From: Linus Torvalds <torvalds@woody.osdl.org>
Date: Sat, 6 Jan 2007 21:28:21 +0000 (-0800)
Subject: Revert "[PATCH] binfmt_elf: randomize PIE binaries (2nd try)"
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=90cb28e8f76e57751ffe14abd09c2d53a6aea7c8;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

Revert "[PATCH] binfmt_elf: randomize PIE binaries (2nd try)"

This reverts commit 59287c0913cc9a6c75712a775f6c1c1ef418ef3b.

Hugh Dickins reports that it causes random failures on x86 with SuSE
10.2, and points out

  "Isn't that randomization, anywhere from 0x10000 to ELF_ET_DYN_BASE,
   sure to place the ET_DYN from time to time just where the comment
   says it's trying to avoid? I assume that somehow results in the error
   reported."

(where the comment in question is the existing comment in the source
code about mmap/brk clashes).

Suggested-by: Hugh Dickins <hugh@veritas.com>
Acked-by: Marcus Meissner <meissner@suse.de>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index d3adfd353ff9..7cb28720f90e 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -854,13 +854,7 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
 			 * default mmap base, as well as whatever program they
 			 * might try to exec.  This is because the brk will
 			 * follow the loader, and is not movable.  */
-			if (current->flags & PF_RANDOMIZE)
-				load_bias = randomize_range(0x10000,
-							    ELF_ET_DYN_BASE,
-							    0);
-			else
-				load_bias = ELF_ET_DYN_BASE;
-			load_bias = ELF_PAGESTART(load_bias - vaddr);
+			load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
 		}
 
 		error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,