On Thu, 22 Oct 2020 at 05:30, Kees Cook <keesc...@chromium.org> wrote: > > On Thu, Oct 22, 2020 at 03:00:06AM +0300, Dmitry Osipenko wrote: > > 22.10.2020 02:40, Kees Cook пишет: > > > On Thu, Oct 22, 2020 at 01:57:37AM +0300, Dmitry Osipenko wrote: > > >> The vfp_kmode_exception() function now is unreachable using relative > > >> branching in THUMB2 kernel configuration, resulting in a "relocation > > >> truncated to fit: R_ARM_THM_JUMP19 against symbol `vfp_kmode_exception'" > > >> linker error. Let's use long jump in order to fix the issue. > > > > > > Eek. Is this with gcc or clang? > > > > GCC 9.3.0 > > > > >> Fixes: eff8728fe698 ("vmlinux.lds.h: Add PGO and AutoFDO input sections") > > > > > > Are you sure it wasn't 512dd2eebe55 ("arm/build: Add missing sections") ? > > > That commit may have implicitly moved the location of .vfp11_veneer, > > > though I thought I had chosen the correct position. > > > > I re-checked that the fixes tag is correct. > > > > >> Signed-off-by: Dmitry Osipenko <dig...@gmail.com> > > >> --- > > >> arch/arm/vfp/vfphw.S | 3 ++- > > >> 1 file changed, 2 insertions(+), 1 deletion(-) > > >> > > >> diff --git a/arch/arm/vfp/vfphw.S b/arch/arm/vfp/vfphw.S > > >> index 4fcff9f59947..6e2b29f0c48d 100644 > > >> --- a/arch/arm/vfp/vfphw.S > > >> +++ b/arch/arm/vfp/vfphw.S > > >> @@ -82,7 +82,8 @@ ENTRY(vfp_support_entry) > > >> ldr r3, [sp, #S_PSR] @ Neither lazy restore nor FP > > >> exceptions > > >> and r3, r3, #MODE_MASK @ are supported in kernel mode > > >> teq r3, #USR_MODE > > >> - bne vfp_kmode_exception @ Returns through lr > > >> + ldr r1, =vfp_kmode_exception > > >> + bxne r1 @ Returns through lr > > >> > > >> VFPFMRX r1, FPEXC @ Is the VFP enabled? > > >> DBGSTR1 "fpexc %08x", r1 > > > > > > This seems like a workaround though? I suspect the vfp11_veneer needs > > > moving? > > > > > > > I don't know where it needs to be moved. Please feel free to make a > > patch if you have a better idea, I'll be glad to test it. > > I might have just been distracted by the common "vfp" prefix. It's > possible that the text section shuffling just ended up being very large, > so probably this patch is right then! >
I already sent a fix for this issue: https://www.armlinux.org.uk/developer/patches/viewpatch.php?id=9018/1