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From: Noam Camus <noamc@ezchip.com>
To: <linux-fsdevel@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Cc: <vgupta@synopsys.com>, <giladb@ezchip.com>, <cmetcalf@ezchip.com>,
	"Noam Camus" <noamc@ezchip.com>
Subject: [PATCH] fs: heap/bss calculation ignore special section.
Date: Tue, 9 Jun 2015 15:32:19 +0300	[thread overview]
Message-ID: <1433853139-28554-1-git-send-email-noamc@ezchip.com> (raw)

From: Noam Camus <noamc@ezchip.com>

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 <noamc@ezchip.com>
---
 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

             reply	other threads:[~2015-06-09 12:32 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-09 12:32 Noam Camus [this message]
2015-06-24  7:28 ` [PATCH] fs: heap/bss calculation ignore special section Noam Camus

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