objtool: Support GCC 9 cold subfunction naming scheme
commit bcb6fb5da77c2a228adf07cc9cb1a0c2aa2001c6 upstream.
Starting with GCC 8, a lot of unlikely code was moved out of line to
"cold" subfunctions in .text.unlikely.
For example, the unlikely bits of:
irq_do_set_affinity()
are moved out to the following subfunction:
irq_do_set_affinity.cold.49()
Starting with GCC 9, the numbered suffix has been removed. So in the
above example, the cold subfunction is instead:
irq_do_set_affinity.cold()
Tweak the objtool subfunction detection logic so that it detects both
GCC 8 and GCC 9 naming schemes.
Reported-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/015e9544b1f188d36a7f02fa31e9e95629aa5f50.1541040800.git.jpoimboe@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index dd4ed7c..d84c28ea 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -305,7 +305,7 @@
if (sym->type != STT_FUNC)
continue;
sym->pfunc = sym->cfunc = sym;
- coldstr = strstr(sym->name, ".cold.");
+ coldstr = strstr(sym->name, ".cold");
if (!coldstr)
continue;