* Re: [PATCH 5/6] powerpc/mm/64s/hash: Add real-mode change_memory_range() for hash LPAR
From: Michael Ellerman @ 2021-03-19 11:56 UTC (permalink / raw)
To: Daniel Axtens, linuxppc-dev; +Cc: aneesh.kumar
In-Reply-To: <87h7m8pyk5.fsf@dja-thinkpad.axtens.net>
Daniel Axtens <dja@axtens.net> writes:
> Michael Ellerman <mpe@ellerman.id.au> writes:
>
>> When we enabled STRICT_KERNEL_RWX we received some reports of boot
>> failures when using the Hash MMU and running under phyp. The crashes
>> are intermittent, and often exhibit as a completely unresponsive
>> system, or possibly an oops.
>>
>> One example, which was caught in xmon:
>>
>> [ 14.068327][ T1] devtmpfs: mounted
>> [ 14.069302][ T1] Freeing unused kernel memory: 5568K
>> [ 14.142060][ T347] BUG: Unable to handle kernel instruction fetch
>> [ 14.142063][ T1] Run /sbin/init as init process
>> [ 14.142074][ T347] Faulting instruction address: 0xc000000000004400
>> cpu 0x2: Vector: 400 (Instruction Access) at [c00000000c7475e0]
>> pc: c000000000004400: exc_virt_0x4400_instruction_access+0x0/0x80
>> lr: c0000000001862d4: update_rq_clock+0x44/0x110
>> sp: c00000000c747880
>> msr: 8000000040001031
>> current = 0xc00000000c60d380
>> paca = 0xc00000001ec9de80 irqmask: 0x03 irq_happened: 0x01
>> pid = 347, comm = kworker/2:1
>> ...
>> enter ? for help
>> [c00000000c747880] c0000000001862d4 update_rq_clock+0x44/0x110 (unreliable)
>> [c00000000c7478f0] c000000000198794 update_blocked_averages+0xb4/0x6d0
>> [c00000000c7479f0] c000000000198e40 update_nohz_stats+0x90/0xd0
>> [c00000000c747a20] c0000000001a13b4 _nohz_idle_balance+0x164/0x390
>> [c00000000c747b10] c0000000001a1af8 newidle_balance+0x478/0x610
>> [c00000000c747be0] c0000000001a1d48 pick_next_task_fair+0x58/0x480
>> [c00000000c747c40] c000000000eaab5c __schedule+0x12c/0x950
>> [c00000000c747cd0] c000000000eab3e8 schedule+0x68/0x120
>> [c00000000c747d00] c00000000016b730 worker_thread+0x130/0x640
>> [c00000000c747da0] c000000000174d50 kthread+0x1a0/0x1b0
>> [c00000000c747e10] c00000000000e0f0 ret_from_kernel_thread+0x5c/0x6c
>>
>> This shows that CPU 2, which was idle, woke up and then appears to
>> randomly take an instruction fault on a completely valid area of
>> kernel text.
>>
>> The cause turns out to be the call to hash__mark_rodata_ro(), late in
>> boot. Due to the way we layout text and rodata, that function actually
>> changes the permissions for all of text and rodata to read-only plus
>> execute.
>>
>> To do the permission change we use a hypervisor call, H_PROTECT. On
>> phyp that appears to be implemented by briefly removing the mapping of
>> the kernel text, before putting it back with the updated permissions.
>> If any other CPU is executing during that window, it will see spurious
>> faults on the kernel text and/or data, leading to crashes.
>
> Jordan asked why we saw this on phyp but not under KVM? We had a look at
> book3s_hv_rm_mmu.c but the code is a bit too obtuse for me to reason
> about!
>
> Nick suggests that the KVM hypervisor is invalidating the HPTE, but
> because we run guests in VPM mode, the hypervisor would catch the page
> fault and not reflect it down to the guest. It looks like Linux-as-a-HV
> will take HPTE_V_HVLOCK, and then because it's running in VPM mode, the
> hypervisor will catch the fault and not pass it to the guest.
Yep.
> But if phyp runs with VPM mode off, the guest will see the fault
> before the hypervisor. (we think this is what's going on anyway.)
Yeah. I assumed phyp always ran with VPM=1, but apparently it can run
with it off or on, depending on various configuration settings.
So I'm fairly sure what we're hitting here is VPM=0, where the faults go
straight to the guest.
cheers
^ permalink raw reply
* Re: [PATCH V2] mm/memtest: Add ARCH_USE_MEMTEST
From: Catalin Marinas @ 2021-03-19 12:34 UTC (permalink / raw)
To: Anshuman Khandual
Cc: Chris Zankel, Thomas Bogendoerfer, linux-kernel, Max Filippov,
linux-xtensa, linuxppc-dev, Russell King, linux-mips, linux-mm,
Ingo Molnar, Paul Mackerras, Thomas Gleixner, Will Deacon,
linux-arm-kernel
In-Reply-To: <1614573126-7740-1-git-send-email-anshuman.khandual@arm.com>
On Mon, Mar 01, 2021 at 10:02:06AM +0530, Anshuman Khandual wrote:
> early_memtest() does not get called from all architectures. Hence enabling
> CONFIG_MEMTEST and providing a valid memtest=[1..N] kernel command line
> option might not trigger the memory pattern tests as would be expected in
> normal circumstances. This situation is misleading.
>
> The change here prevents the above mentioned problem after introducing a
> new config option ARCH_USE_MEMTEST that should be subscribed on platforms
> that call early_memtest(), in order to enable the config CONFIG_MEMTEST.
> Conversely CONFIG_MEMTEST cannot be enabled on platforms where it would
> not be tested anyway.
>
> Cc: Russell King <linux@armlinux.org.uk>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Chris Zankel <chris@zankel.net>
> Cc: Max Filippov <jcmvbkbc@gmail.com>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-mips@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux-xtensa@linux-xtensa.org
> Cc: linux-mm@kvack.org
> Cc: linux-kernel@vger.kernel.org
> Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
For arm64:
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
^ permalink raw reply
* Re: [PATCH 08/10] MIPS: disable CONFIG_IDE in malta*_defconfig
From: Christoph Hellwig @ 2021-03-19 13:03 UTC (permalink / raw)
To: Thomas Bogendoerfer
Cc: Jens Axboe, linux-doc, Russell King, David S. Miller, linux-ide,
linux-m68k, Ivan Kokshaysky, linux-arm-kernel, linux-alpha,
Geert Uytterhoeven, Matt Turner, linux-mips, linuxppc-dev,
Christoph Hellwig, linux-kernel, Richard Henderson
In-Reply-To: <20210318141900.GA10554@alpha.franken.de>
On Thu, Mar 18, 2021 at 03:19:00PM +0100, Thomas Bogendoerfer wrote:
> On Thu, Mar 18, 2021 at 05:57:04AM +0100, Christoph Hellwig wrote:
> > arch/mips/configs/malta_kvm_guest_defconfig | 3 ---
>
> that file is gone in mips-next.
>
> I could take all MIPS patches into mips-next, if you want...
Fine with me - it shouldn't really matter if the defconfig updates
go in independently. Do you want a resend with the typos fixed
against mips-next or are you simply going to fix these things up?
^ permalink raw reply
* [PATCH RFC 2/3] mm: remove xlate_dev_kmem_ptr()
From: David Hildenbrand @ 2021-03-19 14:34 UTC (permalink / raw)
To: linux-kernel
Cc: Rich Felker, linux-ia64, Kuninori Morimoto, David Hildenbrand,
Peter Zijlstra (Intel), Sebastian Andrzej Siewior, Palmer Dabbelt,
Jiaxun Yang, James E.J. Bottomley, linux-mm, Paul Mackerras,
sparclinux, linux-hexagon, Ingo Molnar, linux-arch, linux-s390,
Vasily Gorbik, Brian Cain, Helge Deller, linux-sh, Russell King,
Krzysztof Kozlowski, Christian Borntraeger, Geert Uytterhoeven,
linux-parisc, Matt Turner, Arnd Bergmann, Niklas Schnelle,
Heiko Carstens, linux-m68k, Ivan Kokshaysky, Greentime Hu,
Gerald Schaefer, linux-arm-kernel, Richard Henderson,
Thomas Bogendoerfer, Yoshinori Sato, Pierre Morel, Randy Dunlap,
linux-mips, Luis Chamberlain, Mike Rapoport, linux-alpha,
Mikulas Patocka, Andrew Morton, linuxppc-dev, David S. Miller,
Luc Van Oostenryck
In-Reply-To: <20210319143452.25948-1-david@redhat.com>
Since /dev/kmem has been removed, let's remove the xlate_dev_kmem_ptr()
leftovers.
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Pierre Morel <pmorel@linux.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-hexagon@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-mips@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/alpha/include/asm/io.h | 5 -----
arch/arm/include/asm/io.h | 5 -----
arch/hexagon/include/asm/io.h | 1 -
arch/ia64/include/asm/io.h | 1 -
arch/ia64/include/asm/uaccess.h | 18 ------------------
arch/m68k/include/asm/io_mm.h | 5 -----
arch/mips/include/asm/io.h | 5 -----
arch/parisc/include/asm/io.h | 5 -----
arch/powerpc/include/asm/io.h | 5 -----
arch/s390/include/asm/io.h | 5 -----
arch/sh/include/asm/io.h | 5 -----
arch/sparc/include/asm/io_64.h | 5 -----
include/asm-generic/io.h | 11 -----------
13 files changed, 76 deletions(-)
diff --git a/arch/alpha/include/asm/io.h b/arch/alpha/include/asm/io.h
index 1f6a909d1fa5..0fab5ac90775 100644
--- a/arch/alpha/include/asm/io.h
+++ b/arch/alpha/include/asm/io.h
@@ -602,11 +602,6 @@ extern void outsl (unsigned long port, const void *src, unsigned long count);
*/
#define xlate_dev_mem_ptr(p) __va(p)
-/*
- * Convert a virtual cached pointer to an uncached pointer
- */
-#define xlate_dev_kmem_ptr(p) p
-
#endif /* __KERNEL__ */
#endif /* __ALPHA_IO_H */
diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index fc748122f1e0..f74944c6fe8d 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -430,11 +430,6 @@ extern void pci_iounmap(struct pci_dev *dev, void __iomem *addr);
*/
#define xlate_dev_mem_ptr(p) __va(p)
-/*
- * Convert a virtual cached pointer to an uncached pointer
- */
-#define xlate_dev_kmem_ptr(p) p
-
#include <asm-generic/io.h>
#ifdef CONFIG_MMU
diff --git a/arch/hexagon/include/asm/io.h b/arch/hexagon/include/asm/io.h
index bda2a9c2df78..c33241425a5c 100644
--- a/arch/hexagon/include/asm/io.h
+++ b/arch/hexagon/include/asm/io.h
@@ -64,7 +64,6 @@ static inline void *phys_to_virt(unsigned long address)
* convert a physical pointer to a virtual kernel pointer for
* /dev/mem access.
