Quoting Petr Mladek (2021-04-13 07:41:11) > > diff --git a/lib/dump_stack.c b/lib/dump_stack.c > > index f5a33b6f773f..d685331b065f 100644 > > --- a/lib/dump_stack.c > > +++ b/lib/dump_stack.c > > @@ -5,6 +5,7 @@ > > */ > > > > #include <linux/kernel.h> > > +#include <linux/buildid.h> > > #include <linux/export.h> > > #include <linux/sched.h> > > #include <linux/sched/debug.h> > > @@ -36,6 +37,14 @@ void __init dump_stack_set_arch_desc(const char *fmt, > > ...) > > va_end(args); > > } > > > > +#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) > > +#define BUILD_ID_FMT " %20phN" > > +#define BUILD_ID_VAL vmlinux_build_id > > +#else > > +#define BUILD_ID_FMT "%s" > > +#define BUILD_ID_VAL "" > > +#endif > > 3rd patch always defines and initializes vmlinux_build_id. But it is > used only when CONFIG_STACKTRACE_BUILD_ID is enabled.
It is also used for crash code. > Is it intentional, please? Yes, mostly for simplicity with the other user. > > It is not a big deal for vmlinux_build_id. But it is more questionable > for the per-module id. I am going to open this question for 5th patch > as well. > Right, for the vmlinux_build_id symbol it is not exported, and the whole buildid.c file is part of lib-y, so if the symbol isn't used the linker should drop it during link phase. I can drop the early init call if the config is disabled and crash kernel code isn't enabled, and then rely on the linker to drop the vmlinux_build_id symbol. Let me see if that can work so that we don't have to parse it at boot if it is never used.
