A contrived zero-length write, for example, by using write(2):
...
ret = write(fd, str, 0);
...
to the "flags" file causes:
BUG: KASAN: stack-out-of-bounds in flags_write
Write of size 1 at addr ffff888019be7ddf by task writefile/3787
CPU: 4 PID: 3787 Comm: writefile Not tainted 5.16.0-rc7+ #12
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
due to accessing buf one char before its start.
Prevent such out-of-bounds access.
[ bp: Productize into a proper patch. Link below is the next best
thing because the original mail didn't get archived on lore. ]
Fixes: 0451d14d05 ("EDAC, mce_amd_inj: Modify flags attribute to use string arguments")
Signed-off-by: Zhang Zixun <zhang133010@icloud.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/linux-edac/YcnePfF1OOqoQwrX@zn.tnic/
MCA handlers check the valid bit in each status register
(MCA_STATUS[Val]) and continue processing the error only if the valid
bit is set.
Set the valid bit unconditionally in the corresponding MCA_STATUS
register and correct any Val=0 injections made by the user as such
errors will get ignored and such injections will be largely pointless.
Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211104215846.254012-3-Smita.KoralahalliChannabasappa@amd.com
The MCA_IPID register uniquely identifies a bank's type on Scalable MCA
(SMCA) systems. When an MCA bank is not populated, the MCA_IPID register
will read as zero and writes to it will be ignored.
On a hw-type error injection (injection which writes the actual MCA
registers in an attempt to cause a real MCE) check the value of this
register before trying to inject the error.
Do not impose any limitations on a sw injection and allow the user to
test out all the decoding paths without relying on the available hardware,
as its purpose is to just test the code.
[ bp: Heavily massage. ]
Link: https://lkml.kernel.org/r/20211019233641.140275-2-Smita.KoralahalliChannabasappa@amd.com
Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211104215846.254012-2-Smita.KoralahalliChannabasappa@amd.com
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().
Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210803141621.780504-10-bigeasy@linutronix.de
Add an injection file in order to specify the IPID too when injecting
an error. One use case example is using the machinery to decode MCEs
collected from other machines.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210314201806.12798-1-bp@alien8.de
The Last Level Cache ID is returned by amd_get_nb_id(). In practice,
this value is the same as the AMD NodeId for callers of this function.
The NodeId is saved in struct cpuinfo_x86.cpu_die_id.
Replace calls to amd_get_nb_id() with the logical CPU's cpu_die_id and
remove the function.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201109210659.754018-3-Yazen.Ghannam@amd.com
The original code is a nop as i_mce.status is or'ed with part of itself,
fix it.
Fixes: a1300e5052 ("x86/ras/mce_amd_inj: Trigger deferred and thresholding errors interrupts")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Yazen Ghannam <yazen.ghannam@amd.com>
Link: https://lkml.kernel.org/r/20200611023238.3830-1-zhenzhong.duan@gmail.com
Convert #MC to IDTENTRY_MCE:
- Implement the C entry points with DEFINE_IDTENTRY_MCE
- Emit the ASM stub with DECLARE_IDTENTRY_MCE
- Remove the ASM idtentry in 64bit
- Remove the open coded ASM entry code in 32bit
- Fixup the XEN/PV code
- Remove the old prototypes
- Remove the error code from *machine_check_vector() as
it is always 0 and not used by any of the functions
it can point to. Fixup all the functions as well.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200505135314.334980426@linutronix.de
The mutex in mce_inject_log() became unnecessary with commit
5de97c9f6d ("x86/mce: Factor out and deprecate the /dev/mcelog driver"),
though the original reason for its presence only vanished with commit
7298f08ea8 ("x86/mcelog: Get rid of RCU remnants").
Drop the mutex. And as that makes mce_inject_log() identical to mce_log(),
get rid of the former in favor of the latter.
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191210000733.17979-7-jschoenh@amazon.de
When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.
The only way this can fail is if:
* debugfs superblock can not be pinned - something really went wrong with the
vfs layer.