*/
-#define xlate_dev_kmem_ptr(p) __va(p)
#define xlate_dev_mem_ptr(p) __va(p)
/*
diff --git a/arch/ia64/include/asm/io.h b/arch/ia64/include/asm/io.h
index 3d666a11a2de..6d93b923b379 100644
--- a/arch/ia64/include/asm/io.h
+++ b/arch/ia64/include/asm/io.h
@@ -277,7 +277,6 @@ extern void memset_io(volatile void __iomem *s, int c, long n);
#define memcpy_fromio memcpy_fromio
#define memcpy_toio memcpy_toio
#define memset_io memset_io
-#define xlate_dev_kmem_ptr xlate_dev_kmem_ptr
#define xlate_dev_mem_ptr xlate_dev_mem_ptr
#include <asm-generic/io.h>
#undef PCI_IOBASE
diff --git a/arch/ia64/include/asm/uaccess.h b/arch/ia64/include/asm/uaccess.h
index 179243c3dfc7..e19d2dcc0ced 100644
--- a/arch/ia64/include/asm/uaccess.h
+++ b/arch/ia64/include/asm/uaccess.h
@@ -272,22 +272,4 @@ xlate_dev_mem_ptr(phys_addr_t p)
return ptr;
}
-/*
- * Convert a virtual cached kernel memory pointer to an uncached pointer
- */
-static __inline__ void *
-xlate_dev_kmem_ptr(void *p)
-{
- struct page *page;
- void *ptr;
-
- page = virt_to_page((unsigned long)p);
- if (PageUncached(page))
- ptr = (void *)__pa(p) + __IA64_UNCACHED_OFFSET;
- else
- ptr = p;
-
- return ptr;
-}
-
#endif /* _ASM_IA64_UACCESS_H */
diff --git a/arch/m68k/include/asm/io_mm.h b/arch/m68k/include/asm/io_mm.h
index 819f611dccf2..d41fa488453b 100644
--- a/arch/m68k/include/asm/io_mm.h
+++ b/arch/m68k/include/asm/io_mm.h
@@ -397,11 +397,6 @@ static inline void isa_delay(void)
*/
#define xlate_dev_mem_ptr(p) __va(p)
-/*
- * Convert a virtual cached pointer to an uncached pointer
- */
-#define xlate_dev_kmem_ptr(p) p
-
#define readb_relaxed(addr) readb(addr)
#define readw_relaxed(addr) readw(addr)
#define readl_relaxed(addr) readl(addr)
diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index 78537aa23500..e6373e7ac892 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -552,11 +552,6 @@ extern void (*_dma_cache_inv)(unsigned long start, unsigned long size);
*/
#define xlate_dev_mem_ptr(p) __va(p)
-/*
- * Convert a virtual cached pointer to an uncached pointer
- */
-#define xlate_dev_kmem_ptr(p) p
-
void __ioread64_copy(void *to, const void __iomem *from, size_t count);
#endif /* _ASM_IO_H */
diff --git a/arch/parisc/include/asm/io.h b/arch/parisc/include/asm/io.h
index 8a11b8cf4719..0b5259102319 100644
--- a/arch/parisc/include/asm/io.h
+++ b/arch/parisc/include/asm/io.h
@@ -316,11 +316,6 @@ extern void iowrite64be(u64 val, void __iomem *addr);
*/
#define xlate_dev_mem_ptr(p) __va(p)
-/*
- * Convert a virtual cached pointer to an uncached pointer
- */
-#define xlate_dev_kmem_ptr(p) p
-
extern int devmem_is_allowed(unsigned long pfn);
#endif
diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
index 273edd208ec5..f130783c8301 100644
--- a/arch/powerpc/include/asm/io.h
+++ b/arch/powerpc/include/asm/io.h
@@ -662,11 +662,6 @@ static inline void name at \
*/
#define xlate_dev_mem_ptr(p) __va(p)
-/*
- * Convert a virtual cached pointer to an uncached pointer
- */
-#define xlate_dev_kmem_ptr(p) p
-
/*
* We don't do relaxed operations yet, at least not with this semantic
*/
diff --git a/arch/s390/include/asm/io.h b/arch/s390/include/asm/io.h
index 28664ee0abc1..e3882b012bfa 100644
--- a/arch/s390/include/asm/io.h
+++ b/arch/s390/include/asm/io.h
@@ -20,11 +20,6 @@ void *xlate_dev_mem_ptr(phys_addr_t phys);
#define unxlate_dev_mem_ptr unxlate_dev_mem_ptr
void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr);
-/*
- * Convert a virtual cached pointer to an uncached pointer
- */
-#define xlate_dev_kmem_ptr(p) p
-
#define IO_SPACE_LIMIT 0
void __iomem *ioremap_prot(phys_addr_t addr, size_t size, unsigned long prot);
diff --git a/arch/sh/include/asm/io.h b/arch/sh/include/asm/io.h
index 6d5c6463bc07..cf9a3ec32406 100644
--- a/arch/sh/include/asm/io.h
+++ b/arch/sh/include/asm/io.h
@@ -283,11 +283,6 @@ static inline void __iomem *ioremap_prot(phys_addr_t offset, unsigned long size,
*/
#define xlate_dev_mem_ptr(p) __va(p)
-/*
- * Convert a virtual cached pointer to an uncached pointer
- */
-#define xlate_dev_kmem_ptr(p) p
-
#define ARCH_HAS_VALID_PHYS_ADDR_RANGE
int valid_phys_addr_range(phys_addr_t addr, size_t size);
int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
diff --git a/arch/sparc/include/asm/io_64.h b/arch/sparc/include/asm/io_64.h
index 9bb27e5c22f1..ff6fe387d78c 100644
--- a/arch/sparc/include/asm/io_64.h
+++ b/arch/sparc/include/asm/io_64.h
@@ -450,11 +450,6 @@ void sbus_set_sbus64(struct device *, int);
*/
#define xlate_dev_mem_ptr(p) __va(p)
-/*
- * Convert a virtual cached pointer to an uncached pointer
- */
-#define xlate_dev_kmem_ptr(p) p
-
#endif
#endif /* !(__SPARC64_IO_H) */
diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index c6af40ce03be..33d4746b086f 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -1045,17 +1045,6 @@ static inline void pci_iounmap(struct pci_dev *dev, void __iomem *p)
#endif
#endif /* CONFIG_GENERIC_IOMAP */
-/*
- * Convert a virtual cached pointer to an uncached pointer
- */
-#ifndef xlate_dev_kmem_ptr
-#define xlate_dev_kmem_ptr xlate_dev_kmem_ptr
-static inline void *xlate_dev_kmem_ptr(void *addr)
-{
- return addr;
-}
-#endif
-
#ifndef xlate_dev_mem_ptr
#define xlate_dev_mem_ptr xlate_dev_mem_ptr
static inline void *xlate_dev_mem_ptr(phys_addr_t addr)
--
2.29.2
^ permalink raw reply related
* [PATCH v11 0/6] KASAN for powerpc64 radix
From: Daniel Axtens @ 2021-03-19 14:40 UTC (permalink / raw)
To: linux-kernel, linux-mm, linuxppc-dev, kasan-dev, christophe.leroy,
aneesh.kumar, bsingharora
Cc: Daniel Axtens
Building on the work of Christophe, Aneesh and Balbir, I've ported
KASAN to 64-bit Book3S kernels running on the Radix MMU.
v11 applies to next-20210317. I had hoped to have it apply to
powerpc/next but once again there are changes in the kasan core that
clash. Also, thanks to mpe for fixing a build break with KASAN off.
I'm not sure how best to progress this towards actually being merged
when it has impacts across subsystems. I'd appreciate any input. Maybe
the first four patches could go in via the kasan tree, that should
make things easier for powerpc in a future cycle?
v10 rebases on top of next-20210125, fixing things up to work on top
of the latest changes, and fixing some review comments from
Christophe. I have tested host and guest with 64k pages for this spin.
There is now only 1 failing KUnit test: kasan_global_oob - gcc puts
the ASAN init code in a section called '.init_array'. Powerpc64 module
loading code goes through and _renames_ any section beginning with
'.init' to begin with '_init' in order to avoid some complexities
around our 24-bit indirect jumps. This means it renames '.init_array'
to '_init_array', and the generic module loading code then fails to
recognise the section as a constructor and thus doesn't run it. This
hack dates back to 2003 and so I'm not going to try to unpick it in
this series. (I suspect this may have previously worked if the code
ended up in .ctors rather than .init_array but I don't keep my old
binaries around so I have no real way of checking.)
(The previously failing stack tests are now skipped due to more
accurate configuration settings.)
Details from v9: This is a significant reworking of the previous
versions. Instead of the previous approach which supported inline
instrumentation, this series provides only outline instrumentation.
To get around the problem of accessing the shadow region inside code we run
with translations off (in 'real mode'), we we restrict checking to when
translations are enabled. This is done via a new hook in the kasan core and
by excluding larger quantites of arch code from instrumentation. The upside
is that we no longer require that you be able to specify the amount of
physically contiguous memory on the system at compile time. Hopefully this
is a better trade-off. More details in patch 6.
kexec works. Both 64k and 4k pages work. Running as a KVM host works, but
nothing in arch/powerpc/kvm is instrumented. It's also potentially a bit
fragile - if any real mode code paths call out to instrumented code, things
will go boom.
Kind regards,
Daniel
Daniel Axtens (6):
kasan: allow an architecture to disable inline instrumentation
kasan: allow architectures to provide an outline readiness check
kasan: define and use MAX_PTRS_PER_* for early shadow tables
kasan: Document support on 32-bit powerpc
powerpc/mm/kasan: rename kasan_init_32.c to init_32.c
powerpc: Book3S 64-bit outline-only KASAN support
^ permalink raw reply
* [PATCH v11 1/6] kasan: allow an architecture to disable inline instrumentation
From: Daniel Axtens @ 2021-03-19 14:40 UTC (permalink / raw)
To: linux-kernel, linux-mm, linuxppc-dev, kasan-dev, christophe.leroy,
aneesh.kumar, bsingharora
Cc: Daniel Axtens
In-Reply-To: <20210319144058.772525-1-dja@axtens.net>
For annoying architectural reasons, it's very difficult to support inline
instrumentation on powerpc64.
Add a Kconfig flag to allow an arch to disable inline. (It's a bit
annoying to be 'backwards', but I'm not aware of any way to have
an arch force a symbol to be 'n', rather than 'y'.)
We also disable stack instrumentation in this case as it does things that
are functionally equivalent to inline instrumentation, namely adding
code that touches the shadow directly without going through a C helper.
Signed-off-by: Daniel Axtens <dja@axtens.net>
---
lib/Kconfig.kasan | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
index cffc2ebbf185..7e237dbb6df3 100644
--- a/lib/Kconfig.kasan
+++ b/lib/Kconfig.kasan
@@ -12,6 +12,9 @@ config HAVE_ARCH_KASAN_HW_TAGS
config HAVE_ARCH_KASAN_VMALLOC
bool
+config ARCH_DISABLE_KASAN_INLINE
+ def_bool n
+
config CC_HAS_KASAN_GENERIC
def_bool $(cc-option, -fsanitize=kernel-address)
@@ -130,6 +133,7 @@ config KASAN_OUTLINE
config KASAN_INLINE
bool "Inline instrumentation"
+ depends on !ARCH_DISABLE_KASAN_INLINE
help
Compiler directly inserts code checking shadow memory before
memory accesses. This is faster than outline (in some workloads
@@ -142,6 +146,7 @@ config KASAN_STACK
bool "Enable stack instrumentation (unsafe)" if CC_IS_CLANG && !COMPILE_TEST
depends on KASAN_GENERIC || KASAN_SW_TAGS
default y if CC_IS_GCC
+ depends on !ARCH_DISABLE_KASAN_INLINE
help
The LLVM stack address sanitizer has a know problem that
causes excessive stack usage in a lot of functions, see
@@ -154,6 +159,9 @@ config KASAN_STACK
but clang users can still enable it for builds without
CONFIG_COMPILE_TEST. On gcc it is assumed to always be safe
to use and enabled by default.
+ If the architecture disables inline instrumentation, this is
+ also disabled as it adds inline-style instrumentation that
+ is run unconditionally.
config KASAN_SW_TAGS_IDENTIFY
bool "Enable memory corruption identification"
--
2.27.0
^ permalink raw reply related
* [PATCH v11 2/6] kasan: allow architectures to provide an outline readiness check
From: Daniel Axtens @ 2021-03-19 14:40 UTC (permalink / raw)
To: linux-kernel, linux-mm, linuxppc-dev, kasan-dev, christophe.leroy,
aneesh.kumar, bsingharora
Cc: Aneesh Kumar K . V, Daniel Axtens
In-Reply-To: <20210319144058.772525-1-dja@axtens.net>
Allow architectures to define a kasan_arch_is_ready() hook that bails
out of any function that's about to touch the shadow unless the arch
says that it is ready for the memory to be accessed. This is fairly
uninvasive and should have a negligible performance penalty.
This will only work in outline mode, so an arch must specify
ARCH_DISABLE_KASAN_INLINE if it requires this.
