* Re: [PATCH v2] sched/core: fix illegal RCU from offline CPUs
From: Michael Ellerman @ 2020-04-02 11:24 UTC (permalink / raw)
To: Qian Cai, peterz, mingo
Cc: juri.lelli, James.Bottomley, vincent.guittot, linux-parisc,
paulmck, deller, Nicholas Piggin, linux-kernel, rostedt, bsegall,
linux-mm, Qian Cai, mgorman, tglx, linuxppc-dev, dietmar.eggemann
In-Reply-To: <20200401214033.8448-1-cai@lca.pw>
Qian Cai <cai@lca.pw> writes:
> From: Peter Zijlstra <peterz@infradead.org>
>
> In the CPU-offline process, it calls mmdrop() after idle entry and the
> subsequent call to cpuhp_report_idle_dead(). Once execution passes the
> call to rcu_report_dead(), RCU is ignoring the CPU, which results in
> lockdep complaining when mmdrop() uses RCU from either memcg or
> debugobjects below.
>
> Fix it by cleaning up the active_mm state from BP instead. Every arch
> which has CONFIG_HOTPLUG_CPU should have already called idle_task_exit()
> from AP. The only exception is parisc because it switches them to
> &init_mm unconditionally (see smp_boot_one_cpu() and smp_cpu_init()),
> but the patch will still work there because it calls mmgrab(&init_mm) in
> smp_cpu_init() and then should call mmdrop(&init_mm) in finish_cpu().
Thanks for debugging this. How did you hit it in the first place?
A link to the original thread would have helped me:
https://lore.kernel.org/lkml/20200113190331.12788-1-cai@lca.pw/
> WARNING: suspicious RCU usage
> -----------------------------
> kernel/workqueue.c:710 RCU or wq_pool_mutex should be held!
>
> other info that might help us debug this:
>
> RCU used illegally from offline CPU!
> Call Trace:
> dump_stack+0xf4/0x164 (unreliable)
> lockdep_rcu_suspicious+0x140/0x164
> get_work_pool+0x110/0x150
> __queue_work+0x1bc/0xca0
> queue_work_on+0x114/0x120
> css_release+0x9c/0xc0
> percpu_ref_put_many+0x204/0x230
> free_pcp_prepare+0x264/0x570
> free_unref_page+0x38/0xf0
> __mmdrop+0x21c/0x2c0
> idle_task_exit+0x170/0x1b0
> pnv_smp_cpu_kill_self+0x38/0x2e0
> cpu_die+0x48/0x64
> arch_cpu_idle_dead+0x30/0x50
> do_idle+0x2f4/0x470
> cpu_startup_entry+0x38/0x40
> start_secondary+0x7a8/0xa80
> start_secondary_resume+0x10/0x14
Do we know when this started happening? ie. can we determine a Fixes
tag?
> <Peter to sign off here>
> Signed-off-by: Qian Cai <cai@lca.pw>
> ---
> arch/powerpc/platforms/powernv/smp.c | 1 -
> include/linux/sched/mm.h | 2 ++
> kernel/cpu.c | 18 +++++++++++++++++-
> kernel/sched/core.c | 5 +++--
> 4 files changed, 22 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c
> index 13e251699346..b2ba3e95bda7 100644
> --- a/arch/powerpc/platforms/powernv/smp.c
> +++ b/arch/powerpc/platforms/powernv/smp.c
> @@ -167,7 +167,6 @@ static void pnv_smp_cpu_kill_self(void)
> /* Standard hot unplug procedure */
>
> idle_task_exit();
> - current->active_mm = NULL; /* for sanity */
If I'm reading it right, we'll now be running with active_mm == init_mm
in the offline loop.
I guess that's fine, I can't think of any reason it would matter, and it
seems like we were NULL'ing it out just for paranoia's sake not because
of any actual problem.
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
cheers
> diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
> index c49257a3b510..a132d875d351 100644
> --- a/include/linux/sched/mm.h
> +++ b/include/linux/sched/mm.h
> @@ -49,6 +49,8 @@ static inline void mmdrop(struct mm_struct *mm)
> __mmdrop(mm);
> }
>
> +void mmdrop(struct mm_struct *mm);
> +
> /*
> * This has to be called after a get_task_mm()/mmget_not_zero()
> * followed by taking the mmap_sem for writing before modifying the
> diff --git a/kernel/cpu.c b/kernel/cpu.c
> index 2371292f30b0..244d30544377 100644
> --- a/kernel/cpu.c
> +++ b/kernel/cpu.c
> @@ -3,6 +3,7 @@
> *
> * This code is licenced under the GPL.
> */
> +#include <linux/sched/mm.h>
> #include <linux/proc_fs.h>
> #include <linux/smp.h>
> #include <linux/init.h>
> @@ -564,6 +565,21 @@ static int bringup_cpu(unsigned int cpu)
> return bringup_wait_for_ap(cpu);
> }
>
> +static int finish_cpu(unsigned int cpu)
> +{
> + struct task_struct *idle = idle_thread_get(cpu);
> + struct mm_struct *mm = idle->active_mm;
> +
> + /*
> + * idle_task_exit() will have switched to &init_mm, now
> + * clean up any remaining active_mm state.
> + */
> + if (mm != &init_mm)
> + idle->active_mm = &init_mm;
> + mmdrop(mm);
> + return 0;
> +}
> +
> /*
> * Hotplug state machine related functions
> */
> @@ -1549,7 +1565,7 @@ static struct cpuhp_step cpuhp_hp_states[] = {
> [CPUHP_BRINGUP_CPU] = {
> .name = "cpu:bringup",
> .startup.single = bringup_cpu,
> - .teardown.single = NULL,
> + .teardown.single = finish_cpu,
> .cant_stop = true,
> },
> /* Final state before CPU kills itself */
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index a2694ba82874..8787958339d5 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -6200,13 +6200,14 @@ void idle_task_exit(void)
> struct mm_struct *mm = current->active_mm;
>
> BUG_ON(cpu_online(smp_processor_id()));
> + BUG_ON(current != this_rq()->idle);
>
> if (mm != &init_mm) {
> switch_mm(mm, &init_mm, current);
> - current->active_mm = &init_mm;
> finish_arch_post_lock_switch();
> }
> - mmdrop(mm);
> +
> + /* finish_cpu(), as ran on the BP, will clean up the active_mm state */
> }
>
> /*
> --
> 2.21.0 (Apple Git-122.2)
^ permalink raw reply
* WARNING in ext4_da_update_reserve_space
From: syzbot @ 2020-04-02 11:02 UTC (permalink / raw)
To: a, adilger.kernel, b.a.t.m.a.n, benh, davem, linux-ext4,
linux-kernel, linuxppc-dev, mareklindner, mpe, muriloo, netdev,
paulus, sw, syzkaller-bugs, tytso
Hello,
syzbot found the following crash on:
HEAD commit: 1a147b74 Merge branch 'DSA-mtu'
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14237713e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=46ee14d4915944bc
dashboard link: https://syzkaller.appspot.com/bug?extid=67e4f16db666b1c8253c
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12237713e00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10ec7c97e00000
The bug was bisected to:
commit 658b0f92bc7003bc734471f61bf7cd56339eb8c3
Author: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Date: Wed Aug 1 21:33:15 2018 +0000
powerpc/traps: Print unhandled signals in a separate function
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15979f5be00000
final crash: https://syzkaller.appspot.com/x/report.txt?x=17979f5be00000
console output: https://syzkaller.appspot.com/x/log.txt?x=13979f5be00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+67e4f16db666b1c8253c@syzkaller.appspotmail.com
Fixes: 658b0f92bc70 ("powerpc/traps: Print unhandled signals in a separate function")
EXT4-fs warning (device sda1): ext4_da_update_reserve_space:344: ext4_da_update_reserve_space: ino 15722, used 1 with only 0 reserved data blocks
------------[ cut here ]------------
WARNING: CPU: 1 PID: 359 at fs/ext4/inode.c:348 ext4_da_update_reserve_space+0x622/0x7d0 fs/ext4/inode.c:344
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 359 Comm: kworker/u4:5 Not tainted 5.6.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_workfn (flush-8:0)
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x188/0x20d lib/dump_stack.c:118
panic+0x2e3/0x75c kernel/panic.c:221
__warn.cold+0x2f/0x35 kernel/panic.c:582
report_bug+0x27b/0x2f0 lib/bug.c:195
fixup_bug arch/x86/kernel/traps.c:174 [inline]
fixup_bug arch/x86/kernel/traps.c:169 [inline]
do_error_trap+0x12b/0x220 arch/x86/kernel/traps.c:267
do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286
invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:ext4_da_update_reserve_space+0x622/0x7d0 fs/ext4/inode.c:348
Code: 02 00 0f 85 94 01 00 00 48 8b 7d 28 49 c7 c0 20 72 3c 88 41 56 48 c7 c1 80 60 3c 88 53 ba 58 01 00 00 4c 89 c6 e8 1e 6d 0d 00 <0f> 0b 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 0f b6 04
RSP: 0018:ffffc90002197288 EFLAGS: 00010296
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff820bf066 RDI: fffff52000432e21
RBP: ffff888086b744c8 R08: 0000000000000091 R09: ffffed1015ce6659
R10: ffffed1015ce6658 R11: ffff8880ae7332c7 R12: 0000000000000001
R13: ffff888086b74990 R14: 0000000000000000 R15: ffff888086b74a40
ext4_ext_map_blocks+0x24aa/0x37d0 fs/ext4/extents.c:4500
ext4_map_blocks+0x4cb/0x1650 fs/ext4/inode.c:622
mpage_map_one_extent fs/ext4/inode.c:2365 [inline]
mpage_map_and_submit_extent fs/ext4/inode.c:2418 [inline]
ext4_writepages+0x19eb/0x3080 fs/ext4/inode.c:2772
do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344
__writeback_single_inode+0x12a/0x1410 fs/fs-writeback.c:1452
writeback_sb_inodes+0x515/0xdd0 fs/fs-writeback.c:1716
wb_writeback+0x2a5/0xd90 fs/fs-writeback.c:1892
wb_do_writeback fs/fs-writeback.c:2037 [inline]
wb_workfn+0x339/0x11c0 fs/fs-writeback.c:2078
process_one_work+0x94b/0x1690 kernel/workqueue.c:2266
worker_thread+0x96/0xe20 kernel/workqueue.c:2412
kthread+0x357/0x430 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..
---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches
^ permalink raw reply
* Re: [PATCH v5 1/4] powerpc/papr_scm: Fetch nvdimm health information from PHYP
From: Michael Ellerman @ 2020-04-02 10:20 UTC (permalink / raw)
To: Vaibhav Jain, linuxppc-dev, linux-nvdimm
Cc: Alastair D'Silva, Aneesh Kumar K . V, Jeff Moyer,
Oliver O'Halloran, Vishal Verma, Vaibhav Jain, Dan Williams
In-Reply-To: <20200331143229.306718-2-vaibhav@linux.ibm.com>
Vaibhav Jain <vaibhav@linux.ibm.com> writes:
> Implement support for fetching nvdimm health information via
> H_SCM_HEALTH hcall as documented in Ref[1]. The hcall returns a pair
> of 64-bit big-endian integers which are then stored in 'struct
> papr_scm_priv' and subsequently partially exposed to user-space via
> newly introduced dimm specific attribute 'papr_flags'. Also a new asm
> header named 'papr-scm.h' is added that describes the interface
> between PHYP and guest kernel.
