Alexey Kardashevskiy <a...@ozlabs.ru> writes: > When trapped on WARN_ON(), report_bug() is expected to return > BUG_TRAP_TYPE_WARN so the caller could increment NIP by 4 and continue. > The __builtin_constant_p() path of the PPC's WARN_ON() calls (indirectly) > __WARN_FLAGS() which has BUGFLAG_WARNING set, however the other branch > does not which makes report_bug() report a bug rather than a warning. > > Fixes: 19d436268dde95389 ("debug: Add _ONCE() logic to report_bug()") > Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> > --- > > Actually 19d436268dde95389 replaced __WARN_TAINT() with __WARN_FLAGS() > and lost BUGFLAG_TAINT() and this is not in the commit log so it is > unclear: > 1) why
I think the rename is because previously the argument was a taint value, whereas now it is a flags value (which is a superset of taint). > 2) whether this particular patch should be doing > BUGFLAG_WARNING|BUGFLAG_TAINT(TAINT_WARN) > or > BUGFLAG_WARNING|(flags) There is no flags here so the latter won't work AFAICS. > Any ideas? Thanks. Your patch looks correct to me. I assume it works? The bug isn't introduced by 19d436268dde ("debug: Add _ONCE() logic to report_bug()") as far as I can see. If you check out that revision you see that BUGFLAG_TAINT still contains BUGFLAG_WARNING: #define BUGFLAG_TAINT(taint) (BUGFLAG_WARNING | ((taint) << 8)) But that was removed in f26dee15103f ("debug: Avoid setting BUGFLAG_WARNING twice"). So I think the Fixes: tag should point at that commit. cheers > diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h > index f2c562a0a427..0151af6c2a50 100644 > --- a/arch/powerpc/include/asm/bug.h > +++ b/arch/powerpc/include/asm/bug.h > @@ -104,7 +104,7 @@ > "1: "PPC_TLNEI" %4,0\n" \ > _EMIT_BUG_ENTRY \ > : : "i" (__FILE__), "i" (__LINE__), \ > - "i" (BUGFLAG_TAINT(TAINT_WARN)), \ > + "i" (BUGFLAG_WARNING|BUGFLAG_TAINT(TAINT_WARN)),\ > "i" (sizeof(struct bug_entry)), \ > "r" (__ret_warn_on)); \ > } \ > -- > 2.11.0