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Daniel Axtens <dja@axtens.net>
--
I discuss the justfication for this later in the series. Also,
both previous RFCs for ppc64 - by 2 different people - have
needed this trick! See:
- https://lore.kernel.org/patchwork/patch/592820/ # ppc64 hash series
- https://patchwork.ozlabs.org/patch/795211/ # ppc radix series
---
include/linux/kasan.h | 4 ++++
mm/kasan/common.c | 4 ++++
mm/kasan/generic.c | 3 +++
mm/kasan/shadow.c | 4 ++++
4 files changed, 15 insertions(+)
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 8b3b99d659b7..6bd8343f0033 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -23,6 +23,10 @@ struct kunit_kasan_expectation {
#endif
+#ifndef kasan_arch_is_ready
+static inline bool kasan_arch_is_ready(void) { return true; }
+#endif
+
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
#include <linux/pgtable.h>
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 6bb87f2acd4e..f23a9e2dce9f 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -345,6 +345,10 @@ static inline bool ____kasan_slab_free(struct kmem_cache *cache, void *object,
if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU))
return false;
+ /* We can't read the shadow byte if the arch isn't ready */
+ if (!kasan_arch_is_ready())
+ return false;
+
if (!kasan_byte_accessible(tagged_object)) {
kasan_report_invalid_free(tagged_object, ip);
return true;
diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 53cbf28859b5..c3f5ba7a294a 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -163,6 +163,9 @@ static __always_inline bool check_region_inline(unsigned long addr,
size_t size, bool write,
unsigned long ret_ip)
{
+ if (!kasan_arch_is_ready())
+ return true;
+
if (unlikely(size == 0))
return true;
diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
index 727ad4629173..1f650c521037 100644
--- a/mm/kasan/shadow.c
+++ b/mm/kasan/shadow.c
@@ -80,6 +80,10 @@ void kasan_poison(const void *addr, size_t size, u8 value, bool init)
*/
addr = kasan_reset_tag(addr);
+ /* Don't touch the shadow memory if arch isn't ready */
+ if (!kasan_arch_is_ready())
+ return;
+
/* Skip KFENCE memory if called explicitly outside of sl*b. */
if (is_kfence_address(addr))
return;
--
2.27.0
^ permalink raw reply related
* [PATCH v11 3/6] kasan: define and use MAX_PTRS_PER_* for early shadow tables
From: Daniel Axtens @ 2021-03-19 14:40 UTC (permalink / raw)
To: linux-kernel, linux-mm, linuxppc-dev, kasan-dev, christophe.leroy,
aneesh.kumar, bsingharora
Cc: Daniel Axtens
In-Reply-To: <20210319144058.772525-1-dja@axtens.net>
powerpc has a variable number of PTRS_PER_*, set at runtime based
on the MMU that the kernel is booted under.
This means the PTRS_PER_* are no longer constants, and therefore
breaks the build.
Define default MAX_PTRS_PER_*s in the same style as MAX_PTRS_PER_P4D.
As KASAN is the only user at the moment, just define them in the kasan
header, and have them default to PTRS_PER_* unless overridden in arch
code.
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Suggested-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
---
include/linux/kasan.h | 18 +++++++++++++++---
mm/kasan/init.c | 6 +++---
2 files changed, 18 insertions(+), 6 deletions(-)
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 6bd8343f0033..68cd6e55c872 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -44,10 +44,22 @@ static inline bool kasan_arch_is_ready(void) { return true; }
#define PTE_HWTABLE_PTRS 0
#endif
+#ifndef MAX_PTRS_PER_PTE
+#define MAX_PTRS_PER_PTE PTRS_PER_PTE
+#endif
+
+#ifndef MAX_PTRS_PER_PMD
+#define MAX_PTRS_PER_PMD PTRS_PER_PMD
+#endif
+
+#ifndef MAX_PTRS_PER_PUD
+#define MAX_PTRS_PER_PUD PTRS_PER_PUD
+#endif
+
extern unsigned char kasan_early_shadow_page[PAGE_SIZE];
-extern pte_t kasan_early_shadow_pte[PTRS_PER_PTE + PTE_HWTABLE_PTRS];
-extern pmd_t kasan_early_shadow_pmd[PTRS_PER_PMD];
-extern pud_t kasan_early_shadow_pud[PTRS_PER_PUD];
+extern pte_t kasan_early_shadow_pte[MAX_PTRS_PER_PTE + PTE_HWTABLE_PTRS];
+extern pmd_t kasan_early_shadow_pmd[MAX_PTRS_PER_PMD];
+extern pud_t kasan_early_shadow_pud[MAX_PTRS_PER_PUD];
extern p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D];
int kasan_populate_early_shadow(const void *shadow_start,
diff --git a/mm/kasan/init.c b/mm/kasan/init.c
index c4605ac9837b..b4d822dff1fb 100644
--- a/mm/kasan/init.c
+++ b/mm/kasan/init.c
@@ -41,7 +41,7 @@ static inline bool kasan_p4d_table(pgd_t pgd)
}
#endif
#if CONFIG_PGTABLE_LEVELS > 3
-pud_t kasan_early_shadow_pud[PTRS_PER_PUD] __page_aligned_bss;
+pud_t kasan_early_shadow_pud[MAX_PTRS_PER_PUD] __page_aligned_bss;
static inline bool kasan_pud_table(p4d_t p4d)
{
return p4d_page(p4d) == virt_to_page(lm_alias(kasan_early_shadow_pud));
@@ -53,7 +53,7 @@ static inline bool kasan_pud_table(p4d_t p4d)
}
#endif
#if CONFIG_PGTABLE_LEVELS > 2
-pmd_t kasan_early_shadow_pmd[PTRS_PER_PMD] __page_aligned_bss;
+pmd_t kasan_early_shadow_pmd[MAX_PTRS_PER_PMD] __page_aligned_bss;
static inline bool kasan_pmd_table(pud_t pud)
{
return pud_page(pud) == virt_to_page(lm_alias(kasan_early_shadow_pmd));
@@ -64,7 +64,7 @@ static inline bool kasan_pmd_table(pud_t pud)
return false;
}
#endif
-pte_t kasan_early_shadow_pte[PTRS_PER_PTE + PTE_HWTABLE_PTRS]
+pte_t kasan_early_shadow_pte[MAX_PTRS_PER_PTE + PTE_HWTABLE_PTRS]
__page_aligned_bss;
static inline bool kasan_pte_table(pmd_t pmd)
--
2.27.0
^ permalink raw reply related
* [PATCH v11 4/6] kasan: Document support on 32-bit powerpc
From: Daniel Axtens @ 2021-03-19 14:40 UTC (permalink / raw)
To: linux-kernel, linux-mm, linuxppc-dev, kasan-dev, christophe.leroy,
aneesh.kumar, bsingharora
Cc: Daniel Axtens
In-Reply-To: <20210319144058.772525-1-dja@axtens.net>
KASAN is supported on 32-bit powerpc and the docs should reflect this.
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Daniel Axtens <dja@axtens.net>
---
Documentation/dev-tools/kasan.rst | 8 ++++++--
Documentation/powerpc/kasan.txt | 12 ++++++++++++
2 files changed, 18 insertions(+), 2 deletions(-)
create mode 100644 Documentation/powerpc/kasan.txt
diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
index a8c3e0cff88d..2cfd5d9068c0 100644
--- a/Documentation/dev-tools/kasan.rst
+++ b/Documentation/dev-tools/kasan.rst
@@ -36,7 +36,8 @@ Both software KASAN modes work with SLUB and SLAB memory allocators,
while the hardware tag-based KASAN currently only supports SLUB.
Currently, generic KASAN is supported for the x86_64, arm, arm64, xtensa, s390,
-and riscv architectures, and tag-based KASAN modes are supported only for arm64.
+and riscv architectures. It is also supported on 32-bit powerpc kernels.
+Tag-based KASAN modes are supported only for arm64.
Usage
-----
@@ -334,7 +335,10 @@ CONFIG_KASAN_VMALLOC
With ``CONFIG_KASAN_VMALLOC``, KASAN can cover vmalloc space at the
cost of greater memory usage. Currently, this is supported on x86,
-riscv, s390, and powerpc.
+riscv, s390, and 32-bit powerpc.
+
+It is optional, except on 32-bit powerpc kernels with module support,
+where it is required.
This works by hooking into vmalloc and vmap and dynamically
allocating real shadow memory to back the mappings.
diff --git a/Documentation/powerpc/kasan.txt b/Documentation/powerpc/kasan.txt
new file mode 100644
index 000000000000..26bb0e8bb18c
--- /dev/null
+++ b/Documentation/powerpc/kasan.txt
@@ -0,0 +1,12 @@
+KASAN is supported on powerpc on 32-bit only.
+
+32 bit support
+==============
+
+KASAN is supported on both hash and nohash MMUs on 32-bit.
+
+The shadow area sits at the top of the kernel virtual memory space above the
+fixmap area and occupies one eighth of the total kernel virtual memory space.
+
+Instrumentation of the vmalloc area is optional, unless built with modules,
+in which case it is required.
--
2.27.0
^ permalink raw reply related
* [PATCH v11 5/6] powerpc/mm/kasan: rename kasan_init_32.c to init_32.c
From: Daniel Axtens @ 2021-03-19 14:40 UTC (permalink / raw)
To: linux-kernel, linux-mm, linuxppc-dev, kasan-dev, christophe.leroy,
aneesh.kumar, bsingharora
Cc: Daniel Axtens
In-Reply-To: <20210319144058.772525-1-dja@axtens.net>
kasan is already implied by the directory name, we don't need to
repeat it.
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Daniel Axtens <dja@axtens.net>
---
arch/powerpc/mm/kasan/Makefile | 2 +-
arch/powerpc/mm/kasan/{kasan_init_32.c => init_32.c} | 0
2 files changed, 1 insertion(+), 1 deletion(-)
rename arch/powerpc/mm/kasan/{kasan_init_32.c => init_32.c} (100%)
diff --git a/arch/powerpc/mm/kasan/Makefile b/arch/powerpc/mm/kasan/Makefile
index bb1a5408b86b..42fb628a44fd 100644
--- a/arch/powerpc/mm/kasan/Makefile
+++ b/arch/powerpc/mm/kasan/Makefile
@@ -2,6 +2,6 @@
KASAN_SANITIZE := n
-obj-$(CONFIG_PPC32) += kasan_init_32.o
+obj-$(CONFIG_PPC32) += init_32.o
obj-$(CONFIG_PPC_8xx) += 8xx.o
obj-$(CONFIG_PPC_BOOK3S_32) += book3s_32.o
diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c b/arch/powerpc/mm/kasan/init_32.c
similarity index 100%
rename from arch/powerpc/mm/kasan/kasan_init_32.c
rename to arch/powerpc/mm/kasan/init_32.c
--
2.27.0
^ permalink raw reply related
* [PATCH v11 6/6] powerpc: Book3S 64-bit outline-only KASAN support
From: Daniel Axtens @ 2021-03-19 14:40 UTC (permalink / raw)
To: linux-kernel, linux-mm, linuxppc-dev, kasan-dev, christophe.leroy,
aneesh.kumar, bsingharora
Cc: Daniel Axtens
In-Reply-To: <20210319144058.772525-1-dja@axtens.net>
Implement a limited form of KASAN for Book3S 64-bit machines running under
the Radix MMU, supporting only outline mode.
- Enable the compiler instrumentation to check addresses and maintain the
shadow region. (This is the guts of KASAN which we can easily reuse.)
- Require kasan-vmalloc support to handle modules and anything else in
vmalloc space.
- KASAN needs to be able to validate all pointer accesses, but we can't
instrument all kernel addresses - only linear map and vmalloc. On boot,
set up a single page of read-only shadow that marks all iomap and
vmemmap accesses as valid.
- Make our stack-walking code KASAN-safe by using READ_ONCE_NOCHECK -
generic code, arm64, s390 and x86 all do this for similar sorts of
reasons: when unwinding a stack, we might touch memory that KASAN has
marked as being out-of-bounds. In our case we often get this when
checking for an exception frame because we're checking an arbitrary
offset into the stack frame.
See commit 20955746320e ("s390/kasan: avoid false positives during stack
unwind"), commit bcaf669b4bdb ("arm64: disable kasan when accessing
frame->fp in unwind_frame"), commit 91e08ab0c851 ("x86/dumpstack:
Prevent KASAN false positive warnings") and commit 6e22c8366416
("tracing, kasan: Silence Kasan warning in check_stack of stack_tracer")
- Document KASAN in both generic and powerpc docs.
Background
----------
KASAN support on Book3S is a bit tricky to get right:
- It would be good to support inline instrumentation so as to be able to
catch stack issues that cannot be caught with outline mode.
- Inline instrumentation requires a fixed offset.
- Book3S runs code with translations off ("real mode") during boot,
including a lot of generic device-tree parsing code which is used to
determine MMU features.
[ppc64 mm note: The kernel installs a linear mapping at effective
address c000...-c008.... This is a one-to-one mapping with physical
memory from 0000... onward. Because of how memory accesses work on
powerpc 64-bit Book3S, a kernel pointer in the linear map accesses the
same memory both with translations on (accessing as an 'effective
address'), and with translations off (accessing as a 'real
address'). This works in both guests and the hypervisor. For more
details, see s5.7 of Book III of version 3 of the ISA, in particular
the Storage Control Overview, s5.7.3, and s5.7.5 - noting that this
KASAN implementation currently only supports Radix.]
