Messages in this thread | | | Date | Mon, 20 Jul 2015 12:50:26 -0500 | From | Josh Poimboeuf <> | Subject | Re: [PATCH v7 2/4] x86/stackvalidate: Compile-time stack validation |
| |
On Tue, Jul 21, 2015 at 01:53:25AM +0900, Namhyung Kim wrote: > Hi, > > Just nitpicks below..
Hi Namhyung, thanks for the review!
> On Wed, Jul 15, 2015 at 2:14 AM, Josh Poimboeuf <jpoimboe@redhat.com> wrote: > > +void elf_close(struct elf *elf) > > +{ > > + struct section *sec, *tmpsec; > > + struct symbol *sym, *tmpsym; > > + > > + list_for_each_entry_safe(sec, tmpsec, &elf->sections, list) { > > + list_for_each_entry_safe(sym, tmpsym, &sec->symbols, list) { > > + list_del(&sym->list); > > + free(sym); > > + } > > It seems that it needs to free entries in sec->relas too here.
I must confess that this program has some known memory leaks. I actually have a comment at the top of the file attempting to explain why, but I'll try to improve the comment a little bit.
Many of the leaks are actually intentional, since it's a short running program that needs to run fast (though I haven't yet optimized it for speed). And most of the data structures are needed until it exits anyway.
It's perhaps distasteful, but it improves performance. And I'm a pragmatist at heart ;-)
That said, I will make your suggested change here, since maybe the elf.c code might someday be reused elsewhere, and freeing memory is actually the goal of this function.
> > +int main(int argc, char *argv[]) > > +{ > > + struct elf *elf; > > + int ret = 0, warnings = 0; > > + > > + argp_parse(&argp, argc, argv, 0, 0, &args); > > + > > + elf = elf_open(args.args[0]); > > + if (!elf) { > > + fprintf(stderr, "error reading elf file %s\n", args.args[0]); > > + return 1; > > + } > > + > > + ret = decode_sections(elf); > > + if (ret < 0) > > + goto out; > > + warnings += ret; > > + > > + ret = validate_functions(elf); > > + if (ret < 0) > > + goto out; > > + warnings += ret; > > + > > + ret = validate_uncallable_instructions(elf); > > + if (ret < 0) > > + goto out; > > + warnings += ret; > > + > > +out: > > elf_close(elf); ??
I intentionally left out the call to elf_close() here, since this is the exit path and the kernel will free the memory anyway.
-- Josh
| |