# # CCITT X.25 Packet Layer # config X25 tristate "CCITT X.25 Packet Layer" ---help--- X.25 is a set of standardized network protocols, similar in scope to frame relay; the one physical line from your box to the X.25 network entry point can carry several logical point-to-point connections (called "virtual circuits") to other computers connected to the X.25 network. Governments, banks, and other organizations tend to use it to connect to each other or to form Wide Area Networks (WANs). Many countries have public X.25 networks. X.25 consists of two protocols: the higher level Packet Layer Protocol (PLP) (say Y here if you want that) and the lower level data link layer protocol LAPB (say Y to "LAPB Data Link Driver" below if you want that). You can read more about X.25 at and . Information about X.25 for Linux is contained in the files and . One connects to an X.25 network either with a dedicated network card using the X.21 protocol (not yet supported by Linux) or one can do X.25 over a standard telephone line using an ordinary modem (say Y to "X.25 async driver" below) or over Ethernet using an ordinary Ethernet card and the LAPB over Ethernet (say Y to "LAPB Data Link Driver" and "LAPB over Ethernet driver" below). To compile this driver as a module, choose M here: the module will be called x25. If unsure, say N. e class='tabs'> summaryrefslogtreecommitdiff
path: root/include/trace/trace_events.h
diff options
context:
space:
mode:
authorJiri Kosina <jkosina@suse.cz>2017-01-27 22:25:52 +0000
committerIngo Molnar <mingo@kernel.org>2017-01-28 09:18:56 +0100
commitbf29bddf0417a4783da3b24e8c9e017ac649326f (patch)
tree54a05a4883b73f80e4e1d8c4b15750aa01c39932 /include/trace/trace_events.h
parent883af14e67e8b8702b5560aa64c888c0cd0bd66c (diff)
x86/efi: Always map the first physical page into the EFI pagetables
Commit: 129766708 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode") stopped creating 1:1 mappings for all RAM, when running in native 64-bit mode. It turns out though that there are 64-bit EFI implementations in the wild (this particular problem has been reported on a Lenovo Yoga 710-11IKB), which still make use of the first physical page for their own private use, even though they explicitly mark it EFI_CONVENTIONAL_MEMORY in the memory map. In case there is no mapping for this particular frame in the EFI pagetables, as soon as firmware tries to make use of it, a triple fault occurs and the system reboots (in case of the Yoga 710-11IKB this is very early during bootup). Fix that by always mapping the first page of physical memory into the EFI pagetables. We're free to hand this page to the BIOS, as trim_bios_range() will reserve the first page and isolate it away from memory allocators anyway. Note that just reverting 129766708 alone is not enough on v4.9-rc1+ to fix the regression on affected hardware, as this commit: ab72a27da ("x86/efi: Consolidate region mapping logic") later made the first physical frame not to be mapped anyway. Reported-by: Hanka Pavlikova <hanka@ucw.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Laura Abbott <labbott@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vojtech Pavlik <vojtech@ucw.cz> Cc: Waiman Long <waiman.long@hpe.com> Cc: linux-efi@vger.kernel.org Cc: stable@kernel.org # v4.8+ Fixes: 129766708 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode") Link: http://lkml.kernel.org/r/20170127222552.22336-1-matt@codeblueprint.co.uk [ Tidied up the changelog and the comment. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/trace/trace_events.h')