- Some code - most notably a lot of KVM code - also runs with translations
off after boot.
- Therefore any offset has to point to memory that is valid with
translations on or off.
One approach is just to give up on inline instrumentation. This way
boot-time checks can be delayed until after the MMU is set is up, and we
can just not instrument any code that runs with translations off after
booting. Take this approach for now and require outline instrumentation.
Previous attempts allowed inline instrumentation. However, they came with
some unfortunate restrictions: only physically contiguous memory could be
used and it had to be specified at compile time. Maybe we can do better in
the future.
Cc: Balbir Singh <bsingharora@gmail.com> # ppc64 out-of-line radix version
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> # ppc64 hash version
Cc: Christophe Leroy <christophe.leroy@csgroup.eu> # ppc32 version
Signed-off-by: Daniel Axtens <dja@axtens.net>
---
Documentation/dev-tools/kasan.rst | 11 +--
Documentation/powerpc/kasan.txt | 48 +++++++++-
arch/powerpc/Kconfig | 4 +-
arch/powerpc/Kconfig.debug | 3 +-
arch/powerpc/include/asm/book3s/64/hash.h | 4 +
arch/powerpc/include/asm/book3s/64/pgtable.h | 4 +
arch/powerpc/include/asm/book3s/64/radix.h | 13 ++-
arch/powerpc/include/asm/kasan.h | 22 +++++
arch/powerpc/kernel/Makefile | 11 +++
arch/powerpc/kernel/process.c | 16 ++--
arch/powerpc/kvm/Makefile | 5 ++
arch/powerpc/mm/book3s64/Makefile | 9 ++
arch/powerpc/mm/kasan/Makefile | 1 +
arch/powerpc/mm/kasan/init_book3s_64.c | 95 ++++++++++++++++++++
arch/powerpc/mm/ptdump/ptdump.c | 20 ++++-
arch/powerpc/platforms/Kconfig.cputype | 1 +
arch/powerpc/platforms/powernv/Makefile | 6 ++
arch/powerpc/platforms/pseries/Makefile | 3 +
18 files changed, 257 insertions(+), 19 deletions(-)
create mode 100644 arch/powerpc/mm/kasan/init_book3s_64.c
diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
index 2cfd5d9068c0..8024b55c7aa8 100644
--- a/Documentation/dev-tools/kasan.rst
+++ b/Documentation/dev-tools/kasan.rst
@@ -36,8 +36,9 @@ Both software KASAN modes work with SLUB and SLAB memory allocators,
while the hardware tag-based KASAN currently only supports SLUB.
Currently, generic KASAN is supported for the x86_64, arm, arm64, xtensa, s390,
-and riscv architectures. It is also supported on 32-bit powerpc kernels.
-Tag-based KASAN modes are supported only for arm64.
+and riscv architectures. It is also supported on powerpc for 32-bit kernels and
+for 64-bit kernels running under the Radix MMU. Tag-based KASAN modes are
+supported only for arm64.
Usage
-----
@@ -335,10 +336,10 @@ CONFIG_KASAN_VMALLOC
With ``CONFIG_KASAN_VMALLOC``, KASAN can cover vmalloc space at the
cost of greater memory usage. Currently, this is supported on x86,
-riscv, s390, and 32-bit powerpc.
+riscv, s390, and powerpc.
-It is optional, except on 32-bit powerpc kernels with module support,
-where it is required.
+It is optional, except on 64-bit powerpc kernels, and on 32-bit
+powerpc kernels with module support, where it is required.
This works by hooking into vmalloc and vmap and dynamically
allocating real shadow memory to back the mappings.
diff --git a/Documentation/powerpc/kasan.txt b/Documentation/powerpc/kasan.txt
index 26bb0e8bb18c..f032b4eaf205 100644
--- a/Documentation/powerpc/kasan.txt
+++ b/Documentation/powerpc/kasan.txt
@@ -1,4 +1,4 @@
-KASAN is supported on powerpc on 32-bit only.
+KASAN is supported on powerpc on 32-bit and Radix 64-bit only.
32 bit support
==============
@@ -10,3 +10,49 @@ fixmap area and occupies one eighth of the total kernel virtual memory space.
Instrumentation of the vmalloc area is optional, unless built with modules,
in which case it is required.
+
+64 bit support
+==============
+
+Currently, only the radix MMU is supported. There have been versions for hash
+and Book3E processors floating around on the mailing list, but nothing has been
+merged.
+
+KASAN support on Book3S is a bit tricky to get right:
+
+ - It would be good to support inline instrumentation so as to be able to catch
+ stack issues that cannot be caught with outline mode.
+
+ - Inline instrumentation requires a fixed offset.
+
+ - Book3S runs code with translations off ("real mode") during boot, including a
+ lot of generic device-tree parsing code which is used to determine MMU
+ features.
+
+ - Some code - most notably a lot of KVM code - also runs with translations off
+ after boot.
+
+ - Therefore any offset has to point to memory that is valid with
+ translations on or off.
+
+One approach is just to give up on inline instrumentation. This way boot-time
+checks can be delayed until after the MMU is set is up, and we can just not
+instrument any code that runs with translations off after booting. This is the
+current approach.
+
+To avoid this limitiation, the KASAN shadow would have to be placed inside the
+linear mapping, using the same high-bits trick we use for the rest of the linear
+mapping. This is tricky:
+
+ - We'd like to place it near the start of physical memory. In theory we can do
+ this at run-time based on how much physical memory we have, but this requires
+ being able to arbitrarily relocate the kernel, which is basically the tricky
+ part of KASLR. Not being game to implement both tricky things at once, this
+ is hopefully something we can revisit once we get KASLR for Book3S.
+
+ - Alternatively, we can place the shadow at the _end_ of memory, but this
+ requires knowing how much contiguous physical memory a system has _at compile
+ time_. This is a big hammer, and has some unfortunate consequences: inablity
+ to handle discontiguous physical memory, total failure to boot on machines
+ with less memory than specified, and that machines with more memory than
+ specified can't use it. This was deemed unacceptable.
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 4232d3f539c8..04aa817d1c5a 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -118,6 +118,7 @@ config PPC
# Please keep this list sorted alphabetically.
#
select ARCH_32BIT_OFF_T if PPC32
+ select ARCH_DISABLE_KASAN_INLINE if PPC_RADIX_MMU
select ARCH_HAS_DEBUG_VIRTUAL
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ELF_RANDOMIZE
@@ -183,7 +184,8 @@ config PPC
select HAVE_ARCH_HUGE_VMAP if PPC_BOOK3S_64 && PPC_RADIX_MMU
select HAVE_ARCH_JUMP_LABEL
select HAVE_ARCH_KASAN if PPC32 && PPC_PAGE_SHIFT <= 14
- select HAVE_ARCH_KASAN_VMALLOC if PPC32 && PPC_PAGE_SHIFT <= 14
+ select HAVE_ARCH_KASAN if PPC_RADIX_MMU
+ select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN
select HAVE_ARCH_KGDB
select HAVE_ARCH_MMAP_RND_BITS
select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index ae084357994e..195f7845f41a 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -398,4 +398,5 @@ config PPC_FAST_ENDIAN_SWITCH
config KASAN_SHADOW_OFFSET
hex
depends on KASAN
- default 0xe0000000
+ default 0xe0000000 if PPC32
+ default 0xa80e000000000000 if PPC64
diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
index d959b0195ad9..222669864ff6 100644
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h
@@ -18,6 +18,10 @@
#include <asm/book3s/64/hash-4k.h>
#endif
+#define H_PTRS_PER_PTE (1 << H_PTE_INDEX_SIZE)
+#define H_PTRS_PER_PMD (1 << H_PMD_INDEX_SIZE)
+#define H_PTRS_PER_PUD (1 << H_PUD_INDEX_SIZE)
+
/* Bits to set in a PMD/PUD/PGD entry valid bit*/
#define HASH_PMD_VAL_BITS (0x8000000000000000UL)
#define HASH_PUD_VAL_BITS (0x8000000000000000UL)
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 058601efbc8a..7598a5b055bd 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -230,6 +230,10 @@ extern unsigned long __pmd_frag_size_shift;
#define PTRS_PER_PUD (1 << PUD_INDEX_SIZE)
#define PTRS_PER_PGD (1 << PGD_INDEX_SIZE)
+#define MAX_PTRS_PER_PTE ((H_PTRS_PER_PTE > R_PTRS_PER_PTE) ? H_PTRS_PER_PTE : R_PTRS_PER_PTE)
+#define MAX_PTRS_PER_PMD ((H_PTRS_PER_PMD > R_PTRS_PER_PMD) ? H_PTRS_PER_PMD : R_PTRS_PER_PMD)
+#define MAX_PTRS_PER_PUD ((H_PTRS_PER_PUD > R_PTRS_PER_PUD) ? H_PTRS_PER_PUD : R_PTRS_PER_PUD)
+
/* PMD_SHIFT determines what a second-level page table entry can map */
#define PMD_SHIFT (PAGE_SHIFT + PTE_INDEX_SIZE)
#define PMD_SIZE (1UL << PMD_SHIFT)
diff --git a/arch/powerpc/include/asm/book3s/64/radix.h b/arch/powerpc/include/asm/book3s/64/radix.h
index c7813dc628fc..b3492b80f858 100644
--- a/arch/powerpc/include/asm/book3s/64/radix.h
+++ b/arch/powerpc/include/asm/book3s/64/radix.h
@@ -35,6 +35,11 @@
#define RADIX_PMD_SHIFT (PAGE_SHIFT + RADIX_PTE_INDEX_SIZE)
#define RADIX_PUD_SHIFT (RADIX_PMD_SHIFT + RADIX_PMD_INDEX_SIZE)
#define RADIX_PGD_SHIFT (RADIX_PUD_SHIFT + RADIX_PUD_INDEX_SIZE)
+
+#define R_PTRS_PER_PTE (1 << RADIX_PTE_INDEX_SIZE)
+#define R_PTRS_PER_PMD (1 << RADIX_PMD_INDEX_SIZE)
+#define R_PTRS_PER_PUD (1 << RADIX_PUD_INDEX_SIZE)
+
/*
* Size of EA range mapped by our pagetables.
*/
@@ -68,11 +73,11 @@
*
*
* 3rd quadrant expanded:
- * +------------------------------+
+ * +------------------------------+ Highest address (0xc010000000000000)
+ * +------------------------------+ KASAN shadow end (0xc00fc00000000000)
* | |
* | |
- * | |
- * +------------------------------+ Kernel vmemmap end (0xc010000000000000)
+ * +------------------------------+ Kernel vmemmap end/shadow start (0xc00e000000000000)
* | |
* | 512TB |
* | |
@@ -126,6 +131,8 @@
#define RADIX_VMEMMAP_SIZE RADIX_KERN_MAP_SIZE
#define RADIX_VMEMMAP_END (RADIX_VMEMMAP_START + RADIX_VMEMMAP_SIZE)
+/* For the sizes of the shadow area, see kasan.h */
+
#ifndef __ASSEMBLY__
#define RADIX_PTE_TABLE_SIZE (sizeof(pte_t) << RADIX_PTE_INDEX_SIZE)
#define RADIX_PMD_TABLE_SIZE (sizeof(pmd_t) << RADIX_PMD_INDEX_SIZE)
diff --git a/arch/powerpc/include/asm/kasan.h b/arch/powerpc/include/asm/kasan.h
index 7355ed05e65e..df946165812d 100644
--- a/arch/powerpc/include/asm/kasan.h
+++ b/arch/powerpc/include/asm/kasan.h
@@ -30,9 +30,31 @@
#define KASAN_SHADOW_OFFSET ASM_CONST(CONFIG_KASAN_SHADOW_OFFSET)
+#ifdef CONFIG_PPC32
#define KASAN_SHADOW_END (-(-KASAN_SHADOW_START >> KASAN_SHADOW_SCALE_SHIFT))
+#endif
#ifdef CONFIG_KASAN
+#ifdef CONFIG_PPC_BOOK3S_64
+/*
+ * The shadow ends before the highest accessible address
+ * because we don't need a shadow for the shadow. Instead:
+ * c00e000000000000 << 3 + a80e000000000000000 = c00fc00000000000
+ */
+#define KASAN_SHADOW_END 0xc00fc00000000000UL
+
+DECLARE_STATIC_KEY_FALSE(powerpc_kasan_enabled_key);
+
+static __always_inline bool kasan_arch_is_ready(void)
+{
+ if (static_branch_likely(&powerpc_kasan_enabled_key))
+ return true;
+ return false;
+}
+
+#define kasan_arch_is_ready kasan_arch_is_ready
+#endif
+
void kasan_early_init(void);
void kasan_mmu_init(void);
void kasan_init(void);
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 6084fa499aa3..163755b1cef4 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -32,6 +32,17 @@ KASAN_SANITIZE_early_32.o := n
KASAN_SANITIZE_cputable.o := n
KASAN_SANITIZE_prom_init.o := n
KASAN_SANITIZE_btext.o := n
+KASAN_SANITIZE_paca.o := n
+KASAN_SANITIZE_setup_64.o := n
+KASAN_SANITIZE_mce.o := n
+KASAN_SANITIZE_mce_power.o := n
+
+# we have to be particularly careful in ppc64 to exclude code that
+# runs with translations off, as we cannot access the shadow with
+# translations off. However, ppc32 can sanitize this.
