From 0ea5ad869c85ac604f3e022bf2c5bef54838433b Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 15 Jun 2016 15:45:58 -0500 Subject: [PATCH 1/2] objtool: Fix STACK_FRAME_NON_STANDARD macro checking for function symbols Mathieu Desnoyers reported that the STACK_FRAME_NON_STANDARD macro wasn't working with the lttng_filter_interpret_bytecode() function in the lttng-modules code. Usually the relocation created by STACK_FRAME_NON_STANDARD creates a reference to a section symbol like this: Offset Type Value Addend Name 000000000000000000 X86_64_64 000000000000000000 +3136 .text But in this case it created a reference to a function symbol: Offset Type Value Addend Name 000000000000000000 X86_64_64 0x00000000000003a0 +0 lttng_filter_interpret_bytecode To be honest I have no idea what causes gcc to decide to do one over the other. But both are valid ELF, so add support for the function symbol. Reported-by: Mathieu Desnoyers Signed-off-by: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: lttng-dev@lists.lttng.org Link: http://lkml.kernel.org/r/9cee42843bc6d94e990a152e4e0319cfdf6756ef.1466023450.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar --- tools/objtool/builtin-check.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index e8a1e69eb92c..25d803148f5c 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -122,10 +122,14 @@ static bool ignore_func(struct objtool_file *file, struct symbol *func) /* check for STACK_FRAME_NON_STANDARD */ if (file->whitelist && file->whitelist->rela) - list_for_each_entry(rela, &file->whitelist->rela->rela_list, list) - if (rela->sym->sec == func->sec && + list_for_each_entry(rela, &file->whitelist->rela->rela_list, list) { + if (rela->sym->type == STT_SECTION && + rela->sym->sec == func->sec && rela->addend == func->offset) return true; + if (rela->sym->type == STT_FUNC && rela->sym == func) + return true; + } /* check if it has a context switching instruction */ func_for_each_insn(file, func, insn) From a7c734140aa36413944eef0f8c660e0e2256357d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 12 Jul 2016 21:59:23 +0200 Subject: [PATCH 2/2] cpu/hotplug: Keep enough storage space if SMP=n to avoid array out of bounds scribble Xiaolong Ye reported lock debug warnings triggered by the following commit: 8de4a0066106 ("perf/x86: Convert the core to the hotplug state machine") The bug is the following: the cpuhp_bp_states[] array is cut short when CONFIG_SMP=n, but the dynamically registered callbacks are stored nevertheless and happily scribble outside of the array bounds... We need to store them in case that the state is unregistered so we can invoke the teardown function. That's independent of CONFIG_SMP. Make sure the array is large enough. Reported-by: kernel test robot Signed-off-by: Thomas Gleixner Cc: Adam Borowski Cc: Alexander Shishkin Cc: Anna-Maria Gleixner Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Borislav Petkov Cc: Jiri Olsa Cc: Kan Liang Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Sebastian Andrzej Siewior Cc: Stephane Eranian Cc: Vince Weaver Cc: lkp@01.org Cc: stable@vger.kernel.org Cc: tipbuild@zytor.com Fixes: cff7d378d3fd "cpu/hotplug: Convert to a state machine for the control processor" Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1607122144560.4083@nanos Signed-off-by: Ingo Molnar --- kernel/cpu.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/cpu.c b/kernel/cpu.c index d948e44c471e..7b61887f7ccd 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1201,6 +1201,8 @@ static struct cpuhp_step cpuhp_bp_states[] = { .teardown = takedown_cpu, .cant_stop = true, }, +#else + [CPUHP_BRINGUP_CPU] = { }, #endif };