handling for powerpc.
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
5.11 has support queued up for TIF_NOTIFY_SIGNAL, see this posting
for details:
https://lore.kernel.org/io-uring/20201026203230.386348-1-axboe@kernel.dk/
As part of that work, I'm adding TIF_NOTIFY_SIGNAL support to all archs,
as that will enable a set of cleanups once all of them support it. I'm
happy carrying this patch if need be, or it can be funelled through the
arch tree. Let me know.
arch/powerpc/include/asm/thread_info.h | 5 ++++-
arch/powerpc/kernel/signal.c | 2 +-
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 46a210b03d2b..53115ae61495 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -90,6 +90,7 @@ void arch_setup_new_exec(void);
#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
#define TIF_SIGPENDING 1 /* signal pending */
#define TIF_NEED_RESCHED 2 /* rescheduling necessary */
+#define TIF_NOTIFY_SIGNAL 3 /* signal notifications exist */
#define TIF_SYSCALL_EMU 4 /* syscall emulation active */
#define TIF_RESTORE_TM 5 /* need to restore TM FP/VEC/VSX */
#define TIF_PATCH_PENDING 6 /* pending live patching update */
@@ -115,6 +116,7 @@ void arch_setup_new_exec(void);
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
+#define _TIF_NOTIFY_SIGNAL (1<<TIF_NOTIFY_SIGNAL)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_32BIT (1<<TIF_32BIT)
#define _TIF_RESTORE_TM (1<<TIF_RESTORE_TM)
@@ -136,7 +138,8 @@ void arch_setup_new_exec(void);
#define _TIF_USER_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
_TIF_NOTIFY_RESUME | _TIF_UPROBE | \
- _TIF_RESTORE_TM | _TIF_PATCH_PENDING)
+ _TIF_RESTORE_TM | _TIF_PATCH_PENDING | \
+ _TIF_NOTIFY_SIGNAL)
#define _TIF_PERSYSCALL_MASK (_TIF_RESTOREALL|_TIF_NOERROR)
/* Bits in local_flags */
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index d2c356f37077..a8bb0aca1d02 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -318,7 +318,7 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
if (thread_info_flags & _TIF_PATCH_PENDING)
klp_update_patch_state(current);
- if (thread_info_flags & _TIF_SIGPENDING) {
+ if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) {
BUG_ON(regs != current->thread.regs);
do_signal(current);
}
--
2.29.0
--
Jens Axboe
^ permalink raw reply related
* [PATCH v2 3/4] arch, mm: restore dependency of __kernel_map_pages() of DEBUG_PAGEALLOC
From: Mike Rapoport @ 2020-10-29 16:19 UTC (permalink / raw)
To: Andrew Morton
Cc: David Hildenbrand, Peter Zijlstra, Dave Hansen, linux-mm,
Paul Mackerras, Pavel Machek, H. Peter Anvin, sparclinux,
Christoph Lameter, Will Deacon, linux-riscv, linux-s390, x86,
Mike Rapoport, Christian Borntraeger, Ingo Molnar,
Catalin Marinas, Len Brown, Albert Ou, Vasily Gorbik, linux-pm,
Heiko Carstens, David Rientjes, Borislav Petkov, Andy Lutomirski,
Paul Walmsley, Kirill A. Shutemov, Thomas Gleixner,
linux-arm-kernel, Rafael J. Wysocki, linux-kernel, Pekka Enberg,
Palmer Dabbelt, Joonsoo Kim, Edgecombe, Rick P, linuxppc-dev,
David S. Miller, Mike Rapoport
In-Reply-To: <20201029161902.19272-1-rppt@kernel.org>
From: Mike Rapoport <rppt@linux.ibm.com>
The design of DEBUG_PAGEALLOC presumes that __kernel_map_pages() must never
fail. With this assumption is wouldn't be safe to allow general usage of
this function.
Moreover, some architectures that implement __kernel_map_pages() have this
function guarded by #ifdef DEBUG_PAGEALLOC and some refuse to map/unmap
pages when page allocation debugging is disabled at runtime.