+ifdef CONFIG_PPC64
+KASAN_SANITIZE_traps.o := n
+endif
ifdef CONFIG_KASAN
CFLAGS_early_32.o += -DDISABLE_BRANCH_PROFILING
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 3231c2df9e26..d4ae21b9e9b7 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -2160,8 +2160,8 @@ void show_stack(struct task_struct *tsk, unsigned long *stack,
break;
stack = (unsigned long *) sp;
- newsp = stack[0];
- ip = stack[STACK_FRAME_LR_SAVE];
+ newsp = READ_ONCE_NOCHECK(stack[0]);
+ ip = READ_ONCE_NOCHECK(stack[STACK_FRAME_LR_SAVE]);
if (!firstframe || ip != lr) {
printk("%s["REG"] ["REG"] %pS",
loglvl, sp, ip, (void *)ip);
@@ -2179,17 +2179,19 @@ void show_stack(struct task_struct *tsk, unsigned long *stack,
* See if this is an exception frame.
* We look for the "regshere" marker in the current frame.
*/
- if (validate_sp(sp, tsk, STACK_FRAME_WITH_PT_REGS)
- && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
+ if (validate_sp(sp, tsk, STACK_FRAME_WITH_PT_REGS) &&
+ (READ_ONCE_NOCHECK(stack[STACK_FRAME_MARKER]) ==
+ STACK_FRAME_REGS_MARKER)) {
struct pt_regs *regs = (struct pt_regs *)
(sp + STACK_FRAME_OVERHEAD);
- lr = regs->link;
+ lr = READ_ONCE_NOCHECK(regs->link);
printk("%s--- interrupt: %lx at %pS\n",
- loglvl, regs->trap, (void *)regs->nip);
+ loglvl, READ_ONCE_NOCHECK(regs->trap),
+ (void *)READ_ONCE_NOCHECK(regs->nip));
__show_regs(regs);
printk("%s--- interrupt: %lx\n",
- loglvl, regs->trap);
+ loglvl, READ_ONCE_NOCHECK(regs->trap));
firstframe = 1;
}
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 2bfeaa13befb..7f1592dacbeb 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -136,3 +136,8 @@ obj-$(CONFIG_KVM_BOOK3S_64_PR) += kvm-pr.o
obj-$(CONFIG_KVM_BOOK3S_64_HV) += kvm-hv.o
obj-y += $(kvm-book3s_64-builtin-objs-y)
+
+# KVM does a lot in real-mode, and 64-bit Book3S KASAN doesn't support that
+ifdef CONFIG_PPC_BOOK3S_64
+KASAN_SANITIZE := n
+endif
diff --git a/arch/powerpc/mm/book3s64/Makefile b/arch/powerpc/mm/book3s64/Makefile
index 1b56d3af47d4..a7d8a68bd2c5 100644
--- a/arch/powerpc/mm/book3s64/Makefile
+++ b/arch/powerpc/mm/book3s64/Makefile
@@ -21,3 +21,12 @@ obj-$(CONFIG_PPC_PKEY) += pkeys.o
# Instrumenting the SLB fault path can lead to duplicate SLB entries
KCOV_INSTRUMENT_slb.o := n
+
+# Parts of these can run in real mode and therefore are
+# not safe with the current outline KASAN implementation
+KASAN_SANITIZE_mmu_context.o := n
+KASAN_SANITIZE_pgtable.o := n
+KASAN_SANITIZE_radix_pgtable.o := n
+KASAN_SANITIZE_radix_tlb.o := n
+KASAN_SANITIZE_slb.o := n
+KASAN_SANITIZE_pkeys.o := n
diff --git a/arch/powerpc/mm/kasan/Makefile b/arch/powerpc/mm/kasan/Makefile
index 42fb628a44fd..07eef87abd6c 100644
--- a/arch/powerpc/mm/kasan/Makefile
+++ b/arch/powerpc/mm/kasan/Makefile
@@ -5,3 +5,4 @@ KASAN_SANITIZE := n
obj-$(CONFIG_PPC32) += init_32.o
obj-$(CONFIG_PPC_8xx) += 8xx.o
obj-$(CONFIG_PPC_BOOK3S_32) += book3s_32.o
+obj-$(CONFIG_PPC_BOOK3S_64) += init_book3s_64.o
diff --git a/arch/powerpc/mm/kasan/init_book3s_64.c b/arch/powerpc/mm/kasan/init_book3s_64.c
new file mode 100644
index 000000000000..ca913ed951a2
--- /dev/null
+++ b/arch/powerpc/mm/kasan/init_book3s_64.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KASAN for 64-bit Book3S powerpc
+ *
+ * Copyright (C) 2019-2020 IBM Corporation
+ * Author: Daniel Axtens <dja@axtens.net>
+ */
+
+#define DISABLE_BRANCH_PROFILING
+
+#include <linux/kasan.h>
+#include <linux/printk.h>
+#include <linux/sched/task.h>
+#include <linux/memblock.h>
+#include <asm/pgalloc.h>
+
+DEFINE_STATIC_KEY_FALSE(powerpc_kasan_enabled_key);
+
+static void __init kasan_init_phys_region(void *start, void *end)
+{
+ unsigned long k_start, k_end, k_cur;
+ void *va;
+
+ if (start >= end)
+ return;
+
+ k_start = ALIGN_DOWN((unsigned long)kasan_mem_to_shadow(start), PAGE_SIZE);
+ k_end = ALIGN((unsigned long)kasan_mem_to_shadow(end), PAGE_SIZE);
+
+ va = memblock_alloc(k_end - k_start, PAGE_SIZE);
+ for (k_cur = k_start; k_cur < k_end; k_cur += PAGE_SIZE, va += PAGE_SIZE)
+ map_kernel_page(k_cur, __pa(va), PAGE_KERNEL);
+}
+
+void __init kasan_init(void)
+{
+ /*
+ * We want to do the following things:
+ * 1) Map real memory into the shadow for all physical memblocks
+ * This takes us from c000... to c008...
+ * 2) Leave a hole over the shadow of vmalloc space. KASAN_VMALLOC
+ * will manage this for us.
+ * This takes us from c008... to c00a...
+ * 3) Map the 'early shadow'/zero page over iomap and vmemmap space.
+ * This takes us up to where we start at c00e...
+ */
+
+ void *k_start = kasan_mem_to_shadow((void *)RADIX_VMALLOC_END);
+ void *k_end = kasan_mem_to_shadow((void *)RADIX_VMEMMAP_END);
+ phys_addr_t start, end;
+ u64 i;
+ pte_t zero_pte = pfn_pte(virt_to_pfn(kasan_early_shadow_page), PAGE_KERNEL);
+
+ if (!early_radix_enabled())
+ panic("KASAN requires radix!");
+
+ for_each_mem_range(i, &start, &end)
+ kasan_init_phys_region((void *)start, (void *)end);
+
+ for (i = 0; i < PTRS_PER_PTE; i++)
+ __set_pte_at(&init_mm, (unsigned long)kasan_early_shadow_page,
+ &kasan_early_shadow_pte[i], zero_pte, 0);
+
+ for (i = 0; i < PTRS_PER_PMD; i++)
+ pmd_populate_kernel(&init_mm, &kasan_early_shadow_pmd[i],
+ kasan_early_shadow_pte);
+
+ for (i = 0; i < PTRS_PER_PUD; i++)
+ pud_populate(&init_mm, &kasan_early_shadow_pud[i],
+ kasan_early_shadow_pmd);
+
+ /* map the early shadow over the iomap and vmemmap space */
+ kasan_populate_early_shadow(k_start, k_end);
+
+ /* mark early shadow region as RO and wipe it */
+ zero_pte = pfn_pte(virt_to_pfn(kasan_early_shadow_page), PAGE_KERNEL_RO);
+ for (i = 0; i < PTRS_PER_PTE; i++)
+ __set_pte_at(&init_mm, (unsigned long)kasan_early_shadow_page,
+ &kasan_early_shadow_pte[i], zero_pte, 0);
+
+ /*
+ * clear_page relies on some cache info that hasn't been set up yet.
+ * It ends up looping ~forever and blows up other data.
+ * Use memset instead.
+ */
+ memset(kasan_early_shadow_page, 0, PAGE_SIZE);
+
+ static_branch_inc(&powerpc_kasan_enabled_key);
+
+ /* Enable error messages */
+ init_task.kasan_depth = 0;
+ pr_info("KASAN init done (64-bit Book3S)\n");
+}
+
+void __init kasan_late_init(void) { }
diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
index aca354fb670b..63672aa656e8 100644
--- a/arch/powerpc/mm/ptdump/ptdump.c
+++ b/arch/powerpc/mm/ptdump/ptdump.c
@@ -20,6 +20,7 @@
#include <linux/seq_file.h>
#include <asm/fixmap.h>
#include <linux/const.h>
+#include <linux/kasan.h>
#include <asm/page.h>
#include <asm/hugetlb.h>
@@ -317,6 +318,23 @@ static void walk_pud(struct pg_state *st, p4d_t *p4d, unsigned long start)
unsigned long addr;
unsigned int i;
+#if defined(CONFIG_KASAN) && defined(CONFIG_PPC_BOOK3S_64)
+ /*
+ * On radix + KASAN, we want to check for the KASAN "early" shadow
+ * which covers huge quantities of memory with the same set of
+ * read-only PTEs. If it is, we want to note the first page (to see
+ * the status change), and then note the last page. This gives us good
+ * results without spending ages noting the exact same PTEs over 100s of
+ * terabytes of memory.
