The script "ethtool-common.sh" is not installed in INSTALL_PATH, and
triggers some errors when I try to run the test
'drivers/net/netdevsim/ethtool-coalesce.sh':
TAP version 13
1..1
# timeout set to 600
# selftests: drivers/net/netdevsim: ethtool-coalesce.sh
# ./ethtool-coalesce.sh: line 4: ethtool-common.sh: No such file or directory
# ./ethtool-coalesce.sh: line 25: make_netdev: command not found
# ethtool: bad command line argument(s)
# ./ethtool-coalesce.sh: line 124: check: command not found
# ./ethtool-coalesce.sh: line 126: [: -eq: unary operator expected
# FAILED /0 checks
not ok 1 selftests: drivers/net/netdevsim: ethtool-coalesce.sh # exit=1
Install this file to avoid this error. After this patch:
TAP version 13
1..1
# timeout set to 600
# selftests: drivers/net/netdevsim: ethtool-coalesce.sh
# PASSED all 22 checks
ok 1 selftests: drivers/net/netdevsim: ethtool-coalesce.sh
Fixes: fbb8531e58bd ("selftests: extract common functions in ethtool-common.sh")
Signed-off-by: Wang Liang <wangliang74(a)huawei.com>
---
tools/testing/selftests/drivers/net/netdevsim/Makefile | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/tools/testing/selftests/drivers/net/netdevsim/Makefile b/tools/testing/selftests/drivers/net/netdevsim/Makefile
index daf51113c827..df10c7243511 100644
--- a/tools/testing/selftests/drivers/net/netdevsim/Makefile
+++ b/tools/testing/selftests/drivers/net/netdevsim/Makefile
@@ -20,4 +20,8 @@ TEST_PROGS := \
udp_tunnel_nic.sh \
# end of TEST_PROGS
+TEST_FILES := \
+ ethtool-common.sh
+# end of TEST_FILES
+
include ../../../lib.mk
--
2.34.1
The test 'ethtool-features.sh' failed with the below output:
TAP version 13
1..1
# timeout set to 600
# selftests: drivers/net/netdevsim: ethtool-features.sh
# Warning: file ethtool-features.sh is not executable
# ethtool: bad command line argument(s)
# For more information run ethtool -h
# ethtool: bad command line argument(s)
# For more information run ethtool -h
# ethtool: bad command line argument(s)
# For more information run ethtool -h
# ethtool: bad command line argument(s)
# For more information run ethtool -h
# ethtool: bad command line argument(s)
# For more information run ethtool -h
# ethtool: bad command line argument(s)
# For more information run ethtool -h
# ethtool: bad command line argument(s)
# For more information run ethtool -h
# ethtool: bad command line argument(s)
# For more information run ethtool -h
# ethtool: bad command line argument(s)
# For more information run ethtool -h
# ethtool: bad command line argument(s)
# For more information run ethtool -h
# FAILED 10/10 checks
not ok 1 selftests: drivers/net/netdevsim: ethtool-features.sh # exit=1
Similar to commit 18378b0e49d9 ("selftests/damon: Add executable
permission to test scripts"), the script 'ethtool-features.sh' has no
executable permission, which leads to the warning 'file
ethtool-features.sh is not executable'.
Old version ethtool (my ethtool version is 5.16) does not support command
'ethtool --json -k enp1s0', which leads to the output 'ethtool: bad
command line argument(s)'.
