From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Hocko Subject: Re: ppc elf_map breakage with MAP_FIXED_NOREPLACE Date: Thu, 1 Feb 2018 14:48:29 +0100 Message-ID: <20180201134829.GL21609@dhcp22.suse.cz> References: <5acba3c2-754d-e449-24ff-a72a0ad0d895@linux.vnet.ibm.com> <20180126140415.GD5027@dhcp22.suse.cz> <15da8c87-e6db-13aa-01c8-a913656bfdb6@linux.vnet.ibm.com> <6db9b33d-fd46-c529-b357-3397926f0733@linux.vnet.ibm.com> <20180129132235.GE21609@dhcp22.suse.cz> <87k1w081e7.fsf@concordia.ellerman.id.au> <20180130094205.GS21609@dhcp22.suse.cz> <5eccdc1b-6a10-b48a-c63f-295f69473d97@linux.vnet.ibm.com> <20180131131937.GA6740@dhcp22.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Anshuman Khandual Cc: Michael Ellerman , "akpm@linux-foundation.org" , mm-commits@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-next@vger.kernel.org, sfr@canb.auug.org.au, broonie@kernel.org List-Id: linux-next.vger.kernel.org On Thu 01-02-18 08:43:34, Anshuman Khandual wrote: [...] > $dmesg | grep elf_brk > [ 9.571192] elf_brk 10030328 elf_bss 10030000 > > static int load_elf_binary(struct linux_binprm *bprm) > --------------------- > > if (unlikely (elf_brk > elf_bss)) { > unsigned long nbyte; > > /* There was a PT_LOAD segment with p_memsz > p_filesz > before this one. Map anonymous pages, if needed, > and clear the area. */ > retval = set_brk(elf_bss + load_bias, > elf_brk + load_bias, > bss_prot); > > > --------------------- Just a blind shot... Does the following make any difference? --- diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 021fe78998ea..04b24d00c911 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -895,7 +895,7 @@ static int load_elf_binary(struct linux_binprm *bprm) the correct location in memory. */ for(i = 0, elf_ppnt = elf_phdata; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) { - int elf_prot = 0, elf_flags; + int elf_prot = 0, elf_flags, elf_fixed = MAP_FIXED_NOREPLACE; unsigned long k, vaddr; unsigned long total_size = 0; @@ -927,6 +927,7 @@ static int load_elf_binary(struct linux_binprm *bprm) */ } } + elf_fixed = MAP_FIXED; } if (elf_ppnt->p_flags & PF_R) @@ -944,7 +945,7 @@ static int load_elf_binary(struct linux_binprm *bprm) * the ET_DYN load_addr calculations, proceed normally. */ if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) { - elf_flags |= MAP_FIXED_NOREPLACE; + elf_flags |= elf_fixed; } else if (loc->elf_ex.e_type == ET_DYN) { /* * This logic is run once for the first LOAD Program @@ -980,7 +981,7 @@ static int load_elf_binary(struct linux_binprm *bprm) load_bias = ELF_ET_DYN_BASE; if (current->flags & PF_RANDOMIZE) load_bias += arch_mmap_rnd(); - elf_flags |= MAP_FIXED_NOREPLACE; + elf_flags |= elf_fixed; } else load_bias = 0; -- Michal Hocko SUSE Labs