August 2024 - Linux-kselftest-mirror

[PATCH] selftests/rseq/Makefile: fix relative rpath usage

by Eugene Syromiatnikov

The relative RPATH ("./") supplied to linker options in CFLAGS is resolved relative to current working directory and not the executable directory, which will lead in incorrect resolution when the test executables are run from elsewhere. Changing it to $ORIGIN makes it resolve relative to the directory in which the executables reside, which is supposedly the desired behaviour. Discovered by the /usr/lib/rpm/check-rpaths script[1][2] that checks for insecure RPATH/RUNPATH[3], such as containing relative directories, during an attempt to package BPF selftests for later use in CI: ERROR 0004: file '/usr/libexec/kselftests/bpf/urandom_read' contains an insecure runpath '.' in [.] [1] https://github.com/rpm-software-management/rpm/blob/master/scripts/check-rp… [2] https://github.com/rpm-software-management/rpm/blob/master/scripts/check-rp… [3] https://cwe.mitre.org/data/definitions/426.html Signed-off-by: Eugene Syromiatnikov <esyr(a)redhat.com> --- tools/testing/selftests/rseq/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/rseq/Makefile b/tools/testing/selftests/rseq/Makefile index 5a3432fceb58..27544a67d6f0 100644 --- a/tools/testing/selftests/rseq/Makefile +++ b/tools/testing/selftests/rseq/Makefile @@ -6,7 +6,7 @@ endif top_srcdir = ../../../.. -CFLAGS += -O2 -Wall -g -I./ $(KHDR_INCLUDES) -L$(OUTPUT) -Wl,-rpath=./ \ +CFLAGS += -O2 -Wall -g -I./ $(KHDR_INCLUDES) -L$(OUTPUT) -Wl,-rpath=\$$ORIGIN/ \ $(CLANG_FLAGS) -I$(top_srcdir)/tools/include LDLIBS += -lpthread -ldl -- 2.28.0

1 year, 2 months

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[PATCH] KVM: selftests: arm64: Correct feature test for S1PIE in get-reg-list

by Mark Brown

The ID register for S1PIE is ID_AA64MMFR3_EL1.S1PIE which is bits 11:8 but get-reg-list uses a shift of 4, checking SCTLRX instead. Use a shift of 8 instead. Fixes: 5f0419a0083b ("KVM: selftests: get-reg-list: add Permission Indirection registers") Signed-off-by: Mark Brown <broonie(a)kernel.org> --- tools/testing/selftests/kvm/aarch64/get-reg-list.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/kvm/aarch64/get-reg-list.c b/tools/testing/selftests/kvm/aarch64/get-reg-list.c index 709d7d721760..4abebde78187 100644 --- a/tools/testing/selftests/kvm/aarch64/get-reg-list.c +++ b/tools/testing/selftests/kvm/aarch64/get-reg-list.c @@ -32,13 +32,13 @@ static struct feature_id_reg feat_id_regs[] = { { ARM64_SYS_REG(3, 0, 10, 2, 2), /* PIRE0_EL1 */ ARM64_SYS_REG(3, 0, 0, 7, 3), /* ID_AA64MMFR3_EL1 */ - 4, + 8, 1 }, { ARM64_SYS_REG(3, 0, 10, 2, 3), /* PIR_EL1 */ ARM64_SYS_REG(3, 0, 0, 7, 3), /* ID_AA64MMFR3_EL1 */ - 4, + 8, 1 } }; --- base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b change-id: 20240731-kvm-arm64-fix-s1pie-test-a40b6be58d7b Best regards, -- Mark Brown <broonie(a)kernel.org>

