linux-stable.git/fs/pstore, branch linux-3.12.y

pstore/ram: Use memcpy_fromio() to save old buffer

2016-10-28T18:15:52+00:00

commit d771fdf94180de2bd811ac90cba75f0f346abf8d upstream.

The ramoops buffer may be mapped as either I/O memory or uncached
memory.  On ARM64, this results in a device-type (strongly-ordered)
mapping.  Since unnaligned accesses to device-type memory will
generate an alignment fault (regardless of whether or not strict
alignment checking is enabled), it is not safe to use memcpy().
memcpy_fromio() is guaranteed to only use aligned accesses, so use
that instead.

Signed-off-by: Andrew Bresticker 
Signed-off-by: Enric Balletbo Serra 
Reviewed-by: Puneet Kumar 
Signed-off-by: Kees Cook 
Signed-off-by: Jiri Slaby

pstore/ram: Use memcpy_toio instead of memcpy

2016-10-28T18:15:52+00:00

commit 7e75678d23167c2527e655658a8ef36a36c8b4d9 upstream.

persistent_ram_update uses vmap / iomap based on whether the buffer is in
memory region or reserved region. However, both map it as non-cacheable
memory. For armv8 specifically, non-cacheable mapping requests use a
memory type that has to be accessed aligned to the request size. memcpy()
doesn't guarantee that.

Signed-off-by: Furquan Shaikh 
Signed-off-by: Enric Balletbo Serra 
Reviewed-by: Aaron Durbin 
Reviewed-by: Olof Johansson 
Tested-by: Furquan Shaikh 
Signed-off-by: Kees Cook 
Signed-off-by: Jiri Slaby

pstore/core: drop cmpxchg based updates

2016-10-28T18:15:52+00:00

commit d5a9bf0b38d2ac85c9a693c7fb851f74fd2a2494 upstream.

I have here a FPGA behind PCIe which exports SRAM which I use for
pstore. Now it seems that the FPGA no longer supports cmpxchg based
updates and writes back 0xff…ff and returns the same.  This leads to
crash during crash rendering pstore useless.
Since I doubt that there is much benefit from using cmpxchg() here, I am
dropping this atomic access and use the spinlock based version.

Cc: Anton Vorontsov 
Cc: Colin Cross 
Cc: Kees Cook 
Cc: Tony Luck 
Cc: Rabin Vincent 
Tested-by: Rabin Vincent 
Signed-off-by: Sebastian Andrzej Siewior 
Reviewed-by: Guenter Roeck 
[kees: remove "_locked" suffix since it's the only option now]
Signed-off-by: Kees Cook 
Signed-off-by: Jiri Slaby

pstore: Fix buffer overflow while write offset equal to buffer size

2016-10-28T10:55:48+00:00

commit 017321cf390045dd4c4afc4a232995ea50bcf66d upstream.

In case new offset is equal to prz->buffer_size, it won't wrap at this
time and will return old(overflow) value next time.

Signed-off-by: Liu ShuoX 
Acked-by: Kees Cook 
Signed-off-by: Tony Luck 
Signed-off-by: Jiri Slaby

pstore: Fix NULL pointer fault if get NULL prz in ramoops_get_next_prz

2015-02-08T19:02:06+00:00

commit b0aa931fb84431394d995472d0af2a6c2b61064d upstream.

ramoops_get_next_prz get the prz according the paramters. If it get a
uninitialized prz, access its members by following persistent_ram_old_size(prz)
will cause a NULL pointer crash.
Ex: if ftrace_size is 0, fprz will be NULL.

Fix it by return NULL in advance.

Signed-off-by: Liu ShuoX 
Acked-by: Kees Cook 
Signed-off-by: Tony Luck 
Cc: HuKeping 
Signed-off-by: Jiri Slaby

pstore: skip zero size persistent ram buffer in traverse

2015-02-08T19:02:06+00:00

commit aa9a4a1edfbd3d223af01db833da2f07850bc655 upstream.

In ramoops_pstore_read, a valid prz pointer with zero size buffer will
break traverse of all persistent ram buffers.  The latter buffer might be
lost.

Signed-off-by: Liu ShuoX 
Cc: "Zhang, Yanmin" 
Cc: Colin Cross 
Reviewed-by: Kees Cook 
Signed-off-by: Andrew Morton 
Signed-off-by: Tony Luck 
Cc: HuKeping 
Signed-off-by: Jiri Slaby

pstore: clarify clearing of _read_cnt in ramoops_context

2015-02-08T19:02:05+00:00

commit 57fd835385a043577457a385f28c08be693991bf upstream.