This patch adds executable permission to script 'ethtool-features.sh', and
check 'ethtool --json -k' support. After this patch:
TAP version 13
1..1
# timeout set to 600
# selftests: drivers/net/netdevsim: ethtool-features.sh
# SKIP: No --json -k support in ethtool
ok 1 selftests: drivers/net/netdevsim: ethtool-features.sh
Fixes: 0189270117c3 ("selftests: netdevsim: add a test checking ethtool features")
Signed-off-by: Wang Liang <wangliang74(a)huawei.com>
---
.../selftests/drivers/net/netdevsim/ethtool-features.sh | 5 +++++
1 file changed, 5 insertions(+)
mode change 100644 => 100755 tools/testing/selftests/drivers/net/netdevsim/ethtool-features.sh
diff --git a/tools/testing/selftests/drivers/net/netdevsim/ethtool-features.sh b/tools/testing/selftests/drivers/net/netdevsim/ethtool-features.sh
old mode 100644
new mode 100755
index bc210dc6ad2d..f771dc6839ea
--- a/tools/testing/selftests/drivers/net/netdevsim/ethtool-features.sh
+++ b/tools/testing/selftests/drivers/net/netdevsim/ethtool-features.sh
@@ -7,6 +7,11 @@ NSIM_NETDEV=$(make_netdev)
set -o pipefail
+if ! ethtool --json -k $NSIM_NETDEV > /dev/null 2>&1; then
+ echo "SKIP: No --json -k support in ethtool"
+ exit $ksft_skip
+fi
+
FEATS="
tx-checksum-ip-generic
tx-scatter-gather
--
2.34.1
[Kevin has a done a great job to get through reviews on all these, and
Vasant/Ankit have been looking at it on AMD systems, I think we are close to
being done now!]
Currently each of the iommu page table formats duplicates all of the logic
to maintain the page table and perform map/unmap/etc operations. There are
several different versions of the algorithms between all the different
formats. The io-pgtable system provides an interface to help isolate the
page table code from the iommu driver, but doesn't provide tools to
implement the common algorithms.
This makes it very hard to improve the state of the pagetable code under
the iommu domains as any proposed improvement needs to alter a large
number of different driver code paths. Combined with a lack of software
based testing this makes improvement in this area very hard.
iommufd wants several new page table operations:
- More efficient map/unmap operations, using iommufd's batching logic
- unmap that returns the physical addresses into a batch as it progresses
- cut that allows splitting areas so large pages can have holes
poked in them dynamically (ie guestmemfd hitless shared/private
transitions)
- More agressive freeing of table memory to avoid waste
- Fragmenting large pages so that dirty tracking can be more granular
- Reassembling large pages so that VMs can run at full IO performance
in migration/dirty tracking error flows
- KHO integration for kernel live upgrade
Together these are algorithmically complex enough to be a very significant
task to go and implement in all the page table formats we support. Just
the "server" focused drivers use almost all the formats (ARMv8 S1&S2 / x86
PAE / AMDv1 / VT-d SS / RISCV)
Instead of doing the duplicated work, this series takes the first step to
consolidate the algorithms into one places. In spirit it is similar to the
work Christoph did a few years back to pull the redundant get_user_pages()
implementations out of the arch code into core MM. This unlocked a great
deal of improvement in that space in the following years. I would like to
see the same benefit in iommu as well.
My first RFC showed a bigger picture with all most all formats and more
algorithms. This series reorganizes that to be narrowly focused on just
enough to convert the AMD driver to use the new mechanism.
kunit tests are provided that allow good testing of the algorithms and all
formats on x86, nothing is arch specific.
AMD is one of the simpler options as the HW is quite uniform with few
different options/bugs while still requiring the complicated contiguous
pages support. The HW also has a very simple range based invalidation
approach that is easy to implement.
The AMD v1 and AMD v2 page table formats are implemented bit for bit
identical to the current code, tested using a compare kunit test that
checks against the io-pgtable version (on github, see below).
Updating the AMD driver to replace the io-pgtable layer with the new stuff
is fairly straightforward now. The layering is fixed up in the new version
so that all the invalidation goes through function pointers.
Several small fixing patches have come out of this as I've been fixing the
problems that the test suite uncovers in the current code, and
implementing the fixed version in iommupt.