>
> Following flags are reported via 'papr_flags' sysfs attribute contents
> of which are space separated string flags indicating various nvdimm
> states:
>
> * "not_armed" : Indicating that nvdimm contents wont survive a power
> cycle.
> * "save_fail" : Indicating that nvdimm contents couldn't be flushed
> during last shutdown event.
> * "restore_fail": Indicating that nvdimm contents couldn't be restored
> during dimm initialization.
> * "encrypted" : Dimm contents are encrypted.
> * "smart_notify": There is health event for the nvdimm.
> * "scrubbed" : Indicating that contents of the nvdimm have been
> scrubbed.
> * "locked" : Indicating that nvdimm contents cant be modified
> until next power cycle.
>
> [1]: commit 58b278f568f0 ("powerpc: Provide initial documentation for
> PAPR hcalls")
>
> Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
> ---
> Changelog:
>
> v4..v5 : None
>
> v3..v4 : None
>
> v2..v3 : Removed PAPR_SCM_DIMM_HEALTH_NON_CRITICAL as a condition for
> NVDIMM unarmed [Aneesh]
>
> v1..v2 : New patch in the series.
> ---
> arch/powerpc/include/asm/papr_scm.h | 48 ++++++++++
> arch/powerpc/platforms/pseries/papr_scm.c | 105 +++++++++++++++++++++-
> 2 files changed, 151 insertions(+), 2 deletions(-)
> create mode 100644 arch/powerpc/include/asm/papr_scm.h
>
> diff --git a/arch/powerpc/include/asm/papr_scm.h b/arch/powerpc/include/asm/papr_scm.h
> new file mode 100644
> index 000000000000..868d3360f56a
> --- /dev/null
> +++ b/arch/powerpc/include/asm/papr_scm.h
> @@ -0,0 +1,48 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Structures and defines needed to manage nvdimms for spapr guests.
> + */
> +#ifndef _ASM_POWERPC_PAPR_SCM_H_
> +#define _ASM_POWERPC_PAPR_SCM_H_
> +
> +#include <linux/types.h>
> +#include <asm/bitsperlong.h>
> +
> +/* DIMM health bitmap bitmap indicators */
> +/* SCM device is unable to persist memory contents */
> +#define PAPR_SCM_DIMM_UNARMED PPC_BIT(0)
Please don't use PPC_BIT, it's just unncessary obfuscation for folks
who are reading the code without access to the docs (ie. more or less
everyone other than you :)
> diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
> index 0b4467e378e5..aaf2e4ab1f75 100644
> --- a/arch/powerpc/platforms/pseries/papr_scm.c
> +++ b/arch/powerpc/platforms/pseries/papr_scm.c
> @@ -14,6 +14,7 @@
> #include <linux/delay.h>
>
> #include <asm/plpar_wrappers.h>
> +#include <asm/papr_scm.h>
>
> #define BIND_ANY_ADDR (~0ul)
>
> @@ -39,6 +40,13 @@ struct papr_scm_priv {
> struct resource res;
> struct nd_region *region;
> struct nd_interleave_set nd_set;
> +
> + /* Protect dimm data from concurrent access */
> + struct mutex dimm_mutex;
> +
> + /* Health information for the dimm */
> + __be64 health_bitmap;
> + __be64 health_bitmap_valid;
It's much less error prone to store the data in CPU endian and do the
endian conversion only at the point where the data either comes from or
goes to firmware.
That would also mean you can define flags above without needing PPC_BIT
because they'll be in CPU endian too.
> @@ -144,6 +152,35 @@ static int drc_pmem_query_n_bind(struct papr_scm_priv *p)
> return drc_pmem_bind(p);
> }
>
> +static int drc_pmem_query_health(struct papr_scm_priv *p)
> +{
> + unsigned long ret[PLPAR_HCALL_BUFSIZE];
> + int64_t rc;
Use kernel types please, ie. s64, or just long.
> + rc = plpar_hcall(H_SCM_HEALTH, ret, p->drc_index);
> + if (rc != H_SUCCESS) {
> + dev_err(&p->pdev->dev,
> + "Failed to query health information, Err:%lld\n", rc);
> + return -ENXIO;
> + }
> +
> + /* Protect modifications to papr_scm_priv with the mutex */
> + rc = mutex_lock_interruptible(&p->dimm_mutex);
> + if (rc)
> + return rc;
> +
> + /* Store the retrieved health information in dimm platform data */
> + p->health_bitmap = ret[0];
> + p->health_bitmap_valid = ret[1];
> +
> + dev_dbg(&p->pdev->dev,
> + "Queried dimm health info. Bitmap:0x%016llx Mask:0x%016llx\n",
> + be64_to_cpu(p->health_bitmap),
> + be64_to_cpu(p->health_bitmap_valid));
> +
> + mutex_unlock(&p->dimm_mutex);
> + return 0;
> +}
>
> static int papr_scm_meta_get(struct papr_scm_priv *p,
> struct nd_cmd_get_config_data_hdr *hdr)
> @@ -304,6 +341,67 @@ static inline int papr_scm_node(int node)
> return min_node;
> }
>
> +static ssize_t papr_flags_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct nvdimm *dimm = to_nvdimm(dev);
> + struct papr_scm_priv *p = nvdimm_provider_data(dimm);
> + __be64 health;
No need for __be64 here if health_bitmap was stored in CPU endian.
> + int rc;
> +
> + rc = drc_pmem_query_health(p);
> + if (rc)
> + return rc;
> +
> + /* Protect against modifications to papr_scm_priv with the mutex */
> + rc = mutex_lock_interruptible(&p->dimm_mutex);
> + if (rc)
> + return rc;
> +
> + health = p->health_bitmap & p->health_bitmap_valid;
This is all you ever do with the health_bitmap? In which case why not
just do the masking before storing it into priv and save yourself 8
bytes?
> + /* Check for various masks in bitmap and set the buffer */
> + if (health & PAPR_SCM_DIMM_UNARMED_MASK)
> + rc += sprintf(buf, "not_armed ");
I know buf is "big enough" but using sprintf() in 2020 is a bit ... :)
seq_buf is a pretty thin wrapper over a buffer you can use to make this
cleaner and also handles overflow for you.
See eg. show_user_instructions() for an example.
> +
> + if (health & PAPR_SCM_DIMM_BAD_SHUTDOWN_MASK)
> + rc += sprintf(buf + rc, "save_fail ");
> +
> + if (health & PAPR_SCM_DIMM_BAD_RESTORE_MASK)
> + rc += sprintf(buf + rc, "restore_fail ");
> +
> + if (health & PAPR_SCM_DIMM_ENCRYPTED)
> + rc += sprintf(buf + rc, "encrypted ");
> +
> + if (health & PAPR_SCM_DIMM_SMART_EVENT_MASK)
> + rc += sprintf(buf + rc, "smart_notify ");
> +
> + if (health & PAPR_SCM_DIMM_SCRUBBED_AND_LOCKED)
> + rc += sprintf(buf + rc, "scrubbed locked ");
> +
> + if (rc > 0)
> + rc += sprintf(buf + rc, "\n");
> +
> + mutex_unlock(&p->dimm_mutex);
> + return rc;
> +}
> +DEVICE_ATTR_RO(papr_flags);
cheers
^ permalink raw reply
* Re: [PATCH 0/2] powerpc: Remove support for ppc405/440 Xilinx platforms
From: Arnd Bergmann @ 2020-04-02 11:04 UTC (permalink / raw)
To: Segher Boessenkool
Cc: Mark Rutland, Kate Stewart, Desnes A. Nunes do Rosario,
Geert Uytterhoeven, open list:DOCUMENTATION,
ALSA Development Mailing List, dri-devel, Jaroslav Kysela,
Richard Fontana, Paul Mackerras, Miquel Raynal,
Mauro Carvalho Chehab, Fabio Estevam, Sasha Levin,
Stephen Rothwell, Jonathan Corbet, Masahiro Yamada, YueHaibing,
Michal Simek, Krzysztof Kozlowski, Allison Randal, Leonardo Bras,
DTML, Andrew Donnellan, Bartlomiej Zolnierkiewicz, Marc Zyngier,
Alistair Popple, Nicholas Piggin, Alexios Zavras, Mark Brown, git,
Linux Fbdev development list, Jonathan Cameron, Thomas Gleixner,
Andy Shevchenko, Linux ARM, Enrico Weigelt, Michal Simek, Wei Hu,
Christian Lamparter, Greg Kroah-Hartman, Nick Desaulniers,
Takashi Iwai, linux-kernel@vger.kernel.org, Armijn Hemel,
Rob Herring, linuxppc-dev, David S. Miller, Thiago Jung Bauermann
In-Reply-To: <CAK8P3a34Tw+bH9bCBQ9HeDo4m4RE67fNOyL8cfUf-i09ur8seg@mail.gmail.com>
On Wed, Apr 1, 2020 at 11:07 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
> On Tue, Mar 31, 2020 at 7:51 PM Segher Boessenkool
> <segher@kernel.crashing.org> wrote:
> >
> > On Tue, Mar 31, 2020 at 08:56:23AM +0200, Christophe Leroy wrote:
> > > While we are at it, can we also remove the 601 ? This one is also full
> > > of workarounds and diverges a bit from other 6xx.
> > >
> > > I'm unable to find its end of life date, but it was on the market in
> > > 1994, so I guess it must be outdated by more than 10-15 yr old now ?
> >
> > There probably are still some people running Linux on 601 powermacs.
>
> It could be marked as "BROKEN" for a year to find out for sure ;-)
>
> Apparently there were only two or three models that are old enough to
> have a 601 and new enough to run Linux with PCI and OF: 7200/8200
> and 7500. These were sold for less than 18 months around 1996,
> though one can still find them on eBay.
A. Wilcox said on IRC regarding 601 support in Adélie Linux:
"right now we are primarily targeting G3, though 603 should be supported.
601/601e support is planned to be added for 2.0 (next year)."
Arnd
^ permalink raw reply
* Re: [PATCH V2 3/5] selftests/powerpc: Add NX-GZIP engine compress testcase
From: Michael Ellerman @ 2020-04-02 10:55 UTC (permalink / raw)
To: Daniel Axtens, Raphael Moreira Zinsly, linuxppc-dev, linux-crypto
Cc: abali, haren, herbert, Raphael Moreira Zinsly
In-Reply-To: <87369mwgwy.fsf@dja-thinkpad.axtens.net>
Daniel Axtens <dja@axtens.net> writes:
> Raphael Moreira Zinsly <rzinsly@linux.ibm.com> writes:
>
>> Add a compression testcase for the powerpc NX-GZIP engine.
>>
>> Signed-off-by: Bulent Abali <abali@us.ibm.com>
>> Signed-off-by: Raphael Moreira Zinsly <rzinsly@linux.ibm.com>
...
>> diff --git a/tools/testing/selftests/powerpc/nx-gzip/gzip_vas.c b/tools/testing/selftests/powerpc/nx-gzip/gzip_vas.c
>> new file mode 100644
>> index 000000000000..d28e1efb527b
>> --- /dev/null
>> +++ b/tools/testing/selftests/powerpc/nx-gzip/gzip_vas.c
>> @@ -0,0 +1,259 @@
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>> +
>> +/* Copyright 2020 IBM Corp.