1 year, 2 months

4
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[PATCH net-next] selftests: forwarding: lib.sh: ignore "Address not found"

by Geliang Tang

From: Geliang Tang <tanggeliang(a)kylinos.cn> So many "Address not found" messages occur at the end of forwarding tests when using "ip address del" command for an invalid address: TEST: FDB limits interacting with FDB type local [ OK ] Error: ipv4: Address not found. ... ... TEST: IGMPv3 S,G port entry automatic add to a *,G port [ OK ] Error: ipv4: Address not found. Error: ipv6: address not found. ... ... TEST: Isolated port flooding [ OK ] Error: ipv4: Address not found. Error: ipv6: address not found. ... ... TEST: Externally learned FDB entry - ageing & roaming [ OK ] Error: ipv4: Address not found. Error: ipv6: address not found. This patch gnores these messages and redirects them to /dev/null in __addr_add_del(). Signed-off-by: Geliang Tang <tanggeliang(a)kylinos.cn> --- tools/testing/selftests/net/forwarding/lib.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/net/forwarding/lib.sh b/tools/testing/selftests/net/forwarding/lib.sh index ff96bb7535ff..8670b6053cde 100644 --- a/tools/testing/selftests/net/forwarding/lib.sh +++ b/tools/testing/selftests/net/forwarding/lib.sh @@ -839,7 +839,7 @@ __addr_add_del() array=("${@}") for addrstr in "${array[@]}"; do - ip address $add_del $addrstr dev $if_name + ip address $add_del $addrstr dev $if_name &> /dev/null done } -- 2.43.0

1 year, 2 months

4
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[PATCH v4 0/2] Enhance network interface feature testing

by Abhinav Jain

This small series includes fixes for creation of veth pairs for networkless kernels & adds tests for turning the different network interface features on and off in selftests/net/netdevice.sh script. Changes in v4: Move veth creation/removal to the main shell script. Tested using vng on a networkless kernel and the script works, sample output below the changes. Changes in v3: https://lore.kernel.org/all/20240614113240.41550-1-jain.abhinav177@gmail.co… Add a check for netdev, create veth pair for testing. Restore feature to its initial state. Changes in v2: https://lore.kernel.org/all/20240609132124.51683-1-jain.abhinav177@gmail.co… Remove tail usage; use read to parse the features from temp file. v1: https://lore.kernel.org/all/20240606212714.27472-1-jain.abhinav177@gmail.co… ``` # selftests: net: netdevice.sh # No valid network device found, creating veth pair # PASS: veth0: set interface up # PASS: veth0: set MAC address # SKIP: veth0: set IP address # PASS: veth0: ethtool list features # PASS: veth0: Turned off feature: rx-checksumming # PASS: veth0: Turned on feature: rx-checksumming # PASS: veth0: Restore feature rx-checksumming to initial state on # Actual changes: # tx-checksum-ip-generic: off # tx-tcp-segmentation: off [not requested] .... .... .... # PASS: veth1: Restore feature tx-nocache-copy to initial state off # PASS: veth1: Turned off feature: tx-vlan-stag-hw-insert # PASS: veth1: Turned on feature: tx-vlan-stag-hw-insert # PASS: veth1: Restore feature tx-vlan-stag-hw-insert to initial state on # PASS: veth1: Turned off feature: rx-vlan-stag-hw-parse # PASS: veth1: Turned on feature: rx-vlan-stag-hw-parse # PASS: veth1: Restore feature rx-vlan-stag-hw-parse to initial state on # PASS: veth1: Turned off feature: rx-gro-list # PASS: veth1: Turned on feature: rx-gro-list # PASS: veth1: Restore feature rx-gro-list to initial state off # PASS: veth1: Turned off feature: rx-udp-gro-forwarding # PASS: veth1: Turned on feature: rx-udp-gro-forwarding # PASS: veth1: Restore feature rx-udp-gro-forwarding to initial state off # Cannot get register dump: Operation not supported # SKIP: veth1: ethtool dump not supported # PASS: veth1: ethtool stats # PASS: veth1: stop interface # Removed veth pair ok 12 selftests: net: netdevice.sh ``` Abhinav Jain (2): selftests: net: Create veth pair for testing in networkless kernel selftests: net: Add on/off checks for non-fixed features of interface tools/testing/selftests/net/netdevice.sh | 55 +++++++++++++++++++++++- 1 file changed, 54 insertions(+), 1 deletion(-) -- 2.34.1

