As the mctrl_gpio driver can be built as a module, it needs to have its
license specified with MODULE_LICENSE. Otherwise, it cannot access
required symbols exported through EXPORT_SYMBOL_GPL.
To be able to make use of the mctrl-gpio helper from a module these
functions must be exported. This was forgotten in the commit introducing
support interrupt handling for these functions (while it was done for
mctrl_gpio_enable_ms, *sigh*).
Recent AMD systems support using MWAIT for C1 state. However, MWAIT will
not allow deeper cstates than C1 on current systems.
play_dead() expects to use the deepest state available. The deepest state
available on AMD systems is reached through SystemIO or HALT. If MWAIT is
available, it is preferred over the other methods, so the CPU never reaches
the deepest possible state.
Don't try to use MWAIT to play_dead() on AMD systems. Instead, use CPUIDLE
to enter the deepest state advertised by firmware. If CPUIDLE is not
available then fallback to HALT.
A bugfix broke the x32 shmid64_ds and msqid64_ds data structure layout
(as seen from user space) a few years ago: Originally, __BITS_PER_LONG
was defined as 64 on x32, so we did not have padding after the 64-bit
__kernel_time_t fields, After __BITS_PER_LONG got changed to 32,
applications would observe extra padding.
In other parts of the uapi headers we seem to have a mix of those
expecting either 32 or 64 on x32 applications, so we can't easily revert
the path that broke these two structures.
Instead, this patch decouples x32 from the other architectures and moves
it back into arch specific headers, partially reverting the even older
commit 73a2d096fdf2 ("x86: remove all now-duplicate header files").
It's not clear whether this ever made any difference, since at least
glibc carries its own (correct) copy of both of these header files,
so possibly no application has ever observed the definitions here.
Based on a suggestion from H.J. Lu, I tried out the tool from https://github.com/hjl-tools/linux-header to find other such
bugs, which pointed out the same bug in statfs(), which also has
a separate (correct) copy in glibc.
ceph_con_workfn() validates con->state before calling try_read() and
then try_write(). However, try_read() temporarily releases con->mutex,
notably in process_message() and ceph_con_in_msg_alloc(), opening the
window for ceph_con_close() to sneak in, close the connection and
release con->sock. When try_write() is called on the assumption that
con->state is still valid (i.e. not STANDBY or CLOSED), a NULL sock
gets passed to the networking stack:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
IP: selinux_socket_sendmsg+0x5/0x20
Make sure con->state is valid at the top of try_write() and add an
explicit BUG_ON for this, similar to try_read().
When the desired ratio is less than 256, the savesub (tolerance)
in the calculation would become 0. This will then fail the loop-
search immediately without reporting any errors.
But if the ratio is smaller enough, there is no need to calculate
the tolerance because PM divisor alone is enough to get the ratio.
So a simple fix could be just to set PM directly instead of going
into the loop-search.
When printing the driver_override parameter when it is 4095 and 4094
bytes long, the printing code would access invalid memory because we
need count + 1 bytes for printing.
Cfr. commits 4efe874aace57dba ("PCI: Don't read past the end of sysfs
"driver_override" buffer") and bf563b01c2895a4b ("driver core: platform:
Don't read past the end of "driver_override" buffer").