As all the users of __kernel_map_pages() were converted to use
debug_pagealloc_map_pages() it is safe to make it available only when
DEBUG_PAGEALLOC is set.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
arch/Kconfig | 3 +++
arch/arm64/Kconfig | 4 +---
arch/arm64/mm/pageattr.c | 6 ++++--
arch/powerpc/Kconfig | 5 +----
arch/riscv/Kconfig | 4 +---
arch/riscv/include/asm/pgtable.h | 2 --
arch/riscv/mm/pageattr.c | 2 ++
arch/s390/Kconfig | 4 +---
arch/sparc/Kconfig | 4 +---
arch/x86/Kconfig | 4 +---
arch/x86/mm/pat/set_memory.c | 2 ++
include/linux/mm.h | 10 +++++++---
12 files changed, 24 insertions(+), 26 deletions(-)
diff --git a/arch/Kconfig b/arch/Kconfig
index 56b6ccc0e32d..56d4752b6db6 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -1028,6 +1028,9 @@ config HAVE_STATIC_CALL_INLINE
bool
depends on HAVE_STATIC_CALL
+config ARCH_SUPPORTS_DEBUG_PAGEALLOC
+ bool
+
source "kernel/gcov/Kconfig"
source "scripts/gcc-plugins/Kconfig"
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index f858c352f72a..5a01dfb77b93 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -71,6 +71,7 @@ config ARM64
select ARCH_USE_QUEUED_RWLOCKS
select ARCH_USE_QUEUED_SPINLOCKS
select ARCH_USE_SYM_ANNOTATIONS
+ select ARCH_SUPPORTS_DEBUG_PAGEALLOC
select ARCH_SUPPORTS_MEMORY_FAILURE
select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK
select ARCH_SUPPORTS_ATOMIC_RMW
@@ -1005,9 +1006,6 @@ config HOLES_IN_ZONE
source "kernel/Kconfig.hz"
-config ARCH_SUPPORTS_DEBUG_PAGEALLOC
- def_bool y
-
config ARCH_SPARSEMEM_ENABLE
def_bool y
select SPARSEMEM_VMEMMAP_ENABLE
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index 1b94f5b82654..18613d8834db 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -178,13 +178,15 @@ int set_direct_map_default_noflush(struct page *page)
PAGE_SIZE, change_page_range, &data);
}
+#ifdef CONFIG_DEBUG_PAGEALLOC
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
- if (!debug_pagealloc_enabled() && !rodata_full)
+ if (!rodata_full)
return;
set_memory_valid((unsigned long)page_address(page), numpages, enable);
}
+#endif /* CONFIG_DEBUG_PAGEALLOC */
/*
* This function is used to determine if a linear map page has been marked as
@@ -204,7 +206,7 @@ bool kernel_page_present(struct page *page)
pte_t *ptep;
unsigned long addr = (unsigned long)page_address(page);
- if (!debug_pagealloc_enabled() && !rodata_full)
+ if (!rodata_full)
return true;
pgdp = pgd_offset_k(addr);
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index e9f13fe08492..ad8a83f3ddca 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -146,6 +146,7 @@ config PPC
select ARCH_MIGHT_HAVE_PC_SERIO
select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
select ARCH_SUPPORTS_ATOMIC_RMW
+ select ARCH_SUPPORTS_DEBUG_PAGEALLOC if PPC32 || PPC_BOOK3S_64
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_CMPXCHG_LOCKREF if PPC64
select ARCH_USE_QUEUED_RWLOCKS if PPC_QUEUED_SPINLOCKS
@@ -355,10 +356,6 @@ config PPC_OF_PLATFORM_PCI
depends on PCI
depends on PPC64 # not supported on 32 bits yet
-config ARCH_SUPPORTS_DEBUG_PAGEALLOC
- depends on PPC32 || PPC_BOOK3S_64
- def_bool y
-
config ARCH_SUPPORTS_UPROBES
def_bool y
