From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: linux-efi@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
linux-kernel@vger.kernel.org, Hans de Goede <hdegoede@redhat.com>,
Jonathan Richardson <jonathan.richardson@broadcom.com>,
Luo XinanX <xinanx.luo@intel.com>,
"Prakhya, Sai Praneeth" <sai.praneeth.prakhya@intel.com>,
Qian Cai <cai@lca.pw>, Tian Baofeng <baofeng.tian@intel.com>
Subject: [PATCH 1/4] efi/memreserve: deal with memreserve entries in unmapped memory
Date: Sat, 22 Jun 2019 10:51:03 +0200 [thread overview]
Message-ID: <20190622085106.24859-2-ard.biesheuvel@linaro.org> (raw)
In-Reply-To: <20190622085106.24859-1-ard.biesheuvel@linaro.org>
Ensure that the EFI memreserve entries can be accessed, even if they
are located in memory that the kernel (e.g., a crashkernel) omits from
the linear map.
Fixes: 80424b02d42b ("efi: Reduce the amount of memblock reservations ...")
Cc: <stable@vger.kernel.org> # 5.0+
Reported-by: Jonathan Richardson <jonathan.richardson@broadcom.com>
Reviewed-by: Jonathan Richardson <jonathan.richardson@broadcom.com>
Tested-by: Jonathan Richardson <jonathan.richardson@broadcom.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
drivers/firmware/efi/efi.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 16b2137d117c..4b7cf7bc0ded 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -1009,14 +1009,16 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
/* first try to find a slot in an existing linked list entry */
for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) {
- rsv = __va(prsv);
+ rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
if (index < rsv->size) {
rsv->entry[index].base = addr;
rsv->entry[index].size = size;
+ memunmap(rsv);
return 0;
}
+ memunmap(rsv);
}
/* no slot found - allocate a new linked list entry */
@@ -1024,7 +1026,13 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
if (!rsv)
return -ENOMEM;
- rsv->size = EFI_MEMRESERVE_COUNT(PAGE_SIZE);
+ /*
+ * The memremap() call above assumes that a linux_efi_memreserve entry
+ * never crosses a page boundary, so let's ensure that this remains true
+ * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
+ * using SZ_4K explicitly in the size calculation below.
+ */
+ rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
atomic_set(&rsv->count, 1);
rsv->entry[0].base = addr;
rsv->entry[0].size = size;
--
2.20.1
next prev parent reply other threads:[~2019-06-22 8:51 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-22 8:51 [GIT PULL 0/4] EFI fixes for v5.2 Ard Biesheuvel
2019-06-22 8:51 ` Ard Biesheuvel [this message]
2019-06-22 8:51 ` [PATCH 2/4] efi/bgrt: Drop BGRT status field reserved bits check Ard Biesheuvel
2019-06-22 8:51 ` [PATCH 3/4] x86/efi: fix a -Wtype-limits compilation warning Ard Biesheuvel
2019-06-22 8:51 ` [PATCH 4/4] efibc: Replace variable set function in notifier call Ard Biesheuvel
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=20190622085106.24859-2-ard.biesheuvel@linaro.org \
--to=ard.biesheuvel@linaro.org \
--cc=baofeng.tian@intel.com \
--cc=cai@lca.pw \
--cc=hdegoede@redhat.com \
--cc=jonathan.richardson@broadcom.com \
--cc=linux-efi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=sai.praneeth.prakhya@intel.com \
--cc=tglx@linutronix.de \
--cc=xinanx.luo@intel.com \
/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).