| Message ID | 20210929190810.1597399-1-ndesaulniers@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ARM: mm: proc-macros: ensure *_tlb_fns are 4B aligned | expand |
+ Dave (Dave, I got a bounceback on your linaro.org email address. Consider sending a patch updating the .mailmap) On Wed, Sep 29, 2021 at 12:08 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > QEMU 6.1.0 is more correct about trapping on misaligned accesses. A > kernel built with CONFIG_THUMB2_KERNEL=y and using clang as the > assembler could generate non-naturally-aligned v7wbi_tlb_fns which > results in a boot failure. The original commit adding the macro missed > the .align directive on this data. > > Fixes: 66a625a88174 ("ARM: mm: proc-macros: Add generic proc/cache/tlb struct definition macros") > Link: https://github.com/ClangBuiltLinux/linux/issues/1447 > Link: https://lore.kernel.org/all/0699da7b-354f-aecc-a62f-e25693209af4@linaro.org/ > Debugged-by: Ard Biesheuvel <ardb@kernel.org> > Debugged-by: Nathan Chancellor <nathan@kernel.org> > Debugged-by: Richard Henderson <richard.henderson@linaro.org> > Suggested-by: Ard Biesheuvel <ardb@kernel.org> > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> > --- > arch/arm/Kconfig | 1 + > arch/arm/mm/proc-macros.S | 1 + > 2 files changed, 2 insertions(+) > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index fc196421b2ce..b760dd45b734 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -92,6 +92,7 @@ config ARM > select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL > select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG > select HAVE_FUNCTION_TRACER if !XIP_KERNEL > + select HAVE_FUTEX_CMPXCHG if FUTEX > select HAVE_GCC_PLUGINS > select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7) > select HAVE_IRQ_TIME_ACCOUNTING > diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S > index e2c743aa2eb2..d9f7dfe2a7ed 100644 > --- a/arch/arm/mm/proc-macros.S > +++ b/arch/arm/mm/proc-macros.S > @@ -340,6 +340,7 @@ ENTRY(\name\()_cache_fns) > > .macro define_tlb_functions name:req, flags_up:req, flags_smp > .type \name\()_tlb_fns, #object > + .align 2 > ENTRY(\name\()_tlb_fns) > .long \name\()_flush_user_tlb_range > .long \name\()_flush_kern_tlb_range > -- > 2.33.0.685.g46640cef36-goog >
On Wed, Sep 29, 2021 at 12:10 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > + Dave (Dave, I got a bounceback on your linaro.org email address. > Consider sending a patch updating the .mailmap) > > On Wed, Sep 29, 2021 at 12:08 PM Nick Desaulniers > <ndesaulniers@google.com> wrote: > > > > QEMU 6.1.0 is more correct about trapping on misaligned accesses. A > > kernel built with CONFIG_THUMB2_KERNEL=y and using clang as the > > assembler could generate non-naturally-aligned v7wbi_tlb_fns which > > results in a boot failure. The original commit adding the macro missed > > the .align directive on this data. > > > > Fixes: 66a625a88174 ("ARM: mm: proc-macros: Add generic proc/cache/tlb struct definition macros") > > Link: https://github.com/ClangBuiltLinux/linux/issues/1447 > > Link: https://lore.kernel.org/all/0699da7b-354f-aecc-a62f-e25693209af4@linaro.org/ > > Debugged-by: Ard Biesheuvel <ardb@kernel.org> > > Debugged-by: Nathan Chancellor <nathan@kernel.org> > > Debugged-by: Richard Henderson <richard.henderson@linaro.org> > > Suggested-by: Ard Biesheuvel <ardb@kernel.org> > > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> > > --- > > arch/arm/Kconfig | 1 + d'oh, had an unintentional `-a` when I did `git commit`. Will resend a v2... > > arch/arm/mm/proc-macros.S | 1 + > > 2 files changed, 2 insertions(+) > > > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > > index fc196421b2ce..b760dd45b734 100644 > > --- a/arch/arm/Kconfig > > +++ b/arch/arm/Kconfig > > @@ -92,6 +92,7 @@ config ARM > > select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL > > select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG > > select HAVE_FUNCTION_TRACER if !XIP_KERNEL > > + select HAVE_FUTEX_CMPXCHG if FUTEX > > select HAVE_GCC_PLUGINS > > select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7) > > select HAVE_IRQ_TIME_ACCOUNTING > > diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S > > index e2c743aa2eb2..d9f7dfe2a7ed 100644 > > --- a/arch/arm/mm/proc-macros.S > > +++ b/arch/arm/mm/proc-macros.S > > @@ -340,6 +340,7 @@ ENTRY(\name\()_cache_fns) > > > > .macro define_tlb_functions name:req, flags_up:req, flags_smp > > .type \name\()_tlb_fns, #object > > + .align 2 > > ENTRY(\name\()_tlb_fns) > > .long \name\()_flush_user_tlb_range > > .long \name\()_flush_kern_tlb_range > > -- > > 2.33.0.685.g46640cef36-goog > > > > > -- > Thanks, > ~Nick Desaulniers
On Wed, 29 Sept 2021 at 21:08, Nick Desaulniers <ndesaulniers@google.com> wrote: > > QEMU 6.1.0 is more correct about trapping on misaligned accesses. A > kernel built with CONFIG_THUMB2_KERNEL=y and using clang as the > assembler could generate non-naturally-aligned v7wbi_tlb_fns which > results in a boot failure. The original commit adding the macro missed > the .align directive on this data. > > Fixes: 66a625a88174 ("ARM: mm: proc-macros: Add generic proc/cache/tlb struct definition macros") > Link: https://github.com/ClangBuiltLinux/linux/issues/1447 > Link: https://lore.kernel.org/all/0699da7b-354f-aecc-a62f-e25693209af4@linaro.org/ > Debugged-by: Ard Biesheuvel <ardb@kernel.org> > Debugged-by: Nathan Chancellor <nathan@kernel.org> > Debugged-by: Richard Henderson <richard.henderson@linaro.org> > Suggested-by: Ard Biesheuvel <ardb@kernel.org> > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> > --- > arch/arm/Kconfig | 1 + > arch/arm/mm/proc-macros.S | 1 + > 2 files changed, 2 insertions(+) > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index fc196421b2ce..b760dd45b734 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -92,6 +92,7 @@ config ARM > select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL > select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG > select HAVE_FUNCTION_TRACER if !XIP_KERNEL > + select HAVE_FUTEX_CMPXCHG if FUTEX > select HAVE_GCC_PLUGINS > select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7) > select HAVE_IRQ_TIME_ACCOUNTING I take it this hunk got included by accident? > diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S > index e2c743aa2eb2..d9f7dfe2a7ed 100644 > --- a/arch/arm/mm/proc-macros.S > +++ b/arch/arm/mm/proc-macros.S > @@ -340,6 +340,7 @@ ENTRY(\name\()_cache_fns) > > .macro define_tlb_functions name:req, flags_up:req, flags_smp > .type \name\()_tlb_fns, #object > + .align 2 > ENTRY(\name\()_tlb_fns) > .long \name\()_flush_user_tlb_range > .long \name\()_flush_kern_tlb_range > -- > 2.33.0.685.g46640cef36-goog > For this part, Acked-by: Ard Biesheuvel <ardb@kernel.org>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index fc196421b2ce..b760dd45b734 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -92,6 +92,7 @@ config ARM select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG select HAVE_FUNCTION_TRACER if !XIP_KERNEL + select HAVE_FUTEX_CMPXCHG if FUTEX select HAVE_GCC_PLUGINS select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7) select HAVE_IRQ_TIME_ACCOUNTING diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S index e2c743aa2eb2..d9f7dfe2a7ed 100644 --- a/arch/arm/mm/proc-macros.S +++ b/arch/arm/mm/proc-macros.S @@ -340,6 +340,7 @@ ENTRY(\name\()_cache_fns) .macro define_tlb_functions name:req, flags_up:req, flags_smp .type \name\()_tlb_fns, #object + .align 2 ENTRY(\name\()_tlb_fns) .long \name\()_flush_user_tlb_range .long \name\()_flush_kern_tlb_range
QEMU 6.1.0 is more correct about trapping on misaligned accesses. A kernel built with CONFIG_THUMB2_KERNEL=y and using clang as the assembler could generate non-naturally-aligned v7wbi_tlb_fns which results in a boot failure. The original commit adding the macro missed the .align directive on this data. Fixes: 66a625a88174 ("ARM: mm: proc-macros: Add generic proc/cache/tlb struct definition macros") Link: https://github.com/ClangBuiltLinux/linux/issues/1447 Link: https://lore.kernel.org/all/0699da7b-354f-aecc-a62f-e25693209af4@linaro.org/ Debugged-by: Ard Biesheuvel <ardb@kernel.org> Debugged-by: Nathan Chancellor <nathan@kernel.org> Debugged-by: Richard Henderson <richard.henderson@linaro.org> Suggested-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> --- arch/arm/Kconfig | 1 + arch/arm/mm/proc-macros.S | 1 + 2 files changed, 2 insertions(+)