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[0/7] target/arm: Fix FPCXT_NS accesses when FPU disabled

Message ID 20210618141019.10671-1-peter.maydell@linaro.org
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Series target/arm: Fix FPCXT_NS accesses when FPU disabled | expand

Message

Peter Maydell June 18, 2021, 2:10 p.m. UTC 
This patchseries fixes some bugs in v8.1M M-profile sysreg accesses:

 (1) When the FPU is disabled and there is no active FP context
     (as defined by the pseudocode fpInactive flag), accesses to
     FPCXT_NS should not fail with a NOCP exception
 (2) For cases where VLDR/VSTR sysreg don't perform a memory access
     (VLDR/VSTR of VPR when unprivileged, and VLDR to FPCXT_NS
     when fpInactive), the "side effects" of the load (update of
     writeback base register, and stack limit check) still need
     to happen, but we were skipping them

This patchseries fixes those bugs. Since these were detected by
running tests from the gcc testsuite, I've marked the first four
patches as cc: stable. The last three are a refactoring which
isn't part of the bugfix proper.

Note for backport to stable: the patchset has a semantic dependency
on commit 9a486856e9173af, which was not marked as cc-stable because
we didn't know we'd need it for a for-stable bugfix. So that needs
to be taken as well if this series goes to stable.

thanks
-- PMM

Peter Maydell (7):
  target/arm/translate-vfp.c: Whitespace fixes
  target/arm: Handle FPU being disabled in FPCXT_NS accesses
  target/arm: Don't NOCP fault for FPCXT_NS accesses
  target/arm: Handle writeback in VLDR/VSTR sysreg with no memory access
  target/arm: Factor FP context update code out into helper function
  target/arm: Split vfp_access_check() into A and M versions
  target/arm: Handle FPU check for FPCXT_NS insns via
    vfp_access_check_m()

 target/arm/translate-a32.h    |   1 +
 target/arm/m-nocp.decode      |  24 ++
 target/arm/vfp.decode         |  14 -
 target/arm/translate-m-nocp.c | 550 ++++++++++++++++++++++++++++
 target/arm/translate-vfp.c    | 664 ++++++----------------------------
 5 files changed, 681 insertions(+), 572 deletions(-)