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 44377fd7860e..9283c6f9ae2a 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -14,6 +14,7 @@ config RISCV
def_bool y
select ARCH_CLOCKSOURCE_INIT
select ARCH_SUPPORTS_ATOMIC_RMW
+ select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU
select ARCH_HAS_BINFMT_FLAT
select ARCH_HAS_DEBUG_VM_PGTABLE
select ARCH_HAS_DEBUG_VIRTUAL if MMU
@@ -153,9 +154,6 @@ config ARCH_SELECT_MEMORY_MODEL
config ARCH_WANT_GENERAL_HUGETLB
def_bool y
-config ARCH_SUPPORTS_DEBUG_PAGEALLOC
- def_bool y
-
config SYS_SUPPORTS_HUGETLBFS
depends on MMU
def_bool y
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 183f1f4b2ae6..41a72861987c 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -461,8 +461,6 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
#define VMALLOC_START 0
#define VMALLOC_END TASK_SIZE
-static inline void __kernel_map_pages(struct page *page, int numpages, int enable) {}
-
#endif /* !CONFIG_MMU */
#define kern_addr_valid(addr) (1) /* FIXME */
diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c
index 19fecb362d81..321b09d2e2ea 100644
--- a/arch/riscv/mm/pageattr.c
+++ b/arch/riscv/mm/pageattr.c
@@ -184,6 +184,7 @@ int set_direct_map_default_noflush(struct page *page)
return ret;
}
+#ifdef CONFIG_DEBUG_PAGEALLOC
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
if (!debug_pagealloc_enabled())
@@ -196,3 +197,4 @@ void __kernel_map_pages(struct page *page, int numpages, int enable)
__set_memory((unsigned long)page_address(page), numpages,
__pgprot(0), __pgprot(_PAGE_PRESENT));
}
+#endif
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 4a2a12be04c9..991a850a6c0b 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -35,9 +35,6 @@ config GENERIC_LOCKBREAK
config PGSTE
def_bool y if KVM
-config ARCH_SUPPORTS_DEBUG_PAGEALLOC
- def_bool y
-
config AUDIT_ARCH
def_bool y
@@ -106,6 +103,7 @@ config S390
select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
select ARCH_STACKWALK
select ARCH_SUPPORTS_ATOMIC_RMW
+ select ARCH_SUPPORTS_DEBUG_PAGEALLOC
select ARCH_SUPPORTS_NUMA_BALANCING
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_CMPXCHG_LOCKREF
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index a6ca135442f9..2c729b8d097a 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -88,6 +88,7 @@ config SPARC64
select HAVE_C_RECORDMCOUNT
select HAVE_ARCH_AUDITSYSCALL
select ARCH_SUPPORTS_ATOMIC_RMW
+ select ARCH_SUPPORTS_DEBUG_PAGEALLOC
select HAVE_NMI
select HAVE_REGS_AND_STACK_ACCESS_API
select ARCH_USE_QUEUED_RWLOCKS
@@ -148,9 +149,6 @@ config GENERIC_ISA_DMA
bool
default y if SPARC32
-config ARCH_SUPPORTS_DEBUG_PAGEALLOC
- def_bool y if SPARC64
-
config PGTABLE_LEVELS
default 4 if 64BIT
default 3
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f6946b81f74a..0db3fb1da70c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -91,6 +91,7 @@ config X86
select ARCH_STACKWALK
select ARCH_SUPPORTS_ACPI
select ARCH_SUPPORTS_ATOMIC_RMW
+ select ARCH_SUPPORTS_DEBUG_PAGEALLOC
select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_QUEUED_RWLOCKS
@@ -329,9 +330,6 @@ config ZONE_DMA32
config AUDIT_ARCH
def_bool y if X86_64
-config ARCH_SUPPORTS_DEBUG_PAGEALLOC
- def_bool y
-
config KASAN_SHADOW_OFFSET