1 year, 2 months

2
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[PATCH net-next v13 05/14] mm: page_frag: avoid caller accessing 'page_frag_cache' directly

by Yunsheng Lin

Use appropriate frag_page API instead of caller accessing 'page_frag_cache' directly. CC: Alexander Duyck <alexander.duyck(a)gmail.com> Signed-off-by: Yunsheng Lin <linyunsheng(a)huawei.com> Reviewed-by: Alexander Duyck <alexanderduyck(a)fb.com> Acked-by: Chuck Lever <chuck.lever(a)oracle.com> --- drivers/vhost/net.c | 2 +- include/linux/page_frag_cache.h | 10 ++++++++++ net/core/skbuff.c | 6 +++--- net/rxrpc/conn_object.c | 4 +--- net/rxrpc/local_object.c | 4 +--- net/sunrpc/svcsock.c | 6 ++---- tools/testing/selftests/mm/page_frag/page_frag_test.c | 2 +- 7 files changed, 19 insertions(+), 15 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 6691fac01e0d..b2737dc0dc50 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -1325,7 +1325,7 @@ static int vhost_net_open(struct inode *inode, struct file *f) vqs[VHOST_NET_VQ_RX]); f->private_data = n; - n->pf_cache.va = NULL; + page_frag_cache_init(&n->pf_cache); return 0; } diff --git a/include/linux/page_frag_cache.h b/include/linux/page_frag_cache.h index ef038a07925c..7c9125a9aed3 100644 --- a/include/linux/page_frag_cache.h +++ b/include/linux/page_frag_cache.h @@ -7,6 +7,16 @@ #include <linux/types.h> #include <linux/mm_types_task.h> +static inline void page_frag_cache_init(struct page_frag_cache *nc) +{ + nc->va = NULL; +} + +static inline bool page_frag_cache_is_pfmemalloc(struct page_frag_cache *nc) +{ + return !!nc->pfmemalloc; +} + void page_frag_cache_drain(struct page_frag_cache *nc); void __page_frag_cache_drain(struct page *page, unsigned int count); void *__page_frag_alloc_va_align(struct page_frag_cache *nc, diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 6cf2c51a34e1..bb77c3fd192f 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -752,14 +752,14 @@ struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int len, if (in_hardirq() || irqs_disabled()) { nc = this_cpu_ptr(&netdev_alloc_cache); data = page_frag_alloc_va(nc, len, gfp_mask); - pfmemalloc = nc->pfmemalloc; + pfmemalloc = page_frag_cache_is_pfmemalloc(nc); } else { local_bh_disable(); local_lock_nested_bh(&napi_alloc_cache.bh_lock); nc = this_cpu_ptr(&napi_alloc_cache.page); data = page_frag_alloc_va(nc, len, gfp_mask); - pfmemalloc = nc->pfmemalloc; + pfmemalloc = page_frag_cache_is_pfmemalloc(nc); local_unlock_nested_bh(&napi_alloc_cache.bh_lock); local_bh_enable(); @@ -849,7 +849,7 @@ struct sk_buff *napi_alloc_skb(struct napi_struct *napi, unsigned int len) len = SKB_HEAD_ALIGN(len); data = page_frag_alloc_va(&nc->page, len, gfp_mask); - pfmemalloc = nc->page.pfmemalloc; + pfmemalloc = page_frag_cache_is_pfmemalloc(&nc->page); } local_unlock_nested_bh(&napi_alloc_cache.bh_lock); diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c index 1539d315afe7..694c4df7a1a3 100644 --- a/net/rxrpc/conn_object.c +++ b/net/rxrpc/conn_object.c @@ -337,9 +337,7 @@ static void rxrpc_clean_up_connection(struct work_struct *work) */ rxrpc_purge_queue(&conn->rx_queue); - if (conn->tx_data_alloc.va) - __page_frag_cache_drain(virt_to_page(conn->tx_data_alloc.va), - conn->tx_data_alloc.pagecnt_bias); + page_frag_cache_drain(&conn->tx_data_alloc); call_rcu(&conn->rcu, rxrpc_rcu_free_connection); } diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c index 504453c688d7..a8cffe47cf01 100644 --- a/net/rxrpc/local_object.c +++ b/net/rxrpc/local_object.c @@ -452,9 +452,7 @@ void rxrpc_destroy_local(struct rxrpc_local *local) #endif rxrpc_purge_queue(&local->rx_queue); rxrpc_purge_client_connections(local); - if (local->tx_alloc.va) - __page_frag_cache_drain(virt_to_page(local->tx_alloc.va), - local->tx_alloc.pagecnt_bias); + page_frag_cache_drain(&local->tx_alloc); } /* diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 42d20412c1c3..4b1e87187614 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -1609,7 +1609,6 @@ static void svc_tcp_sock_detach(struct svc_xprt *xprt) static void svc_sock_free(struct svc_xprt *xprt) { struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); - struct page_frag_cache *pfc = &svsk->sk_frag_cache; struct socket *sock = svsk->sk_sock; trace_svcsock_free(svsk, sock); @@ -1619,8 +1618,7 @@ static void svc_sock_free(struct svc_xprt *xprt) sockfd_put(sock); else sock_release(sock); - if (pfc->va) - __page_frag_cache_drain(virt_to_head_page(pfc->va), - pfc->pagecnt_bias); + + page_frag_cache_drain(&svsk->sk_frag_cache); kfree(svsk); } diff --git a/tools/testing/selftests/mm/page_frag/page_frag_test.c b/tools/testing/selftests/mm/page_frag/page_frag_test.c index e522611452c9..3b98df379ce6 100644 --- a/tools/testing/selftests/mm/page_frag/page_frag_test.c +++ b/tools/testing/selftests/mm/page_frag/page_frag_test.c @@ -120,7 +120,7 @@ static int __init page_frag_test_init(void) u64 duration; int ret; - test_frag.va = NULL; + page_frag_cache_init(&test_frag); atomic_set(&nthreads, 2); init_completion(&wait); -- 2.33.0

