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2017-08-28serial: pch_uart: Make port type explicitAndy Shevchenko1-20/+15
It used to be a gap in port definitions after PORT_MAX_8250. Since the new drivers are coming the gap become shorter and shorter until the commit a2d6a987bfe4 ("serial: 8250: Add new port type for TI DA8xx/66AK2x") completely removed it. So, while type here is just a formality, make things a little bit more explicit for this driver and move port types to UAPI header. Note, it uses two types for now. Fixes: fddceb8b5399 ("tty: 8250: Add 64byte UART support for FSL platforms") Cc: Priyanka Jain <Priyanka.Jain@freescale.com> Cc: Poonam Aggrwal <poonam.aggrwal@freescale.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28serial: core: remove unneeded irq_wake flagAndy Shevchenko1-6/+3
There is no need to duplicate a flag which IRQ core takes care of. Replace custom flag by IRQ core API that retrieves its state. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28serial: stm32-usart: Avoid using irq_wake flagAndy Shevchenko1-1/+1
There is no need to duplicate a flag which IRQ core takes care of. Replace custom flag by IRQ core API that retrieves its state. Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28serial: st-asc: Avoid using irq_wake flagAndy Shevchenko1-1/+1
There is no need to duplicate a flag which IRQ core takes care of. Replace custom flag by IRQ core API that retrieves its state. Cc: Patrice Chotard <patrice.chotard@st.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28serial: fsl_lpuart: Avoid using irq_wake flagAndy Shevchenko1-4/+9
There is no need to duplicate a flag which IRQ core takes care of. Replace custom flag by IRQ core API that retrieves its state. Cc: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com> Cc: Dong Aisheng <aisheng.dong@nxp.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28tty: serial: msm: Move request_irq to the end of startupNeeraj Upadhyay1-5/+14
Move the request_irq() call to the end of the msm_startup(), so that we don't handle interrupts while msm_startup() is running. This avoids potential races while initialization is in progress. For example, consider below scenario where rx handler reads the intermediate value of dma->chan, set in msm_request_rx_dma(), and tries to do dma mapping, which results in data abort. uart_port_startup() msm_startup() request_irq() ... msm_request_rx_dma() ... dma->chan = dma_request_slave_channel_reason(dev, "rx"); <UART RX IRQ> msm_uart_irq() msm_handle_rx_dm() msm_start_rx_dma() dma->desc = dma_map_single() <data abort> Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org> Reviewd-by: Andy Gross <andy.gross@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28serial: pch_uart: Remove unneeded NULL checkFabio Estevam1-2/+1
There is no need to do a NULL check for debugfs_remove(). Quoting Documentation/filesystems/debugfs.txt: "The dentry value can be NULL, in which case nothing will be removed." , so remove the unneeded NULL check. Signed-off-by: Fabio Estevam <festevam@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28tty: serial: sprd: fix error return code in sprd_probe()Gustavo A. R. Silva1-2/+2
platform_get_irq() returns an error code, but the sprd_serial driver ignores it and always returns -ENODEV. This is not correct and, prevents -EPROBE_DEFER from being propagated properly. Also, notice that platform_get_irq() no longer returns 0 on error: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e330b9a6bb35dc7097a4f02cb1ae7b6f96df92af Print and propagate the return value of platform_get_irq on failure. This issue was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28serial: meson: constify uart_ops structuresJulia Lawall1-1/+1
These uart_ops structures are only stored in the ops field of a uart_port structure and this fields is const, so the uart_ops structures can also be const. Done with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28serial: owl: constify uart_ops structuresJulia Lawall1-1/+1
These uart_ops structures are only stored in the ops field of a uart_port structure and this fields is const, so the uart_ops structures can also be const. Done with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28serial: stm32: fix pio transmit timeoutGerald Baeza1-1/+1
100µs was too short for low speed transmission (9600bps) Signed-off-by: Gerald Baeza <gerald.baeza@st.com> Signed-off-by: Bich Hemon <bich.hemon@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28serial: pl011: constify amba_idArvind Yadav1-1/+1
amba_id are not supposed to change at runtime. All functions working with const amba_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>
2017-08-28serial: pl010: constify amba_idArvind Yadav1-1/+1
amba_id are not supposed to change at runtime. All functions working with const amba_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>
2017-08-28tty: amba-pl011: constify vendor_data structuresJulia Lawall1-2/+2
These vendor_data structures are only stored in the vendor field of the uart_amba_port structure, as defined in the same file, and this field is declared as const. Thus the vendor_data structures can be const too. Done with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28tty: undo export of tty_open_by_driverOkash Khawaja1-2/+1
