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path: root/drivers/tty/hvc/hvc_vio.c
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2020-01-09powerpc/pseries/hvconsole: Fix stack overread via udbgDaniel Axtens
[ Upstream commit 934bda59f286d0221f1a3ebab7f5156a996cc37d ] While developing KASAN for 64-bit book3s, I hit the following stack over-read. It occurs because the hypercall to put characters onto the terminal takes 2 longs (128 bits/16 bytes) of characters at a time, and so hvc_put_chars() would unconditionally copy 16 bytes from the argument buffer, regardless of supplied length. However, udbg_hvc_putc() can call hvc_put_chars() with a single-byte buffer, leading to the error. ================================================================== BUG: KASAN: stack-out-of-bounds in hvc_put_chars+0xdc/0x110 Read of size 8 at addr c0000000023e7a90 by task swapper/0 CPU: 0 PID: 0 Comm: swapper Not tainted 5.2.0-rc2-next-20190528-02824-g048a6ab4835b #113 Call Trace: dump_stack+0x104/0x154 (unreliable) print_address_description+0xa0/0x30c __kasan_report+0x20c/0x224 kasan_report+0x18/0x30 __asan_report_load8_noabort+0x24/0x40 hvc_put_chars+0xdc/0x110 hvterm_raw_put_chars+0x9c/0x110 udbg_hvc_putc+0x154/0x200 udbg_write+0xf0/0x240 console_unlock+0x868/0xd30 register_console+0x970/0xe90 register_early_udbg_console+0xf8/0x114 setup_arch+0x108/0x790 start_kernel+0x104/0x784 start_here_common+0x1c/0x534 Memory state around the buggy address: c0000000023e7980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c0000000023e7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 >c0000000023e7a80: f1 f1 01 f2 f2 f2 00 00 00 00 00 00 00 00 00 00 ^ c0000000023e7b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c0000000023e7b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== Document that a 16-byte buffer is requred, and provide it in udbg. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2017-09-07Merge tag 'powerpc-4.14-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Nothing really major this release, despite quite a lot of activity. Just lots of things all over the place. Some things of note include: - Access via perf to a new type of PMU (IMC) on Power9, which can count both core events as well as nest unit events (Memory controller etc). - Optimisations to the radix MMU TLB flushing, mostly to avoid unnecessary Page Walk Cache (PWC) flushes when the structure of the tree is not changing. - Reworks/cleanups of do_page_fault() to modernise it and bring it closer to other architectures where possible. - Rework of our page table walking so that THP updates only need to send IPIs to CPUs where the affected mm has run, rather than all CPUs. - The size of our vmalloc area is increased to 56T on 64-bit hash MMU systems. This avoids problems with the percpu allocator on systems with very sparse NUMA layouts. - STRICT_KERNEL_RWX support on PPC32. - A new sched domain topology for Power9, to capture the fact that pairs of cores may share an L2 cache. - Power9 support for VAS, which is a new mechanism for accessing coprocessors, and initial support for using it with the NX compression accelerator. - Major work on the instruction emulation support, adding support for many new instructions, and reworking it so it can be used to implement the emulation needed to fixup alignment faults. - Support for guests under PowerVM to use the Power9 XIVE interrupt controller. And probably that many things again that are almost as interesting, but I had to keep the list short. Plus the usual fixes and cleanups as always. Thanks to: Alexey Kardashevskiy, Alistair Popple, Andreas Schwab, Aneesh Kumar K.V, Anju T Sudhakar, Arvind Yadav, Balbir Singh, Benjamin Herrenschmidt, Bhumika Goyal, Breno Leitao, Bryant G. Ly, Christophe Leroy, Cédric Le Goater, Dan Carpenter, Dou Liyang, Frederic Barrat, Gautham R. Shenoy, Geliang Tang, Geoff Levand, Hannes Reinecke, Haren Myneni, Ivan Mikhaylov, John Allen, Julia Lawall, LABBE Corentin, Laurentiu Tudor, Madhavan Srinivasan, Markus Elfring, Masahiro Yamada, Matt Brown, Michael Neuling, Murilo Opsfelder Araujo, Nathan Fontenot, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Rashmica Gupta, Rob Herring, Rui Teng, Sam Bobroff, Santosh Sivaraj, Scott Wood, Shilpasri G Bhat, Sukadev Bhattiprolu, Suraj Jitindar Singh, Tobin C. Harding, Victor Aoqui" * tag 'powerpc-4.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (321 commits) powerpc/xive: Fix section __init warning powerpc: Fix kernel crash in emulation of vector loads and stores powerpc/xive: improve debugging macros powerpc/xive: add XIVE Exploitation Mode to CAS powerpc/xive: introduce H_INT_ESB hcall powerpc/xive: add the HW IRQ number under xive_irq_data powerpc/xive: introduce xive_esb_write() powerpc/xive: rename xive_poke_esb() in xive_esb_read() powerpc/xive: guest exploitation of the XIVE interrupt controller powerpc/xive: introduce a common routine xive_queue_page_alloc() powerpc/sstep: Avoid used uninitialized error axonram: Return directly after a failed kzalloc() in axon_ram_probe() axonram: Improve a size determination in axon_ram_probe() axonram: Delete an error message for a failed memory allocation in axon_ram_probe() powerpc/powernv/npu: Move tlb flush before launching ATSD powerpc/macintosh: constify wf_sensor_ops structures powerpc/iommu: Use permission-specific DEVICE_ATTR variants powerpc/eeh: Delete an error out of memory message at init time powerpc/mm: Use seq_putc() in two functions macintosh: Convert to using %pOF instead of full_name ...