1 year, 2 months

1
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[PATCH] selftests: kvm: fix mkdir error when building for non-supported arch

by Muhammad Usama Anjum

The mkdir generates an error when kvm suite is build for non-supported architecture such as arm. Fix it by ignoring the error from mkdir. mkdir: missing operand Try 'mkdir --help' for more information. Signed-off-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com> --- tools/testing/selftests/kvm/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 48d32c5aa3eb7..8ff46a0a8d1cd 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -317,7 +317,7 @@ $(LIBKVM_S_OBJ): $(OUTPUT)/%.o: %.S $(GEN_HDRS) $(LIBKVM_STRING_OBJ): $(OUTPUT)/%.o: %.c $(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c -ffreestanding $< -o $@ -$(shell mkdir -p $(sort $(dir $(TEST_GEN_PROGS)))) +$(shell mkdir -p $(sort $(dir $(TEST_GEN_PROGS))) > /dev/null 2>&1) $(SPLIT_TEST_GEN_OBJ): $(GEN_HDRS) $(TEST_GEN_PROGS): $(LIBKVM_OBJS) $(TEST_GEN_PROGS_EXTENDED): $(LIBKVM_OBJS) -- 2.39.2

1 year, 2 months

3
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[RFC PATCH 0/1] Add kselftest to detect boot event slowdowns