Since we have tty_kopen, we no longer need to export tty_open_by_driver. This patch makes this function static. Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28tty: resolve tty contention between kernel and user spaceOkash Khawaja1-5/+95
The commit 12e84c71b7d4 ("tty: export tty_open_by_driver") exports tty_open_by_device to allow tty to be opened from inside kernel which works fine except that it doesn't handle contention with user space or another kernel-space open of the same tty. For example, opening a tty from user space while it is kernel opened results in failure and a kernel log message about mismatch between tty->count and tty's file open count. This patch makes kernel access to tty exclusive, so that if a user process or kernel opens a kernel opened tty, it gets -EBUSY. It does this by adding TTY_KOPENED flag to tty->flags. When this flag is set, tty_open_by_driver returns -EBUSY. Instead of overloading tty_open_by_driver for both kernel and user space, this patch creates a separate function tty_kopen which closely follows tty_open_by_driver. tty_kclose closes the tty opened by tty_kopen. To address the mismatch between tty->count and #fd's, this patch adds #kopen's to the count before comparing it with tty->count. That way check_tty_count reflects correct usage count. Returning -EBUSY on tty open is a change in the interface. I have tested this with minicom, picocom and commands like "echo foo > /dev/ttyS0". They all correctly report "Device or resource busy" when the tty is already kernel opened. Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-24pty: Repair TIOCGPTPEEREric W. Biederman2-37/+30
The implementation of TIOCGPTPEER has two issues. When /dev/ptmx (as opposed to /dev/pts/ptmx) is opened the wrong vfsmount is passed to dentry_open. Which results in the kernel displaying the wrong pathname for the peer. The second is simply by caching the vfsmount and dentry of the peer it leaves them open, in a way they were not previously Which because of the inreased reference counts can cause unnecessary behaviour differences resulting in regressions. To fix these move the ioctl into tty_io.c at a generic level allowing the ioctl to have access to the struct file on which the ioctl is being called. This allows the path of the slave to be derived when opening the slave through TIOCGPTPEER instead of requiring the path to the slave be cached. Thus removing the need for caching the path. A new function devpts_ptmx_path is factored out of devpts_acquire and used to implement a function devpts_mntget. The new function devpts_mntget takes a filp to perform the lookup on and fsi so that it can confirm that the superblock that is found by devpts_ptmx_path is the proper superblock. v2: Lots of fixes to make the code actually work v3: Suggestions by Linus - Removed the unnecessary initialization of filp in ptm_open_peer - Simplified devpts_ptmx_path as gotos are no longer required [ This is the fix for the issue that was reverted in commit 143c97cc6529, but this time without breaking 'pbuilder' due to increased reference counts - Linus ] Fixes: 54ebbfb16034 ("tty: add TIOCGPTPEER ioctl") Reported-by: Christian Brauner <christian.brauner@canonical.com> Reported-and-tested-by: Stefan Lippers-Hollmann <s.l-h@gmx.de> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-24x86/lguest: Remove lguest supportJuergen Gross1-1/+1
Lguest seems to be rather unused these days. It has seen only patches ensuring it still builds the last two years and its official state is "Odd Fixes". Remove it in order to be able to clean up the paravirt code. Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: boris.ostrovsky@oracle.com Cc: lguest@lists.ozlabs.org Cc: rusty@rustcorp.com.au Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/20170816173157.8633-3-jgross@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-23Revert "pty: fix the cached path of the pty slave file descriptor in the master"Linus Torvalds1-5/+2
This reverts commit c8c03f1858331e85d397bacccd34ef409aae993c. It turns out that while fixing the ptmx file descriptor to have the correct 'struct path' to the associated slave pty is a really good thing, it breaks some user space tools for a very annoying reason. The problem is that /dev/ptmx and its associated slave pty (/dev/pts/X) are on different mounts. That was what caused us to have the wrong path in the first place (we would mix up the vfsmount of the 'ptmx' node, with the dentry of the pty slave node), but it also means that now while we use the right vfsmount, having the pty master open also keeps the pts mount busy. And it turn sout that that makes 'pbuilder' very unhappy, as noted by Stefan Lippers-Hollmann: "This patch introduces a regression for me when using pbuilder 0.228.7[2] (a helper to build Debian packages in a chroot and to create and update its chroots) when trying to umount /dev/ptmx (inside the chroot) on Debian/ unstable (full log and pbuilder configuration file[3] attached). [...] Setting up build-essential (12.3) ... Processing triggers for libc-bin (2.24-15) ... I: unmounting dev/ptmx filesystem