From: Balbir Singh <bsingharora@gmail.com>
To: linuxppc-dev@lists.ozlabs.org, mpe@ellerman.id.au
Subject: [PATCH 2/3] powerpc/mm/hash: WARN if relocation is enabled and CONFIG_STRICT_KERNEL_RWX
Date: Wed, 5 Jul 2017 17:14:24 +1000 [thread overview]
Message-ID: <20170705071425.5417-3-bsingharora@gmail.com> (raw)
In-Reply-To: <20170705071425.5417-1-bsingharora@gmail.com>
For radix we split the mapping into smaller page sizes (at the cost of
additional TLB overhead), but for hash its best to print a warning. In
the case of hash and no-relocation, the kernel should be well aligned
to provide the least overhead with the current linear mapping size (16M)
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
---
arch/powerpc/mm/pgtable-hash64.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/mm/pgtable-hash64.c b/arch/powerpc/mm/pgtable-hash64.c
index 0809102b..7c2479d 100644
--- a/arch/powerpc/mm/pgtable-hash64.c
+++ b/arch/powerpc/mm/pgtable-hash64.c
@@ -438,6 +438,11 @@ void hash__mark_rodata_ro(void)
return;
}
+ if (PHYSICAL_START > MEMORY_START)
+ pr_warn("Detected relocation and CONFIG_STRICT_KERNEL_RWX "
+ "permissions are best effort, some non-text area "
+ "might still be left as executable");
+
shift = mmu_psize_defs[mmu_linear_psize].shift;
step = 1 << shift;
@@ -448,7 +453,7 @@ void hash__mark_rodata_ro(void)
start, end, step);
if (start == end) {
- pr_warn("could not set rodata ro, relocate the start"
+ pr_warn("Could not set rodata ro, relocate the start"
" of the kernel to a 0x%x boundary\n", step);
return;
}
--
2.9.4
next prev parent reply other threads:[~2017-07-05 7:14 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-05 7:14 [PATCH 0/3] Have CONFIG_STRICT_KERNEL_RWX work with CONFIG_RELOCATABLE Balbir Singh
2017-07-05 7:14 ` [PATCH 1/3] powerpc/mm/radix: Fix relocatable radix mappings for STRICT_RWX Balbir Singh
2017-07-05 7:14 ` Balbir Singh [this message]
2017-07-05 7:14 ` [PATCH 3/3] powerpc/strict_kernel_rwx: Don't depend on !RELOCATABLE Balbir Singh
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20170705071425.5417-3-bsingharora@gmail.com \
--to=bsingharora@gmail.com \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mpe@ellerman.id.au \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).