Messages in this thread Patch in this message | | | Date | Tue, 19 May 2020 10:38:26 +0200 | From | Peter Zijlstra <> | Subject | Re: [patch V6 00/37] x86/entry: Rework leftovers and merge plan |
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On Mon, May 18, 2020 at 10:24:53PM +0200, Thomas Gleixner wrote: > Peter Zijlstra <peterz@infradead.org> writes: > > So on top of you entry-v8-full; I had to chase one of those > > instrumentation_end() escapes an (extended) basic block chase (again!). > > > > --- a/arch/x86/include/asm/bug.h > > +++ b/arch/x86/include/asm/bug.h > > @@ -79,8 +79,8 @@ do { \ > > do { \ > > instrumentation_begin(); \ > > _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \ > > - instrumentation_end(); \ > > annotate_reachable(); \ > > + instrumentation_end(); \ > > } while (0) > > I just applied this part and rebuilt: > > vmlinux.o: warning: objtool: rcu_eqs_enter.constprop.77()+0xa9: call to > rcu_preempt_deferred_qs() leaves .noinstr.text section > > Did it go away after you disabled DEBUG_ENTRY perhaps?
Hehe, then all complaints would be gone :-)
So tglx/entry-v8-full + below patch:
$ make O=defconfig-build clean ... $ make CC=gcc-9 O=defconfig-build/ vmlinux -j40 -s vmlinux.o: warning: objtool: exc_debug()+0x158: call to trace_hwlat_timestamp() leaves .noinstr.text section vmlinux.o: warning: objtool: exc_nmi()+0x190: call to trace_hwlat_timestamp() leaves .noinstr.text section vmlinux.o: warning: objtool: do_machine_check()+0x46: call to mce_rdmsrl() leaves .noinstr.text section $
(it really isn't defconfig, but your config-fail + DEBUG_ENTRY)
--- arch/x86/include/asm/bug.h | 2 +- include/linux/compiler.h | 11 ++++++++--- 2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h index f128e5c2ed42..fb34ff641e0a 100644 --- a/arch/x86/include/asm/bug.h +++ b/arch/x86/include/asm/bug.h @@ -79,8 +79,8 @@ do { \ do { \ instrumentation_begin(); \ _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \ - instrumentation_end(); \ annotate_reachable(); \ + instrumentation_end(); \ } while (0) #include <asm-generic/bug.h> diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 7db5902f8f6e..f6f54e8e0797 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -120,25 +120,30 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, /* Annotate a C jump table to allow objtool to follow the code flow */ #define __annotate_jump_table __section(.rodata..c_jump_table) +#ifdef CONFIG_DEBUG_ENTRY /* Begin/end of an instrumentation safe region */ -#define instrumentation_begin() ({ \ +#define instrumentation_begin() ({ \ asm volatile("%c0:\n\t" \ ".pushsection .discard.instr_begin\n\t" \ ".long %c0b - .\n\t" \ ".popsection\n\t" : : "i" (__COUNTER__)); \ }) -#define instrumentation_end() ({ \ - asm volatile("%c0:\n\t" \ +#define instrumentation_end() ({ \ + asm volatile("%c0: nop\n\t" \ ".pushsection .discard.instr_end\n\t" \ ".long %c0b - .\n\t" \ ".popsection\n\t" : : "i" (__COUNTER__)); \ }) +#endif /* CONFIG_DEBUG_ENTRY */ #else #define annotate_reachable() #define annotate_unreachable() #define __annotate_jump_table +#endif + +#ifndef instrumentation_begin #define instrumentation_begin() do { } while(0) #define instrumentation_end() do { } while(0) #endif
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