On performance, there is a quite wide variety of implementation designs
across all the drivers. Looking at some key performance across
the main formats:
iommu_map():
pgsz ,avg new,old ns, min new,old ns , min % (+ve is better)
2^12, 53,66 , 51,63 , 19.19 (AMDV1)
256*2^12, 386,1909 , 367,1795 , 79.79
256*2^21, 362,1633 , 355,1556 , 77.77
2^12, 56,62 , 52,59 , 11.11 (AMDv2)
256*2^12, 405,1355 , 357,1292 , 72.72
256*2^21, 393,1160 , 358,1114 , 67.67
2^12, 55,65 , 53,62 , 14.14 (VT-d second stage)
256*2^12, 391,518 , 332,512 , 35.35
256*2^21, 383,635 , 336,624 , 46.46
2^12, 57,65 , 55,63 , 12.12 (ARM 64 bit)
256*2^12, 380,389 , 361,369 , 2.02
256*2^21, 358,419 , 345,400 , 13.13
iommu_unmap():
pgsz ,avg new,old ns, min new,old ns , min % (+ve is better)
2^12, 69,88 , 65,85 , 23.23 (AMDv1)
256*2^12, 353,6498 , 331,6029 , 94.94
256*2^21, 373,6014 , 360,5706 , 93.93
2^12, 71,72 , 66,69 , 4.04 (AMDv2)
256*2^12, 228,891 , 206,871 , 76.76
256*2^21, 254,721 , 245,711 , 65.65
2^12, 69,87 , 65,82 , 20.20 (VT-d second stage)
256*2^12, 210,321 , 200,315 , 36.36
256*2^21, 255,349 , 238,342 , 30.30
2^12, 72,77 , 68,74 , 8.08 (ARM 64 bit)
256*2^12, 521,357 , 447,346 , -29.29
256*2^21, 489,358 , 433,345 , -25.25
* Above numbers include additional patches to remove the iommu_pgsize()
overheads. gcc 13.3.0, i7-12700
This version provides fairly consistent performance across formats. ARM
unmap performance is quite different because this version supports
contiguous pages and uses a very different algorithm for unmapping. Though
why it is so worse compared to AMDv1 I haven't figured out yet.
The per-format commits include a more detailed chart.
There is a second branch:
https://github.com/jgunthorpe/linux/commits/iommu_pt_all
Containing supporting work and future steps:
- ARM short descriptor (32 bit), ARM long descriptor (64 bit) formats
- RISCV format and RISCV conversion
https://github.com/jgunthorpe/linux/commits/iommu_pt_riscv
- Support for a DMA incoherent HW page table walker
- VT-d second stage format and VT-d conversion
https://github.com/jgunthorpe/linux/commits/iommu_pt_vtd
- DART v1 & v2 format
- Draft of a iommufd 'cut' operation to break down huge pages
- A compare test that checks the iommupt formats against the iopgtable
interface, including updating AMD to have a working iopgtable and patches
to make VT-d have an iopgtable for testing.
- A performance test to micro-benchmark map and unmap against iogptable
My strategy is to go one by one for the drivers:
- AMD driver conversion
- RISCV page table and driver
- Intel VT-d driver and VTDSS page table
- Flushing improvements for RISCV
- ARM SMMUv3
And concurrently work on the algorithm side:
- debugfs content dump, like VT-d has
- Cut support
- Increase/Decrease page size support
- map/unmap batching
- KHO
As we make more algorithm improvements the value to convert the drivers
increases.