hex
depends on KASAN
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index 40baa90e74f4..7f248fc45317 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -2194,6 +2194,7 @@ int set_direct_map_default_noflush(struct page *page)
return __set_pages_p(page, 1);
}
+#ifdef CONFIG_DEBUG_PAGEALLOC
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
if (PageHighMem(page))
@@ -2225,6 +2226,7 @@ void __kernel_map_pages(struct page *page, int numpages, int enable)
arch_flush_lazy_mmu_mode();
}
+#endif /* CONFIG_DEBUG_PAGEALLOC */
#ifdef CONFIG_HIBERNATION
bool kernel_page_present(struct page *page)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 14e397f3752c..ab0ef6bd351d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2924,7 +2924,11 @@ static inline bool debug_pagealloc_enabled_static(void)
return static_branch_unlikely(&_debug_pagealloc_enabled);
}
-#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP)
+#ifdef CONFIG_DEBUG_PAGEALLOC
+/*
+ * To support DEBUG_PAGEALLOC architecture must ensure that
+ * __kernel_map_pages() never fails
+ */
extern void __kernel_map_pages(struct page *page, int numpages, int enable);
static inline void debug_pagealloc_map_pages(struct page *page,
@@ -2937,13 +2941,13 @@ static inline void debug_pagealloc_map_pages(struct page *page,
#ifdef CONFIG_HIBERNATION
extern bool kernel_page_present(struct page *page);
#endif /* CONFIG_HIBERNATION */
-#else /* CONFIG_DEBUG_PAGEALLOC || CONFIG_ARCH_HAS_SET_DIRECT_MAP */
+#else /* CONFIG_DEBUG_PAGEALLOC */
static inline void debug_pagealloc_map_pages(struct page *page,
int numpages, int enable) {}
#ifdef CONFIG_HIBERNATION
static inline bool kernel_page_present(struct page *page) { return true; }
#endif /* CONFIG_HIBERNATION */
-#endif /* CONFIG_DEBUG_PAGEALLOC || CONFIG_ARCH_HAS_SET_DIRECT_MAP */
+#endif /* CONFIG_DEBUG_PAGEALLOC */
#ifdef __HAVE_ARCH_GATE_AREA
extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm);
--
2.28.0
^ permalink raw reply related
* [PATCH v2 4/4] arch, mm: make kernel_page_present() always available
From: Mike Rapoport @ 2020-10-29 16:19 UTC (permalink / raw)
To: Andrew Morton
Cc: David Hildenbrand, Peter Zijlstra, Dave Hansen, linux-mm,
Paul Mackerras, Pavel Machek, H. Peter Anvin, sparclinux,
Christoph Lameter, Will Deacon, linux-riscv, linux-s390, x86,
Mike Rapoport, Christian Borntraeger, Ingo Molnar,
Catalin Marinas, Len Brown, Albert Ou, Vasily Gorbik, linux-pm,
Heiko Carstens, David Rientjes, Borislav Petkov, Andy Lutomirski,
Paul Walmsley, Kirill A. Shutemov, Thomas Gleixner,
linux-arm-kernel, Rafael J. Wysocki, linux-kernel, Pekka Enberg,
Palmer Dabbelt, Joonsoo Kim, Edgecombe, Rick P, linuxppc-dev,
David S. Miller, Mike Rapoport
In-Reply-To: <20201029161902.19272-1-rppt@kernel.org>
From: Mike Rapoport <rppt@linux.ibm.com>
For architectures that enable ARCH_HAS_SET_MEMORY having the ability to
verify that a page is mapped in the kernel direct map can be useful
regardless of hibernation.
Add RISC-V implementation of kernel_page_present(), update its forward
declarations and stubs to be a part of set_memory API and remove ugly
ifdefery in inlcude/linux/mm.h around current declarations of
kernel_page_present().
