user/sven/linux.git/include/linux/serial_core.h, branch v4.9.162

serial: core: Make sure compiler barfs for 16-byte earlycon names

2018-08-03T05:55:25Z

[ Upstream commit c1c734cb1f54b062f7e67ffc9656d82f5b412b9c ] As part of bringup I ended up wanting to call an earlycon driver by a name that was exactly 16-bytes big, specifically "qcom_geni_serial". Unfortunately, when I tried this I found that things compiled just fine. They just didn't work. Specifically the compiler felt perfectly justified in initting the ".name" field of "struct earlycon_id" with the full 16-bytes and just skipping the '\0'. Needless to say, that behavior didn't seem ideal, but I guess someone must have allowed it for a reason. One way to fix this is to shorten the name field to 15 bytes and then add an extra byte after that nobody touches. This should always be initted to 0 and we're golden. There are, of course, other ways to fix this too. We could audit all the users of the "name" field and make them stop at both null termination or at 16 bytes. We could also just make the name field much bigger so that we're not likely to run into this. ...but both seem like we'll just hit the bug again. Signed-off-by: Douglas Anderson Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

earlycon: Use a pointer table to fix __earlycon_table stride

2018-05-01T22:13:09Z

commit dd709e72cb934eefd44de8d9969097173fbf45dc upstream. Commit 99492c39f39f ("earlycon: Fix __earlycon_table stride") tried to fix __earlycon_table stride by forcing the earlycon_id struct alignment to 32 and asking the linker to 32-byte align the __earlycon_table symbol. This fix was based on commit 07fca0e57fca92 ("tracing: Properly align linker defined symbols") which tried a similar fix for the tracing subsystem. However, this fix doesn't quite work because there is no guarantee that gcc will place structures packed into an array format. In fact, gcc 4.9 chooses to 64-byte align these structs by inserting additional padding between the entries because it has no clue that they are supposed to be in an array. If we are unlucky, the linker will assign symbol "__earlycon_table" to a 32-byte aligned address which does not correspond to the 64-byte aligned contents of section "__earlycon_table". To address this same problem, the fix to the tracing system was subsequently re-implemented using a more robust table of pointers approach by commits: 3d56e331b653 ("tracing: Replace syscall_meta_data struct array with pointer array") 654986462939 ("tracepoints: Fix section alignment using pointer array") e4a9ea5ee7c8 ("tracing: Replace trace_event struct array with pointer array") Let's use this same "array of pointers to structs" approach for EARLYCON_TABLE. Fixes: 99492c39f39f ("earlycon: Fix __earlycon_table stride") Signed-off-by: Daniel Kurtz Suggested-by: Aaron Durbin Reviewed-by: Rob Herring Tested-by: Guenter Roeck Reviewed-by: Guenter Roeck Cc: stable Signed-off-by: Greg Kroah-Hartman

ACPI: parse SPCR and enable matching console

2016-09-28T15:46:46Z

'ARM Server Base Boot Requiremets' [1] mentions SPCR (Serial Port Console Redirection Table) [2] as a mandatory ACPI table that specifies the configuration of serial console. Defer initialization of DT earlycon until ACPI/DT decision is made. Parse the ACPI SPCR table, setup earlycon if required, enable specified console. Thanks to Peter Hurley for explaining how this should work. [1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0044a/index.html [2] https://msdn.microsoft.com/en-us/library/windows/hardware/dn639132(v=vs.85).aspx Signed-off-by: Aleksey Makarov Acked-by: Rafael J. Wysocki Reviewed-by: Peter Hurley Tested-by: Kefeng Wang Tested-by: Christopher Covington Signed-off-by: Greg Kroah-Hartman

tty: serial_core: add tty NULL check to uart_tx_stopped

2016-09-15T10:37:09Z

Commit 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") created a case where a port used for a console does not get shutdown on tty closing. Then a call to uart_tx_stopped() segfaults because the tty is NULL. This could be fixed to restore old behavior, but we also want to allow tty_ports to work without a tty attached. So this change to allow a NULL tty_struct is needed either way. Fixes: 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") Reported-by: kernel test robot Signed-off-by: Rob Herring Signed-off-by: Greg Kroah-Hartman

serial: earlycon: Extend earlycon command line option to support 64-bit addresses

2016-09-02T13:03:35Z

earlycon implementation used "unsigned long" internally, but there are systems (ARM with LPAE) where sizeof(unsigned long) == 4 and uart is mapped beyond 4GiB address range. Switch to resource_size_t internally and replace obsoleted simple_strtoul() with kstrtoull(). Signed-off-by: Alexander Sverdlin Signed-off-by: Greg Kroah-Hartman

earlycon: mark earlycon code as __used iif the caller is built-in

2016-06-25T21:31:04Z

Keep earlycon related symbols only when CONFIG_SERIAL_EARLYCON is enabled and the driver is built-in. This will be helpful to clean up ifdefs surrounding earlycon code in serial drivers. Signed-off-by: Masahiro Yamada Acked-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman

serial: 8250: export get_mctrl function

2016-04-30T16:26:55Z

Exposes get_mctrl() function so that it can be overriden with platform specific implementation. Signed-off-by: Wan Ahmad Zainie Reviewed-by: Andy Shevchenko Reviewed-by: Heikki Krogerus Signed-off-by: Greg Kroah-Hartman

serial: core: Prevent unsafe uart port access, part 2

2016-04-30T16:26:55Z

For serial core operations not already excluded by holding port->mutex, use reference counting to protect deferencing the state->uart_port. Introduce helper functions, uart_port_ref() and uart_port_deref(), to wrap uart_port access, and helper macros, uart_port_lock() and uart_port_unlock(), to wrap combination uart_port access with uart port lock sections. Port removal in uart_remove_one_port() waits for reference count to drop to zero before detaching the uart port from struct uart_state. For functions only reading the tx circular buffer indexes (where the uart port lock is claimed to prevent concurrent users), a NULL uart port is simply ignored and the operation completes normally. For functions change the tx circular buffer indexes (where the uart port lock is claimed to prevent concurrent users), the operation is aborted if the uart port is NULL (ie., has been detached). Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

of: earlycon: Move address translation to of_setup_earlycon()

2016-02-07T06:07:37Z

Cleanup the early DT/earlycon separation; remove the 'addr' parameter from of_setup_earlycon() and get the uart phys addr directly with a new wrapper function, of_flat_dt_translate_addr(). Limit fdt_translate_address() to file scope. Acked-by: Rob Herring Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

of: earlycon: Initialize port fields from DT properties

2016-02-07T06:07:37Z

Read the optional "reg-offset", "reg-shift", "reg-io-width" and endianness properties and initialize the respective struct uart_port field if found. NB: These bindings are common to several drivers and the values merely indicate the default value; the registering earlycon setup() method can simply override the values if required. Acked-by: Rob Herring Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman