From: Noam Camus <[email protected]>
Today bss/heap is placed above last loaded sections.
However if STACK_TOP is not equal to TASK_SIZE we wish to ignore
such sections mapped to this gap between STACK_TOP and TASK_SIZE.
set_brk will never work for such case.
So at the moment this addition is just a sanity check.
An alternative (more complex):
Linux would make use of LMA field in ELF, then we can set VMA below
STACK_TOP and set LMA to be between STACK_TOP and TASK_SIZE to match
such special memory mapping.
Signed-off-by: Noam Camus <[email protected]>
---
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 241ef68..09f9483 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
Andreas Dilger suggested that my previous email may be discarded due to my Sender Policy Framework (SPF) .
So I email this from different location, just in case.
Noam
________________________________________
From: Noam Camus
Sent: Tuesday, June 9, 2015 3:32 PM
To: [email protected]; [email protected]
Cc: [email protected]; Gilad Ben Yossef; Chris Metcalf; Noam Camus
Subject: [PATCH] fs: heap/bss calculation ignore special section.
From: Noam Camus <[email protected]>
Today bss/heap is placed above last loaded sections.
However if STACK_TOP is not equal to TASK_SIZE we wish to ignore
such sections mapped to this gap between STACK_TOP and TASK_SIZE.
set_brk will never work for such case.
So at the moment this addition is just a sanity check.
An alternative (more complex):
Linux would make use of LMA field in ELF, then we can set VMA below
STACK_TOP and set LMA to be between STACK_TOP and TASK_SIZE to match
such special memory mapping.
Signed-off-by: Noam Camus <[email protected]>
---
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 241ef68..09f9483 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