On Mon, 2015-06-15 at 14:28 -0700, Josh Stone wrote: > CC elfutils-devel, this appears to be a regression. I'm top-posting my > own findings, but I'll leave the kernel report below... > > With elfutils-0.162, it appears that "strip" doesn't reduce the file > size when operating in-place (without -o). This isn't particular to > funny kernel ELF -- I reproduced it on a local stap binary. > > My full stap is 31MB. With strip -o, I get a new 2.5MB file. With > strip in-place, stap remains 31MB even though the ELF section data does > indicate all the DWARF sections are gone. > > I bisected it to commit 77482c4bf63a. > https://git.fedorahosted.org/cgit/elfutils.git/commit/?id=77482c4bf63a92166191e0b8531e9781f6fddbf3 > > if (elf->parent == NULL > && (elf->maximum_size == ~((size_t) 0) > || (size_t) size > elf->maximum_size) > - && unlikely (ftruncate (elf->fildes, size) != 0)) > + && unlikely (posix_fallocate (elf->fildes, 0, size) != 0)) > > In elf_begin() w/ ELF_C_RDWR, we get maximum_size == ~0, but now this > posix_fallocate can only increase the file size. The later part of > write_file() to reduce the size is only called for maximum_size != ~0. Yes, you are right. Of course it is the smallest one-liner patch of the release with the most comments and discussions across multiple lists. And still people (me) failed to spot the maximum_size == -1 case. Sigh. Sorry about that. Simplest probably is to just revert this one patch and do a elfutils 0.163 release with just that (and the translation updates). The issue that this was preventing (disk full with ELF_C_RDWR_MMAP, ftruncate appear to succeed, write in memory map causes SIGBUS) is probably less likely to trigger than this regression. I have to get me some sleep now. I look over the other options tomorrow. Cheers, Mark _______________________________________________ kernel mailing list kernel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/kernel