W: Could not unmount dev/ptmx: umount: /var/cache/pbuilder/build/1340/dev/ptmx: target is busy (In some cases useful info about processes that use the device is found by lsof(8) or fuser(1).)" apparently pbuilder tries to unmount the /dev/pts filesystem while still holding at least one master node open, which is arguably not very nice, but we don't break user space even when fixing other bugs. So this commit has to be reverted. I'll try to figure out a way to avoid caching the path to the slave pty in the master pty. The only thing that actually wants that slave pty path is the "TIOCGPTPEER" ioctl, and I think we could just recreate the path at that time. Reported-by: Stefan Lippers-Hollmann <s.l-h@gmx.de> Cc: Eric W Biederman <ebiederm@xmission.com> Cc: Christian Brauner <christian.brauner@canonical.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-22parisc/8250_gsc: Fix section mismatchesHelge Deller1-4/+4
Signed-off-by: Helge Deller <deller@gmx.de>
2017-08-22parisc/mux: Fix section mismatchesHelge Deller1-7/+7
Signed-off-by: Helge Deller <deller@gmx.de>
2017-08-17pty: fix the cached path of the pty slave file descriptor in the masterLinus Torvalds1-2/+5
Christian Brauner reported that if you use the TIOCGPTPEER ioctl() to get a slave pty file descriptor, the resulting file descriptor doesn't look right in /proc/<pid>/fd/<fd>. In particular, he wanted to use readlink() on /proc/self/fd/<fd> to get the pathname of the slave pty (basically implementing "ptsname{_r}()"). The reason for that was that we had generated the wrong 'struct path' when we create the pty in ptmx_open(). In particular, the dentry was correct, but the vfsmount pointed to the mount of the ptmx node. That _can_ be correct - in case you use "/dev/pts/ptmx" to open the master - but usually is not. The normal case is to use /dev/ptmx, which then looks up the pts/ directory, and then the vfsmount of the ptmx node is obviously the /dev directory, not the /dev/pts/ directory. We actually did have the right vfsmount available, but in the wrong place (it gets looked up in 'devpts_acquire()' when we get a reference to the pts filesystem), and so ptmx_open() used the wrong mnt pointer. The end result of this confusion was that the pty worked fine, but when if you did TIOCGPTPEER to get the slave side of the pty, end end result would also work, but have that dodgy 'struct path'. And then when doing "d_path()" on to get the pathname, the vfsmount would not match the root of the pts directory, and d_path() would return an empty pathname thinking that the entry had escaped a bind mount into another mount. This fixes the problem by making devpts_acquire() return the vfsmount for the pts filesystem, allowing ptmx_open() to trivially just use the right mount for the pts dentry, and create the proper 'struct path'. Reported-by: Christian Brauner <christian.brauner@ubuntu.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-15sparc64: vcc: Add install & cleanup TTY operationsJag Raman1-0/+73
Add handlers to support TTY install & cleanup operations Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15sparc64: vcc: Add break_ctl TTY operationJag Raman1-0/+35
Add handler to support TTY break_ctl operation Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15sparc64: vcc: Add chars_in_buffer TTY operationJag Raman1-5/+29
Add handler to support TTY chars_in_buffer operation Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15sparc64: vcc: Add write & write_room TTY operationsJag Raman1-3/+98
Add handlers to support TTY write & write_room operations Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15sparc64: vcc: Add hangup TTY operationJag Raman1-0/+41
Add handler to support TTY hangup operation Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15sparc64: vcc: Add open & close TTY operationsJag Raman1-1/+62
Add handlers to support TTY open & close operations Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15sparc64: vcc: Enable LDC event processing engineJag Raman1-0/+34
Enable event processing engine to handle LDC events Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15sparc64: vcc: Add RX & TX timer for delayed LDC operationJag Raman1-2/+193
Add RX & TX timers to perform delayed/asynchronous LDC read and write operations. Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15sparc64: vcc: Create sysfs attribute groupJag Raman1-0/+82
Create sysfs attribute group to show the domain name and send break command. Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15sparc64: vcc: Enable VCC port probe and removalJag Raman1-0/+379
Enables VCC port probe and removal to initialize and terminate VCC ports respectively. When a device/port matching the VCC driver is added, the probe function is invoked along with a reference to the device. remove function is called when the device is removed. Also add APIs to cache and retrieve VCC ports from a VCC table Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15sparc64: vcc: TTY driver initialization and cleanupJag Raman1-1/+82
Allocate and register TTY driver during module init. Cleanup TTY driver during module exit. Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15sparc64: vcc: Add VCC debug message macrosJag Raman1-0/+41
