[PATCH v2 0/1] iommu/generic_pt: fix GCOV build failure for amdv1

[Konstantin Khorenko]

This patch fixes a build failure in drivers/iommu/generic_pt/fmt/iommu_amdv1.o
when -fprofile-update=atomic is added to global CFLAGS_GCOV.

v2: Use __always_inline instead of disabling GCOV for the file, as
    suggested by Jason Gunthorpe.  The root cause is that
    amdv1pt_install_leaf_entry() is "static inline" (not __always_inline),
    so GCC may choose not to inline it.  Without inlining, the compiler
    cannot see constant arguments at the call site and fails to eliminate
    the impossible branch in FIELD_PREP().  Forcing inlining via
    __always_inline solves the problem without losing GCOV coverage.

v1: https://lore.kernel.org/lkml/20260401142020.1434243-4-khorenko@xxxxxxxxxxxxx/

This is part of a larger effort to add -fprofile-update=atomic to
global CFLAGS_GCOV to fix GCOV counter races that cause crashes on SMP
(posted earlier as a combined series):
  https://lore.kernel.org/lkml/20260401142020.1434243-1-khorenko@xxxxxxxxxxxxx/T/#t

That combined series was split per subsystem as requested by reviewers.
The companion patches are:

- net: fix skb_ext BUILD_BUG_ON failures (sent to netdev) [1]
- gcov: add -fprofile-update=atomic globally (sent to gcov/kbuild
  maintainers, depends on this patch and the net patches) [2]

[1] https://lore.kernel.org/lkml/20260402140558.1437002-1-khorenko@xxxxxxxxxxxxx/T/#t
[2] https://lore.kernel.org/lkml/20260402141831.1437357-1-khorenko@xxxxxxxxxxxxx/T/#t

Konstantin Khorenko (1):
  iommu/generic_pt: use __always_inline for amdv1pt_install_leaf_entry()

 drivers/iommu/generic_pt/fmt/amdv1.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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2.43.5