2017-08-28tty: hvc_vio: constify vio_device_idArvind Yadav
vio_device_id are not supposed to change at runtime. All functions working with vio_device_id provided by <asm/vio.h> work with const vio_device_id. So mark the non-const structs as const. Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-31powerpc/udbg: Reduce the footgun potential of EARLY_DEBUG_LPAR(_HVSI)Michael Ellerman
For debugging very early boot problems we have CONFIG_PPC_EARLY_DEBUG, which allows configuring the kernel such that it unconditionally writes to a particular type of console, regardless of whether that console exists or not. This is useful sometimes when the kernel crashes before it can even determine what platform it's on, and therefore what consoles exist. However if you boot a kernel built this way on a different platform, it will generally crash because it writes to a console that doesn't exist. A particularly nasty instance of this is if you enable the hypervisor console early debug, and then boot that kernel on bare metal. The result is that the kernel calls "the hypervisor" very early in boot, but the kernel *is* the hypervisor, so we jump to the system call handler and start executing all sorts of code that isn't ready to be run. This may lead to a machine check or check stop depending on how lucky you are. Luckily there is an easy way to avoid this particular case. We simply read the MSR before installing the hooks, and if we see MSR_HV is set then we are the hypervisor and we definitely should not use the hypervisor console. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-07-30tty: Convert to using %pOF instead of full_nameRob Herring
Now that we have a custom printf format specifier, convert users of full_name to use %pOF instead. This is preparation to remove storing of the full path string for each node. Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: David S. Miller <davem@davemloft.net> Cc: Jiri Slaby <jslaby@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "David S. Miller" <davem@davemloft.net> Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-serial@vger.kernel.org Cc: sparclinux@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06drivers/tty: make hvc/hvc_vio.c explicitly non-modularPaul Gortmaker
The Kconfig currently controlling compilation of this code is: drivers/tty/hvc/Kconfig:config HVC_CONSOLE drivers/tty/hvc/Kconfig: bool "pSeries Hypervisor Virtual Console support" ...meaning that it currently is not being built as a module by anyone. Lets remove the modular code that is essentially orphaned, so that when reading the driver there is no doubt it is builtin-only. Since module_init translates to device_initcall in the non-modular case, the init ordering remains unchanged with this commit. We explicitly disallow a driver unbind, since that doesn't have a sensible use case anyway, and it allows us to drop the ".remove" code for non-modular drivers. We don't replace module.h with init.h since the file already has that. Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Anton Blanchard <anton@samba.org> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-02powerpc: Remove powerpc specific cmd_lineAnton Blanchard
There is no need for yet another copy of the command line, just use boot_command_line like everyone else. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-06-26tty: Update hypervisor tty drivers to use core stdout parsing code.Grant Likely
The evh_bytechan, hvc_opal and hvc_vio drivers all open code the parsing of the stdout node in the device tree. This patch simplifies the driver by removing the duplicated functionality. Signed-off-by: Grant Likely <grant.likely@linaro.org>
2013-09-26hvc_vio: Do not override preferred console set by kernel parameterBen Hutchings
The original version of this was done by Bastian Blank, who wrote: > The problem is the following: > - Architecture specific code sets preferred console to something bogus. > - Command line handling tries to set preferred console but is overruled > by the old setting. > > The udbg0 console is a boot console and independant. References: http://bugs.debian.org/492703 Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-14powerpc: Make device tree accesses in HVC VIO console endian safeAnton Blanchard
Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-12-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial branch from Jiri Kosina: "Usual stuff -- comment/printk typo fixes, documentation updates, dead code elimination." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) HOWTO: fix double words typo x86 mtrr: fix comment typo in mtrr_bp_init propagate name change to comments in kernel source doc: Update the name of profiling based on sysfs treewide: Fix typos in various drivers treewide: Fix typos in various Kconfig wireless: mwifiex: Fix typo in wireless/mwifiex driver messages: i2o: Fix typo in messages/i2o scripts/kernel-doc: check that non-void fcts describe their return value Kernel-doc: Convention: Use a "Return" section to describe return values radeon: Fix typo and copy/paste error in comments doc: Remove unnecessary declarations from Documentation/accounting/getdelays.c various: Fix spelling of "asynchronous" in comments. Fix misspellings of "whether" in comments. eisa: Fix spelling of "asynchronous". various: Fix spelling of "registered" in comments. doc: fix quite a few typos within Documentation target: iscsi: fix comment typos in target/iscsi drivers treewide: fix typo of "suport" in various comments and Kconfig treewide: fix typo of "suppport" in various comments ...
2012-11-21tty: remove use of __devexitBill Pemberton
CONFIG_HOTPLUG is going away as an option so __devexit is no longer needed. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Alan Cox <alan@linux.intel.com> Acked-by: Tobias Klauser <tklauser@distanz.ch> Cc: Lucas Tavares <lucaskt@linux.vnet.ibm.com> Cc: Daniel Walker <dwalker@fifo99.com> Cc: Bryan Huntsman <bryanh@codeaurora.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Tony Prisk <linux@prisktech.co.nz> Acked-by: David Brown <davidb@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-21tty: remove use of __devinitdataBill Pemberton
CONFIG_HOTPLUG is going away as an option so __devinitdata is no longer needed. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Cc: Alan Cox <alan@linux.intel.com> Cc: Peter Korsgaard <jacmet@sunsite.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-21tty: remove use of __devinitBill Pemberton
CONFIG_HOTPLUG is going away as an option so __devinit is no longer needed. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: Alan Cox <alan@linux.intel.com> Cc: Lucas Tavares <lucaskt@linux.vnet.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Tony Prisk <linux@prisktech.co.nz> Acked-by: Tobias Klauser <tklauser@distanz.ch> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-28Merge branch 'master' into for-nextJiri Kosina
Sync up with Linus' tree to be able to apply Cesar's patch against newer version of the code. Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-10-25tty: Fix typo in tty driversMasanari Iida
Correct spelling typo in debug messages within tty drivers. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-09-05hvc_vio: Improve registration of udbg backendBenjamin Herrenschmidt
The pseries hvterm driver only registers a udbg backend (for xmon and other low level debugging mechanisms) when hvc0 is recognized as the firmware console at boot time, not if it's detected later on, for example because the firmware is using a graphics card. This can make debugging challenging especially under X11, and there's really no good reason for that limitation, so let's hookup udbg whenever hvc0 is detected instead. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-03-28powerpc+sparc/vio: Modernize driver registrationBenjamin Herrenschmidt
This makes vio_register_driver() get the module owner & name at compile time like PCI drivers do, and adds a name pointer directly in struct vio_driver to avoid having to explicitly initialize the embedded struct device. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: David S. Miller <davem@davemloft.net>
2012-03-21tty/hvc_vio: FW_FEATURE_ISERIES is no longer selectableStephen Rothwell
so remove the code that tests for it. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-10-31tty: Add module.h to drivers/tty users who just expect it there.Paul Gortmaker
We are cleaning up the issue that means module.h is omnipresent. These tty users are the people who implictly are relying on that. Fix up the real users to call out the include that they really need. In the case of jsm_driver.c file, it had moduleparam.h but that isn't enough and it needs the full module.h Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-07-20powerpc/pseries: Fix hvc_vio.c build due to recent changesBenjamin Herrenschmidt