>> + *
>> + * Author: Bulent Abali <abali@us.ibm.com>
>> + *
>> + */
>> +#include <stdio.h>
>> +#include <stdlib.h>
>> +#include <string.h>
>> +#include <unistd.h>
>> +#include <stdint.h>
>> +#include <sys/types.h>
>> +#include <sys/stat.h>
>> +#include <sys/time.h>
>> +#include <sys/fcntl.h>
>> +#include <sys/mman.h>
>> +#include <endian.h>
>> +#include <bits/endian.h>
>> +#include <sys/ioctl.h>
>> +#include <assert.h>
>> +#include <errno.h>
>> +#include <signal.h>
>> +#include "nx-gzip.h"
>> +#include "nx.h"
>> +#include "copy-paste.h"
>> +#include "nxu.h"
>> +#include "nx_dbg.h"
>> +#include <sys/platform/ppc.h>
>> +
>> +#define barrier()
>> +#define hwsync() ({ asm volatile("hwsync" ::: "memory"); })
>
> This doesn't compile on the clang version I tried as it doesn't
> recognise 'hwsync'.
What assembler are you using? I guess the LLVM one?
Can you try with -fno-integrated-as ?
> Does asm volatile("sync" ::: "memory");
> do the same thing? That is recognised by clang, but I don't know if
> dropping the hw prefix matters!
It shouldn't matter.
But you can just try it and look at the generated code to be sure, you
should get 0x7c0004ac.
cheers
^ permalink raw reply
* Re: [PATCH v4 03/25] powerpc/powernv: Map & release OpenCAPI LPC memory
From: Benjamin Herrenschmidt @ 2020-04-02 10:41 UTC (permalink / raw)
To: Dan Williams, Alastair D'Silva
Cc: Madhavan Srinivasan, Alexey Kardashevskiy, Mahesh Salgaonkar,
Masahiro Yamada, Oliver O'Halloran, Mauro Carvalho Chehab,
Ira Weiny, Rob Herring, Dave Jiang, linux-nvdimm,
Aneesh Kumar K . V, Krzysztof Kozlowski, Anju T Sudhakar,
Andrew Donnellan, Arnd Bergmann, Greg Kurz, Nicholas Piggin,
Cédric Le Goater, Thomas Gleixner, Hari Bathini, Linux MM,
Greg Kroah-Hartman, Linux Kernel Mailing List, Vishal Verma,
Frederic Barrat, Paul Mackerras, Andrew Morton, linuxppc-dev,
David S. Miller
In-Reply-To: <CAPcyv4iGEHJpZctEm+Do1-kOZBUDeKKcREr=BqcK4kCvLWhAQQ@mail.gmail.com>
On Wed, 2020-04-01 at 01:48 -0700, Dan Williams wrote:
> >
> > +u64 pnv_ocxl_platform_lpc_setup(struct pci_dev *pdev, u64 size)
> > +{
> > + struct pci_controller *hose = pci_bus_to_host(pdev->bus);
> > + struct pnv_phb *phb = hose->private_data;
>
> Is calling the local variable 'hose' instead of 'host' on purpose?
Haha that's funny :-)
It's an oooooooold usage that comes iirc from sparc ? or maybe alpha ?
I somewhat accidentally picked it up when adding multiple host-bridge
support on powerpc in the early 2000's and it hasn't quite died yet :)
Cheers,
Ben.
^ permalink raw reply
* Re: [PATCH 0/2] powerpc: Remove support for ppc405/440 Xilinx platforms
From: Benjamin Herrenschmidt @ 2020-04-02 10:27 UTC (permalink / raw)
To: Michael Ellerman, Christophe Leroy, Andy Shevchenko,
Arnd Bergmann
Cc: Kate Stewart, Mark Rutland, Desnes A. Nunes do Rosario,
Geert Uytterhoeven, open list:DOCUMENTATION,
ALSA Development Mailing List, dri-devel, Jaroslav Kysela,
Richard Fontana, Paul Mackerras, Miquel Raynal,
Mauro Carvalho Chehab, Fabio Estevam, Sasha Levin,
Stephen Rothwell, Jonathan Corbet, Masahiro Yamada, Takashi Iwai,
YueHaibing, Michal Simek, Krzysztof Kozlowski, Linux ARM,
Leonardo Bras, DTML, Andrew Donnellan, Bartlomiej Zolnierkiewicz,
Marc Zyngier, Alistair Popple, linuxppc-dev, Nicholas Piggin,
Alexios Zavras, Mark Brown, git, Linux Fbdev development list,
Jonathan Cameron, Thomas Gleixner, Allison Randal, Michal Simek,
Wei Hu, Christian Lamparter, Greg Kroah-Hartman, Nick Desaulniers,
linux-kernel@vger.kernel.org, Armijn Hemel, Rob Herring,
Enrico Weigelt, David S. Miller, Thiago Jung Bauermann
In-Reply-To: <87mu7xum41.fsf@mpe.ellerman.id.au>
On Tue, 2020-03-31 at 16:30 +1100, Michael Ellerman wrote:
> I have no attachment to 40x, and I'd certainly be happy to have less
> code in the tree, we struggle to keep even the modern platforms well
> maintained.
>
> At the same time I don't want to render anyone's hardware obsolete
> unnecessarily. But if there's really no one using 40x then we should
> remove it, it could well be broken already.
>
> So I guess post a series to do the removal and we'll see if anyone
> speaks up.
We shouldn't remove 40x completely. Just remove the Xilinx 405 stuff.
Cheers,
Ben.
^ permalink raw reply
* Re: [PATCH v1 06/46] powerpc/kasan: Refactor update of early shadow mappings
From: Christophe Leroy @ 2020-04-02 10:19 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
Cc: linuxppc-dev, linux-kernel
In-Reply-To: <5eb93a773184aa0d36faa93c096b21cbe0a069c9.1584360344.git.christophe.leroy@c-s.fr>
Michael,
Le 16/03/2020 à 13:35, Christophe Leroy a écrit :
> kasan_remap_early_shadow_ro() and kasan_unmap_early_shadow_vmalloc()
> are both updating the early shadow mapping: the first one sets
> the mapping read-only while the other clears the mapping.
>
> Refactor and create kasan_update_early_region()
There is a trivial conflict with this patch on powerpc/next.
Do you plan to take this series for 5.7 ? I so, I can repost the series
now with the fix, or just this patch ?
Otherwise, what are your plans ? This series (Patches 18 and 19) will
conflict with the 40x removal series as both do things about that
PTE_ATOMIC_UPDATE stuff. Which series would go first ?
Thanks
Christophe
>
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> ---
> arch/powerpc/mm/kasan/kasan_init_32.c | 39 +++++++++++++--------------
> 1 file changed, 18 insertions(+), 21 deletions(-)
>
> diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c b/arch/powerpc/mm/kasan/kasan_init_32.c
> index c9d053078c37..65fd8b891f8e 100644
> --- a/arch/powerpc/mm/kasan/kasan_init_32.c
> +++ b/arch/powerpc/mm/kasan/kasan_init_32.c
> @@ -79,45 +79,42 @@ static int __init kasan_init_region(void *start, size_t size)
> return 0;
> }
>
> -static void __init kasan_remap_early_shadow_ro(void)
> +static void __init
> +kasan_update_early_region(unsigned long k_start, unsigned long k_end, pte_t pte)
> {
> - pgprot_t prot = kasan_prot_ro();
> - unsigned long k_start = KASAN_SHADOW_START;
> - unsigned long k_end = KASAN_SHADOW_END;
> unsigned long k_cur;
> phys_addr_t pa = __pa(kasan_early_shadow_page);
>
> - kasan_populate_pte(kasan_early_shadow_pte, prot);
> -
> - for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
> + for (k_cur = k_start; k_cur < k_end; k_cur += PAGE_SIZE) {
> pmd_t *pmd = pmd_ptr_k(k_cur);
> pte_t *ptep = pte_offset_kernel(pmd, k_cur);
>
> if ((pte_val(*ptep) & PTE_RPN_MASK) != pa)
> continue;
>
> - __set_pte_at(&init_mm, k_cur, ptep, pfn_pte(PHYS_PFN(pa), prot), 0);
> + __set_pte_at(&init_mm, k_cur, ptep, pte, 0);
> }
> - flush_tlb_kernel_range(KASAN_SHADOW_START, KASAN_SHADOW_END);
> +
> + flush_tlb_kernel_range(k_start, k_end);
> }
>
> -static void __init kasan_unmap_early_shadow_vmalloc(void)
> +static void __init kasan_remap_early_shadow_ro(void)
> {
> - unsigned long k_start = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_START);
> - unsigned long k_end = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_END);
> - unsigned long k_cur;
> + pgprot_t prot = kasan_prot_ro();
> phys_addr_t pa = __pa(kasan_early_shadow_page);
>
> - for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
> - pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(k_cur), k_cur), k_cur);
> - pte_t *ptep = pte_offset_kernel(pmd, k_cur);
> + kasan_populate_pte(kasan_early_shadow_pte, prot);
>
> - if ((pte_val(*ptep) & PTE_RPN_MASK) != pa)
> - continue;
> + kasan_update_early_region(KASAN_SHADOW_START, KASAN_SHADOW_END,
> + pfn_pte(PHYS_PFN(pa), prot));
> +}
>
> - __set_pte_at(&init_mm, k_cur, ptep, __pte(0), 0);
> - }
> - flush_tlb_kernel_range(k_start, k_end);
> +static void __init kasan_unmap_early_shadow_vmalloc(void)
> +{
> + unsigned long k_start = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_START);
> + unsigned long k_end = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_END);
> +
> + kasan_update_early_region(k_start, k_end, __pte(0));
> }
>
> static void __init kasan_mmu_init(void)
>
^ permalink raw reply
* Re: [PATCH v1 39/46] powerpc/8xx: Add a function to early map kernel via huge pages
From: Christophe Leroy @ 2020-04-02 10:13 UTC (permalink / raw)
To: Paul Mackerras, Michael Ellerman
Cc: linuxppc-dev, kbuild-all, kbuild test robot, linux-kernel
In-Reply-To: <22bc0bba-533f-548b-8eec-a3392acc8e3d@c-s.fr>
Le 17/03/2020 à 15:43, Christophe Leroy a écrit :
>
>
> Le 17/03/2020 à 02:39, kbuild test robot a écrit :
>> Hi Christophe,
>>
>> Thank you for the patch! Yet something to improve:
>>
>> [auto build test ERROR on next-20200316]
>> [cannot apply to powerpc/next v5.6-rc6 v5.6-rc5 v5.6-rc4 v5.6-rc6]
>> [if your patch is applied to the wrong git tree, please drop us a note
>> to help
>> improve the system. BTW, we also suggest to use '--base' option to
>> specify the
>> base tree in git format-patch, please see
>> https://stackoverflow.com/a/37406982]
>>
>> url:
>> https://github.com/0day-ci/linux/commits/Christophe-Leroy/Use-hugepages-to-map-kernel-mem-on-8xx/20200317-065610
>>
>> base: 8548fd2f20ed19b0e8c0585b71fdfde1ae00ae3c
>> config: powerpc-tqm8xx_defconfig (attached as .config)
>> compiler: powerpc-linux-gcc (GCC) 9.2.0
>> reproduce:
>> wget
>> https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross
>> -O ~/bin/make.cross
>> chmod +x ~/bin/make.cross
>> # save the attached .config to linux build tree
>> GCC_VERSION=9.2.0 make.cross ARCH=powerpc
>>
>> If you fix the issue, kindly add following tag
>> Reported-by: kbuild test robot <lkp@intel.com>
>>
>> All errors (new ones prefixed by >>):
>>
>> In file included from arch/powerpc/mm/fault.c:33:
>> include/linux/hugetlb.h: In function 'hstate_inode':
>>>> include/linux/hugetlb.h:522:9: error: implicit declaration of
>>>> function 'HUGETLBFS_SB'; did you mean 'HUGETLBFS_MAGIC'?