by Laura Nao

Add a new kselftest to detect and report slowdowns in key boot events. The test uses ftrace to track timings for specific boot events and compares these timestamps against reference values provided in YAML format. The test includes the following files: - `bootconfig` file: configures ftrace and lists reference key boot events. - `config` fragment: enables boot time tracing and attaches the bootconfig file to the kernel image. - `kprobe_timestamps_to_yaml.py` script: parses the current trace file to extract event names and timestamps and writes them to a YAML file. The script is intended to be run once to generate initial reference values; the generated file is not meant to be stored in the kernel sources but should be provided as input to the test itself. YAML format was chosen to allow easy integration with per-platform data used in other tests, such as the discoverable devices probe test in tools/testing/selftests/devices. Another option is to use JSON, as the file is not intended for manual editing and JSON is already supported by the Python standard library. - `test_boot_time.py` script: parses the current trace file and compares timestamps against the values in the YAML file provided as input. Reports a failure if any timestamp differs from the reference value by more than the specified delta. - `trace_utils.py` file: utility functions to mount debugfs and parse the trace file to extract relevant information. The bootconfig file provided is an initial draft with some reference kprobe events to showcase how the test works. I would appreciate feedback from those interested in running this test on which boot events should be added. Different key events might be relevant depending on the platform and its boot time requirements. This file should serve as a common ground and be populated with critical events and functions common to different platforms. Feedback on the overall approach of this test and suggestions for additional boot events to trace would be greatly appreciated. Example output with a deliberately small delta of 0.01 to demonstrate failures: TAP version 13 1..4 ok 1 populate_rootfs_begin # 'run_init_process_begin' differs by 0.033990 seconds. not ok 2 run_init_process_begin # 'run_init_process_end' differs by 0.033796 seconds. not ok 3 run_init_process_end ok 4 unpack_to_rootfs_begin # Totals: pass:2 fail:2 xfail:0 xpass:0 skip:0 error:0 This patch depends on "kselftest: Move ksft helper module to common directory": https://lore.kernel.org/all/20240705-dev-err-log-selftest-v2-2-163b9cd7b3c1… which was picked through the usb tree and is queued for 6.11-rc1. Best, Laura Laura Nao (1): kselftests: Add test to detect boot event slowdowns tools/testing/selftests/Makefile | 1 + tools/testing/selftests/boot-time/Makefile | 17 ++++ tools/testing/selftests/boot-time/bootconfig | 8 ++ tools/testing/selftests/boot-time/config | 4 + .../boot-time/kprobe_timestamps_to_yaml.py | 55 +++++++++++ .../selftests/boot-time/test_boot_time.py | 94 +++++++++++++++++++ .../selftests/boot-time/trace_utils.py | 63 +++++++++++++ 7 files changed, 242 insertions(+) create mode 100644 tools/testing/selftests/boot-time/Makefile create mode 100644 tools/testing/selftests/boot-time/bootconfig create mode 100644 tools/testing/selftests/boot-time/config create mode 100755 tools/testing/selftests/boot-time/kprobe_timestamps_to_yaml.py create mode 100755 tools/testing/selftests/boot-time/test_boot_time.py create mode 100644 tools/testing/selftests/boot-time/trace_utils.py -- 2.30.2

1 year, 2 months

2
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[PATCH v3 0/4] Introduce userspace-driven ALSA timers

by Ivan Orlov

There are multiple possible timer sources which could be useful for the sound stream synchronization: hrtimers, hardware clocks (e.g. PTP), timer wheels (jiffies). Currently, using one of them to synchronize the audio stream of snd-aloop module would require writing a kernel-space driver which exports an ALSA timer through the snd_timer interface. However, it is not really convenient for application developers, who may want to define their custom timer sources for audio synchronization. For instance, we could have a network application which receives frames and sends them to snd-aloop pcm device, and another application listening on the other end of snd-aloop. It makes sense to transfer a new period of data only when certain amount of frames is received through the network, but definitely not when a certain amount of jiffies on a local system elapses. Since all of the devices are purely virtual it won't introduce any glitches and will help the application developers to avoid using sample-rate conversion. This patch series introduces userspace-driven ALSA timers: virtual timers which are created and controlled from userspace. The timer can be created from the userspace using the new ioctl SNDRV_TIMER_IOCTL_CREATE. After creating a timer, it becomes available for use system-wide, so it can be passed to snd-aloop as a timer source (timer_source parameter would be "-1.SNDRV_TIMER_GLOBAL_UDRIVEN.{timer_id}"). When the userspace app decides to trigger a timer, it calls another ioctl SNDRV_TIMER_IOCTL_TRIGGER on the file descriptor of a timer. It initiates a transfer of a new period of data. Userspace-driven timers are associated with file descriptors. If the application wishes to destroy the timer, it can simply release the file descriptor of a virtual timer. I believe introducing new ioctl calls is quite inconvenient (as we have a limited amount of them), but other possible ways of app <-> kernel communication (like virtual FS) seem completely inappropriate for this task (but I'd love to discuss alternative solutions). This patch series also updates the snd-aloop module so the global timers can be used as a timer_source for it (it allows using userspace-driven timers as timer source). V1 -> V2: - Fix some problems found by Christophe Jaillet <christophe.jaillet(a)wanadoo.fr> V2 -> V3: - Add improvements suggested by Takashi Iwai <tiwai(a)suse.de> Please, find the patch-specific changelog in the following patches. Ivan Orlov (4): ALSA: aloop: Allow using global timers Docs/sound: Add documentation for userspace-driven ALSA timers ALSA: timer: Introduce virtual userspace-driven timers selftests: ALSA: Cover userspace-driven timers with test Documentation/sound/index.rst | 1 + Documentation/sound/utimers.rst | 120 +++++++++++ include/uapi/sound/asound.h | 20 +- sound/core/Kconfig | 10 + sound/core/timer.c | 221 ++++++++++++++++++++ sound/drivers/aloop.c | 2 + tools/testing/selftests/alsa/Makefile | 2 +- tools/testing/selftests/alsa/global-timer.c | 87 ++++++++ tools/testing/selftests/alsa/utimer-test.c | 170 +++++++++++++++ 9 files changed, 631 insertions(+), 2 deletions(-) create mode 100644 Documentation/sound/utimers.rst create mode 100644 tools/testing/selftests/alsa/global-timer.c create mode 100644 tools/testing/selftests/alsa/utimer-test.c -- 2.34.1

