| From bcb6fb5da77c2a228adf07cc9cb1a0c2aa2001c6 Mon Sep 17 00:00:00 2001 |
| From: Josh Poimboeuf <jpoimboe@redhat.com> |
| Date: Wed, 31 Oct 2018 21:57:30 -0500 |
| Subject: objtool: Support GCC 9 cold subfunction naming scheme |
| |
| From: Josh Poimboeuf <jpoimboe@redhat.com> |
| |
| 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> |
| |
| --- |
| tools/objtool/elf.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/tools/objtool/elf.c |
| +++ b/tools/objtool/elf.c |
| @@ -305,7 +305,7 @@ static int read_symbols(struct elf *elf) |
| if (sym->type != STT_FUNC) |
| continue; |
| sym->pfunc = sym->cfunc = sym; |
| - coldstr = strstr(sym->name, ".cold."); |
| + coldstr = strstr(sym->name, ".cold"); |
| if (!coldstr) |
| continue; |
| |