>>>> [-Werror=implicit-function-declaration]
>> 522 | return HUGETLBFS_SB(i->i_sb)->hstate;
>> | ^~~~~~~~~~~~
>> | HUGETLBFS_MAGIC
>>>> include/linux/hugetlb.h:522:30: error: invalid type argument of '->'
>>>> (have 'int')
>> 522 | return HUGETLBFS_SB(i->i_sb)->hstate;
>> | ^~
>> cc1: all warnings being treated as errors
>
> hstate_inode() shouldn't use HUGETLBFS_SB() which CONFIG_HUGETLBFS is
> not set.
>
> Proposed fix at https://patchwork.ozlabs.org/patch/1256108/
The fix is going in 5.7 via mm tree it seems, see
https://patchwork.kernel.org/patch/11470105/
Christophe
>
> [...]
>
>
>>>> include/linux/hugetlb.h:522:30: error: invalid type argument of '->'
>>>> (have 'int')
>> 522 | return HUGETLBFS_SB(i->i_sb)->hstate;
>> | ^~
>> At top level:
>> arch/powerpc//mm/nohash/8xx.c:73:18: error:
>> '__early_map_kernel_hugepage' defined but not used
>> [-Werror=unused-function]
>> 73 | static int __ref __early_map_kernel_hugepage(unsigned long
>> va, phys_addr_t pa,
>> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~
>> cc1: all warnings being treated as errors
>
> This patch is a preparation patch. The function is not used yet, that's
> normal. Ok, it breaks bisectability. Should it be squashed with the
> first user of the function ?
>
> Christophe
^ permalink raw reply
* Re: [PATCH v4 00/25] Add support for OpenCAPI Persistent Memory devices
From: Michael Ellerman @ 2020-04-02 10:06 UTC (permalink / raw)
To: Oliver O'Halloran
Cc: Madhavan Srinivasan, Alexey Kardashevskiy, Mahesh Salgaonkar,
Masahiro Yamada, Paul Mackerras, Mauro Carvalho Chehab, Ira Weiny,
Thomas Gleixner, Rob Herring, Dave Jiang, linux-nvdimm,
Aneesh Kumar K . V, Krzysztof Kozlowski, Anju T Sudhakar,
Alastair D'Silva, Andrew Donnellan, Arnd Bergmann, Greg Kurz,
Nicholas Piggin, Cédric Le Goater, Dan Williams,
Hari Bathini, Linux MM, Greg Kroah-Hartman,
Linux Kernel Mailing List, Vishal Verma, Frederic Barrat,
Andrew Morton, linuxppc-dev, David S. Miller
In-Reply-To: <CAOSf1CHdpFyT_6zetKM6eHDK3AT8-UNTzjdd2y+QqYT2AO9VDw@mail.gmail.com>
"Oliver O'Halloran" <oohall@gmail.com> writes:
> On Thu, Apr 2, 2020 at 2:42 PM Michael Ellerman <mpe@ellerman.id.au> wrote:
>> "Alastair D'Silva" <alastair@d-silva.org> writes:
>> >> -----Original Message-----
>> >> From: Dan Williams <dan.j.williams@intel.com>
>> >>
>> >> On Sun, Mar 29, 2020 at 10:23 PM Alastair D'Silva <alastair@d-silva.org>
>> >> wrote:
>> >> >
>> >> > *snip*
>> >> Are OPAL calls similar to ACPI DSMs? I.e. methods for the OS to invoke
>> >> platform firmware services? What's Skiboot?
>> >
>> > Yes, OPAL is the interface to firmware for POWER. Skiboot is the open-source (and only) implementation of OPAL.
>>
>> https://github.com/open-power/skiboot
>>
>> In particular the tokens for calls are defined here:
>>
>> https://github.com/open-power/skiboot/blob/master/include/opal-api.h#L220
>>
>> And you can grep for the token to find the implementation:
>>
>> https://github.com/open-power/skiboot/blob/master/hw/npu2-opencapi.c#L2328
>
> I'm not sure I'd encourage anyone to read npu2-opencapi.c. I find it
> hard enough to follow even with access to the workbooks.
Compared to certain firmwares that run on certain other platforms it's
actually pretty readable code ;)
> There's an OPAL call API reference here:
> http://open-power.github.io/skiboot/doc/opal-api/index.html
Even better.
cheers
^ permalink raw reply
* [powerpc:next] BUILD SUCCESS c17eb4dca5a353a9dbbb8ad6934fe57af7165e91
From: kbuild test robot @ 2020-04-02 9:37 UTC (permalink / raw)
To: Michael Ellerman; +Cc: linuxppc-dev
tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
branch HEAD: c17eb4dca5a353a9dbbb8ad6934fe57af7165e91 powerpc: Make setjmp/longjmp signature standard
elapsed time: 1281m
configs tested: 187
configs skipped: 0
The following configs have been built successfully.
More configs may be tested in the coming days.
arm allmodconfig
arm allnoconfig
arm allyesconfig
arm64 allmodconfig
arm64 allnoconfig
arm64 allyesconfig
arm efm32_defconfig
arm at91_dt_defconfig
arm shmobile_defconfig
arm64 defconfig
arm exynos_defconfig
arm multi_v5_defconfig
arm sunxi_defconfig
arm multi_v7_defconfig
h8300 h8300h-sim_defconfig
m68k m5475evb_defconfig
c6x allyesconfig
powerpc ppc64_defconfig
ia64 defconfig
powerpc defconfig
i386 allnoconfig
i386 alldefconfig
i386 allyesconfig
i386 defconfig
ia64 alldefconfig
ia64 allmodconfig
ia64 allnoconfig
ia64 allyesconfig
nios2 3c120_defconfig
nios2 10m50_defconfig
c6x evmc6678_defconfig
xtensa iss_defconfig
xtensa common_defconfig
openrisc simple_smp_defconfig
openrisc or1ksim_defconfig
nds32 defconfig
nds32 allnoconfig
csky defconfig
alpha defconfig
h8300 h8s-sim_defconfig
h8300 edosk2674_defconfig
m68k allmodconfig
m68k sun3_defconfig
m68k multi_defconfig
arc allyesconfig
arc defconfig
microblaze mmu_defconfig
microblaze nommu_defconfig
powerpc allnoconfig
powerpc rhel-kconfig
mips 32r2_defconfig
mips 64r6el_defconfig
mips allmodconfig
mips allnoconfig
mips allyesconfig
mips fuloong2e_defconfig
mips malta_kvm_defconfig
parisc allnoconfig
parisc allyesconfig
parisc generic-32bit_defconfig
parisc generic-64bit_defconfig
x86_64 randconfig-a001-20200401
x86_64 randconfig-a002-20200401
x86_64 randconfig-a003-20200401
i386 randconfig-a001-20200401
i386 randconfig-a002-20200401
i386 randconfig-a003-20200401
mips randconfig-a001-20200401
nds32 randconfig-a001-20200401
m68k randconfig-a001-20200401
alpha randconfig-a001-20200401
parisc randconfig-a001-20200401
riscv randconfig-a001-20200401
alpha randconfig-a001-20200402
m68k randconfig-a001-20200402
mips randconfig-a001-20200402
nds32 randconfig-a001-20200402
parisc randconfig-a001-20200402
riscv randconfig-a001-20200402
c6x randconfig-a001-20200401
h8300 randconfig-a001-20200401
microblaze randconfig-a001-20200401
nios2 randconfig-a001-20200401
sparc64 randconfig-a001-20200401
csky randconfig-a001-20200401
openrisc randconfig-a001-20200401
s390 randconfig-a001-20200401
sh randconfig-a001-20200401
xtensa randconfig-a001-20200401
csky randconfig-a001-20200402
openrisc randconfig-a001-20200402
s390 randconfig-a001-20200402
sh randconfig-a001-20200402
xtensa randconfig-a001-20200402
x86_64 randconfig-b001-20200402
x86_64 randconfig-b002-20200402
x86_64 randconfig-b003-20200402
i386 randconfig-b001-20200402
i386 randconfig-b002-20200402
i386 randconfig-b003-20200402
x86_64 randconfig-c001-20200401
x86_64 randconfig-c002-20200401
x86_64 randconfig-c003-20200401
i386 randconfig-c001-20200401
i386 randconfig-c002-20200401
i386 randconfig-c003-20200401
x86_64 randconfig-d001-20200401
x86_64 randconfig-d002-20200401
x86_64 randconfig-d003-20200401
i386 randconfig-d001-20200401
i386 randconfig-d002-20200401
i386 randconfig-d003-20200401
x86_64 randconfig-d001-20200402
x86_64 randconfig-d002-20200402
x86_64 randconfig-d003-20200402
i386 randconfig-d001-20200402
i386 randconfig-d002-20200402
i386 randconfig-d003-20200402
x86_64 randconfig-e001-20200401
x86_64 randconfig-e002-20200401
x86_64 randconfig-e003-20200401
i386 randconfig-e001-20200401
i386 randconfig-e002-20200401
i386 randconfig-e003-20200401
i386 randconfig-f001-20200402
i386 randconfig-f003-20200402
x86_64 randconfig-f003-20200402
x86_64 randconfig-f001-20200402
i386 randconfig-f002-20200402
x86_64 randconfig-f002-20200402
x86_64 randconfig-f001-20200401
x86_64 randconfig-f002-20200401
x86_64 randconfig-f003-20200401
i386 randconfig-f001-20200401
i386 randconfig-f002-20200401
i386 randconfig-f003-20200401
x86_64 randconfig-g001-20200402
x86_64 randconfig-g002-20200402
x86_64 randconfig-g003-20200402
i386 randconfig-g001-20200402
i386 randconfig-g002-20200402
i386 randconfig-g003-20200402
arc randconfig-a001-20200401
arm randconfig-a001-20200401
arm64 randconfig-a001-20200401
ia64 randconfig-a001-20200401
powerpc randconfig-a001-20200401
sparc randconfig-a001-20200401
arc randconfig-a001-20200402
arm randconfig-a001-20200402
arm64 randconfig-a001-20200402
ia64 randconfig-a001-20200402
powerpc randconfig-a001-20200402
sparc randconfig-a001-20200402
riscv allyesconfig
riscv nommu_virt_defconfig
riscv allnoconfig
riscv defconfig
riscv rv32_defconfig
riscv allmodconfig
s390 alldefconfig
s390 allmodconfig
s390 allnoconfig
s390 allyesconfig
s390 debug_defconfig
s390 defconfig
s390 zfcpdump_defconfig
sh rsk7269_defconfig
sh allmodconfig
sh titan_defconfig
sh sh7785lcr_32bit_defconfig
sh allnoconfig
sparc allyesconfig
sparc defconfig
sparc64 allmodconfig
sparc64 allnoconfig
sparc64 allyesconfig
sparc64 defconfig
um defconfig
um i386_defconfig
um x86_64_defconfig
x86_64 rhel
x86_64 rhel-7.6
x86_64 rhel-7.2-clear
x86_64 lkp
x86_64 fedora-25
x86_64 kexec
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
^ permalink raw reply
* Re: [RFC PATCH v2 1/1] powerpc/kernel: Enables memory hot-remove after reboot on pseries guests
From: Bharata B Rao @ 2020-04-02 9:14 UTC (permalink / raw)
To: Leonardo Bras
Cc: linux-kernel@vger.kernel.org, Michael Anderson, Claudio Carvalho,
Mike Rapoport, Bharata B Rao, Paul Mackerras, Greg Kroah-Hartman,
Hari Bathini, Nathan Fontenot, Thomas Gleixner, linuxppc-dev,
Allison Randal
In-Reply-To: <33333c2ffe9fedbee252a1731d7c10cd3308252b.camel@linux.ibm.com>
On Wed, Apr 1, 2020 at 8:38 PM Leonardo Bras <leonardo@linux.ibm.com> wrote:
>
> On Thu, 2020-03-05 at 20:32 -0300, Leonardo Bras wrote:
> > ---
> > The new flag was already proposed on Power Architecture documentation,
> > and it's waiting for approval.