This is on github: https://github.com/jgunthorpe/linux/commits/iommu_pt
v7:
- Rebase to v6.18-rc2
- Improve comments and documentation
- Add a few missed __sme_sets() for AMD CC
- Rename pt_iommu_flush_ops -> pt_iommu_driver_ops
VT-D -> VT-d
pt_clear_entry -> pt_clear_entries
pt_entry_write_is_dirty -> pt_entry_is_write_dirty
pt_entry_set_write_clean -> pt_entry_make_write_clean
- Tidy some of the map flow into a new function do_map()
- Fix ffz64()
v6: https://patch.msgid.link/r/0-v6-0fb54a1d9850+36b-iommu_pt_jgg@nvidia.com
- Improve comments and documentation
- Rename pt_entry_oa_full -> pt_entry_oa_exact
pt_has_system_page -> pt_has_system_page_size
pt_max_output_address_lg2 -> pt_max_oa_lg2
log2_f*() -> vaf* / oaf* / f*_t
pt_item_fully_covered -> pt_entry_fully_covered
- Fix missed constant propogation causing division
- Consolidate debugging checks to pt_check_install_leaf_args()
- Change collect->ignore_mapped to check_mapped
- Shuffle some hunks around to more appropriate patches
- Two new mini kunit tests
v5: https://patch.msgid.link/r/0-v5-116c4948af3d+68091-iommu_pt_jgg@nvidia.com
- Text grammar updates and kdoc fixes
v4: https://patch.msgid.link/r/0-v4-0d6a6726a372+18959-iommu_pt_jgg@nvidia.com
- Rebase on v6.16-rc3
- Integrate the HATS/HATDis changes
- Remove 'default n' from kconfig
- Remove unused 'PT_FIXED_TOP_LEVEL'
- Improve comments and documentation
- Fix some compile warnings from kbuild robots
v3: https://patch.msgid.link/r/0-v3-a93aab628dbc+521-iommu_pt_jgg@nvidia.com
- Rebase on v6.16-rc2
- s/PT_ENTRY_WORD_SIZE/PT_ITEM_WORD_SIZE/s to follow the language better
- Comment and documentation updates
- Add PT_TOP_PHYS_MASK to help manage alignment restrictions on the top
pointer
- Add missed force_aperture = true
- Make pt_iommu_deinit() take care of the not-yet-inited error case
internally as AMD/RISCV/VTD all shared this logic
- Change gather_range() into gather_range_pages() so it also deals with
the page list. This makes the following cache flushing series simpler
- Fix missed update of unmap->unmapped in some error cases
- Change clear_contig() to order the gather more logically
- Remove goto from the error handling in __map_range_leaf()
- s/log2_/oalog2_/ in places where the argument is an oaddr_t
- Pass the pts to pt_table_install64/32()
- Do not use SIGN_EXTEND for the AMDv2 page table because of Vasant's
information on how PASID 0 works.
v2: https://patch.msgid.link/r/0-v2-5c26bde5c22d+58b-iommu_pt_jgg@nvidia.com
- AMD driver only, many code changes
RFC: https://lore.kernel.org/all/0-v1-01fa10580981+1d-iommu_pt_jgg@nvidia.com/
Cc: Michael Roth <michael.roth(a)amd.com>
Cc: Alexey Kardashevskiy <aik(a)amd.com>
Cc: Pasha Tatashin <pasha.tatashin(a)soleen.com>
Cc: James Gowans <jgowans(a)amazon.com>
Signed-off-by: Jason Gunthorpe <jgg(a)nvidia.com>
Alejandro Jimenez (1):
iommu/amd: Use the generic iommu page table
Jason Gunthorpe (14):
genpt: Generic Page Table base API
genpt: Add Documentation/ files
iommupt: Add the basic structure of the iommu implementation
iommupt: Add the AMD IOMMU v1 page table format
iommupt: Add iova_to_phys op
iommupt: Add unmap_pages op
iommupt: Add map_pages op
iommupt: Add read_and_clear_dirty op
iommupt: Add a kunit test for Generic Page Table
iommupt: Add a mock pagetable format for iommufd selftest to use
iommufd: Change the selftest to use iommupt instead of xarray
iommupt: Add the x86 64 bit page table format
iommu/amd: Remove AMD io_pgtable support
iommupt: Add a kunit test for the IOMMU implementation
.clang-format | 1 +