* file is created with same name - the caller's fault.
* new_inode() fails - happens if memory is exhausted.
so failing to clean up debugfs properly is the least of the system's
sproblems in uch a situation.
[ bp: Extend commit message, remove unused err var in inject_init(). ]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190612151531.GA16278@kroah.com
Based on 1 normalized pattern(s):
this file may be distributed under the terms of the gnu general
public license version 2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 9 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.395589349@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull RAS updates from Borislav Petkov:
- Support for varying MCA bank numbers per CPU: this is in preparation
for future CPU enablement (Yazen Ghannam)
- MCA banks read race fix (Tony Luck)
- Facility to filter MCEs which should not be logged (Yazen Ghannam)
- The usual round of cleanups and fixes
* 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/MCE/AMD: Don't report L1 BTB MCA errors on some family 17h models
x86/MCE: Add an MCE-record filtering function
RAS/CEC: Increment cec_entered under the mutex lock
x86/mce: Fix debugfs_simple_attr.cocci warnings
x86/mce: Remove mce_report_event()
x86/mce: Handle varying MCA bank counts
x86/mce: Fix machine_check_poll() tests for error types
MAINTAINERS: Fix file pattern for X86 MCE INFRASTRUCTURE
x86/MCE: Group AMD function prototypes in <asm/mce.h>
Using static_cpu_has() is pointless on those paths, convert them to the
boot_cpu_has() variant.
No functional changes.
Reported-by: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Juergen Gross <jgross@suse.com> # for paravirt
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Thomas Lendacky <Thomas.Lendacky@amd.com>
Cc: linux-edac@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: virtualization@lists.linux-foundation.org
Cc: x86@kernel.org
Link: https://lkml.kernel.org/r/20190330112022.28888-3-bp@alien8.de
Linux reads MCG_CAP[Count] to find the number of MCA banks visible to a
CPU. Currently, this number is the same for all CPUs and a warning is
shown if there is a difference. The number of banks is overwritten with
the MCG_CAP[Count] value of each following CPU that boots.
According to the Intel SDM and AMD APM, the MCG_CAP[Count] value gives
the number of banks that are available to a "processor implementation".
The AMD BKDGs/PPRs further clarify that this value is per core. This
value has historically been the same for every core in the system, but
that is not an architectural requirement.
Future AMD systems may have different MCG_CAP[Count] values per core,
so the assumption that all CPUs will have the same MCG_CAP[Count] value
will no longer be valid.
Also, the first CPU to boot will allocate the struct mce_banks[] array
using the number of banks based on its MCG_CAP[Count] value. The machine
check handler and other functions use the global number of banks to
iterate and index into the mce_banks[] array. So it's possible to use an
out-of-bounds index on an asymmetric system where a following CPU sees a
MCG_CAP[Count] value greater than its predecessors.
Thus, allocate the mce_banks[] array to the maximum number of banks.
This will avoid the potential out-of-bounds index since the value of
mca_cfg.banks is capped to MAX_NR_BANKS.
Set the value of mca_cfg.banks equal to the max of the previous value
and the value for the current CPU. This way mca_cfg.banks will always
represent the max number of banks detected on any CPU in the system.
This will ensure that all CPUs will access all the banks that are
visible to them. A CPU that can access fewer than the max number of
banks will find the registers of the extra banks to be read-as-zero.
Furthermore, print the resulting number of MCA banks in use. Do this in
mcheck_late_init() so that the final value is printed after all CPUs
have been initialized.
Finally, get bank count from target CPU when doing injection with mce-inject
module.
[ bp: Remove out-of-bounds example, passify and cleanup commit message. ]
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: Pu Wen <puwen@hygon.cn>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20180727214009.78289-1-Yazen.Ghannam@amd.com
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
2018-12-05 18:00:29 +01:00
Renamed from arch/x86/kernel/cpu/mcheck/mce-inject.c (Browse further)
