From: Noam Camus <noamc@ezchip.com>
To: <linux-kernel@vger.kernel.org>, <linux-fsdevel@vger.kernel.org>,
        <viro@zeniv.linux.org.uk>
CC: <Alexey.Brodkin@synopsys.com>, <vgupta@synopsys.com>, <adilger@dilger.ca>,
        <giladb@ezchip.com>, Noam Camus <noamc@ezchip.com>
Subject: [PATCH] fs: heap/bss calculation ignore section above STACK_TOP.
Date: Sun, 26 Jul 2015 09:21:01 +0300
Message-ID: <1437891661-32007-1-git-send-email-noamc@ezchip.com>
MIME-Version: 1.0
Content-Type: text/plain
HE1PR02MB1147: X-MS-Exchange-Organization-RulesExecuted
SpamDiagnosticOutput: 1:23
SpamDiagnosticMetadata: NSPM
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Jul 2015 06:21:33.8173
 (UTC)
X-MS-Exchange-CrossTenant-Id: 0fc16e0a-3cd3-4092-8b2f-0a42cff122c3
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=0fc16e0a-3cd3-4092-8b2f-0a42cff122c3;Ip=[212.179.42.66];Helo=[ezex10.ezchip.com]
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: HE1PR02MB1147
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 1245
Lines: 40

From: Noam Camus <noamc@ezchip.com>

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@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 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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/