For some reason I didn't notice the failure in my test builds, probably lacking caffeine or something... Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-07-19powerpc/pseries: Fix hvterm_raw_get_chars to accept < 16 chars, fixing xmonAnton Blanchard
commit 4d2bb3f50036 (powerpc/pseries: Re-implement HVSI as part of hvc_vio) changed udbg_getc to be based on hvterm_raw_get_chars. Unfortunately hvterm_raw_get_chars returns -EAGAIN if you ask for anything less than 16 characters. As a result xmon no longer accepts input and prints a stream of junk to the screen. The recent change highlights a problem that xmon on pseries VIO has had all along, that it can drop input characters. The issue is the hypervisor call does not take a count argument and can return up to 16 characters. This patch adds a per vterm buffer that we copy input data into and give it out as requested. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-07-01powerpc/hvsi: Fix conflict with old HVSI driverBenjamin Herrenschmidt
A mix of think & mismerge on my side caused a problem where both the new hvsi_lib and the old hvsi driver gets compiled and try to define symbols with the same name. This fixes it by renaming the hvsi_lib exported symbols. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-06-29powerpc/pseries: Move hvsi support into a libraryBenjamin Herrenschmidt
This will allow a different backend to share it Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-06-29powerpc/pseries: Re-implement HVSI as part of hvc_vioBenjamin Herrenschmidt
On pseries machines, consoles are provided by the hypervisor using a low level get_chars/put_chars type interface. However, this is really just a transport to the service processor which implements them either as "raw" console (networked consoles, HMC, ...) or as "hvsi" serial ports. The later is a simple packet protocol on top of the raw character interface that is supposed to convey additional "serial port" style semantics. In practice however, all it does is provide a way to read the CD line and set/clear our DTR line, that's it. We currently implement the "raw" protocol as an hvc console backend (/dev/hvcN) and the "hvsi" protocol using a separate tty driver (/dev/hvsi0). However this is quite impractical. The arbitrary difference between the two type of devices has been a major source of user (and distro) confusion. Additionally, there's an additional mini -hvsi implementation in the pseries platform code for our low level debug console and early boot kernel messages, which means code duplication, though that low level variant is impractical as it's incapable of doing the initial protocol negociation to establish the link to the FSP. This essentially replaces the dedicated hvsi driver and the platform udbg code completely by extending the existing hvc_vio backend used in "raw" mode so that: - It now supports HVSI as well - We add support for hvc backend providing tiocm{get,set} - It also provides a udbg interface for early debug and boot console This is overall less code, though this will only be obvious once we remove the old "hvsi" driver, which is still available for now. When the old driver is enabled, the new code still kicks in for the low level udbg console, replacing the old mini implementation in the platform code, it just doesn't provide the higher level "hvc" interface. In addition to producing generally simler code, this has several benefits over our current situation: - The user/distro only has to deal with /dev/hvcN for the hypervisor console, avoiding all sort of confusion that has plagued us in the past - The tty, kernel and low level debug console all use the same code base which supports the full protocol establishment process, thus the console is now available much earlier than it used to be with the old HVSI driver. The kernel console works much earlier and udbg is available much earlier too. Hackers can enable a hard coded very-early debug console as well that works with HVSI (previously that was only supported for the "raw" mode). I've tried to keep the same semantics as hvsi relative to how I react to things like CD changes, with some subtle differences though: - I clear DTR on close if HUPCL is set - Current hvsi triggers a hangup if it detects a up->down transition on CD (you can still open a console with CD down). My new implementation triggers a hangup if the link to the FSP is severed, and severs it upon detecting a up->down transition on CD. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-01-13tty: move hvc drivers to drivers/tty/hvc/Greg Kroah-Hartman
As requested by Arnd Bergmann, the hvc drivers are now moved to the drivers/tty/hvc/ directory. The virtio_console.c driver was also moved, as it required the hvc_console.h file to be able to be built, and it really is a hvc driver. Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>