*_read_cnt in ramoops_context need to be cleared during pstore ->open to
support mutli times getting the records.  The patch added missed
ftrace_read_cnt clearing and removed duplicate clearing in ramoops_probe.

Signed-off-by: Liu ShuoX 
Cc: "Zhang, Yanmin" 
Cc: Colin Cross 
Cc: Kees Cook 
Signed-off-by: Andrew Morton 
Signed-off-by: Tony Luck 
Cc: HuKeping 
Signed-off-by: Jiri Slaby

pstore-ram: Allow optional mapping with pgprot_noncached

2015-01-26T13:38:46+00:00

commit 027bc8b08242c59e19356b4b2c189f2d849ab660 upstream.

On some ARMs the memory can be mapped pgprot_noncached() and still
be working for atomic operations. As pointed out by Colin Cross
, in some cases you do want to use
pgprot_noncached() if the SoC supports it to see a debug printk
just before a write hanging the system.

On ARMs, the atomic operations on strongly ordered memory are
implementation defined. So let's provide an optional kernel parameter
for configuring pgprot_noncached(), and use pgprot_writecombine() by
default.

Cc: Arnd Bergmann 
Cc: Rob Herring 
Cc: Randy Dunlap 
Cc: Anton Vorontsov 
Cc: Colin Cross 
Cc: Olof Johansson 
Cc: Russell King 
Acked-by: Kees Cook 
Signed-off-by: Tony Lindgren 
Signed-off-by: Tony Luck 
Signed-off-by: Jiri Slaby

pstore-ram: Fix hangs by using write-combine mappings

2015-01-26T13:38:45+00:00

commit 7ae9cb81933515dc7db1aa3c47ef7653717e3090 upstream.

Currently trying to use pstore on at least ARMs can hang as we're
mapping the peristent RAM with pgprot_noncached().

On ARMs, pgprot_noncached() will actually make the memory strongly
ordered, and as the atomic operations pstore uses are implementation
defined for strongly ordered memory, they may not work. So basically
atomic operations have undefined behavior on ARM for device or strongly
ordered memory types.

Let's fix the issue by using write-combine variants for mappings. This
corresponds to normal, non-cacheable memory on ARM. For many other
architectures, this change does not change the mapping type as by
default we have:

#define pgprot_writecombine pgprot_noncached

The reason why pgprot_noncached() was originaly used for pstore
is because Colin Cross  had observed lost
debug prints right before a device hanging write operation on some
systems. For the platforms supporting pgprot_noncached(), we can
add a an optional configuration option to support that. But let's
get pstore working first before adding new features.

Cc: Arnd Bergmann 
Cc: Anton Vorontsov 
Cc: Colin Cross 
Cc: Olof Johansson 
Cc: linux-kernel@vger.kernel.org
Acked-by: Kees Cook 
Signed-off-by: Rob Herring 
[tony@atomide.com: updated description]
Signed-off-by: Tony Lindgren 
Signed-off-by: Tony Luck 
Signed-off-by: Jiri Slaby

pstore: Fix duplicate {console,ftrace}-efi entries

2014-11-13T18:02:18+00:00

commit d4bf205da618bbd0b038e404d646f14e76915718 upstream.

The pstore filesystem still creates duplicate filename/inode pairs for
some pstore types.  Add the id to the filename to prevent that.

Before patch:

[/sys/fs/pstore] ls -li
total 0
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi
1250 -r--r--r--. 1 root root 67 Sep 29 17:09 console-efi

After:

[/sys/fs/pstore] ls -li
total 0
1232 -r--r--r--. 1 root root 148 Sep 29 17:09 console-efi-141202499100000
1231 -r--r--r--. 1 root root  67 Sep 29 17:09 console-efi-141202499200000
1230 -r--r--r--. 1 root root 148 Sep 29 17:44 console-efi-141202705400000
1229 -r--r--r--. 1 root root  67 Sep 29 17:44 console-efi-141202705500000
1228 -r--r--r--. 1 root root  67 Sep 29 20:42 console-efi-141203772600000
1227 -r--r--r--. 1 root root 148 Sep 29 23:42 console-efi-141204854900000
1226 -r--r--r--. 1 root root  67 Sep 29 23:42 console-efi-141204855000000
1225 -r--r--r--. 1 root root 148 Sep 29 23:59 console-efi-141204954200000
1224 -r--r--r--. 1 root root  67 Sep 29 23:59 console-efi-141204954400000

Signed-off-by: Valdis Kletnieks 
Acked-by: Kees Cook 
Signed-off-by: Tony Luck 
Signed-off-by: Jiri Slaby