1 year, 2 months

4
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Converting kselftest test modules to kunit

by Muhammad Usama Anjum

Hi Kees and All, There are several tests in kselftest subsystem which load modules to tests the internals of the kernel. Most of these test modules are just loaded by the kselftest, their status isn't read and reported to the user logs. Hence they don't provide benefit of executing those tests. I've found patches from Kees where he has been converting such kselftests to kunit tests [1]. The probable motivation is to move tests output of kselftest subsystem which only triggers tests without correctly reporting the results. On the other hand, kunit is there to test the kernel's internal functions which can't be done by userspace. Kselftest: Test user facing APIs from userspace Kunit: Test kernel's internal functions from kernelspace This brings me to conclusion that kselftest which are loading modules to test kernelspace should be converted to kunit tests. I've noted several such kselftests. This is just my understanding. Please mention if I'm correct above or more reasons to support kselftest test modules transformation into kunit test. [1] https://lore.kernel.org/all/20221018082824.never.845-kees@kernel.org/ -- BR, Muhammad Usama Anjum

1 year, 2 months

6
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[PATCH RFT v7 0/9] fork: Support shadow stacks in clone3()

by Mark Brown

The kernel has recently added support for shadow stacks, currently x86 only using their CET feature but both arm64 and RISC-V have equivalent features (GCS and Zicfiss respectively), I am actively working on GCS[1]. With shadow stacks the hardware maintains an additional stack containing only the return addresses for branch instructions which is not generally writeable by userspace and ensures that any returns are to the recorded addresses. This provides some protection against ROP attacks and making it easier to collect call stacks. These shadow stacks are allocated in the address space of the userspace process. Our API for shadow stacks does not currently offer userspace any flexiblity for managing the allocation of shadow stacks for newly created threads, instead the kernel allocates a new shadow stack with the same size as the normal stack whenever a thread is created with the feature enabled. The stacks allocated in this way are freed by the kernel when the thread exits or shadow stacks are disabled for the thread. This lack of flexibility and control isn't ideal, in the vast majority of cases the shadow stack will be over allocated and the implicit allocation and deallocation is not consistent with other interfaces. As far as I can tell the interface is done in this manner mainly because the shadow stack patches were in development since before clone3() was implemented. Since clone3() is readily extensible let's add support for specifying a shadow stack when creating a new thread or process in a similar manner to how the normal stack is specified, keeping the current implicit allocation behaviour if one is not specified either with clone3() or through the use of clone(). The user must provide a shadow stack address and size, this must point to memory mapped for use as a shadow stackby map_shadow_stack() with a shadow stack token at the top of the stack. Please note that the x86 portions of this code are build tested only, I don't appear to have a system that can run CET avaible to me, I have done testing with an integration into my pending work for GCS. There is some possibility that the arm64 implementation may require the use of clone3() and explicit userspace allocation of shadow stacks, this