[Devel] [PATCH hci-8.1 v2 0/6] ve/printk: Fix logs leakage via ve_printk called from IRQ context

[Vladimir Riabchun]

Printk function that printed logs to containers' dmesgs mostly used
get_exec_env() for getting VE. This is fine for task contexts and
might be wrong for IRQ contexts.

This patchset fixes this in the following way:
 - Report non-task usages of ve_printk function which get
   VE from current task. Do it with WARN so users will be
   frightened and will report it to us so we can fix it.
   This will also make an issue visible to our internal tests.
 - Reject printing to containers when VE is unreliable.
 - Calculate correct time offsets when calling printk. It can
   be delayed and the context might change, we can see time
   travels if time was taken from a different container.

With these fixes failcounts can be now used in any context,
so the last failcount - neigh_tbl - is added.

This was tested by our neoltp tests on host and inside containers.
No tests crashed, so there an no obvious IRQ callers of ve_printk
functions.

https://virtuozzo.atlassian.net/browse/VSTOR-146839

Feature: ve printk
Signed-off-by: Vladimir Riabchun <vladimir.riabchun at virtuozzo.com>
---
Changes in v2:
- Patch 2: fixed uninitialized r value in ve_dev_printk_emit.
- Patch 3: fixed incorrect __printf annotation for ve_printk_deferred.
- Patch 3: now on IRQ case ve_printk_ratelimited falls back to ve0.
- Patch 3: removed forgotten get_exec_env() usages from ve_printk
  functions.
- Patch 4: completely reworked and simplified.
- Patch 5: fix __ve_printk_ratelimited stub.
- Patch 6: brought back table type logging to host.
- Link to v1: http://lore.virtuozzo.com/20261002-ve-printk-irq-v1-0-cb55896d455c@virtuozzo.com

---
Vladimir Riabchun (6):
      ve/printk: Add sanity checks in ve_printk functions
      ve/printk: Report potentially leaking usage of ve_printk functions
      ve/printk: Specify ve in printks
      ve/printk: Fix time virtualization
      ve/failcount: Use ve_printk with specified ve
      ve: add neigh_tbl failcounter

 drivers/base/core.c                 |   8 ++-
 include/linux/net.h                 |  16 +++---
 include/linux/printk.h              |  42 ++++++++++++---
 include/linux/ratelimit_types.h     |   6 ++-
 include/linux/ve.h                  |  17 +++---
 kernel/printk/internal.h            |   4 ++
 kernel/printk/printk.c              | 101 ++++++++++++++++++++++++++++--------
 kernel/ve/ve.c                      |   3 ++
 lib/ratelimit.c                     |   7 +--
 net/core/neighbour.c                |   5 +-
 net/core/utils.c                    |   4 +-
 net/netfilter/nf_conntrack_core.c   |   2 +-
 net/netfilter/nf_conntrack_expect.c |   2 +-
 net/netfilter/xt_TCPMSS.c           |   4 +-
 14 files changed, 162 insertions(+), 59 deletions(-)
---
base-commit: ca54f152160587a74ff17cb52feef16f7b9d4e2b
change-id: 20260923-ve-printk-irq-027c3378660f

Best regards,
-- 
Vladimir Riabchun <vladimir.riabchun at virtuozzo.com>