+ */
+ if (p4d_page(*p4d) == virt_to_page(lm_alias(kasan_early_shadow_pud))) {
+ walk_pmd(st, pud, start);
+ addr = start + (PTRS_PER_PUD - 1) * PUD_SIZE;
+ walk_pmd(st, pud, addr);
+ return;
+ }
+#endif
+
for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
addr = start + i * PUD_SIZE;
if (!pud_none(*pud) && !pud_is_leaf(*pud))
@@ -387,11 +405,11 @@ static void populate_markers(void)
#endif
address_markers[i++].start_address = FIXADDR_START;
address_markers[i++].start_address = FIXADDR_TOP;
+#endif /* CONFIG_PPC64 */
#ifdef CONFIG_KASAN
address_markers[i++].start_address = KASAN_SHADOW_START;
address_markers[i++].start_address = KASAN_SHADOW_END;
#endif
-#endif /* CONFIG_PPC64 */
}
static int ptdump_show(struct seq_file *m, void *v)
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 3ce907523b1e..9063c13e7221 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -101,6 +101,7 @@ config PPC_BOOK3S_64
select ARCH_SUPPORTS_NUMA_BALANCING
select IRQ_WORK
select PPC_MM_SLICES
+ select KASAN_VMALLOC if KASAN
config PPC_BOOK3E_64
bool "Embedded processors"
diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
index 2eb6ae150d1f..f277e4793696 100644
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/arch/powerpc/platforms/powernv/Makefile
@@ -1,4 +1,10 @@
# SPDX-License-Identifier: GPL-2.0
+
+# nothing that deals with real mode is safe to KASAN
+# in particular, idle code runs a bunch of things in real mode
+KASAN_SANITIZE_idle.o := n
+KASAN_SANITIZE_pci-ioda.o := n
+
obj-y += setup.o opal-call.o opal-wrappers.o opal.o opal-async.o
obj-y += idle.o opal-rtc.o opal-nvram.o opal-lpc.o opal-flash.o
obj-y += rng.o opal-elog.o opal-dump.o opal-sysparam.o opal-sensor.o
diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile
index c8a2b0b05ac0..202199ef9e5c 100644
--- a/arch/powerpc/platforms/pseries/Makefile
+++ b/arch/powerpc/platforms/pseries/Makefile
@@ -30,3 +30,6 @@ obj-$(CONFIG_PPC_SVM) += svm.o
obj-$(CONFIG_FA_DUMP) += rtas-fadump.o
obj-$(CONFIG_SUSPEND) += suspend.o
+
+# nothing that operates in real mode is safe for KASAN
+KASAN_SANITIZE_ras.o := n
--
2.27.0
^ permalink raw reply related
* Re: [PATCH RFC 2/3] mm: remove xlate_dev_kmem_ptr()
From: Geert Uytterhoeven @ 2021-03-19 14:54 UTC (permalink / raw)
To: David Hildenbrand
Cc: Rich Felker, linux-ia64@vger.kernel.org, Kuninori Morimoto,
Linux-sh list, Peter Zijlstra (Intel), Sebastian Andrzej Siewior,
Palmer Dabbelt, Jiaxun Yang, open list:BROADCOM NVRAM DRIVER,
James E.J. Bottomley, Linux MM, Paul Mackerras, sparclinux,
open list:QUALCOMM HEXAGON..., Ingo Molnar, Linux-Arch,
linux-s390, Arnd Bergmann, Brian Cain, Helge Deller, Russell King,
Krzysztof Kozlowski, Christian Borntraeger, Parisc List,
Matt Turner, Vasily Gorbik, Niklas Schnelle, Heiko Carstens,
linux-m68k, Ivan Kokshaysky, Greentime Hu, Gerald Schaefer,
Linux ARM, Richard Henderson, Thomas Bogendoerfer, Yoshinori Sato,
Pierre Morel, Randy Dunlap, Linux Kernel Mailing List,
Luis Chamberlain, Mike Rapoport, alpha, Mikulas Patocka,
Andrew Morton, linuxppc-dev, David S. Miller, Luc Van Oostenryck
In-Reply-To: <20210319143452.25948-3-david@redhat.com>
On Fri, Mar 19, 2021 at 3:36 PM David Hildenbrand <david@redhat.com> wrote:
> Since /dev/kmem has been removed, let's remove the xlate_dev_kmem_ptr()
> leftovers.
> Signed-off-by: David Hildenbrand <david@redhat.com>
> arch/m68k/include/asm/io_mm.h | 5 -----
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply
* Re: [PATCH 01/10] alpha: use libata instead of the legacy ide driver
From: Serge Belyshev @ 2021-03-19 16:23 UTC (permalink / raw)
To: Al Viro
Cc: Jens Axboe, Thomas Bogendoerfer, linux-doc, Russell King,
David S. Miller, linux-ide, linux-m68k, Ivan Kokshaysky,
linux-arm-kernel, linux-alpha, Geert Uytterhoeven, Matt Turner,
linux-mips, linuxppc-dev, Christoph Hellwig, linux-kernel,
Richard Henderson
In-Reply-To: <YFLrLwjZubWUvA2J@zeniv-ca.linux.org.uk>
Al Viro <viro@zeniv.linux.org.uk> writes:
> ...
>
> Do you have reports of libata variants of drivers actually tested on
> those?
PATA_CMD64X works fine on my 164LX for many years, last tested with 5.12-rc3.
(with a caveat: in my setup with CF card DMA is broken, but it is broken
with BLK_DEV_CMD64X as well).
^ permalink raw reply
* Re: remove the legacy ide driver
From: Maciej W. Rozycki @ 2021-03-19 16:48 UTC (permalink / raw)
To: Christoph Hellwig
Cc: Jens Axboe, Thomas Bogendoerfer, linux-doc, Russell King,
linux-kernel, linux-ide, linux-m68k, Ivan Kokshaysky, linux-alpha,
Geert Uytterhoeven, Matt Turner, linux-mips, linuxppc-dev,
David S. Miller, linux-arm-kernel, Richard Henderson
In-Reply-To: <20210318045706.200458-1-hch@lst.de>
On Thu, 18 Mar 2021, Christoph Hellwig wrote:
> we've been trying to get rid of the legacy ide driver for a while now,
> and finally scheduled a removal for 2021, which is three month old now.
Hmm, there's still a regression in that pata_legacy unconditionally pokes
at random I/O port locations corresponding to all the known possible ATA
interface mappings with ISA option cards:
scsi host0: pata_legacy
ata1: PATA max PIO4 cmd 0x1f0 ctl 0x3f6 irq 14
ata1.00: ATA-4: ST310211A, 3.54, max UDMA/100
ata1.00: 19541088 sectors, multi 16: LBA
ata1.00: configured for PIO
scsi 0:0:0:0: Direct-Access ATA ST310211A 3.54 PQ: 0 ANSI: 5
scsi 0:0:0:0: Attached scsi generic sg0 type 0
sd 0:0:0:0: [sda] 19541088 512-byte logical blocks: (10.0 GB/9.32 GiB)
sd 0:0:0:0: [sda] Write Protect is off
sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't
support DPO or FUA
sda: sda1 sda2 sda3
sd 0:0:0:0: [sda] Attached SCSI disk
scsi host1: pata_legacy
ata2: PATA max PIO4 cmd 0x170 ctl 0x376 irq 15
scsi host1: pata_legacy
ata3: PATA max PIO4 cmd 0x1e8 ctl 0x3ee irq 11
scsi host1: pata_legacy
ata4: PATA max PIO4 cmd 0x168 ctl 0x36e irq 10
scsi host1: pata_legacy
ata5: PATA max PIO4 cmd 0x1e0 ctl 0x3e6 irq 8
scsi host1: pata_legacy
ata6: PATA max PIO4 cmd 0x160 ctl 0x366 irq 12
This seems needlessly dangerous to me. With the old IDE driver I could
(and did) specify "ide_generic.probe_mask=1" to avoid this clutter (the
ISA card used with this system has a single ATA port only).
I guess it's easy to fix by carrying the `probe_mask' parameter over and
I think we'd rather wait with the removal of the IDE subsystem until we
have a release with this option supported. I may look into it unless
someone beats me to it.
Overall I find it rather disturbing that nobody has noticed this issue
over all these years.
NB it is only earlier this year that I recovered this system from a PSU
failure several years ago, which took the disk the system previously had
with it, so myself I had no chance to get at it any earlier, though I did
mean to have a look as soon as I saw the notice about the scheduled IDE
removal.
Maciej
^ permalink raw reply
* Re: Clang: powerpc: kvm/book3s_hv_nested.c:264:6: error: stack frame size of 2480 bytes in function 'kvmhv_enter_nested_guest'
From: Nathan Chancellor @ 2021-03-19 17:01 UTC (permalink / raw)
To: Naresh Kamboju
Cc: Arnd Bergmann, Nick Desaulniers, open list, kvm-ppc,
clang-built-linux, lkft-triage, Nathan Chancellor, linuxppc-dev
In-Reply-To: <CA+G9fYu=a0pk79He2DoQ9NGHkbG58PMhqJsEk=xiQv+v495Dmw@mail.gmail.com>
Hi Naresh,
Thank you for the testing and report.
On Fri, Mar 19, 2021 at 12:50:42PM +0530, Naresh Kamboju wrote:
> Linux mainline master build breaks for powerpc defconfig.
> There are multiple errors / warnings with clang-12 and clang-11 and 10.
> - powerpc (defconfig) with clang-12
> - powerpc (defconfig) with clang-11
> - powerpc (defconfig) with clang-10
>
> The following build errors / warnings triggered with clang-12.
> make --silent --keep-going --jobs=8
> O=/home/tuxbuild/.cache/tuxmake/builds/1/tmp LLVM=1 ARCH=powerpc
> CROSS_COMPILE=powerpc64le-linux-gnu- 'HOSTCC=sccache clang'
> 'CC=sccache clang'
> /builds/linux/arch/powerpc/kvm/book3s_hv_nested.c:264:6: error: stack
> frame size of 2480 bytes in function 'kvmhv_enter_nested_guest'
> [-Werror,-Wframe-larger-than=]
> long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
> ^
> 1 error generated.
> make[3]: *** [/builds/linux/scripts/Makefile.build:271:
> arch/powerpc/kvm/book3s_hv_nested.o] Error 1
>
> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Yes, unfortunately, this is a clang-12 regression that was exposed by
commit 97e4910232fa ("linux/compiler-clang.h: define HAVE_BUILTIN_BSWAP*")
and it is being tracked on both our GitHub issue tracker and LLVM's
bugzilla:
https://github.com/ClangBuiltLinux/linux/issues/1292
https://bugs.llvm.org/show_bug.cgi?id=49610
Once it has been sorted out, we can potentially work around that by just
raising the limit for that particular file (not sure what the PowerPC
maintainers will want to do).
> The following build errors / warnings triggered with clang-10 and clang-11.
> - powerpc (defconfig) with clang-11
> - powerpc (defconfig) with clang-10
> make --silent --keep-going --jobs=8
> O=/home/tuxbuild/.cache/tuxmake/builds/1/tmp LLVM=1 ARCH=powerpc
> CROSS_COMPILE=powerpc64le-linux-gnu- 'HOSTCC=sccache clang'
> 'CC=sccache clang'
>
> /usr/bin/powerpc64le-linux-gnu-ld:
> arch/powerpc/kernel/vdso32/sigtramp.o: compiled for a little endian
> system and target is big endian
> /usr/bin/powerpc64le-linux-gnu-ld: failed to merge target specific
> data of file arch/powerpc/kernel/vdso32/sigtramp.o
> /usr/bin/powerpc64le-linux-gnu-ld:
> arch/powerpc/kernel/vdso32/gettimeofday.o: compiled for a little
> endian system and target is big endian
> /usr/bin/powerpc64le-linux-gnu-ld: failed to merge target specific
> data of file arch/powerpc/kernel/vdso32/gettimeofday.o
> /usr/bin/powerpc64le-linux-gnu-ld:
> arch/powerpc/kernel/vdso32/datapage.o: compiled for a little endian
> system and target is big endian
> /usr/bin/powerpc64le-linux-gnu-ld: failed to merge target specific
> data of file arch/powerpc/kernel/vdso32/datapage.o
> /usr/bin/powerpc64le-linux-gnu-ld:
> arch/powerpc/kernel/vdso32/cacheflush.o: compiled for a little endian
> system and target is big endian
> /usr/bin/powerpc64le-linux-gnu-ld: failed to merge target specific
> data of file arch/powerpc/kernel/vdso32/cacheflush.o
> /usr/bin/powerpc64le-linux-gnu-ld: arch/powerpc/kernel/vdso32/note.o:
> compiled for a little endian system and target is big endian
> /usr/bin/powerpc64le-linux-gnu-ld: failed to merge target specific
> data of file arch/powerpc/kernel/vdso32/note.o
> /usr/bin/powerpc64le-linux-gnu-ld:
> arch/powerpc/kernel/vdso32/getcpu.o: compiled for a little endian
> system and target is big endian
> /usr/bin/powerpc64le-linux-gnu-ld: failed to merge target specific
> data of file arch/powerpc/kernel/vdso32/getcpu.o
> /usr/bin/powerpc64le-linux-gnu-ld:
> arch/powerpc/kernel/vdso32/vgettimeofday.o: compiled for a little
> endian system and target is big endian
> /usr/bin/powerpc64le-linux-gnu-ld: failed to merge target specific
> data of file arch/powerpc/kernel/vdso32/vgettimeofday.o
> clang: error: unable to execute command: Segmentation fault (core dumped)
> clang: error: linker command failed due to signal (use -v to see invocation)
> make[2]: *** [/builds/linux/arch/powerpc/kernel/vdso32/Makefile:51:
> arch/powerpc/kernel/vdso32/vdso32.so.dbg] Error 254
> make[2]: Target 'include/generated/vdso32-offsets.h' not remade
> because of errors.
>
> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
>
> build link,
> https://gitlab.com/Linaro/lkft/mirrors/torvalds/linux-mainline/-/jobs/1110841371#L59
>
This is a deficiency in clang that has been fixed in clang-12:
https://github.com/llvm/llvm-project/commit/0a23fbd28c7509f2f980946091e6055bf27164d2
but tuxmake can resolve it by using a more appropriate CROSS_COMPILE
variable for powerpc64 big-endian (powerpc64-linux-gnu-):
https://gitlab.com/Linaro/tuxmake/-/issues/108
Cheers,
Nathan
^ permalink raw reply
* Re: [PATCH 02/10] ARM: disable CONFIG_IDE in footbridge_defconfig
From: Russell King - ARM Linux admin @ 2021-03-19 17:07 UTC (permalink / raw)
To: Christoph Hellwig
Cc: Jens Axboe, Thomas Bogendoerfer, linux-doc, linux-kernel,
linux-mips, linux-ide, linux-m68k, Ivan Kokshaysky, linux-alpha,
Geert Uytterhoeven, Matt Turner, linuxppc-dev, David S. Miller,
linux-arm-kernel, Richard Henderson
In-Reply-To: <20210318045706.200458-3-hch@lst.de>
On Thu, Mar 18, 2021 at 05:56:58AM +0100, Christoph Hellwig wrote:
> footbridge_defconfig enables CONFIG_IDE but no actual host controller
> driver, so just drop it.
I have been using the Cypress 82C693 IDE driver on Footbridge for a
CD ROM drive, and I know it doesn't work with the PATA driver - as
I need to disable BM DMA, otherwise the 82C693/DC21285 combination
deadlocks the PCI bus. The PATA driver doesn't support disabling
BM DMA without disabling it for all PATA ports, which is really
annoying for my IT821x card in the same machine.
So, I'm rather stuck using the PATA driver for the HDDs and the
IDE driver for the CD ROM.
That said, a commit a while back "cleaning up" the PCI layer appears
to have totally shafted the 82C693, as the kernel tries to request
IO resources at the legacy IDE addresses against the PCI bus resource
which only covers 0x1000-0xffff. Hence, the 82C693 IDE ports are non-
functional at the moment.
I'm debating about trying to find a fix to the PCI breakage that was
introduced by "ARM: move PCI i/o resource setup into common code".
I hadn't noticed it because I don't use the CD ROM drive very often,
and I don't upgrade the kernel that often either on the machine -
but it has been running 24x7 for almost two decades.
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
^ permalink raw reply
* Re: [PATCH 02/10] ARM: disable CONFIG_IDE in footbridge_defconfig
From: Russell King - ARM Linux admin @ 2021-03-19 17:53 UTC (permalink / raw)
To: Christoph Hellwig
Cc: Jens Axboe, Thomas Bogendoerfer, linux-doc, linux-kernel,
linux-mips, linux-ide, linux-m68k, Ivan Kokshaysky, linux-alpha,
Geert Uytterhoeven, Matt Turner, linuxppc-dev, David S. Miller,
linux-arm-kernel, Richard Henderson
In-Reply-To: <20210319170753.GV1463@shell.armlinux.org.uk>
On Fri, Mar 19, 2021 at 05:07:53PM +0000, Russell King - ARM Linux admin wrote:
> On Thu, Mar 18, 2021 at 05:56:58AM +0100, Christoph Hellwig wrote:
> > footbridge_defconfig enables CONFIG_IDE but no actual host controller
> > driver, so just drop it.
>
> I have been using the Cypress 82C693 IDE driver on Footbridge for a
> CD ROM drive, and I know it doesn't work with the PATA driver - as
> I need to disable BM DMA, otherwise the 82C693/DC21285 combination
> deadlocks the PCI bus. The PATA driver doesn't support disabling
> BM DMA without disabling it for all PATA ports, which is really
> annoying for my IT821x card in the same machine.
>
> So, I'm rather stuck using the PATA driver for the HDDs and the
> IDE driver for the CD ROM.
>
> That said, a commit a while back "cleaning up" the PCI layer appears
> to have totally shafted the 82C693, as the kernel tries to request
> IO resources at the legacy IDE addresses against the PCI bus resource
> which only covers 0x1000-0xffff. Hence, the 82C693 IDE ports are non-
> functional at the moment.
>
> I'm debating about trying to find a fix to the PCI breakage that was
> introduced by "ARM: move PCI i/o resource setup into common code".
>
> I hadn't noticed it because I don't use the CD ROM drive very often,
> and I don't upgrade the kernel that often either on the machine -
> but it has been running 24x7 for almost two decades.
Okay, a bit more on this...
If I extend the arch/arm/kernel/bios32.c code to kill BARs 2/3 (which
actually are not present on the CY82C693) then the IDE driver works
for me, but the PATA driver does not:
cy82c693 0000:00:06.1: IDE controller (0x1080:0xc693 rev 0x00)
cy82c693 0000:00:06.1: not 100% native mode: will probe irqs later
legacy IDE will be removed in 2021, please switch to libata
Report any missing HW support to linux-ide@vger.kernel.org
ide0: BM-DMA at 0x1080-0x1087
ide1: BM-DMA at 0x1088-0x108f
Probing IDE interface ide0...
hda: PIONEER DVD-RW DVR-105, ATAPI CD/DVD-ROM drive
hda: host max PIO4 wanted PIO255(auto-tune) selected PIO4
...
(unbind Cypress_IDE and try binding pata_cypress)
pata_cypress 0000:00:06.1: no available native port
--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
^ permalink raw reply
* Re: [PATCH 0/6] mm: some config cleanups
From: Catalin Marinas @ 2021-03-19 18:35 UTC (permalink / raw)
To: Anshuman Khandual
Cc: linux-s390, linux-ia64, linux-parisc, linux-sh, x86, linux-mips,
linux-kernel, linux-mm, linux-fsdevel, linux-riscv,
linux-snps-arc, linuxppc-dev, linux-arm-kernel
In-Reply-To: <1615278790-18053-1-git-send-email-anshuman.khandual@arm.com>
On Tue, Mar 09, 2021 at 02:03:04PM +0530, Anshuman Khandual wrote:
> This series contains config cleanup patches which reduces code duplication
> across platforms and also improves maintainability. There is no functional
> change intended with this series. This has been boot tested on arm64 but
> only build tested on some other platforms.
>
> This applies on 5.12-rc2
>
> Cc: x86@kernel.org
> Cc: linux-ia64@vger.kernel.org
> Cc: linux-s390@vger.kernel.org
> Cc: linux-snps-arc@lists.infradead.org
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-mips@vger.kernel.org
> Cc: linux-parisc@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux-riscv@lists.infradead.org
> Cc: linux-sh@vger.kernel.org
> Cc: linux-fsdevel@vger.kernel.org
> Cc: linux-mm@kvack.org
> Cc: linux-kernel@vger.kernel.org
>
> Anshuman Khandual (6):
> mm: Generalize ARCH_HAS_CACHE_LINE_SIZE
> mm: Generalize SYS_SUPPORTS_HUGETLBFS (rename as ARCH_SUPPORTS_HUGETLBFS)
> mm: Generalize ARCH_ENABLE_MEMORY_[HOTPLUG|HOTREMOVE]
> mm: Drop redundant ARCH_ENABLE_[HUGEPAGE|THP]_MIGRATION
> mm: Drop redundant ARCH_ENABLE_SPLIT_PMD_PTLOCK
> mm: Drop redundant HAVE_ARCH_TRANSPARENT_HUGEPAGE
>
> arch/arc/Kconfig | 9 ++------
> arch/arm/Kconfig | 10 ++-------
> arch/arm64/Kconfig | 30 ++++++--------------------
For arm64:
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
^ permalink raw reply
* [PATCH 0/2] Fix EH race and MQ support
From: Tyrel Datwyler @ 2021-03-19 20:50 UTC (permalink / raw)
To: james.bottomley
Cc: Tyrel Datwyler, martin.petersen, linux-scsi, linux-kernel, brking,
linuxppc-dev
Changes to the locking pattern protecting the event lists and handling of scsi
command completion introduced a race where an ouststanding command that EH is
waiting ifor to complete is no longer identifiable by being on the sent list, but
instead as a command that is not on the free list. This is a result of moving
commands to be completed off the sent list to a private list to be completed
outside the list lock.
Second, during MQ enablement the ibmvfc_wait_for_ops helper used during EH to
ensure commands were properely completed failed to be converted to check for
commands on the sub-queues isntead of the primary CRQ.
Tyrel Datwyler (2):
ibmvfc: fix potential race in ibmvfc_wait_for_ops
ibmvfc: make ibmvfc_wait_for_ops MQ aware
drivers/scsi/ibmvscsi/ibmvfc.c | 67 +++++++++++++++++++++++++++-------
1 file changed, 54 insertions(+), 13 deletions(-)
--
2.27.0
^ permalink raw reply
* [PATCH 2/2] ibmvfc: make ibmvfc_wait_for_ops MQ aware
From: Tyrel Datwyler @ 2021-03-19 20:50 UTC (permalink / raw)
To: james.bottomley
Cc: Tyrel Datwyler, martin.petersen, linux-scsi, linux-kernel, brking,
linuxppc-dev
In-Reply-To: <20210319205029.312969-1-tyreld@linux.ibm.com>
During MQ enablement of the ibmvfc driver ibmvfc_wait_for_ops() was
missed. This function is responsible for waiting on commands to complete
that match a certain criteria such as LUN or cancel key. The
implementation as is only scans the CRQ for events ignoring any
sub-queues and as a result will exit successfully without doing
anything when operating in MQ channelized mode.
Check the mq and channel use flags to determine which queues are
applicable, and scan each queue accordingly. Note in MQ mode scsi
commands are only issued down sub-queues and the CRQ is only used for
driver specific management commands. As such the CRQ events are ignored
when operating in MQ mode with channels.
Fixes: 9000cb998bcf ("scsi: ibmvfc: Enable MQ and set reasonable defaults")
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
---
drivers/scsi/ibmvscsi/ibmvfc.c | 51 ++++++++++++++++++++++------------
1 file changed, 34 insertions(+), 17 deletions(-)
diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index 5414b465a92f..61831f2fdb30 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -2403,41 +2403,58 @@ static int ibmvfc_wait_for_ops(struct ibmvfc_host *vhost, void *device,
{
struct ibmvfc_event *evt;
DECLARE_COMPLETION_ONSTACK(comp);
- int wait, i;
+ int wait, i, q_index, q_size;
unsigned long flags;
signed long timeout = IBMVFC_ABORT_WAIT_TIMEOUT * HZ;
+ struct ibmvfc_queue *queues;
ENTER;
+ if (vhost->mq_enabled && vhost->using_channels) {
+ queues = vhost->scsi_scrqs.scrqs;
+ q_size = vhost->scsi_scrqs.active_queues;
+ } else {
+ queues = &vhost->crq;
+ q_size = 1;
+ }
+
do {
wait = 0;
- spin_lock_irqsave(&vhost->crq.l_lock, flags);
- for (i = 0; i < vhost->crq.evt_pool.size; i++) {
- evt = &vhost->crq.evt_pool.events[i];
- if (!ibmvfc_event_is_free(evt)) {
- if (match(evt, device)) {
- evt->eh_comp = ∁
- wait++;
+ spin_lock_irqsave(vhost->host->host_lock, flags);
+ for (q_index = 0; q_index < q_size; q_index++) {
+ spin_lock(&queues[q_index].l_lock);
+ for (i = 0; i < queues[q_index].evt_pool.size; i++) {
+ evt = &queues[q_index].evt_pool.events[i];
+ if (!ibmvfc_event_is_free(evt)) {
+ if (match(evt, device)) {
+ evt->eh_comp = ∁
+ wait++;
+ }
}
}
+ spin_unlock(&queues[q_index].l_lock);
}
- spin_unlock_irqrestore(&vhost->crq.l_lock, flags);
+ spin_unlock_irqrestore(vhost->host->host_lock, flags);
if (wait) {
timeout = wait_for_completion_timeout(&comp, timeout);
if (!timeout) {
wait = 0;
- spin_lock_irqsave(&vhost->crq.l_lock, flags);
- for (i = 0; i < vhost->crq.evt_pool.size; i++) {
- evt = &vhost->crq.evt_pool.events[i];
- if (!ibmvfc_event_is_free(evt)) {
- if (match(evt, device)) {
- evt->eh_comp = NULL;
- wait++;
+ spin_lock_irqsave(vhost->host->host_lock, flags);
+ for (q_index = 0; q_index < q_size; q_index++) {
+ spin_lock(&queues[q_index].l_lock);
+ for (i = 0; i < queues[q_index].evt_pool.size; i++) {
+ evt = &queues[q_index].evt_pool.events[i];
+ if (!ibmvfc_event_is_free(evt)) {
+ if (match(evt, device)) {
+ evt->eh_comp = NULL;
+ wait++;
+ }
}
}
+ spin_unlock(&queues[q_index].l_lock);
}
- spin_unlock_irqrestore(&vhost->crq.l_lock, flags);
+ spin_unlock_irqrestore(vhost->host->host_lock, flags);
if (wait)
dev_err(vhost->dev, "Timed out waiting for aborted commands\n");
LEAVE;
--
2.27.0
^ permalink raw reply related
* [PATCH 1/2] ibmvfc: fix potential race in ibmvfc_wait_for_ops
From: Tyrel Datwyler @ 2021-03-19 20:50 UTC (permalink / raw)
To: james.bottomley
Cc: Tyrel Datwyler, martin.petersen, linux-scsi, linux-kernel, brking,
linuxppc-dev
In-Reply-To: <20210319205029.312969-1-tyreld@linux.ibm.com>
For various EH activities the ibmvfc driver uses ibmvfc_wait_for_ops()
to wait for the completion of commands that match a given criteria be it
cancel key, or specific LUN. With recent changes commands are completed
outside the lock in bulk by removing them from the sent list and adding
them to a private completion list. This introduces a potential race in
ibmvfc_wait_for_ops() since the criteria for a command to be oustsanding
is no longer simply being on the sent list, but instead not being on the
free list.
