From: "tip-bot2 for Marc Zyngier" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Moritz Fischer <mdf@kernel.org>, Marc Zyngier <maz@kernel.org>,
stable@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>,
James Morse <james.morse@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: efi/urgent] firmware/efi: Tell memblock about EFI iomem reservations
Date: Tue, 20 Jul 2021 11:37:19 -0000 [thread overview]
Message-ID: <162678103917.395.13758847379699183265.tip-bot2@tip-bot2> (raw)
The following commit has been merged into the efi/urgent branch of tip:
Commit-ID: 2bab693a608bdf614b9fcd44083c5100f34b9f77
Gitweb: https://git.kernel.org/tip/2bab693a608bdf614b9fcd44083c5100f34b9f77
Author: Marc Zyngier <maz@kernel.org>
AuthorDate: Tue, 13 Jul 2021 19:43:26 +01:00
Committer: Ard Biesheuvel <ardb@kernel.org>
CommitterDate: Fri, 16 Jul 2021 18:05:49 +02:00
firmware/efi: Tell memblock about EFI iomem reservations
kexec_load_file() relies on the memblock infrastructure to avoid
stamping over regions of memory that are essential to the survival
of the system.
However, nobody seems to agree how to flag these regions as reserved,
and (for example) EFI only publishes its reservations in /proc/iomem
for the benefit of the traditional, userspace based kexec tool.
On arm64 platforms with GICv3, this can result in the payload being
placed at the location of the LPI tables. Shock, horror!
Let's augment the EFI reservation code with a memblock_reserve() call,
protecting our dear tables from the secondary kernel invasion.
Reported-by: Moritz Fischer <mdf@kernel.org>
Tested-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
drivers/firmware/efi/efi.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 4b7ee3f..847f33f 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -896,6 +896,7 @@ static int __init efi_memreserve_map_root(void)
static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size)
{
struct resource *res, *parent;
+ int ret;
res = kzalloc(sizeof(struct resource), GFP_ATOMIC);
if (!res)
@@ -908,7 +909,17 @@ static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size)
/* we expect a conflict with a 'System RAM' region */
parent = request_resource_conflict(&iomem_resource, res);
- return parent ? request_resource(parent, res) : 0;
+ ret = parent ? request_resource(parent, res) : 0;
+
+ /*
+ * Given that efi_mem_reserve_iomem() can be called at any
+ * time, only call memblock_reserve() if the architecture
+ * keeps the infrastructure around.
+ */
+ if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK) && !ret)
+ memblock_reserve(addr, size);
+
+ return ret;
}
int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
reply other threads:[~2021-07-20 11:38 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=162678103917.395.13758847379699183265.tip-bot2@tip-bot2 \
--to=tip-bot2@linutronix.de \
--cc=ardb@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=james.morse@arm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=maz@kernel.org \
--cc=mdf@kernel.org \
--cc=stable@vger.kernel.org \
--cc=will@kernel.org \
--cc=x86@kernel.org \
/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).