> >
> > I would like to get your comments on this change, but it's still not
> > ready for being merged.
>
> New flag got approved on the documentation.
> Please review this patch.
Looks good to me, also tested with PowerKVM guests.
Reviewed-by: Bharata B Rao <bharata@linux.ibm.com>
Regards,
Bharata.
--
http://raobharata.wordpress.com/
^ permalink raw reply
* [PATCH v8 7/7] powerpc/32: use set_memory_attr()
From: Russell Currey @ 2020-04-02 8:40 UTC (permalink / raw)
To: linuxppc-dev; +Cc: ajd, kernel-hardening, npiggin, Russell Currey, dja
In-Reply-To: <20200402084053.188537-1-ruscur@russell.cc>
From: Christophe Leroy <christophe.leroy@c-s.fr>
Use set_memory_attr() instead of the PPC32 specific change_page_attr()
change_page_attr() was checking that the address was not mapped by
blocks and was handling highmem, but that's unneeded because the
affected pages can't be in highmem and block mapping verification
is already done by the callers.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[ruscur: rebase on powerpc/merge with Christophe's new patches]
Signed-off-by: Russell Currey <ruscur@russell.cc>
---
v8: Rebase on powerpc/merge
arch/powerpc/mm/pgtable_32.c | 60 ++++++------------------------------
1 file changed, 10 insertions(+), 50 deletions(-)
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index f62de06e3d07..0d9d164fad26 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -23,6 +23,7 @@
#include <linux/highmem.h>
#include <linux/memblock.h>
#include <linux/slab.h>
+#include <linux/set_memory.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -121,64 +122,20 @@ void __init mapin_ram(void)
}
}
-static int __change_page_attr_noflush(struct page *page, pgprot_t prot)
-{
- pte_t *kpte;
- unsigned long address;
-
- BUG_ON(PageHighMem(page));
- address = (unsigned long)page_address(page);
-
- if (v_block_mapped(address))
- return 0;
- kpte = virt_to_kpte(address);
- if (!kpte)
- return -EINVAL;
- __set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0);
-
- return 0;
-}
-
-/*
- * Change the page attributes of an page in the linear mapping.
- *
- * THIS DOES NOTHING WITH BAT MAPPINGS, DEBUG USE ONLY
- */
-static int change_page_attr(struct page *page, int numpages, pgprot_t prot)
-{
- int i, err = 0;
- unsigned long flags;
- struct page *start = page;
-
- local_irq_save(flags);
- for (i = 0; i < numpages; i++, page++) {
- err = __change_page_attr_noflush(page, prot);
- if (err)
- break;
- }
- wmb();
- local_irq_restore(flags);
- flush_tlb_kernel_range((unsigned long)page_address(start),
- (unsigned long)page_address(page));
- return err;
-}
-
void mark_initmem_nx(void)
{
- struct page *page = virt_to_page(_sinittext);
unsigned long numpages = PFN_UP((unsigned long)_einittext) -
PFN_DOWN((unsigned long)_sinittext);
if (v_block_mapped((unsigned long)_stext + 1))
mmu_mark_initmem_nx();
else
- change_page_attr(page, numpages, PAGE_KERNEL);
+ set_memory_attr((unsigned long)_sinittext, numpages, PAGE_KERNEL);
}
#ifdef CONFIG_STRICT_KERNEL_RWX
void mark_rodata_ro(void)
{
- struct page *page;
unsigned long numpages;
if (v_block_mapped((unsigned long)_sinittext)) {
@@ -187,20 +144,18 @@ void mark_rodata_ro(void)
return;
}
- page = virt_to_page(_stext);
numpages = PFN_UP((unsigned long)_etext) -
PFN_DOWN((unsigned long)_stext);
- change_page_attr(page, numpages, PAGE_KERNEL_ROX);
+ set_memory_attr((unsigned long)_stext, numpages, PAGE_KERNEL_ROX);
/*
* mark .rodata as read only. Use __init_begin rather than __end_rodata
* to cover NOTES and EXCEPTION_TABLE.
*/
- page = virt_to_page(__start_rodata);
numpages = PFN_UP((unsigned long)__init_begin) -
PFN_DOWN((unsigned long)__start_rodata);
- change_page_attr(page, numpages, PAGE_KERNEL_RO);
+ set_memory_attr((unsigned long)__start_rodata, numpages, PAGE_KERNEL_RO);
// mark_initmem_nx() should have already run by now
ptdump_check_wx();
@@ -210,9 +165,14 @@ void mark_rodata_ro(void)
#ifdef CONFIG_DEBUG_PAGEALLOC
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
+ unsigned long addr = (unsigned long)page_address(page);
+
if (PageHighMem(page))
return;
- change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
+ if (enable)
+ set_memory_attr(addr, numpages, PAGE_KERNEL);
+ else
+ set_memory_attr(addr, numpages, __pgprot(0));
}
#endif /* CONFIG_DEBUG_PAGEALLOC */
--
2.26.0
^ permalink raw reply related
* [PATCH v8 6/7] powerpc/mm: implement set_memory_attr()
From: Russell Currey @ 2020-04-02 8:40 UTC (permalink / raw)
To: linuxppc-dev
Cc: ajd, kernel-hardening, npiggin, kbuild test robot, Russell Currey,
dja
In-Reply-To: <20200402084053.188537-1-ruscur@russell.cc>
From: Christophe Leroy <christophe.leroy@c-s.fr>
In addition to the set_memory_xx() functions which allows to change
the memory attributes of not (yet) used memory regions, implement a
set_memory_attr() function to:
- set the final memory protection after init on currently used
kernel regions.
- enable/disable kernel memory regions in the scope of DEBUG_PAGEALLOC.
Unlike the set_memory_xx() which can act in three step as the regions
are unused, this function must modify 'on the fly' as the kernel is
executing from them. At the moment only PPC32 will use it and changing
page attributes on the fly is not an issue.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reported-by: kbuild test robot <lkp@intel.com>
[ruscur: cast "data" to unsigned long instead of int]
Signed-off-by: Russell Currey <ruscur@russell.cc>
---
arch/powerpc/include/asm/set_memory.h | 2 ++
arch/powerpc/mm/pageattr.c | 33 +++++++++++++++++++++++++++
2 files changed, 35 insertions(+)
diff --git a/arch/powerpc/include/asm/set_memory.h b/arch/powerpc/include/asm/set_memory.h
index 64011ea444b4..b040094f7920 100644
--- a/arch/powerpc/include/asm/set_memory.h
+++ b/arch/powerpc/include/asm/set_memory.h
@@ -29,4 +29,6 @@ static inline int set_memory_x(unsigned long addr, int numpages)
return change_memory_attr(addr, numpages, SET_MEMORY_X);
}
+int set_memory_attr(unsigned long addr, int numpages, pgprot_t prot);
+
#endif
diff --git a/arch/powerpc/mm/pageattr.c b/arch/powerpc/mm/pageattr.c
index 2da3fbab6ff7..2fde1b195c85 100644
--- a/arch/powerpc/mm/pageattr.c
+++ b/arch/powerpc/mm/pageattr.c
@@ -79,3 +79,36 @@ int change_memory_attr(unsigned long addr, int numpages, long action)
return apply_to_existing_page_range(&init_mm, start, sz,
change_page_attr, (void *)action);
}
+
+/*
+ * Set the attributes of a page:
+ *
+ * This function is used by PPC32 at the end of init to set final kernel memory
+ * protection. It includes changing the maping of the page it is executing from
+ * and data pages it is using.
+ */
+static int set_page_attr(pte_t *ptep, unsigned long addr, void *data)
+{
+ pgprot_t prot = __pgprot((unsigned long)data);
+
+ spin_lock(&init_mm.page_table_lock);
+
+ set_pte_at(&init_mm, addr, ptep, pte_modify(*ptep, prot));
+ flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
+
+ spin_unlock(&init_mm.page_table_lock);
+
+ return 0;
+}
+
+int set_memory_attr(unsigned long addr, int numpages, pgprot_t prot)
+{
+ unsigned long start = ALIGN_DOWN(addr, PAGE_SIZE);
+ unsigned long sz = numpages * PAGE_SIZE;
+
+ if (numpages <= 0)
+ return 0;
+
+ return apply_to_existing_page_range(&init_mm, start, sz, set_page_attr,
+ (void *)pgprot_val(prot));
+}
--
2.26.0
^ permalink raw reply related
* [PATCH v8 5/7] powerpc/configs: Enable STRICT_MODULE_RWX in skiroot_defconfig
From: Russell Currey @ 2020-04-02 8:40 UTC (permalink / raw)
To: linuxppc-dev
Cc: ajd, kernel-hardening, Joel Stanley, npiggin, Russell Currey, dja
In-Reply-To: <20200402084053.188537-1-ruscur@russell.cc>
skiroot_defconfig is the only powerpc defconfig with STRICT_KERNEL_RWX
enabled, and if you want memory protection for kernel text you'd want it
for modules too, so enable STRICT_MODULE_RWX there.