Documentation/driver-api/generic_pt.rst | 142 ++
Documentation/driver-api/index.rst | 1 +
drivers/iommu/Kconfig | 2 +
drivers/iommu/Makefile | 1 +
drivers/iommu/amd/Kconfig | 5 +-
drivers/iommu/amd/Makefile | 2 +-
drivers/iommu/amd/amd_iommu.h | 1 -
drivers/iommu/amd/amd_iommu_types.h | 110 +-
drivers/iommu/amd/io_pgtable.c | 577 --------
drivers/iommu/amd/io_pgtable_v2.c | 370 ------
drivers/iommu/amd/iommu.c | 538 ++++----
drivers/iommu/generic_pt/.kunitconfig | 13 +
drivers/iommu/generic_pt/Kconfig | 68 +
drivers/iommu/generic_pt/fmt/Makefile | 26 +
drivers/iommu/generic_pt/fmt/amdv1.h | 415 ++++++
drivers/iommu/generic_pt/fmt/defs_amdv1.h | 21 +
drivers/iommu/generic_pt/fmt/defs_x86_64.h | 21 +
drivers/iommu/generic_pt/fmt/iommu_amdv1.c | 15 +
drivers/iommu/generic_pt/fmt/iommu_mock.c | 10 +
drivers/iommu/generic_pt/fmt/iommu_template.h | 48 +
drivers/iommu/generic_pt/fmt/iommu_x86_64.c | 11 +
drivers/iommu/generic_pt/fmt/x86_64.h | 259 ++++
drivers/iommu/generic_pt/iommu_pt.h | 1162 +++++++++++++++++
drivers/iommu/generic_pt/kunit_generic_pt.h | 713 ++++++++++
drivers/iommu/generic_pt/kunit_iommu.h | 183 +++
drivers/iommu/generic_pt/kunit_iommu_pt.h | 487 +++++++
drivers/iommu/generic_pt/pt_common.h | 358 +++++
drivers/iommu/generic_pt/pt_defs.h | 329 +++++
drivers/iommu/generic_pt/pt_fmt_defaults.h | 233 ++++
drivers/iommu/generic_pt/pt_iter.h | 636 +++++++++
drivers/iommu/generic_pt/pt_log2.h | 122 ++
drivers/iommu/io-pgtable.c | 4 -
drivers/iommu/iommufd/Kconfig | 1 +
drivers/iommu/iommufd/iommufd_test.h | 11 +-
drivers/iommu/iommufd/selftest.c | 438 +++----
include/linux/generic_pt/common.h | 167 +++
include/linux/generic_pt/iommu.h | 271 ++++
include/linux/io-pgtable.h | 2 -
include/linux/irqchip/riscv-imsic.h | 3 +-
tools/testing/selftests/iommu/iommufd.c | 60 +-
tools/testing/selftests/iommu/iommufd_utils.h | 12 +
42 files changed, 6237 insertions(+), 1612 deletions(-)
create mode 100644 Documentation/driver-api/generic_pt.rst
delete mode 100644 drivers/iommu/amd/io_pgtable.c
delete mode 100644 drivers/iommu/amd/io_pgtable_v2.c
create mode 100644 drivers/iommu/generic_pt/.kunitconfig
create mode 100644 drivers/iommu/generic_pt/Kconfig
create mode 100644 drivers/iommu/generic_pt/fmt/Makefile
create mode 100644 drivers/iommu/generic_pt/fmt/amdv1.h
create mode 100644 drivers/iommu/generic_pt/fmt/defs_amdv1.h
create mode 100644 drivers/iommu/generic_pt/fmt/defs_x86_64.h
create mode 100644 drivers/iommu/generic_pt/fmt/iommu_amdv1.c
create mode 100644 drivers/iommu/generic_pt/fmt/iommu_mock.c
create mode 100644 drivers/iommu/generic_pt/fmt/iommu_template.h
create mode 100644 drivers/iommu/generic_pt/fmt/iommu_x86_64.c
create mode 100644 drivers/iommu/generic_pt/fmt/x86_64.h
create mode 100644 drivers/iommu/generic_pt/iommu_pt.h
create mode 100644 drivers/iommu/generic_pt/kunit_generic_pt.h
create mode 100644 drivers/iommu/generic_pt/kunit_iommu.h
create mode 100644 drivers/iommu/generic_pt/kunit_iommu_pt.h
create mode 100644 drivers/iommu/generic_pt/pt_common.h
create mode 100644 drivers/iommu/generic_pt/pt_defs.h
create mode 100644 drivers/iommu/generic_pt/pt_fmt_defaults.h
create mode 100644 drivers/iommu/generic_pt/pt_iter.h
create mode 100644 drivers/iommu/generic_pt/pt_log2.h
create mode 100644 include/linux/generic_pt/common.h
create mode 100644 include/linux/generic_pt/iommu.h
base-commit: bf3db0366052dcdf7dea89a07929b690aac59b15
--
2.43.0
Currently, guard regions are not visible to users except through
/proc/$pid/pagemap, with no explicit visibility at the VMA level.