Add C macros to print debug messages from VCC module Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15sparc64: vcc: Enable VCC module in linuxJag Raman3-0/+24
Enables the Virtual Console Concentrator (VCC) module in linux kernel Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-14Merge 4.13-rc5 into tty-nextGreg Kroah-Hartman3-27/+39
We want the fixes in here, and we resolve the merge issue in the 8250_core.c file. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-13Merge tag 'tty-4.13-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/ttyLinus Torvalds2-24/+36
Pull tty/serial fixes from Greg KH: "Here are two tty serial driver fixes for 4.13-rc5. One is a revert of a -rc1 patch that turned out to not be a good idea, and the other is a fix for the pl011 serial driver. Both have been in linux-next with no reported issues" * tag 'tty-4.13-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: Revert "serial: Delete dead code for CIR serial ports" tty: pl011: fix initialization order of QDF2400 E44
2017-08-02tty: fix __tty_insert_flip_char regressionArnd Bergmann1-1/+2
Sergey noticed a small but fatal mistake in __tty_insert_flip_char, leading to an oops in an interrupt handler when using any serial port. The problem is that I accidentally took the tty_buffer pointer before calling __tty_buffer_request_room(), which replaces the buffer. This moves the pointer lookup to the right place after allocating the new buffer space. Fixes: 979990c62848 ("tty: improve tty_insert_flip_char() fast path") Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-01Revert "serial: Delete dead code for CIR serial ports"Sean Young1-6/+17
This reverts commit 1104321a7b3bb670dc614ffa7958c553e7b3b836. The code is not dead at all and breaks winbond-cir. Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled 00:02: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A 00:03: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a CIR port lirc lirc0: lirc_dev: driver ir-lirc-codec (winbond-cir) registered at minor = 0 winbond-cir 00:03: Region 0x2f8-0x2ff already in use! winbond-cir: probe of 00:03 failed with error -16 Signed-off-by: Sean Young <sean@mess.org> Reviewed-by: Matthias Brugger <mbrugger@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-01gpio: exar: Use correct property prefix and document bindingsJan Kiszka1-2/+2
The device-specific property should be prefixed with the vendor name, not "linux,", as Linus Walleij pointed out. Change this and document the bindings of this platform device. We didn't ship the old binding in a release yet. So we can still change it without breaking an official API. Fixes: 380b1e2f3a2f ("gpio-exar/8250-exar: Make set of exported GPIOs configurable") Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-07-31powerpc/udbg: Reduce the footgun potential of EARLY_DEBUG_LPAR(_HVSI)Michael Ellerman1-0/+12
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: pl011: fix initialization order of QDF2400 E44Timur Tabi1-18/+19
The work-around for Qualcomm Technologies QDF2400 Erratum 44 hinges on a global variable defined in the pl011 driver. The ACPI SPCR parsing code determines whether the work-around is needed, and if so, it changes the console name from "pl011" to "qdf2400_e44". The expectation is that the pl011 driver will implement the work-around when it sees the console name. The global variable qdf2400_e44_present is set when that happens. The problem is that work-around needs to be enabled when the pl011 driver probes, not when the console name is queried. However, sbsa_probe() is called before pl011_console_match(). The work-around appeared to work previously because the default console on QDF2400 platforms was always ttyAMA1. The first time sbsa_probe() is called (for ttyAMA0), qdf2400_e44_present is still false. Then pl011_console_match() is called, and it sets qdf2400_e44_present to true. All subsequent calls to sbsa_probe() enable the work-around. The solution is to move the global variable into spcr.c and let the pl011 driver query it during probe time. This works because all QDF2400 platforms require SPCR, so parse_spcr() will always be called. pl011_console_match still checks for the "qdf2400_e44" console name, but it doesn't do anything else special. Fixes: 5a0722b898f8 ("tty: pl011: use "qdf2400_e44" as the earlycon name for QDF2400 E44") Tested-by: Jeffrey Hugo <jhugo@codeaurora.org> Signed-off-by: Timur Tabi <timur@codeaurora.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-30tty: improve tty_insert_flip_char() slow pathArnd Bergmann1-2/+3
While working on improving the fast path of tty_insert_flip_char(), I noticed that by calling tty_buffer_request_room(), we needlessly move to the separate flag buffer mode for the tty, even when all characters use TTY_NORMAL as the flag. This changes the code to call __tty_buffer_request_room() with the correct flag, which will then allocate a regular buffer when it rounds out of space but no special flags have been used. I'm guessing that this is the behavior that Peter Hurley intended when he introduced the compacted flip buffers. Fixes: acc0f67f307f ("tty: Halve flip buffer GFP_ATOMIC memory consumption") Cc: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-30tty: improve tty_insert_flip_char() fast pathArnd Bergmann1-0/+24
