linux-toradex.git/fs/pstore, branch v4.4.72

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

2016-10-28T07:01:27+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: Greg Kroah-Hartman

pstore/ram: Use memcpy_toio instead of memcpy

2016-10-28T07:01:27+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: Greg Kroah-Hartman

pstore/core: drop cmpxchg based updates

2016-10-28T07:01:27+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: Greg Kroah-Hartman

pstore/ramoops: fixup driver removal

2016-10-28T07:01:27+00:00

commit 4407de74df18ed405cc5998990004c813ccfdbde upstream.

A basic rmmod ramoops segfaults. Let's see why.

Since commit 34f0ec82e0a9 ("pstore: Correct the max_dump_cnt clearing of
ramoops") sets ->max_dump_cnt to zero before looping over ->przs but we
didn't use it before that either.

And since commit ee1d267423a1 ("pstore: add pstore unregister") we free
that memory on rmmod.

But even then, we looped until a NULL pointer or ERR. I don't see where
it is ensured that the last member is NULL. Let's try this instead:
simply error recovery and free. Clean up in error case where resources
were allocated. And then, in the free path, rely on ->max_dump_cnt in
the free path.

Cc: Anton Vorontsov 
Cc: Colin Cross 
Cc: Kees Cook 
Cc: Tony Luck 
Cc: Namhyung Kim 
Acked-by: Namhyung Kim 
Signed-off-by: Sebastian Andrzej Siewior 
Signed-off-by: Kees Cook 
Signed-off-by: Greg Kroah-Hartman

pstore: drop file opened reference count

2016-10-07T13:23:44+00:00

commit 52d210d961a62a9662e27f14d6505d6741b2fb02 upstream.

In ee1d267423a1 ("pstore: add pstore unregister") I added:
	.owner = THIS_MODULE,
in both pstore_fs_type and pstore_file_operations to increase a reference
count when pstore filesystem is mounted and pstore file is opened.

But, it's repetitive. There is no need to increase the opened reference
count. We only need to increase the mounted reference count. When a file
is opened, the filesystem can't be unmounted. Hence the pstore module
can't be unloaded either.

So I drop the opened reference count in this patch.

Fixes: ee1d267423a1 ("pstore: add pstore unregister")
Signed-off-by: Geliang Tang 
Signed-off-by: Kees Cook 
Signed-off-by: Greg Kroah-Hartman

pstore: fix code comment to match code

2015-11-02T21:41:52+00:00

Fix code comment about kmsg_dump register so it matches the code.

Signed-off-by: Geliang Tang 
Signed-off-by: Tony Luck

pstore: Fix return type of pstore_is_mounted()

2015-10-22T17:57:33+00:00

This patch changes return type of pstore_is_mounted from int to bool.

Signed-off-by: Geliang Tang 
Acked-by: Kees Cook 
Signed-off-by: Tony Luck

pstore: add pstore unregister

2015-10-22T15:59:18+00:00

pstore doesn't support unregistering yet. It was marked as TODO.
This patch adds some code to fix it:
 1) Add functions to unregister kmsg/console/ftrace/pmsg.
 2) Add a function to free compression buffer.
 3) Unmap the memory and free it.
 4) Add a function to unregister pstore filesystem.

Signed-off-by: Geliang Tang 
Acked-by: Kees Cook 
[Removed __exit annotation from ramoops_remove(). Reported by Arnd Bergmann]
Signed-off-by: Tony Luck

pstore: add a helper function pstore_register_kmsg

2015-10-21T16:27:10+00:00

Add a new wrapper function pstore_register_kmsg to keep the
consistency with other similar pstore_register_* functions.

Signed-off-by: Geliang Tang 
Signed-off-by: Tony Luck

pstore: add vmalloc error check

2015-10-21T16:27:10+00:00

If vmalloc fails, make write_pmsg return -ENOMEM.

Signed-off-by: Geliang Tang 
Acked-by: Kees Cook 
Signed-off-by: Tony Luck