Avoid this race by scanning the entire command event pool and checking
that any matching command that ibmvfc needs to wait on is not already on
the free list.
Fixes: 1f4a4a19508d ("scsi: ibmvfc: Complete commands outside the host/queue lock")
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
---
drivers/scsi/ibmvscsi/ibmvfc.c | 42 ++++++++++++++++++++++++++--------
1 file changed, 33 insertions(+), 9 deletions(-)
diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index f140eafc0d6a..5414b465a92f 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -2371,6 +2371,24 @@ static int ibmvfc_match_lun(struct ibmvfc_event *evt, void *device)
return 0;
}
+/**
+ * ibmvfc_event_is_free - Check if event is free or not
+ * @evt: ibmvfc event struct
+ *
+ * Returns:
+ * true / false
+ **/
+static bool ibmvfc_event_is_free(struct ibmvfc_event *evt)
+{
+ struct ibmvfc_event *loop_evt;
+
+ list_for_each_entry(loop_evt, &evt->queue->free, queue_list)
+ if (loop_evt == evt)
+ return true;
+
+ return false;
+}
+
/**
* ibmvfc_wait_for_ops - Wait for ops to complete
* @vhost: ibmvfc host struct
@@ -2385,7 +2403,7 @@ static int ibmvfc_wait_for_ops(struct ibmvfc_host *vhost, void *device,
{
struct ibmvfc_event *evt;
DECLARE_COMPLETION_ONSTACK(comp);
- int wait;
+ int wait, i;
unsigned long flags;
signed long timeout = IBMVFC_ABORT_WAIT_TIMEOUT * HZ;
@@ -2393,10 +2411,13 @@ static int ibmvfc_wait_for_ops(struct ibmvfc_host *vhost, void *device,
do {
wait = 0;
spin_lock_irqsave(&vhost->crq.l_lock, flags);
- list_for_each_entry(evt, &vhost->crq.sent, queue_list) {
- if (match(evt, device)) {
- evt->eh_comp = ∁
- wait++;
+ for (i = 0; i < vhost->crq.evt_pool.size; i++) {
+ evt = &vhost->crq.evt_pool.events[i];
+ if (!ibmvfc_event_is_free(evt)) {
+ if (match(evt, device)) {
+ evt->eh_comp = ∁
+ wait++;
+ }
}
}
spin_unlock_irqrestore(&vhost->crq.l_lock, flags);
@@ -2407,10 +2428,13 @@ static int ibmvfc_wait_for_ops(struct ibmvfc_host *vhost, void *device,
if (!timeout) {
wait = 0;
spin_lock_irqsave(&vhost->crq.l_lock, flags);
- list_for_each_entry(evt, &vhost->crq.sent, queue_list) {
- if (match(evt, device)) {
- evt->eh_comp = NULL;
- wait++;
+ for (i = 0; i < vhost->crq.evt_pool.size; i++) {
+ evt = &vhost->crq.evt_pool.events[i];
+ if (!ibmvfc_event_is_free(evt)) {
+ if (match(evt, device)) {
+ evt->eh_comp = NULL;
+ wait++;
+ }
}
}
spin_unlock_irqrestore(&vhost->crq.l_lock, flags);
--
2.27.0
^ permalink raw reply related
* Re: [PATCH 1/2] ibmvfc: fix potential race in ibmvfc_wait_for_ops
From: Brian King @ 2021-03-19 21:12 UTC (permalink / raw)
To: Tyrel Datwyler, james.bottomley
Cc: brking, linuxppc-dev, linux-scsi, martin.petersen, linux-kernel
In-Reply-To: <20210319205029.312969-2-tyreld@linux.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
--
Brian King
Power Linux I/O
IBM Linux Technology Center
^ permalink raw reply
* Re: [PATCH 2/2] ibmvfc: make ibmvfc_wait_for_ops MQ aware
From: Brian King @ 2021-03-19 21:12 UTC (permalink / raw)
To: Tyrel Datwyler, james.bottomley
Cc: brking, linuxppc-dev, linux-scsi, martin.petersen, linux-kernel
In-Reply-To: <20210319205029.312969-3-tyreld@linux.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
--
Brian King
Power Linux I/O
IBM Linux Technology Center
^ permalink raw reply
* Re: [for-stable-4.19 PATCH 1/2] vmlinux.lds.h: Create section for protection against instrumentation
From: Nicolas Boichat @ 2021-03-19 22:48 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Sasha Levin, linux-arch, Michal Marek, Alexandre Chartre,
Arnd Bergmann, linux-kbuild, Peter Zijlstra, Christopher Li, lkml,
stable, Masahiro Yamada, linux-sparse, Paul Mackerras,
Nicholas Piggin, Guenter Roeck, Thomas Gleixner, linuxppc-dev,
Naveen N. Rao, Daniel Axtens
In-Reply-To: <YFSRRux3FHJVgWXt@kroah.com>
On Fri, Mar 19, 2021 at 7:55 PM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Fri, Mar 19, 2021 at 12:20:22PM +0100, Alexandre Chartre wrote:
> >
> > On 3/19/21 11:39 AM, Greg Kroah-Hartman wrote:
> > > On Fri, Mar 19, 2021 at 07:54:15AM +0800, Nicolas Boichat wrote:
> > > > From: Thomas Gleixner <tglx@linutronix.de>
> > > >
> > > > commit 6553896666433e7efec589838b400a2a652b3ffa upstream.
> > > >
> > > > Some code pathes, especially the low level entry code, must be protected
> > > > against instrumentation for various reasons:
> > > >
> > > > - Low level entry code can be a fragile beast, especially on x86.
> > > >
> > > > - With NO_HZ_FULL RCU state needs to be established before using it.
> > > >
> > > > Having a dedicated section for such code allows to validate with tooling
> > > > that no unsafe functions are invoked.
> > > >
> > > > Add the .noinstr.text section and the noinstr attribute to mark
> > > > functions. noinstr implies notrace. Kprobes will gain a section check
> > > > later.
> > > >
> > > > Provide also a set of markers: instrumentation_begin()/end()
> > > >
> > > > These are used to mark code inside a noinstr function which calls
> > > > into regular instrumentable text section as safe.
> > > >
> > > > The instrumentation markers are only active when CONFIG_DEBUG_ENTRY is
> > > > enabled as the end marker emits a NOP to prevent the compiler from merging
> > > > the annotation points. This means the objtool verification requires a
> > > > kernel compiled with this option.
> > > >
> > > > Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> > > > Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
> > > > Acked-by: Peter Zijlstra <peterz@infradead.org>
> > > > Link: https://lkml.kernel.org/r/20200505134100.075416272@linutronix.de
> > > >
> > > > [Nicolas: context conflicts in:
> > > > arch/powerpc/kernel/vmlinux.lds.S
> > > > include/asm-generic/vmlinux.lds.h
> > > > include/linux/compiler.h
> > > > include/linux/compiler_types.h]
> > > > Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
> > >
> > > Did you build this on x86?
> > >
> > > I get the following build error:
> > >
> > > ld:./arch/x86/kernel/vmlinux.lds:20: syntax error
> > >
> > > And that line looks like:
> > >
> > > . = ALIGN(8); *(.text.hot .text.hot.*) *(.text .text.fixup) *(.text.unlikely .text.unlikely.*) *(.text.unknown .text.unknown.*) . = ALIGN(8); __noinstr_text_start = .; *(.__attribute__((noinline)) __attribute__((no_instrument_function)) __attribute((__section__(".noinstr.text"))).text) __noinstr_text_end = .; *(.text..refcount) *(.ref.text) *(.meminit.text*) *(.memexit.text*)
> > >
> >
> > In the NOINSTR_TEXT macro, noinstr is expanded with the value of the noinstr
> > macro from linux/compiler_types.h while it shouldn't.
> >
> > The problem is possibly that the noinstr macro is defined for assembly. Make
> > sure that the macro is not defined for assembly e.g.:
> >
> > #ifndef __ASSEMBLY__
> >
> > /* Section for code which can't be instrumented at all */
> > #define noinstr \
> > noinline notrace __attribute((__section__(".noinstr.text")))
> >
> > #endif
>
> This implies that the backport is incorrect, so I'll wait for an updated
> version...
Yep, sorry about that. I did test on ARM64 only and these patches
happily went through our Chrome OS CQ (we don't have gcc coverage
though).
Guenter has a fixup here with explanation:
https://crrev.com/c/2776332, I'll look carefully and resubmit.
Thanks,
> thanks,
>
> greg k-h
^ permalink raw reply
* Re: [PATCH v11 0/6] KASAN for powerpc64 radix
From: Balbir Singh @ 2021-03-20 1:40 UTC (permalink / raw)
To: Daniel Axtens
Cc: aneesh.kumar, linux-kernel, linux-mm, kasan-dev, linuxppc-dev
In-Reply-To: <20210319144058.772525-1-dja@axtens.net>
On Sat, Mar 20, 2021 at 01:40:52AM +1100, Daniel Axtens wrote:
> Building on the work of Christophe, Aneesh and Balbir, I've ported
> KASAN to 64-bit Book3S kernels running on the Radix MMU.
>
> v11 applies to next-20210317. I had hoped to have it apply to
> powerpc/next but once again there are changes in the kasan core that
> clash. Also, thanks to mpe for fixing a build break with KASAN off.
>
> I'm not sure how best to progress this towards actually being merged
> when it has impacts across subsystems. I'd appreciate any input. Maybe
> the first four patches could go in via the kasan tree, that should
> make things easier for powerpc in a future cycle?
>
> v10 rebases on top of next-20210125, fixing things up to work on top
> of the latest changes, and fixing some review comments from
> Christophe. I have tested host and guest with 64k pages for this spin.
>
> There is now only 1 failing KUnit test: kasan_global_oob - gcc puts
> the ASAN init code in a section called '.init_array'. Powerpc64 module
> loading code goes through and _renames_ any section beginning with
> '.init' to begin with '_init' in order to avoid some complexities
> around our 24-bit indirect jumps. This means it renames '.init_array'
> to '_init_array', and the generic module loading code then fails to
> recognise the section as a constructor and thus doesn't run it. This
> hack dates back to 2003 and so I'm not going to try to unpick it in
> this series. (I suspect this may have previously worked if the code
> ended up in .ctors rather than .init_array but I don't keep my old
> binaries around so I have no real way of checking.)
>
> (The previously failing stack tests are now skipped due to more
> accurate configuration settings.)
>
> Details from v9: This is a significant reworking of the previous
> versions. Instead of the previous approach which supported inline
> instrumentation, this series provides only outline instrumentation.
>
> To get around the problem of accessing the shadow region inside code we run
> with translations off (in 'real mode'), we we restrict checking to when
> translations are enabled. This is done via a new hook in the kasan core and
> by excluding larger quantites of arch code from instrumentation. The upside
> is that we no longer require that you be able to specify the amount of
> physically contiguous memory on the system at compile time. Hopefully this
> is a better trade-off. More details in patch 6.
>
> kexec works. Both 64k and 4k pages work. Running as a KVM host works, but
> nothing in arch/powerpc/kvm is instrumented. It's also potentially a bit
> fragile - if any real mode code paths call out to instrumented code, things
> will go boom.
>
The last time I checked, the changes for real mode, made the code hard to
review/maintain. I am happy to see that we've decided to leave that off
the table for now, reviewing the series
Balbir Singh.
^ permalink raw reply
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