lkml.org 
[lkml]   [2018]   [Feb]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: ppc elf_map breakage with MAP_FIXED_NOREPLACE
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

\
 
 \ /
  Last update: 2018-02-01 14:49    [W:0.120 / U:0.104 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site