x86/mce/dev-mcelog: use strscpy() to instead of strncpy()

The implementation of strscpy() is more robust and safer.
That's now the recommended way to copy NUL terminated strings.

Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Yang Yang <yang.yang29@zte.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/202212031419324523731@zte.com.cn

x86/mce/dev-mcelog: Do not update kflags on AMD systems

The mcelog utility is not commonly used on AMD systems. Therefore,
errors logged only by the dev_mce_log() notifier will be missed. This
may occur if the EDAC modules are not loaded, in which case it's
preferable to print the error record by the default notifier.

However, the mce->kflags set by dev_mce_log() notifier makes the
default notifier skip over the errors assuming they are processed by
dev_mce_log().

Do not update kflags in the dev_mce_log() notifier on AMD systems.

Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200903234531.162484-3-Smita.KoralahalliChannabasappa@amd.com

x86/mce/dev-mcelog: Use struct_size() helper in kzalloc()

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

This code was detected with the help of Coccinelle and, audited and
fixed manually.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20200617211734.GA9636@embeddedor

x86/mce/dev-mcelog: Fix -Wstringop-truncation warning about strncpy()

The kbuild test robot reported this warning:

arch/x86/kernel/cpu/mce/dev-mcelog.c: In function 'dev_mcelog_init_device':
arch/x86/kernel/cpu/mce/dev-mcelog.c:346:2: warning: 'strncpy' output \
truncated before terminating nul copying 12 bytes from a string of the \
same length [-Wstringop-truncation]

This is accurate, but I don't care that the trailing NUL character isn't
copied. The string being copied is just a magic number signature so that
crash dump tools can be sure they are decoding the right blob of memory.

Use memcpy() instead of strncpy().

Fixes: d8ecca4043f2 ("x86/mce/dev-mcelog: Dynamically allocate space for machine check records")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200527182808.27737-1-tony.luck@intel.com

x86/mcelog: Add compat_ioctl for 32-bit mcelog support

A 32-bit version of mcelog issuing ioctls on /dev/mcelog causes errors
like the following:

MCE_GET_RECORD_LEN: Inappropriate ioctl for device

This is due to a missing compat_ioctl callback.

Assign to it compat_ptr_ioctl() as a generic implementation of the
.compat_ioctl file operation to ioctl functions that either ignore the
argument or pass a pointer to a compatible data type.

[ bp: Massage commit message. ]

Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/1583303947-49858-1-git-send-email-zhe.he@windriver.com

x86/mce: Fix all mce notifiers to update the mce->kflags bitmask

If the handler took any action to log or deal with the error, set a bit
in mce->kflags so that the default handler on the end of the machine
check chain can see what has been done.

Get rid of NOTIFY_STOP returns. Make the EDAC and dev-mcelog handlers
skip over errors already processed by CEC.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20200214222720.13168-5-tony.luck@intel.com

x86/mce/dev-mcelog: Dynamically allocate space for machine check records

We have had a hard coded limit of 32 machine check records since the
dawn of time. But as numbers of cores increase, it is possible for
more than 32 errors to be reported before a user process reads from
/dev/mcelog. In this case the additional errors are lost.

Keep 32 as the minimum. But tune the maximum value up based on the
number of processors.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200218184408.GA23048@agluck-desk2.amr.corp.intel.com

treewide: Add SPDX license identifier for missed files

Add SPDX license identifiers to all files which:

- Have no license information of any form

- Have EXPORT_.*_SYMBOL_GPL inside which was used in the
initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

x86/mce: Unify pr_* prefix

Move the pr_fmt prefix to internal.h and include it everywhere. This
way, all pr_* printed strings will be prepended with "mce: ".

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20181205200913.GR29510@zn.tnic

x86/mce: Streamline MCE subsystem's naming

Rename the containing folder to "mce" which is the most widespread name.
Drop the "mce[-_]" filename prefix of some compilation units (while
others don't have it).

This unifies the file naming in the MCE subsystem:

mce/
|-- amd.c
|-- apei.c
|-- core.c
|-- dev-mcelog.c
|-- genpool.c
|-- inject.c
|-- intel.c
|-- internal.h
|-- Makefile
|-- p5.c
|-- severity.c
|-- therm_throt.c
|-- threshold.c
`-- winchip.c

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20181205141323.14995-1-bp@alien8.de