This makes the feature less useful, as it isn't entirely apparent which
VMAs may have these entries present, especially when performing actions
which walk through memory regions such as those performed by CRIU.
This series addresses this issue by introducing the VM_MAYBE_GUARD flag
which fulfils this role, updating the smaps logic to display an entry for
these.
The semantics of this flag are that a guard region MAY be present if set
(we cannot be sure, as we can't efficiently track whether an
MADV_GUARD_REMOVE finally removes all the guard regions in a VMA) - but if
not set the VMA definitely does NOT have any guard regions present.
It's problematic to establish this flag without further action, because
that means that VMAs with guard regions in them become non-mergeable with
adjacent VMAs for no especially good reason.
To work around this, this series also introduces the concept of 'sticky'
VMA flags - that is flags which:
a. if set in one VMA and not in another still permit those VMAs to be
merged (if otherwise compatible).
b. When they are merged, the resultant VMA must have the flag set.
The VMA logic is updated to propagate these flags correctly.
Additionally, VM_MAYBE_GUARD being an explicit VMA flag allows us to solve
an issue with file-backed guard regions - previously these established an
anon_vma object for file-backed mappings solely to have vma_needs_copy()
correctly propagate guard region mappings to child processes.
We introduce a new flag alias VM_COPY_ON_FORK (which currently only
specifies VM_MAYBE_GUARD) and update vma_needs_copy() to check explicitly
for this flag and to copy page tables if it is present, which resolves this
issue.
Finally we introduce extensive VMA userland tests to assert that the sticky
VMA logic behaves correctly as well as guard region self tests to assert
that smaps visibility is correctly implemented.
Lorenzo Stoakes (3):
mm: introduce VM_MAYBE_GUARD and make visible for guard regions
mm: implement sticky, copy on fork VMA flags
selftests/mm/guard-regions: add smaps visibility test
Documentation/filesystems/proc.rst | 1 +
fs/proc/task_mmu.c | 1 +
include/linux/mm.h | 33 ++++++
include/trace/events/mmflags.h | 1 +
mm/madvise.c | 22 ++--
mm/memory.c | 3 +
mm/vma.c | 22 ++--
tools/testing/selftests/mm/guard-regions.c | 120 +++++++++++++++++++++
tools/testing/selftests/mm/vm_util.c | 5 +
tools/testing/selftests/mm/vm_util.h | 1 +
tools/testing/vma/vma.c | 89 +++++++++++++--
tools/testing/vma/vma_internal.h | 33 ++++++
12 files changed, 303 insertions(+), 28 deletions(-)
--
2.51.0
The bareudp.sh script uses /bin/sh and it will load another lib.sh
BASH script at the very beginning.
But on some operating systems like Ubuntu, /bin/sh is actually pointed to
DASH, thus it will try to run BASH commands with DASH and consequently
leads to syntax issues.