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
arch/arm64/include/asm/cacheflush.h | 1 +
arch/riscv/include/asm/set_memory.h | 1 +
arch/riscv/mm/pageattr.c | 29 +++++++++++++++++++++++++++++
arch/x86/include/asm/set_memory.h | 1 +
arch/x86/mm/pat/set_memory.c | 2 --
include/linux/mm.h | 7 -------
include/linux/set_memory.h | 5 +++++
7 files changed, 37 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h
index 9384fd8fc13c..45217f21f1fe 100644
--- a/arch/arm64/include/asm/cacheflush.h
+++ b/arch/arm64/include/asm/cacheflush.h
@@ -140,6 +140,7 @@ int set_memory_valid(unsigned long addr, int numpages, int enable);
int set_direct_map_invalid_noflush(struct page *page);
int set_direct_map_default_noflush(struct page *page);
+bool kernel_page_present(struct page *page);
#include <asm-generic/cacheflush.h>
diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h
index 4c5bae7ca01c..d690b08dff2a 100644
--- a/arch/riscv/include/asm/set_memory.h
+++ b/arch/riscv/include/asm/set_memory.h
@@ -24,6 +24,7 @@ static inline int set_memory_nx(unsigned long addr, int numpages) { return 0; }
int set_direct_map_invalid_noflush(struct page *page);
int set_direct_map_default_noflush(struct page *page);
+bool kernel_page_present(struct page *page);
#endif /* __ASSEMBLY__ */
diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c
index 321b09d2e2ea..87ba5a68bbb8 100644
--- a/arch/riscv/mm/pageattr.c
+++ b/arch/riscv/mm/pageattr.c
@@ -198,3 +198,32 @@ void __kernel_map_pages(struct page *page, int numpages, int enable)
__pgprot(0), __pgprot(_PAGE_PRESENT));
}
#endif
+
+bool kernel_page_present(struct page *page)
+{
+ unsigned long addr = (unsigned long)page_address(page);
+ pgd_t *pgd;
+ pud_t *pud;
+ p4d_t *p4d;
+ pmd_t *pmd;
+ pte_t *pte;
+
+ pgd = pgd_offset_k(addr);
+ if (!pgd_present(*pgd))
+ return false;
+
+ p4d = p4d_offset(pgd, addr);
+ if (!p4d_present(*p4d))
+ return false;
+
+ pud = pud_offset(p4d, addr);
+ if (!pud_present(*pud))
+ return false;
+
+ pmd = pmd_offset(pud, addr);
+ if (!pmd_present(*pmd))
+ return false;
+
+ pte = pte_offset_kernel(pmd, addr);
+ return pte_present(*pte);
+}
diff --git a/arch/x86/include/asm/set_memory.h b/arch/x86/include/asm/set_memory.h
index 5948218f35c5..4352f08bfbb5 100644
--- a/arch/x86/include/asm/set_memory.h
+++ b/arch/x86/include/asm/set_memory.h
@@ -82,6 +82,7 @@ int set_pages_rw(struct page *page, int numpages);
int set_direct_map_invalid_noflush(struct page *page);
int set_direct_map_default_noflush(struct page *page);
+bool kernel_page_present(struct page *page);
extern int kernel_set_to_readonly;
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index 7f248fc45317..16f878c26667 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -2228,7 +2228,6 @@ void __kernel_map_pages(struct page *page, int numpages, int enable)
}
#endif /* CONFIG_DEBUG_PAGEALLOC */
-#ifdef CONFIG_HIBERNATION
bool kernel_page_present(struct page *page)
{
unsigned int level;
@@ -2240,7 +2239,6 @@ bool kernel_page_present(struct page *page)
pte = lookup_address((unsigned long)page_address(page), &level);
return (pte_val(*pte) & _PAGE_PRESENT);
}
-#endif /* CONFIG_HIBERNATION */
int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address,
unsigned numpages, unsigned long page_flags)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index ab0ef6bd351d..44b82f22e76a 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2937,16 +2937,9 @@ static inline void debug_pagealloc_map_pages(struct page *page,
if (debug_pagealloc_enabled_static())
__kernel_map_pages(page, numpages, enable);
}
-
-#ifdef CONFIG_HIBERNATION
-extern bool kernel_page_present(struct page *page);
-#endif /* CONFIG_HIBERNATION */
#else /* CONFIG_DEBUG_PAGEALLOC */
static inline void debug_pagealloc_map_pages(struct page *page,
int numpages, int enable) {}
-#ifdef CONFIG_HIBERNATION
-static inline bool kernel_page_present(struct page *page) { return true; }
-#endif /* CONFIG_HIBERNATION */
#endif /* CONFIG_DEBUG_PAGEALLOC */
#ifdef __HAVE_ARCH_GATE_AREA
diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h
index 860e0f843c12..fe1aa4e54680 100644
--- a/include/linux/set_memory.h
+++ b/include/linux/set_memory.h
@@ -23,6 +23,11 @@ static inline int set_direct_map_default_noflush(struct page *page)
{
return 0;
}
+
+static inline bool kernel_page_present(struct page *page)
+{
+ return true;
+}
#endif
#ifndef set_mce_nospec
--
2.28.0
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