kernelci.org reports a crazy stack usage for the VT code when CONFIG_KASAN is enabled: drivers/tty/vt/keyboard.c: In function 'kbd_keycode': drivers/tty/vt/keyboard.c:1452:1: error: the frame size of 2240 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] The problem is that tty_insert_flip_char() gets inlined many times into kbd_keycode(), and also into other functions, and each copy requires 128 bytes for stack redzone to check for a possible out-of-bounds access on the 'ch' and 'flags' arguments that are passed into tty_insert_flip_string_flags as a variable-length string. This introduces a new __tty_insert_flip_char() function for the slow path, which receives the two arguments by value. This completely avoids the problem and the stack usage goes back down to around 100 bytes. Without KASAN, this is also slightly better, as we don't have to spill the arguments to the stack but can simply pass 'ch' and 'flag' in registers, saving a few bytes in .text for each call site. This should be backported to linux-4.0 or later, which first introduced the stack sanitizer in the kernel. Cc: stable@vger.kernel.org Fixes: c420f167db8c ("kasan: enable stack instrumentation") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-30serial: fsl_lpuart: clear unsupported options in .rs485_config()Uwe Kleine-König1-0/+5
The struct serial_rs485 parameter is both input and output and is supposed to hold the actually used configuration on return. So clear unsupported settings. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-30serial: 8250_pci: Enable device after we check black listAndy Shevchenko1-10/+29
If the board we are guessing has been listed in black list we don't need to enable it twice. The associated driver, if any, will take care about proper initialization. To achieve this we split out two helper functions, i.e. serial_pci_is_class_communication() and serial_pci_is_blacklisted() which will be called before pcim_enable_device(). We can do this since PCI specification requires class, device and vendor ID registers to be always present in the configuration space. As an example what happens before this patch applied (These are some debug prints, don't search for them in kernel sources): serial 0000:00:04.1: Mapped GSI28 to IRQ28 serial 0000:00:04.2: Mapped GSI29 to IRQ29 serial 0000:00:04.3: Mapped GSI54 to IRQ54 8250_mid 0000:00:04.1: Mapped GSI28 to IRQ28 8250_mid 0000:00:04.2: Mapped GSI29 to IRQ29 8250_mid 0000:00:04.3: Mapped GSI54 to IRQ54 After we will have just last three lines out of above. 8250_mid 0000:00:04.1: Mapped GSI28 to IRQ28 8250_mid 0000:00:04.2: Mapped GSI29 to IRQ29 8250_mid 0000:00:04.3: Mapped GSI54 to IRQ54 While here, correct a value of error code mentioned in the comment of serial_pci_guess_board(). Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-30serial: core: move UPF_NO_TXEN_TEST to quirks and renameAndy Shevchenko3-10/+10
First 16 bits in the flags field are user-visible except UPF_NO_TXEN_TEST. To keep it clean we introduce internal quirks and move UPF_NO_TXEN_TEST to them. Rename the constant to UPQ_NO_TXEN_TEST to distinguish with port flags. Users are converted accordingly. The quirks field might be extended later to hold the additional ones. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-30serial: core: enforce type for upf_t when copyingAndy Shevchenko1-2/+2
upf_t is a bitwise defined type and any assignment from different, but compatible, types makes static analyzer unhappy. drivers/tty/serial/serial_core.c:793:29: warning: incorrect type in assignment (different base types) drivers/tty/serial/serial_core.c:793:29: expected int [signed] flags drivers/tty/serial/serial_core.c:793:29: got restricted upf_t [usertype] flags drivers/tty/serial/serial_core.c:867:19: warning: incorrect type in assignment (different base types) drivers/tty/serial/serial_core.c:867:19: expected restricted upf_t [usertype] new_flags drivers/tty/serial/serial_core.c:867:19: got int [signed] flags Enforce corresponding types when upf_t being assigned. Note, we need __force attribute due to the scope of variable. It's being used in user space with plain old type while kernel uses bitwise one. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-30serial: 8250_early: Remove __init marking from early writeJeffy Chen1-4/+4
The earlycon would be alive outside the init code in these cases: 1/ we have keep_bootcon in cmdline. 2/ we don't have a real console to switch to. So remove the __init marking to avoid invalid memory access. Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Brian Norris <briannorris@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-30serial: 8250_ingenic: Remove __init marking from early writeJeffy Chen1-4/+4
The earlycon would be alive outside the init code in these cases: 1/ we have keep_bootcon in cmdline. 2/ we don't have a real console to switch to. So remove the __init marking to avoid invalid memory access. Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Brian Norris <briannorris@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>