Acked-by: Joel Stanley <joel@joel.id.au>
Signed-off-by: Russell Currey <ruscur@russell.cc>
---
arch/powerpc/configs/skiroot_defconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/powerpc/configs/skiroot_defconfig b/arch/powerpc/configs/skiroot_defconfig
index 1b6bdad36b13..66d20dbe67b7 100644
--- a/arch/powerpc/configs/skiroot_defconfig
+++ b/arch/powerpc/configs/skiroot_defconfig
@@ -51,6 +51,7 @@ CONFIG_CMDLINE="console=tty0 console=hvc0 ipr.fast_reboot=1 quiet"
# CONFIG_PPC_MEM_KEYS is not set
CONFIG_JUMP_LABEL=y
CONFIG_STRICT_KERNEL_RWX=y
+CONFIG_STRICT_MODULE_RWX=y
CONFIG_MODULES=y
CONFIG_MODULE_UNLOAD=y
CONFIG_MODULE_SIG_FORCE=y
--
2.26.0
^ permalink raw reply related
* [PATCH v8 4/7] powerpc: Set ARCH_HAS_STRICT_MODULE_RWX
From: Russell Currey @ 2020-04-02 8:40 UTC (permalink / raw)
To: linuxppc-dev; +Cc: ajd, kernel-hardening, npiggin, Russell Currey, dja
In-Reply-To: <20200402084053.188537-1-ruscur@russell.cc>
To enable strict module RWX on powerpc, set:
CONFIG_STRICT_MODULE_RWX=y
You should also have CONFIG_STRICT_KERNEL_RWX=y set to have any real
security benefit.
ARCH_HAS_STRICT_MODULE_RWX is set to require ARCH_HAS_STRICT_KERNEL_RWX.
This is due to a quirk in arch/Kconfig and arch/powerpc/Kconfig that
makes STRICT_MODULE_RWX *on by default* in configurations where
STRICT_KERNEL_RWX is *unavailable*.
Since this doesn't make much sense, and module RWX without kernel RWX
doesn't make much sense, having the same dependencies as kernel RWX
works around this problem.
Signed-off-by: Russell Currey <ruscur@russell.cc>
---
arch/powerpc/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 399a4de28ff0..1488bb5f4179 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -131,6 +131,7 @@ config PPC
select ARCH_HAS_SCALED_CPUTIME if VIRT_CPU_ACCOUNTING_NATIVE && PPC_BOOK3S_64
select ARCH_HAS_SET_MEMORY
select ARCH_HAS_STRICT_KERNEL_RWX if ((PPC_BOOK3S_64 || PPC32) && !HIBERNATION)
+ select ARCH_HAS_STRICT_MODULE_RWX if ARCH_HAS_STRICT_KERNEL_RWX
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UACCESS_FLUSHCACHE
select ARCH_HAS_UACCESS_MCSAFE if PPC64
--
2.26.0
^ permalink raw reply related
* [PATCH v8 3/7] powerpc/mm/ptdump: debugfs handler for W+X checks at runtime
From: Russell Currey @ 2020-04-02 8:40 UTC (permalink / raw)
To: linuxppc-dev
Cc: ajd, Kees Cook, kernel-hardening, npiggin, Russell Currey, dja
In-Reply-To: <20200402084053.188537-1-ruscur@russell.cc>
Very rudimentary, just
echo 1 > [debugfs]/check_wx_pages
and check the kernel log. Useful for testing strict module RWX.
Updated the Kconfig entry to reflect this.
Also fixed a typo.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Russell Currey <ruscur@russell.cc>
---
arch/powerpc/Kconfig.debug | 6 ++++--
arch/powerpc/mm/ptdump/ptdump.c | 21 ++++++++++++++++++++-
2 files changed, 24 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index 0b063830eea8..e37960ef68c6 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -370,7 +370,7 @@ config PPC_PTDUMP
If you are unsure, say N.
config PPC_DEBUG_WX
- bool "Warn on W+X mappings at boot"
+ bool "Warn on W+X mappings at boot & enable manual checks at runtime"
depends on PPC_PTDUMP && STRICT_KERNEL_RWX
help
Generate a warning if any W+X mappings are found at boot.
@@ -384,7 +384,9 @@ config PPC_DEBUG_WX
of other unfixed kernel bugs easier.
There is no runtime or memory usage effect of this option
- once the kernel has booted up - it's a one time check.
+ once the kernel has booted up, it only automatically checks once.
+
+ Enables the "check_wx_pages" debugfs entry for checking at runtime.
If in doubt, say "Y".
diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
index d92bb8ea229c..525ca5aeaa01 100644
--- a/arch/powerpc/mm/ptdump/ptdump.c
+++ b/arch/powerpc/mm/ptdump/ptdump.c
@@ -4,7 +4,7 @@
*
* This traverses the kernel pagetables and dumps the
* information about the used sections of memory to
- * /sys/kernel/debug/kernel_pagetables.
+ * /sys/kernel/debug/kernel_page_tables.
*
* Derived from the arm64 implementation:
* Copyright (c) 2014, The Linux Foundation, Laura Abbott.
@@ -413,6 +413,25 @@ void ptdump_check_wx(void)
else
pr_info("Checked W+X mappings: passed, no W+X pages found\n");
}
+
+static int check_wx_debugfs_set(void *data, u64 val)
+{
+ if (val != 1ULL)
+ return -EINVAL;
+
+ ptdump_check_wx();
+
+ return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(check_wx_fops, NULL, check_wx_debugfs_set, "%llu\n");
+
+static int ptdump_check_wx_init(void)
+{
+ return debugfs_create_file("check_wx_pages", 0200, NULL,
+ NULL, &check_wx_fops) ? 0 : -ENOMEM;
+}
+device_initcall(ptdump_check_wx_init);
#endif
static int ptdump_init(void)
--
2.26.0
^ permalink raw reply related
* [PATCH v8 1/7] powerpc/mm: Implement set_memory() routines
From: Russell Currey @ 2020-04-02 8:40 UTC (permalink / raw)
To: linuxppc-dev; +Cc: ajd, kernel-hardening, npiggin, Russell Currey, dja
The set_memory_{ro/rw/nx/x}() functions are required for STRICT_MODULE_RWX,
and are generally useful primitives to have. This implementation is
designed to be completely generic across powerpc's many MMUs.
It's possible that this could be optimised to be faster for specific
MMUs, but the focus is on having a generic and safe implementation for
now.
This implementation does not handle cases where the caller is attempting
to change the mapping of the page it is executing from, or if another
CPU is concurrently using the page being altered. These cases likely
shouldn't happen, but a more complex implementation with MMU-specific code
could safely handle them, so that is left as a TODO for now.
These functions do nothing if STRICT_KERNEL_RWX is not enabled.
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/Kconfig | 1 +
arch/powerpc/include/asm/set_memory.h | 32 +++++++++++
arch/powerpc/mm/Makefile | 2 +-
arch/powerpc/mm/pageattr.c | 81 +++++++++++++++++++++++++++
4 files changed, 115 insertions(+), 1 deletion(-)
create mode 100644 arch/powerpc/include/asm/set_memory.h
create mode 100644 arch/powerpc/mm/pageattr.c
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 6f40af294685..399a4de28ff0 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -129,6 +129,7 @@ config PPC
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_MEMBARRIER_CALLBACKS
select ARCH_HAS_SCALED_CPUTIME if VIRT_CPU_ACCOUNTING_NATIVE && PPC_BOOK3S_64
+ select ARCH_HAS_SET_MEMORY
select ARCH_HAS_STRICT_KERNEL_RWX if ((PPC_BOOK3S_64 || PPC32) && !HIBERNATION)
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAS_UACCESS_FLUSHCACHE
diff --git a/arch/powerpc/include/asm/set_memory.h b/arch/powerpc/include/asm/set_memory.h
new file mode 100644
index 000000000000..64011ea444b4
--- /dev/null
+++ b/arch/powerpc/include/asm/set_memory.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_SET_MEMORY_H
+#define _ASM_POWERPC_SET_MEMORY_H
+
+#define SET_MEMORY_RO 0
+#define SET_MEMORY_RW 1
+#define SET_MEMORY_NX 2
+#define SET_MEMORY_X 3
+
+int change_memory_attr(unsigned long addr, int numpages, long action);
+
+static inline int set_memory_ro(unsigned long addr, int numpages)
+{
+ return change_memory_attr(addr, numpages, SET_MEMORY_RO);
+}
+
+static inline int set_memory_rw(unsigned long addr, int numpages)
+{
+ return change_memory_attr(addr, numpages, SET_MEMORY_RW);
+}
+
+static inline int set_memory_nx(unsigned long addr, int numpages)
+{
+ return change_memory_attr(addr, numpages, SET_MEMORY_NX);
+}
+
+static inline int set_memory_x(unsigned long addr, int numpages)
+{
+ return change_memory_attr(addr, numpages, SET_MEMORY_X);
+}
+
+#endif
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index 5e147986400d..a998fdac52f9 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -5,7 +5,7 @@
ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
-obj-y := fault.o mem.o pgtable.o mmap.o \
+obj-y := fault.o mem.o pgtable.o mmap.o pageattr.o \
init_$(BITS).o pgtable_$(BITS).o \
pgtable-frag.o ioremap.o ioremap_$(BITS).o \
init-common.o mmu_context.o drmem.o
diff --git a/arch/powerpc/mm/pageattr.c b/arch/powerpc/mm/pageattr.c
new file mode 100644
index 000000000000..2da3fbab6ff7
--- /dev/null
+++ b/arch/powerpc/mm/pageattr.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * MMU-generic set_memory implementation for powerpc
+ *
+ * Copyright 2019, IBM Corporation.
+ */
+
+#include <linux/mm.h>
+#include <linux/set_memory.h>
+
+#include <asm/mmu.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+
+
+/*
+ * Updates the attributes of a page in three steps:
+ *
+ * 1. invalidate the page table entry
+ * 2. flush the TLB
+ * 3. install the new entry with the updated attributes
+ *
+ * This is unsafe if the caller is attempting to change the mapping of the
+ * page it is executing from, or if another CPU is concurrently using the
+ * page being altered.
+ *
+ * TODO make the implementation resistant to this.
+ *
+ * NOTE: can be dangerous to call without STRICT_KERNEL_RWX
+ */
+static int change_page_attr(pte_t *ptep, unsigned long addr, void *data)
+{
+ long action = (long)data;
+ pte_t pte;
+
+ spin_lock(&init_mm.page_table_lock);
+
+ /* invalidate the PTE so it's safe to modify */
+ pte = ptep_get_and_clear(&init_mm, addr, ptep);
+ flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
+
+ /* modify the PTE bits as desired, then apply */
+ switch (action) {
+ case SET_MEMORY_RO:
+ pte = pte_wrprotect(pte);
+ break;
+ case SET_MEMORY_RW:
+ pte = pte_mkwrite(pte);
+ break;
+ case SET_MEMORY_NX:
+ pte = pte_exprotect(pte);
+ break;
+ case SET_MEMORY_X:
+ pte = pte_mkexec(pte);
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ break;
+ }
+
+ set_pte_at(&init_mm, addr, ptep, pte);
+ spin_unlock(&init_mm.page_table_lock);
+
+ return 0;
+}
+
+int change_memory_attr(unsigned long addr, int numpages, long action)
+{
+ unsigned long start = ALIGN_DOWN(addr, PAGE_SIZE);
+ unsigned long sz = numpages * PAGE_SIZE;
+
+ if (!IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
+ return 0;
+
+ if (numpages <= 0)
+ return 0;
+
+ return apply_to_existing_page_range(&init_mm, start, sz,
+ change_page_attr, (void *)action);
+}
--
2.26.0
^ permalink raw reply related
* [PATCH v8 2/7] powerpc/kprobes: Mark newly allocated probes as RO
From: Russell Currey @ 2020-04-02 8:40 UTC (permalink / raw)
To: linuxppc-dev; +Cc: ajd, kernel-hardening, npiggin, Russell Currey, dja
In-Reply-To: <20200402084053.188537-1-ruscur@russell.cc>
With CONFIG_STRICT_KERNEL_RWX=y and CONFIG_KPROBES=y, there will be one
W+X page at boot by default. This can be tested with
CONFIG_PPC_PTDUMP=y and CONFIG_PPC_DEBUG_WX=y set, and checking the
kernel log during boot.
powerpc doesn't implement its own alloc() for kprobes like other
architectures do, but we couldn't immediately mark RO anyway since we do
a memcpy to the page we allocate later. After that, nothing should be
allowed to modify the page, and write permissions are removed well
before the kprobe is armed.
