kernel/linux.git/drivers/hv/ring_buffer.c, branch v4.14.263

Drivers: hv: vmbus: Check for ring when getting debug info

2019-01-31T07:13:44+00:00

commit ba50bf1ce9a51fc97db58b96d01306aa70bc3979 upstream. fc96df16a1ce is good and can already fix the "return stack garbage" issue, but let's also improve hv_ringbuffer_get_debuginfo(), which would silently return stack garbage, if people forget to check channel->state or ring_info->ring_buffer, when using the function in the future. Having an error check in the function would eliminate the potential risk. Add a Fixes tag to indicate the patch depdendency. Fixes: fc96df16a1ce ("Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels") Cc: stable@vger.kernel.org Cc: K. Y. Srinivasan Cc: Haiyang Zhang Signed-off-by: Stephen Hemminger Signed-off-by: Dexuan Cui Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Fix ring buffer signaling

2018-03-28T16:24:34+00:00

commit 655296c8bbeffcf020558c4455305d597a73bde1 upstream. Fix bugs in signaling the Hyper-V host when freeing space in the host->guest ring buffer: 1. The interrupt_mask must not be used to determine whether to signal on the host->guest ring buffer 2. The ring buffer write_index must be read (via hv_get_bytes_to_write) *after* pending_send_sz is read in order to avoid a race condition 3. Comparisons with pending_send_sz must treat the "equals" case as not-enough-space 4. Don't signal if the pending_send_sz feature is not present. Older versions of Hyper-V that don't implement this feature will poll. Fixes: 03bad714a161 ("vmbus: more host signalling avoidance") Cc: Stable # 4.14 and above Signed-off-by: Michael Kelley Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

vmbus: add prefetch to ring buffer iterator

2017-07-17T15:16:05+00:00

When iterating over incoming ring elements from the host, prefetch the next descriptor so that it is cache hot. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

vmbus: more host signalling avoidance

2017-07-17T15:16:05+00:00

Don't signal host if it has disabled interrupts for that ring buffer. Check the feature bit to see if host supports pending send size flag. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

vmbus: eliminate duplicate cached index

2017-07-17T15:16:05+00:00

Don't need cached read index anymore now that packet iterator is used. The iterator has the original read index until the visible read_index is updated. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

vmbus: refactor hv_signal_on_read

2017-07-17T15:16:05+00:00

The function hv_signal_on_read was defined in hyperv.h and only used in one place in ring_buffer code. Clearer to just move it inline there. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

vmbus: simplify hv_ringbuffer_read

2017-07-17T15:15:10+00:00

With new iterator functions (and the double mapping) the ring buffer read function can be greatly simplified. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

Merge tag 'char-misc-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2017-05-05T02:15:35+00:00

Pull char/misc driver updates from Greg KH: "Here is the big set of new char/misc driver drivers and features for 4.12-rc1. There's lots of new drivers added this time around, new firmware drivers from Google, more auxdisplay drivers, extcon drivers, fpga drivers, and a bunch of other driver updates. Nothing major, except if you happen to have the hardware for these drivers, and then you will be happy :) All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (136 commits) firmware: google memconsole: Fix return value check in platform_memconsole_init() firmware: Google VPD: Fix return value check in vpd_platform_init() goldfish_pipe: fix build warning about using too much stack. goldfish_pipe: An implementation of more parallel pipe fpga fr br: update supported version numbers fpga: region: release FPGA region reference in error path fpga altera-hps2fpga: disable/unprepare clock on error in alt_fpga_bridge_probe() mei: drop the TODO from samples firmware: Google VPD sysfs driver firmware: Google VPD: import lib_vpd source files misc: lkdtm: Add volatile to intentional NULL pointer reference eeprom: idt_89hpesx: Add OF device ID table misc: ds1682: Add OF device ID table misc: tsl2550: Add OF device ID table w1: Remove unneeded use of assert() and remove w1_log.h w1: Use kernel common min() implementation uio_mf624: Align memory regions to page size and set correct offsets uio_mf624: Refactor memory info initialization uio: Allow handling of non page-aligned memory regions hangcheck-timer: Fix typo in comment ...

vmbus: expose debug info for drivers

2017-03-17T06:10:49+00:00

Allow driver to get debug information about state of the ring. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

hyperv: remove unnecessary return variable

2017-03-17T06:10:49+00:00

hv_ringbuffer_read cleanup. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman