[PATCH] fs: heap/bss calculation ignore section above STACK_TOP.

From: Noam Camus
Date: Sun Jul 26 2015 - 02:21:57 EST


From: Noam Camus <noamc@xxxxxxxxxx>

Today bss/heap is placed above last loaded sections.
Current check is only against TASK_SIZE, maybe since most architectures do:

But this is not true for all of them and a gap between TASK_SIZE
and STACK_TOP is possible and may be used for variant purposes.
For example we use it for a special physical memory mapping.

In such case of section in this gap we skip it for matter of
heap/bss calculation.
set_brk will never work for such case anyway.

Signed-off-by: Noam Camus <noamc@xxxxxxxxxx>
---
fs/binfmt_elf.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 6b65996..e445886 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -962,6 +962,9 @@ static int load_elf_binary(struct linux_binprm *bprm)

k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;

+ if (k >= STACK_TOP)
+ continue;
+
if (k > elf_bss)
elf_bss = k;
if ((elf_ppnt->p_flags & PF_X) && end_code < k)
--
1.7.1

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