The memcpy() would fail if >1 probes were allocated, so use
patch_instruction() instead which is safe for RO.
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/kernel/kprobes.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 81efb605113e..fa4502b4de35 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -24,6 +24,8 @@
#include <asm/sstep.h>
#include <asm/sections.h>
#include <linux/uaccess.h>
+#include <linux/set_memory.h>
+#include <linux/vmalloc.h>
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
@@ -102,6 +104,16 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset)
return addr;
}
+void *alloc_insn_page(void)
+{
+ void *page = vmalloc_exec(PAGE_SIZE);
+
+ if (page)
+ set_memory_ro((unsigned long)page, 1);
+
+ return page;
+}
+
int arch_prepare_kprobe(struct kprobe *p)
{
int ret = 0;
@@ -124,11 +136,8 @@ int arch_prepare_kprobe(struct kprobe *p)
}
if (!ret) {
- memcpy(p->ainsn.insn, p->addr,
- MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
+ patch_instruction(p->ainsn.insn, *p->addr);
p->opcode = *p->addr;
- flush_icache_range((unsigned long)p->ainsn.insn,
- (unsigned long)p->ainsn.insn + sizeof(kprobe_opcode_t));
}
p->ainsn.boostable = 0;
--
2.26.0
^ permalink raw reply related
* Re: [PATCH v10 03/14] powerpc/vas: Alloc and setup IRQ and trigger port address
From: Cédric Le Goater @ 2020-04-02 8:08 UTC (permalink / raw)
To: Haren Myneni, mpe
Cc: mikey, ajd, frederic.barrat, linux-kernel, npiggin, hch, oohall,
herbert, sukadev, linuxppc-dev, srikar
In-Reply-To: <1585811431.2275.39.camel@hbabu-laptop>
On 4/2/20 9:10 AM, Haren Myneni wrote:
>
> Allocate a xive irq on each chip with a vas instance. The NX coprocessor
> raises a host CPU interrupt via vas if it encounters page fault on user
> space request buffer. Subsequent patches register the trigger port with
> the NX coprocessor, and create a vas fault handler for this interrupt
> mapping.
Looks good !
> Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Thanks,
C.
> ---
> arch/powerpc/platforms/powernv/vas.c | 44 +++++++++++++++++++++++++++++++-----
> arch/powerpc/platforms/powernv/vas.h | 2 ++
> 2 files changed, 40 insertions(+), 6 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/vas.c b/arch/powerpc/platforms/powernv/vas.c
> index ed9cc6d..3303cfe 100644
> --- a/arch/powerpc/platforms/powernv/vas.c
> +++ b/arch/powerpc/platforms/powernv/vas.c
> @@ -15,6 +15,7 @@
> #include <linux/of_address.h>
> #include <linux/of.h>
> #include <asm/prom.h>
> +#include <asm/xive.h>
>
> #include "vas.h"
>
> @@ -25,10 +26,12 @@
>
> static int init_vas_instance(struct platform_device *pdev)
> {
> - int rc, cpu, vasid;
> - struct resource *res;
> - struct vas_instance *vinst;
> struct device_node *dn = pdev->dev.of_node;
> + struct vas_instance *vinst;
> + struct xive_irq_data *xd;
> + uint32_t chipid, hwirq;
> + struct resource *res;
> + int rc, cpu, vasid;
>
> rc = of_property_read_u32(dn, "ibm,vas-id", &vasid);
> if (rc) {
> @@ -36,6 +39,12 @@ static int init_vas_instance(struct platform_device *pdev)
> return -ENODEV;
> }
>
> + rc = of_property_read_u32(dn, "ibm,chip-id", &chipid);
> + if (rc) {
> + pr_err("No ibm,chip-id property for %s?\n", pdev->name);
> + return -ENODEV;
> + }
> +
> if (pdev->num_resources != 4) {
> pr_err("Unexpected DT configuration for [%s, %d]\n",
> pdev->name, vasid);
> @@ -69,9 +78,32 @@ static int init_vas_instance(struct platform_device *pdev)
>
> vinst->paste_win_id_shift = 63 - res->end;
>
> - pr_devel("Initialized instance [%s, %d], paste_base 0x%llx, "
> - "paste_win_id_shift 0x%llx\n", pdev->name, vasid,
> - vinst->paste_base_addr, vinst->paste_win_id_shift);
> + hwirq = xive_native_alloc_irq_on_chip(chipid);
> + if (!hwirq) {
> + pr_err("Inst%d: Unable to allocate global irq for chip %d\n",
> + vinst->vas_id, chipid);
> + return -ENOENT;
> + }
> +
> + vinst->virq = irq_create_mapping(NULL, hwirq);
> + if (!vinst->virq) {
> + pr_err("Inst%d: Unable to map global irq %d\n",
> + vinst->vas_id, hwirq);
> + return -EINVAL;
> + }
> +
> + xd = irq_get_handler_data(vinst->virq);
> + if (!xd) {
> + pr_err("Inst%d: Invalid virq %d\n",
> + vinst->vas_id, vinst->virq);
> + return -EINVAL;
> + }
> +
> + vinst->irq_port = xd->trig_page;
> + pr_devel("Initialized instance [%s, %d] paste_base 0x%llx paste_win_id_shift 0x%llx IRQ %d Port 0x%llx\n",
> + pdev->name, vasid, vinst->paste_base_addr,
> + vinst->paste_win_id_shift, vinst->virq,
> + vinst->irq_port);
>
> for_each_possible_cpu(cpu) {
> if (cpu_to_chip_id(cpu) == of_get_ibm_chip_id(dn))
> diff --git a/arch/powerpc/platforms/powernv/vas.h b/arch/powerpc/platforms/powernv/vas.h
> index 5574aec..598608b 100644
> --- a/arch/powerpc/platforms/powernv/vas.h
> +++ b/arch/powerpc/platforms/powernv/vas.h
> @@ -313,6 +313,8 @@ struct vas_instance {
> u64 paste_base_addr;
> u64 paste_win_id_shift;
>
> + u64 irq_port;
> + int virq;
> struct mutex mutex;
> struct vas_window *rxwin[VAS_COP_TYPE_MAX];
> struct vas_window *windows[VAS_WINDOWS_PER_CHIP];
>
^ permalink raw reply
* Re: [PATCH RFC] mm: remove CONFIG_HAVE_MEMBLOCK_NODE_MAP (was: Re: [PATCH v3 0/5] mm: Enable CONFIG_NODES_SPAN_OTHER_NODES by default for NUMA)
From: Michal Hocko @ 2020-04-02 8:01 UTC (permalink / raw)
To: Mike Rapoport
Cc: mmorana, Catalin Marinas, Will Deacon,
open list:MEMORY MANAGEMENT, Paul Mackerras, H. Peter Anvin,
sparclinux, Alexander Duyck, linux-s390, Baoquan He, x86,
Christian Borntraeger, Ingo Molnar, Hoan Tran, Pavel Tatashin,
lho, Vasily Gorbik, Vlastimil Babka, Heiko Carstens,
Borislav Petkov, Thomas Gleixner, linux-arm-kernel,
Oscar Salvador, linux-kernel, Andrew Morton, linuxppc-dev,
David S. Miller
In-Reply-To: <20200401075155.GH30942@linux.ibm.com>
On Wed 01-04-20 10:51:55, Mike Rapoport wrote:
> Hi,
>
> On Wed, Apr 01, 2020 at 01:42:27PM +0800, Baoquan He wrote:
[...]
> > From above information, we can remove HAVE_MEMBLOCK_NODE_MAP, and
> > replace it with CONFIG_NUMA. That sounds more sensible to store nid into
> > memblock when NUMA support is enabled.
>
> Replacing CONFIG_HAVE_MEMBLOCK_NODE_MAP with CONFIG_NUMA will work, but
> this will not help cleaning up the whole node/zone initialization mess and
> we'll be stuck with two implementations.
Yeah, this is far from optimal.
> The overhead of enabling HAVE_MEMBLOCK_NODE_MAP is only for init time as
> most architectures will anyway discard the entire memblock, so having it in
> a UMA arch won't be a problem. The only exception is arm that uses
> memblock for pfn_valid(), here we may also think about a solution to
> compensate the addition of nid to the memblock structures.
Well, we can make memblock_region->nid defined only for CONFIG_NUMA.
memblock_get_region_node would then unconditionally return 0 on UMA.
Essentially the same way we do NUMA for other MM code. I only see few
direct usage of region->nid.
--
Michal Hocko
SUSE Labs
^ permalink raw reply
* Re: [PATCH RESEND 2/4] uaccess: Selectively open read or write user access
From: Christophe Leroy @ 2020-04-02 8:00 UTC (permalink / raw)
To: Kees Cook
Cc: linux-arch, linuxppc-dev, airlied, hpa, linux-kernel, linux-mm,
Paul Mackerras, viro, daniel, akpm, torvalds
In-Reply-To: <202004020047.401CEBED2@keescook>
Le 02/04/2020 à 09:51, Kees Cook a écrit :
> On Thu, Apr 02, 2020 at 07:34:17AM +0000, Christophe Leroy wrote:
>> [...]
>> diff --git a/kernel/compat.c b/kernel/compat.c
>> index 843dd17e6078..705ca7e418c6 100644
>> --- a/kernel/compat.c
>> +++ b/kernel/compat.c
>> @@ -199,7 +199,7 @@ long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
>> bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
>> nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
>>
>> - if (!user_access_begin(umask, bitmap_size / 8))
>> + if (!user_write_access_begin(umask, bitmap_size / 8))
>
> This looks mismatched: should be user_read_access_begin()?
Oops, looks like a copy/paste/modify where I modified the original
instead of the copy.
>
>> return -EFAULT;
>>
>> while (nr_compat_longs > 1) {
>> @@ -211,11 +211,11 @@ long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
>> }
>> if (nr_compat_longs)
>> unsafe_get_user(*mask, umask++, Efault);
>> - user_access_end();
>> + user_read_access_end();
>> return 0;
>>
>> Efault:
>> - user_access_end();
>> + user_read_access_end();
>> return -EFAULT;
>> }
>
> (These correctly end read access.)
>
>>
>> @@ -228,7 +228,7 @@ long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
>> bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
>> nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
>>
>> - if (!user_access_begin(umask, bitmap_size / 8))
>> + if (!user_read_access_begin(umask, bitmap_size / 8))
>
> And ..._write_... here?
>
>> return -EFAULT;
>>
>> while (nr_compat_longs > 1) {
>> @@ -239,10 +239,10 @@ long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
>> }
>> if (nr_compat_longs)
>> unsafe_put_user((compat_ulong_t)*mask, umask++, Efault);
>> - user_access_end();
>> + user_write_access_end();
>> return 0;
>> Efault:
>> - user_access_end();
>> + user_write_access_end();
>> return -EFAULT;
>> }
>
> (These correctly end write access.)
