linux.git/arch/s390/kernel/debug.c, branch v4.13

s390: convert debug_info.ref_count from atomic_t to refcount_t

2017-05-11T14:35:32+00:00

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Cook 
Signed-off-by: David Windsor 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390: kernel: Audit and remove any unnecessary uses of module.h

2017-02-17T06:40:31+00:00

Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends.  That changed
when we forked out support for the latter into the export.h file.

This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.  The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.

Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each change instance
for the presence of either and replace as needed.  Build testing
revealed some implicit header usage that was fixed up accordingly.

Signed-off-by: Paul Gortmaker 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/debug: make debug event time stamps relative to the boot TOD clock

2017-02-07T06:27:13+00:00

The debug features currently uses absolute TOD time stamps for the
debug events. Given that the TOD clock can jump forward and backward
due to STP sync checks the order of debug events can get obfuscated.

Replace the absolute TOD time stamps with a delta to the IPL time
stamp. On a STP sync check the TOD clock correction is added to
the IPL time stamp as well to make the deltas unaffected by STP
sync check.

The readout of the debug feature entries will convert the deltas
back to absolute time stamps based on the Unix epoch.

Signed-off-by: Martin Schwidefsky

Replace with globally

2016-12-24T19:46:01+00:00

This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*'
  sed -i -e "s!$PATT!#include !" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro 
Signed-off-by: Linus Torvalds

s390: Use pr_warn instead of pr_warning

2016-03-07T12:12:04+00:00

Convert the uses of pr_warning to pr_warn so there are fewer
uses of the old pr_warning.

Miscellanea:

o Align arguments
o Coalesce formats

Signed-off-by: Joe Perches 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390: remove all usages of PSW_ADDR_INSN

2016-01-19T11:14:03+00:00

Yet another leftover from the 31 bit era. The usual operation
"y = x & PSW_ADDR_INSN" with the PSW_ADDR_INSN mask is a nop for
CONFIG_64BIT.

Therefore remove all usages and hope the code is a bit less confusing.

Signed-off-by: Heiko Carstens 
Reviewed-by: David Hildenbrand

s390: time: Provide read_boot_clock64() and read_persistent_clock64()

2015-05-22T17:36:29+00:00

As part of addressing the "y2038 problem" for in-kernel uses,
this patch converts read_boot_clock() to read_boot_clock64()
and read_persistent_clock() to read_persistent_clock64() using
timespec64.

Rename some instances of 'timespec' to 'timespec64' in time.c and
related references

Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: linux390@de.ibm.com
Signed-off-by: Xunlei Pang 
[jstultz: Fixed minor style and grammer tweaks
 pointed out by Ingo]
Signed-off-by: John Stultz

s390/debug: avoid function call for debug_sprintf_*

2014-12-08T08:42:29+00:00

debug_sprintf_event/exception are called even for debug events
with a disabling debug level. All other functions already do
the check in a wrapper function. Lets do the same here.
Due to the var_args the compiler rejects to make this function
inline. So let's wrap this via a macro.
This patch saves around 80 ns on my z196 for a KVM round trip (we
have two debug statements for entry and exit) when KVM is build as
a module.
The savings for built-in drivers is smaller as we then avoid the
PLT overhead for a function call.

Signed-off-by: Christian Borntraeger 
Reviewed-by: Michael Holzheu 
Reviewed-by: David Hildenbrand 
Signed-off-by: Martin Schwidefsky

s390: convert use of typedef ctl_table to struct ctl_table

2013-10-28T07:36:25+00:00

This typedef is unnecessary and should just be removed.

Signed-off-by: Joe Perches 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/time: correct use of store clock fast

2013-10-22T07:16:40+00:00

The result of the store-clock-fast (STCKF) instruction is a bit fuzzy.
It can happen that the value stored on one CPU is smaller than the value
stored on another CPU, although the order of the stores is the other
way around. This can cause deltas of get_tod_clock() values to become
negative when they should not be.

We need to be more careful with store-clock-fast, this patch partially
reverts git commit e4b7b4238e666682555461fa52eecd74652f36bb "time:
always use stckf instead of stck if available". The get_tod_clock()
function now uses the store-clock-extended (STCKE) instruction.
get_tod_clock_fast() can be used if the fuzziness of store-clock-fast
is acceptable e.g. for wait loops local to a CPU.

Signed-off-by: Martin Schwidefsky