From: Anshuman Khandual <khandual@linux.vnet.ibm.com>
To: Michal Hocko <mhocko@kernel.org>,
Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
"akpm@linux-foundation.org" <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
Subject: Re: ppc elf_map breakage with MAP_FIXED_NOREPLACE
Date: Tue, 13 Feb 2018 12:19:18 +0530 [thread overview]
Message-ID: <b0a751c4-9552-87b4-c768-3e1b02c18b5c@linux.vnet.ibm.com> (raw)
In-Reply-To: <20180201134829.GL21609@dhcp22.suse.cz>
On 02/01/2018 07:18 PM, Michal Hocko wrote:
> 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;
>
>
Yeah, it does solve the problem on mmotm-2018-01-25-16-20.
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next prev parent reply other threads:[~2018-02-13 6:49 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-05 0:20 mmotm 2018-01-04-16-19 uploaded akpm
2018-01-05 6:43 ` Anshuman Khandual
2018-01-05 8:46 ` Michal Hocko
2018-01-07 6:49 ` Anshuman Khandual
2018-01-07 9:02 ` ppc elf_map breakage with MAP_FIXED_NOREPLACE (was: Re: mmotm 2018-01-04-16-19 uploaded) Michal Hocko
2018-01-07 11:26 ` Michael Ellerman
2018-01-08 3:02 ` ppc elf_map breakage with MAP_FIXED_NOREPLACE Anshuman Khandual
2018-01-08 22:12 ` Michael Ellerman
2018-01-09 11:48 ` Anshuman Khandual
2018-01-09 16:13 ` Michal Hocko
2018-01-11 10:08 ` Anshuman Khandual
2018-01-17 8:07 ` Michal Hocko
2018-01-23 11:25 ` Anshuman Khandual
2018-01-23 12:45 ` Michal Hocko
2018-01-23 15:58 ` Anshuman Khandual
2018-01-23 16:06 ` Michal Hocko
2018-01-24 5:09 ` Anshuman Khandual
2018-01-24 9:05 ` Michal Hocko
2018-01-26 12:34 ` Anshuman Khandual
2018-01-26 14:04 ` Michal Hocko
2018-01-29 2:47 ` Anshuman Khandual
2018-01-29 5:32 ` Anshuman Khandual
2018-01-29 13:22 ` Michal Hocko
2018-01-30 3:35 ` Michael Ellerman
2018-01-30 9:42 ` Michal Hocko
2018-01-31 5:05 ` Anshuman Khandual
2018-01-31 13:19 ` Michal Hocko
2018-02-01 3:13 ` Anshuman Khandual
2018-02-01 13:10 ` Michal Hocko
2018-02-01 13:40 ` Michal Hocko
2018-02-01 20:55 ` Kees Cook
2018-02-13 10:04 ` [RFC PATCH] elf: enforce MAP_FIXED on overlaying elf segments (was: Re: ppc elf_map breakage with MAP_FIXED_NOREPLACE) Michal Hocko
2018-02-14 16:30 ` Khalid Aziz
2018-02-01 13:48 ` ppc elf_map breakage with MAP_FIXED_NOREPLACE Michal Hocko
2018-02-01 21:06 ` Kees Cook
2018-02-12 14:48 ` Michal Hocko
2018-02-13 1:02 ` Anshuman Khandual
2018-02-13 6:49 ` Anshuman Khandual [this message]
2018-02-13 10:00 ` Michal Hocko
2018-01-05 12:14 ` mmotm 2018-01-04-16-19 uploaded Michal Hocko
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