>
>
> All the others look correct. With the above fixed:
>
> Reviewed-by: Kees Cook <keescook@chromium.org>
>
Thanks
Christophe
^ permalink raw reply
* Re: [PATCH RESEND 3/4] drm/i915/gem: Replace user_access_begin by user_write_access_begin
From: Christophe Leroy @ 2020-04-02 7:59 UTC (permalink / raw)
To: Kees Cook
Cc: linux-arch, linuxppc-dev, airlied, hpa, linux-kernel, linux-mm,
Paul Mackerras, viro, daniel, akpm, torvalds
In-Reply-To: <202004020051.649C6B8@keescook>
Le 02/04/2020 à 09:52, Kees Cook a écrit :
> On Thu, Apr 02, 2020 at 07:34:18AM +0000, Christophe Leroy wrote:
>> When i915_gem_execbuffer2_ioctl() is using user_access_begin(),
>> that's only to perform unsafe_put_user() so use
>> user_write_access_begin() in order to only open write access.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
>
> Why is this split from the other conversions?
I split it from the other because this one is in drivers while other
ones are in core part of the kernel.
Is it better to squash it in the previous patch ?
Christophe
>
> Reviewed-by: Kees Cook <keescook@chromium.org>
>
>
>> ---
>> drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 11 ++++++-----
>> 1 file changed, 6 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
>> index 7643a30ba4cd..4be8205a70b6 100644
>> --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
>> @@ -1611,14 +1611,14 @@ static int eb_copy_relocations(const struct i915_execbuffer *eb)
>> * happened we would make the mistake of assuming that the
>> * relocations were valid.
>> */
>> - if (!user_access_begin(urelocs, size))
>> + if (!user_write_access_begin(urelocs, size))
>> goto end;
>>
>> for (copied = 0; copied < nreloc; copied++)
>> unsafe_put_user(-1,
>> &urelocs[copied].presumed_offset,
>> end_user);
>> - user_access_end();
>> + user_write_access_end();
>>
>> eb->exec[i].relocs_ptr = (uintptr_t)relocs;
>> }
>> @@ -1626,7 +1626,7 @@ static int eb_copy_relocations(const struct i915_execbuffer *eb)
>> return 0;
>>
>> end_user:
>> - user_access_end();
>> + user_write_access_end();
>> end:
>> kvfree(relocs);
>> err = -EFAULT;
>> @@ -2991,7 +2991,8 @@ i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
>> * And this range already got effectively checked earlier
>> * when we did the "copy_from_user()" above.
>> */
>> - if (!user_access_begin(user_exec_list, count * sizeof(*user_exec_list)))
>> + if (!user_write_access_begin(user_exec_list,
>> + count * sizeof(*user_exec_list)))
>> goto end;
>>
>> for (i = 0; i < args->buffer_count; i++) {
>> @@ -3005,7 +3006,7 @@ i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
>> end_user);
>> }
>> end_user:
>> - user_access_end();
>> + user_write_access_end();
>> end:;
>> }
>>
>> --
>> 2.25.0
>>
>
^ permalink raw reply
* Re: [PATCH RESEND 1/4] uaccess: Add user_read_access_begin/end and user_write_access_begin/end
From: Kees Cook @ 2020-04-02 7:46 UTC (permalink / raw)
To: Christophe Leroy
Cc: linux-arch, linuxppc-dev, airlied, hpa, linux-kernel, linux-mm,
Paul Mackerras, viro, daniel, akpm, torvalds
In-Reply-To: <27106d62fdbd4ffb47796236050e418131cb837f.1585811416.git.christophe.leroy@c-s.fr>
On Thu, Apr 02, 2020 at 07:34:16AM +0000, Christophe Leroy wrote:
> Some architectures like powerpc64 have the capability to separate
> read access and write access protection.
> For get_user() and copy_from_user(), powerpc64 only open read access.
> For put_user() and copy_to_user(), powerpc64 only open write access.
> But when using unsafe_get_user() or unsafe_put_user(),
> user_access_begin open both read and write.
>
> Other architectures like powerpc book3s 32 bits only allow write
> access protection. And on this architecture protection is an heavy
> operation as it requires locking/unlocking per segment of 256Mbytes.
> On those architecture it is therefore desirable to do the unlocking
> only for write access. (Note that book3s/32 ranges from very old
> powermac from the 90's with powerpc 601 processor, till modern
> ADSL boxes with PowerQuicc II modern processors for instance so it
> is still worth considering)
>
> In order to avoid any risk based of hacking some variable parameters
> passed to user_access_begin/end that would allow hacking and
> leaving user access open or opening too much, it is preferable to
> use dedicated static functions that can't be overridden.
>
> Add a user_read_access_begin and user_read_access_end to only open
> read access.
>
> Add a user_write_access_begin and user_write_access_end to only open
> write access.
>
> By default, when undefined, those new access helpers default on the
> existing user_access_begin and user_access_end.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Kees Cook <keescook@chromium.org>
-Kees
> Link: https://patchwork.ozlabs.org/patch/1227926/
> ---
> Resending this series as I mistakenly only sent it to powerpc list
> begining of February (https://patchwork.ozlabs.org/patch/1233172/)
>
> This series is based on the discussion we had in January, see
> https://patchwork.ozlabs.org/patch/1227926/ . I tried to
> take into account all remarks, especially @hpa 's remark to use
> a fixed API on not base the relocking on a magic id returned at
> unlocking.
>
> This series is awaited for implementing selective lkdtm test to
> test powerpc64 independant read and write protection, see
> https://patchwork.ozlabs.org/patch/1231765/
>
> include/linux/uaccess.h | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
> index 67f016010aad..9861c89f93be 100644
> --- a/include/linux/uaccess.h
> +++ b/include/linux/uaccess.h
> @@ -378,6 +378,14 @@ extern long strnlen_unsafe_user(const void __user *unsafe_addr, long count);
> static inline unsigned long user_access_save(void) { return 0UL; }
> static inline void user_access_restore(unsigned long flags) { }
> #endif
> +#ifndef user_write_access_begin
> +#define user_write_access_begin user_access_begin
> +#define user_write_access_end user_access_end
> +#endif
> +#ifndef user_read_access_begin
> +#define user_read_access_begin user_access_begin
> +#define user_read_access_end user_access_end
> +#endif
>
> #ifdef CONFIG_HARDENED_USERCOPY
> void usercopy_warn(const char *name, const char *detail, bool to_user,
> --
> 2.25.0
>
--
Kees Cook
^ permalink raw reply
* Re: [PATCH RESEND 4/4] powerpc/uaccess: Implement user_read_access_begin and user_write_access_begin
From: Kees Cook @ 2020-04-02 7:52 UTC (permalink / raw)
To: Christophe Leroy
Cc: linux-arch, linuxppc-dev, airlied, hpa, linux-kernel, linux-mm,
Paul Mackerras, viro, daniel, akpm, torvalds
In-Reply-To: <ebcf8256e02a7dffb292f3d800e264dce263cac5.1585811416.git.christophe.leroy@c-s.fr>
On Thu, Apr 02, 2020 at 07:34:19AM +0000, Christophe Leroy wrote:
> Add support for selective read or write user access with
> user_read_access_begin/end and user_write_access_begin/end.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Kees Cook <keescook@chromium.org>
-Kees
> ---
> arch/powerpc/include/asm/book3s/32/kup.h | 4 ++--
> arch/powerpc/include/asm/kup.h | 14 +++++++++++++-
> arch/powerpc/include/asm/uaccess.h | 22 ++++++++++++++++++++++
> 3 files changed, 37 insertions(+), 3 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
> index 3c0ba22dc360..1617e73bee30 100644
> --- a/arch/powerpc/include/asm/book3s/32/kup.h
> +++ b/arch/powerpc/include/asm/book3s/32/kup.h
> @@ -108,7 +108,7 @@ static __always_inline void allow_user_access(void __user *to, const void __user
> u32 addr, end;
>
> BUILD_BUG_ON(!__builtin_constant_p(dir));
> - BUILD_BUG_ON(dir == KUAP_CURRENT);
> + BUILD_BUG_ON(dir & ~KUAP_READ_WRITE);
>
> if (!(dir & KUAP_WRITE))
> return;
> @@ -131,7 +131,7 @@ static __always_inline void prevent_user_access(void __user *to, const void __us
>
> BUILD_BUG_ON(!__builtin_constant_p(dir));
>
> - if (dir == KUAP_CURRENT) {
> + if (dir & KUAP_CURRENT_WRITE) {
> u32 kuap = current->thread.kuap;
>
> if (unlikely(!kuap))
> diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
> index 92bcd1a26d73..c745ee41ad66 100644
> --- a/arch/powerpc/include/asm/kup.h
> +++ b/arch/powerpc/include/asm/kup.h
> @@ -10,7 +10,9 @@
> * Use the current saved situation instead of the to/from/size params.
> * Used on book3s/32
> */
> -#define KUAP_CURRENT 4
> +#define KUAP_CURRENT_READ 4
> +#define KUAP_CURRENT_WRITE 8
> +#define KUAP_CURRENT (KUAP_CURRENT_READ | KUAP_CURRENT_WRITE)
>
> #ifdef CONFIG_PPC64
> #include <asm/book3s/64/kup-radix.h>
> @@ -101,6 +103,16 @@ static inline void prevent_current_access_user(void)
> prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT);
> }
>
> +static inline void prevent_current_read_from_user(void)
> +{
> + prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_READ);
> +}
> +
> +static inline void prevent_current_write_to_user(void)
> +{
> + prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_WRITE);
> +}
> +
> #endif /* !__ASSEMBLY__ */
>
> #endif /* _ASM_POWERPC_KUAP_H_ */
> diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
> index 2f500debae21..4427d419eb1d 100644
> --- a/arch/powerpc/include/asm/uaccess.h
> +++ b/arch/powerpc/include/asm/uaccess.h
> @@ -468,6 +468,28 @@ static __must_check inline bool user_access_begin(const void __user *ptr, size_t
> #define user_access_save prevent_user_access_return
> #define user_access_restore restore_user_access
>
> +static __must_check inline bool
> +user_read_access_begin(const void __user *ptr, size_t len)
> +{
> + if (unlikely(!access_ok(ptr, len)))
> + return false;
> + allow_read_from_user(ptr, len);
> + return true;
> +}
> +#define user_read_access_begin user_read_access_begin
> +#define user_read_access_end prevent_current_read_from_user
> +
> +static __must_check inline bool
> +user_write_access_begin(const void __user *ptr, size_t len)
> +{
> + if (unlikely(!access_ok(ptr, len)))
> + return false;
> + allow_write_to_user((void __user *)ptr, len);
> + return true;
> +}
> +#define user_write_access_begin user_write_access_begin
> +#define user_write_access_end prevent_current_write_to_user
> +
> #define unsafe_op_wrap(op, err) do { if (unlikely(op)) goto err; } while (0)
> #define unsafe_get_user(x, p, e) unsafe_op_wrap(__get_user_allowed(x, p), e)
> #define unsafe_put_user(x, p, e) unsafe_op_wrap(__put_user_allowed(x, p), e)
> --
> 2.25.0
>
--
Kees Cook
^ permalink raw reply
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