linux-stable.git/fs/pstore, branch linux-3.10.y

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

2017-02-10T10:04:02+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: Willy Tarreau

pstore/ram: Use memcpy_toio instead of memcpy

2017-02-10T10:04:01+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: Willy Tarreau

pstore/core: drop cmpxchg based updates

2017-02-10T10:04:01+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 0xffâ¦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: Willy Tarreau

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

2017-02-10T10:03:50+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: Willy Tarreau

pstore/ram: avoid atomic accesses for ioremapped regions

2015-02-06T06:35:40+00:00

commit 0405a5cec3406f19e69da07c8111a6bf1088ac29 upstream.

For persistent RAM outside of main memory, the memory may have limitations
on supported accesses. For internal RAM on highbank platform exclusive
accesses are not supported and will hang the system. So atomic_cmpxchg
cannot be used. This commit uses spinlock protection for buffer size and
start updates on ioremapped regions instead.

Signed-off-by: Rob Herring 
Acked-by: Anton Vorontsov 
Signed-off-by: Tony Luck 
[hkp: Backported to 3.10: adjust context]
Signed-off-by: HuKeping

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

2015-02-06T06:35:40+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: Greg Kroah-Hartman

pstore: skip zero size persistent ram buffer in traverse

2015-02-06T06:35:40+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: Greg Kroah-Hartman

pstore: clarify clearing of _read_cnt in ramoops_context

2015-02-06T06:35:40+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: Greg Kroah-Hartman

pstore: d_alloc_name() doesn't return an ERR_PTR

2015-02-06T06:35:39+00:00

commit c39524e6744284452ef45480d3153bec28960c32 upstream.

d_alloc_name() returns NULL on error.  Also I changed the error code
from -ENOSPC to -ENOMEM to reflect that we were short on RAM not disk
space.

Signed-off-by: Dan Carpenter 
Acked-by: Kees Cook 
Signed-off-by: Tony Luck 
Cc: HuKeping 
Signed-off-by: Greg Kroah-Hartman

pstore: Fail to unlink if a driver has not defined pstore_erase

2015-02-06T06:35:39+00:00

commit bf2883339a33b7544b92ea465b90c3de55082032 upstream.

pstore_erase is used to erase the record from the persistent store.
So if a driver has not defined pstore_erase callback return
-EPERM instead of unlinking a file as deleting the file without
erasing its record in persistent store will give a wrong impression
to customers.

Signed-off-by: Aruna Balakrishnaiah 
Acked-by: Kees Cook 
Signed-off-by: Tony Luck 
Cc: HuKeping 
Signed-off-by: Greg Kroah-Hartman