is still under discussion. Please further note that the token consumption done by clone3() is not currently implemented in an atomic fashion, Rick indicated that he would look into fixing this if people are OK with the implementation. A new architecture feature Kconfig option for shadow stacks is added as here, this was suggested as part of the review comments for the arm64 GCS series and since we need to detect if shadow stacks are supported it seemed sensible to roll it in here. [1] https://lore.kernel.org/r/20231009-arm64-gcs-v6-0-78e55deaa4dd@kernel.org/ Signed-off-by: Mark Brown <broonie(a)kernel.org> --- Changes in v7: - Rebase onto v6.11-rc1. - Typo fixes. - Link to v6: https://lore.kernel.org/r/20240623-clone3-shadow-stack-v6-0-9ee7783b1fb9@ke… Changes in v6: - Rebase onto v6.10-rc3. - Ensure we don't try to free the parent shadow stack in error paths of x86 arch code. - Spelling fixes in userspace API document. - Additional cleanups and improvements to the clone3() tests to support the shadow stack tests. - Link to v5: https://lore.kernel.org/r/20240203-clone3-shadow-stack-v5-0-322c69598e4b@ke… Changes in v5: - Rebase onto v6.8-rc2. - Rework ABI to have the user allocate the shadow stack memory with map_shadow_stack() and a token. - Force inlining of the x86 shadow stack enablement. - Move shadow stack enablement out into a shared header for reuse by other tests. - Link to v4: https://lore.kernel.org/r/20231128-clone3-shadow-stack-v4-0-8b28ffe4f676@ke… Changes in v4: - Formatting changes. - Use a define for minimum shadow stack size and move some basic validation to fork.c. - Link to v3: https://lore.kernel.org/r/20231120-clone3-shadow-stack-v3-0-a7b8ed3e2acc@ke… Changes in v3: - Rebase onto v6.7-rc2. - Remove stale shadow_stack in internal kargs. - If a shadow stack is specified unconditionally use it regardless of CLONE_ parameters. - Force enable shadow stacks in the selftest. - Update changelogs for RISC-V feature rename. - Link to v2: https://lore.kernel.org/r/20231114-clone3-shadow-stack-v2-0-b613f8681155@ke… Changes in v2: - Rebase onto v6.7-rc1. - Remove ability to provide preallocated shadow stack, just specify the desired size. - Link to v1: https://lore.kernel.org/r/20231023-clone3-shadow-stack-v1-0-d867d0b5d4d0@ke… --- Mark Brown (9): Documentation: userspace-api: Add shadow stack API documentation selftests: Provide helper header for shadow stack testing mm: Introduce ARCH_HAS_USER_SHADOW_STACK fork: Add shadow stack support to clone3() selftests/clone3: Remove redundant flushes of output streams selftests/clone3: Factor more of main loop into test_clone3() selftests/clone3: Explicitly handle child exits due to signals selftests/clone3: Allow tests to flag if -E2BIG is a valid error code selftests/clone3: Test shadow stack support Documentation/userspace-api/index.rst | 1 + Documentation/userspace-api/shadow_stack.rst | 41 ++++ arch/x86/Kconfig | 1 + arch/x86/include/asm/shstk.h | 11 +- arch/x86/kernel/process.c | 2 +- arch/x86/kernel/shstk.c | 104 +++++++--- fs/proc/task_mmu.c | 2 +- include/linux/mm.h | 2 +- include/linux/sched/task.h | 13 ++ include/uapi/linux/sched.h | 13 +- kernel/fork.c | 76 ++++++-- mm/Kconfig | 6 + tools/testing/selftests/clone3/clone3.c | 224 ++++++++++++++++++---- tools/testing/selftests/clone3/clone3_selftests.h | 40 +++- tools/testing/selftests/ksft_shstk.h | 63 ++++++ 15 files changed, 511 insertions(+), 88 deletions(-) --- base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b change-id: 20231019-clone3-shadow-stack-15d40d2bf536 Best regards, -- Mark Brown <broonie(a)kernel.org>

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Linux-kselftest-mirror August 2024