This patch fixes syntax failures on systems where /bin/sh is not BASH by
explicitily using BASH for bareudp.sh.
Po-Hsu Lin (1):
selftests: net: use BASH for bareudp testing
tools/testing/selftests/net/bareudp.sh | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--
2.34.1
Socket APIs like recvfrom(), accept(), and getsockname() expect socklen_t*
arg, but tests were using int variables. This causes -Wpointer-sign
warnings on platforms where socklen_t is unsigned.
Change the variable type from int to socklen_t to resolve the warning and
ensure type safety across platforms.
warning fixed:
sctp_collision.c:62:70: warning: passing 'int *' to parameter of
type 'socklen_t *' (aka 'unsigned int *') converts between pointers to
integer types with different sign [-Wpointer-sign]
62 | ret = recvfrom(sd, buf, sizeof(buf),
0, (struct sockaddr *)&daddr, &len);
| ^~~~
/usr/include/sys/socket.h:165:27: note: passing argument to
parameter '__addr_len' here
165 | socklen_t *__restrict __addr_len);
| ^
Reviewed-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com>
Signed-off-by: Ankit Khushwaha <ankitkhushwaha.linux(a)gmail.com>
---
tools/testing/selftests/net/netfilter/sctp_collision.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/net/netfilter/sctp_collision.c b/tools/testing/selftests/net/netfilter/sctp_collision.c
index 21bb1cfd8a85..91df996367e9 100644
--- a/tools/testing/selftests/net/netfilter/sctp_collision.c
+++ b/tools/testing/selftests/net/netfilter/sctp_collision.c
@@ -9,7 +9,8 @@
int main(int argc, char *argv[])
{
struct sockaddr_in saddr = {}, daddr = {};
- int sd, ret, len = sizeof(daddr);
+ socklen_t len = sizeof(daddr);
struct timeval tv = {25, 0};
char buf[] = "hello";
+ int sd, ret;
--
2.51.0
This series fixes a memory corruption bug in KHO that occurs when KFENCE
is enabled.
The root cause is that KHO metadata, allocated via kzalloc(), can be
randomly serviced by kfence_alloc(). When a kernel boots via KHO, the
early memblock allocator is restricted to a "scratch area". This forces
the KFENCE pool to be allocated within this scratch area, creating a
conflict. If KHO metadata is subsequently placed in this pool, it gets
corrupted during the next kexec operation.
Patch 1/3 introduces a debug-only feature (CONFIG_KEXEC_HANDOVER_DEBUG)
that adds checks to detect and fail any operation that attempts to place
KHO metadata or preserved memory within the scratch area. This serves as
a validation and diagnostic tool to confirm the problem without
affecting production builds.
Patch 2/3 Increases bitmap to PAGE_SIZE, so buddy allocator can be used.
Patch 3/3 Provides the fix by modifying KHO to allocate its metadata
directly from the buddy allocator instead of slab. This bypasses the
KFENCE interception entirely.
Pasha Tatashin (3):
liveupdate: kho: warn and fail on metadata or preserved memory in
scratch area
liveupdate: kho: Increase metadata bitmap size to PAGE_SIZE
liveupdate: kho: allocate metadata directly from the buddy allocator
include/linux/gfp.h | 3 ++
kernel/Kconfig.kexec | 9 ++++
kernel/Makefile | 1 +
kernel/kexec_handover.c | 72 ++++++++++++++++++++------------
kernel/kexec_handover_debug.c | 25 +++++++++++
kernel/kexec_handover_internal.h | 16 +++++++
6 files changed, 100 insertions(+), 26 deletions(-)
create mode 100644 kernel/kexec_handover_debug.c
create mode 100644 kernel/kexec_handover_internal.h
base-commit: 6548d364a3e850326831799d7e3ea2d7bb97ba08
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2.51.0.869.ge66316f041-goog