talos-op-linux/arch/x86/kernel/cpu/mtrr, branch master

proc: convert everything to "struct proc_ops"

2020-02-04T03:05:26+00:00

The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in seq_file.h. Conversion rule is: llseek => proc_lseek unlocked_ioctl => proc_ioctl xxx => proc_xxx delete ".owner = THIS_MODULE" line [akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c] [sfr@canb.auug.org.au: fix kernel/sched/psi.c] Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2 Signed-off-by: Alexey Dobriyan Signed-off-by: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'x86-mtrr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-01-28T21:06:05+00:00

Pull x86 mtrr updates from Ingo Molnar: "Two changes: restrict /proc/mtrr to CAP_SYS_ADMIN, plus a cleanup" * 'x86-mtrr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mtrr: Require CAP_SYS_ADMIN for all access x86/mtrr: Get rid of mtrr_seq_show() forward declaration

x86/mm/pat: Rename =>

2019-12-10T09:12:55+00:00

pat.h is a file whose main purpose is to provide the memtype_*() APIs. PAT is the low level hardware mechanism - but the high level abstraction is memtype. So name the header as well - this goes hand in hand with memtype.c and memtype_interval.c. Signed-off-by: Ingo Molnar

x86/mtrr: Require CAP_SYS_ADMIN for all access

2019-12-09T08:24:24+00:00

Zhang Xiaoxu noted that physical address locations for MTRR were visible to non-root users, which could be considered an information leak. In discussing[1] the options for solving this, it sounded like just moving the capable check into open() was the first step. If this breaks userspace, then we will have a test case for the more conservative approaches discussed in the thread. In summary: - MTRR should check capabilities at open time (or retain the checks on the opener's permissions for later checks). - changing the DAC permissions might break something that expects to open mtrr when not uid 0. - if we leave the DAC permissions alone and just move the capable check to the opener, we should get the desired protection. (i.e. check against CAP_SYS_ADMIN not just the wider uid 0.) - if that still breaks things, as in userspace expects to be able to read other parts of the file as non-uid-0 and non-CAP_SYS_ADMIN, then we need to censor the contents using the opener's permissions. For example, as done in other /proc cases, like commit 51d7b120418e ("/proc/iomem: only expose physical resource addresses to privileged users"). [1] https://lore.kernel.org/lkml/201911110934.AC5BA313@keescook/ Reported-by: Zhang Xiaoxu Signed-off-by: Kees Cook Signed-off-by: Borislav Petkov Acked-by: James Morris Cc: "H. Peter Anvin" Cc: Colin Ian King Cc: Ingo Molnar Cc: linux-security-module@vger.kernel.org Cc: Matthew Garrett Cc: Thomas Gleixner Cc: Tyler Hicks Cc: x86-ml Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/201911181308.63F06502A1@keescook

x86/mtrr: Get rid of mtrr_seq_show() forward declaration

2019-12-09T08:23:44+00:00

... by moving the function up in the file. No functional changes. Signed-off-by: Borislav Petkov Cc: x86@kernel.org Link: https://lkml.kernel.org/r/20191108200815.24589-1-bp@alien8.de

x86: mtrr: cyrix: Mark expected switch fall-through

2019-08-07T13:12:01+00:00

Mark switch cases where we are expecting to fall through. Fix the following warning (Building: i386_defconfig i386): arch/x86/kernel/cpu/mtrr/cyrix.c:99:6: warning: this statement may fall through [-Wimplicit-fallthrough=] Signed-off-by: Gustavo A. R. Silva Signed-off-by: Thomas Gleixner Reviewed-by: Kees Cook Link: https://lkml.kernel.org/r/20190805201712.GA19927@embeddedor

x86/mtrr: Skip cache flushes on CPUs with cache self-snooping

2019-06-28T05:21:00+00:00

Programming MTRR registers in multi-processor systems is a rather lengthy process. Furthermore, all processors must program these registers in lock step and with interrupts disabled; the process also involves flushing caches and TLBs twice. As a result, the process may take a considerable amount of time. On some platforms, this can lead to a large skew of the refined-jiffies clock source. Early when booting, if no other clock is available (e.g., booting with hpet=disabled), the refined-jiffies clock source is used to monitor the TSC clock source. If the skew of refined-jiffies is too large, Linux wrongly assumes that the TSC is unstable: clocksource: timekeeping watchdog on CPU1: Marking clocksource 'tsc-early' as unstable because the skew is too large: clocksource: 'refined-jiffies' wd_now: fffedc10 wd_last: fffedb90 mask: ffffffff clocksource: 'tsc-early' cs_now: 5eccfddebc cs_last: 5e7e3303d4 mask: ffffffffffffffff tsc: Marking TSC unstable due to clocksource watchdog As per measurements, around 98% of the time needed by the procedure to program MTRRs in multi-processor systems is spent flushing caches with wbinvd(). As per the Section 11.11.8 of the Intel 64 and IA 32 Architectures Software Developer's Manual, it is not necessary to flush caches if the CPU supports cache self-snooping. Thus, skipping the cache flushes can reduce by several tens of milliseconds the time needed to complete the programming of the MTRR registers: Platform Before After 104-core (208 Threads) Skylake 1437ms 28ms 2-core ( 4 Threads) Haswell 114ms 2ms Reported-by: Mohammad Etemadi Signed-off-by: Ricardo Neri Signed-off-by: Thomas Gleixner Cc: Borislav Petkov Cc: Alan Cox Cc: Tony Luck Cc: "H. Peter Anvin" Cc: Andy Shevchenko Cc: Andi Kleen Cc: Hans de Goede Cc: Greg Kroah-Hartman Cc: Jordan Borgner Cc: "Ravi V. Shankar" Cc: Ricardo Neri Cc: Andy Shevchenko Cc: Andi Kleen Cc: Peter Feiner Cc: "Rafael J. Wysocki" Link: https://lkml.kernel.org/r/1561689337-19390-3-git-send-email-ricardo.neri-calderon@linux.intel.com

treewide: Add SPDX license identifier - Makefile/Kconfig

2019-05-21T08:50:46+00:00

Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form 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 Signed-off-by: Greg Kroah-Hartman

treewide: Add SPDX license identifier for missed files

2019-05-21T08:50:45+00:00

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 Signed-off-by: Greg Kroah-Hartman

x86/mtrr: Remove unused variable

2019-02-08T13:32:33+00:00

Compiling the kernel with W=1 results in the following warning: arch/x86/kernel/cpu/mtrr/cleanup.c:299:16: warning: variable ‘second_basek’ set but not used [-Wunused-but-set-variable] unsigned long second_basek, second_sizek; Remove the unused variable. [ tglx: Massaged changelog ] Signed-off-by: Bo Yu Signed-off-by: Thomas Gleixner Cc: bp@alien8.de Cc: hpa@zytor.com Cc: puwen@hygon.cn Link: https://lkml.kernel.org/r/20190208125343.11451-1-tsu.yubo@gmail.com