Linux kernel stable tree (mirror) https://git.radix-linux.su/kernel/linux.git/atom?h=v4.14.286 2022-04-20T07:08:31+00:00 2022-04-20T07:08:31+00:00 Michael Kelley mikelley@microsoft.com 2022-03-27T15:25:10+00:00 urn:sha1:3e876ea92c97dc819891a79dd97882dffac62f8f [ Upstream commit b6cae15b5710c8097aad26a2e5e752c323ee5348 ] When reading a packet from a host-to-guest ring buffer, there is no memory barrier between reading the write index (to see if there is a packet to read) and reading the contents of the packet. The Hyper-V host uses store-release when updating the write index to ensure that writes of the packet data are completed first. On the guest side, the processor can reorder and read the packet data before the write index, and sometimes get stale packet data. Getting such stale packet data has been observed in a reproducible case in a VM on ARM64. Fix this by using virt_load_acquire() to read the write index, ensuring that reads of the packet data cannot be reordered before it. Preventing such reordering is logically correct, and with this change, getting stale data can no longer be reproduced. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/1648394710-33480-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 2019-01-31T07:13:44+00:00 Dexuan Cui decui@microsoft.com 2018-12-17T20:16:09+00:00 urn:sha1:be0cb9e226b7c594070eb64ef8c18f3793f63976 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 <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2018-03-28T16:24:34+00:00 Michael Kelley mhkelley@outlook.com 2018-03-05T05:24:08+00:00 urn:sha1:a1da0548a932db416d69ded28418dff11b05eecd 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 <stable@vger.kernel.org> # 4.14 and above Signed-off-by: Michael Kelley <mhkelley@outlook.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2017-07-17T15:16:05+00:00 Stephen Hemminger stephen@networkplumber.org 2017-06-25T19:30:29+00:00 urn:sha1:15e1674de747d58c5a6154ba6e85bc61e5009b08 When iterating over incoming ring elements from the host, prefetch the next descriptor so that it is cache hot. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2017-07-17T15:16:05+00:00 Stephen Hemminger stephen@networkplumber.org 2017-06-25T19:30:28+00:00 urn:sha1:03bad714a1619c0074eb44d6f217c505fe27030f 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 <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2017-07-17T15:16:05+00:00 Stephen Hemminger stephen@networkplumber.org 2017-06-25T19:30:27+00:00 urn:sha1:05d00bc94ac27d220d8a78e365d7fa3a26dcca17 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 <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2017-07-17T15:16:05+00:00 Stephen Hemminger stephen@networkplumber.org 2017-06-25T19:30:26+00:00 urn:sha1:8dd45f2ab005a1f3301296059b23b03ec3dbf79b 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 <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2017-07-17T15:15:10+00:00 Stephen Hemminger stephen@networkplumber.org 2017-06-25T19:30:24+00:00 urn:sha1:4226ff69a3dff78bead7d9a270423cd21f8d40b8 With new iterator functions (and the double mapping) the ring buffer read function can be greatly simplified. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2017-05-05T02:15:35+00:00 Linus Torvalds torvalds@linux-foundation.org 2017-05-05T02:07:10+00:00 urn:sha1:af82455f7dbd9dc20244d80d033721b30d22c065 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 ... 2017-03-17T06:10:49+00:00 Stephen Hemminger stephen@networkplumber.org 2017-03-05T01:27:18+00:00 urn:sha1:4827ee1dca5691c9fc568883170a568db94f9b38 Allow driver to get debug information about state of the ring. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>