On Fri, Nov 15, 2024 at 10:40:08AM -0800, Josh Poimboeuf wrote:
> On Mon, Nov 11, 2024 at 12:59:39PM +0100, Peter Zijlstra wrote:
> > +++ b/include/linux/objtool.h
> > @@ -51,13 +51,16 @@
> > ".long 998b\n\t" \
> > ".popsection\n\t"
> >
> > -#define ASM_ANNOTATE(x) \
> > - "911:\n\t" \
> > +#define __ASM_ANNOTATE(s, x) \
> > ".pushsection .discard.annotate,\"M\",@progbits,8\n\t" \
> > - ".long 911b - .\n\t" \
> > + ".long " __stringify(s) "b - .\n\t" \
>
> It would probably be better for __ASM_ANNOTATE's callers to pass in the
> full label name (e.g. '911b') since they know where the label is? It
> could even be a named label.
This seems to work.
--- a/include/linux/instrumentation.h
+++ b/include/linux/instrumentation.h
@@ -6,11 +6,12 @@
#include <linux/objtool.h>
#include <linux/stringify.h>
+#include <linux/args.h>
/* Begin/end of an instrumentation safe region */
#define __instrumentation_begin(c) ({ \
asm volatile(__stringify(c) ": nop\n\t" \
- __ASM_ANNOTATE(c, ANNOTYPE_INSTR_BEGIN) \
+ __ASM_ANNOTATE(CONCATENATE(c, b), ANNOTYPE_INSTR_BEGIN) \
: : "i" (c)); \
})
#define instrumentation_begin() __instrumentation_begin(__COUNTER__)
@@ -48,7 +49,7 @@
*/
#define __instrumentation_end(c) ({ \
asm volatile(__stringify(c) ": nop\n\t" \
- __ASM_ANNOTATE(c, ANNOTYPE_INSTR_END) \
+ __ASM_ANNOTATE(CONCATENATE(c, b), ANNOTYPE_INSTR_END) \
: : "i" (c)); \
})
#define instrumentation_end() __instrumentation_end(__COUNTER__)
--- a/include/linux/objtool.h
+++ b/include/linux/objtool.h
@@ -53,13 +53,13 @@
#define __ASM_ANNOTATE(s, x) \
".pushsection .discard.annotate,\"M\",@progbits,8\n\t" \
- ".long " __stringify(s) "b - .\n\t" \
+ ".long " __stringify(s) " - .\n\t" \
".long " __stringify(x) "\n\t" \
".popsection\n\t"
#define ASM_ANNOTATE(x) \
"911:\n\t" \
- __ASM_ANNOTATE(911, x)
+ __ASM_ANNOTATE(911b, x)
#define ANNOTATE_NOENDBR ASM_ANNOTATE(ANNOTYPE_NOENDBR)
