October 2025 - Linux-kselftest-mirror

[PATCH v2] selftest: net: fix variable sized type issue not at the end of a struct

by Ankit Khushwaha

Some network selftests defined variable-sized types variable at the middle of struct causing -Wgnu-variable-sized-type-not-at-end warning. warning: timestamping.c:285:18: warning: field 'cm' with variable sized type 'struct cmsghdr' not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end] 285 | struct cmsghdr cm; | ^ ipsec.c:835:5: warning: field 'u' with variable sized type 'union (unnamed union at ipsec.c:831:3)' not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end] 835 | } u; | ^ This patch move these field at the end of struct to fix these warnings. Signed-off-by: Ankit Khushwaha <ankitkhushwaha.linux(a)gmail.com> --- Changelog: v2: https://lore.kernel.org/linux-kselftest/20251027050856.30270-1-ankitkhushwa… - fixed typos in the commit msg. --- tools/testing/selftests/net/ipsec.c | 2 +- tools/testing/selftests/net/timestamping.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/net/ipsec.c b/tools/testing/selftests/net/ipsec.c index 0ccf484b1d9d..36083c8f884f 100644 --- a/tools/testing/selftests/net/ipsec.c +++ b/tools/testing/selftests/net/ipsec.c @@ -828,12 +828,12 @@ static int xfrm_state_pack_algo(struct nlmsghdr *nh, size_t req_sz, struct xfrm_desc *desc) { struct { + char buf[XFRM_ALGO_KEY_BUF_SIZE]; union { struct xfrm_algo alg; struct xfrm_algo_aead aead; struct xfrm_algo_auth auth; } u; - char buf[XFRM_ALGO_KEY_BUF_SIZE]; } alg = {}; size_t alen, elen, clen, aelen; unsigned short type; diff --git a/tools/testing/selftests/net/timestamping.c b/tools/testing/selftests/net/timestamping.c index 044bc0e9ed81..ad2be2143698 100644 --- a/tools/testing/selftests/net/timestamping.c +++ b/tools/testing/selftests/net/timestamping.c @@ -282,8 +282,8 @@ static void recvpacket(int sock, int recvmsg_flags, struct iovec entry; struct sockaddr_in from_addr; struct { - struct cmsghdr cm; char control[512]; + struct cmsghdr cm; } control; int res; -- 2.51.0

2 days, 20 hours

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next-20251027: backlight.c:59:39: error: implicit declaration of function 'of_find_node_by_name'; did you mean 'bus_find_device_by_name'?

by Naresh Kamboju

The following powerpc ppc6xx_defconfig build regressions noticed on the Linux next-20251027 tag with gcc-14 and gcc-8. * powerpc, build - gcc-14-ppc6xx_defconfig - gcc-8-ppc6xx_defconfig First seen on next-20251027 Good: next-20251024 Bad: next-20251027 Regression Analysis: - New regression? yes - Reproducibility? yes Build regression: next-20251027: backlight.c:59:39: error: implicit declaration of function 'of_find_node_by_name'; did you mean 'bus_find_device_by_name'? Build regression: next-20251027: include/linux/math.h:167:43: error: first argument to '__builtin_choose_expr' not a constant Build regression: next-20251027: via-pmu-backlight.c:22:20: error: 'FB_BACKLIGHT_LEVELS' undeclared here (not in a function) Build regression: next-20251027: minmax.h:71:17: error: first argument to '__builtin_choose_expr' not a constant Build regression: next-20251027: compiler.h:168:17: error: '__UNIQUE_ID_x__286' undeclared (first use in this function); did you mean '__UNIQUE_ID_y__287'? Reported-by: Linux Kernel Functional Testing <lkft(a)linaro.org> ## Build error arch/powerpc/platforms/powermac/backlight.c: In function 'pmac_has_backlight_type': arch/powerpc/platforms/powermac/backlight.c:59:39: error: implicit declaration of function 'of_find_node_by_name'; did you mean 'bus_find_device_by_name'? [-Wimplicit-function-declaration] 59 | struct device_node* bk_node = of_find_node_by_name(NULL, "backlight"); | ^~~~~~~~~~~~~~~~~~~~ | bus_find_device_by_name arch/powerpc/platforms/powermac/backlight.c:59:39: error: initialization of 'struct device_node *' from 'int' makes pointer from integer without a cast [-Wint-conversion] arch/powerpc/platforms/powermac/backlight.c:60:17: error: implicit declaration of function 'of_property_match_string' [-Wimplicit-function-declaration] 60 | int i = of_property_match_string(bk_node, "backlight-control", type); | ^~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/platforms/powermac/backlight.c:62:9: error: implicit declaration of function 'of_node_put' [-Wimplicit-function-declaration] 62 | of_node_put(bk_node); | ^~~~~~~~~~~ drivers/macintosh/via-pmu-backlight.c:22:20: error: 'FB_BACKLIGHT_LEVELS' undeclared here (not in a function) 22 | static u8 bl_curve[FB_BACKLIGHT_LEVELS]; | ^~~~~~~~~~~~~~~~~~~ In file included from <command-line>: drivers/macintosh/via-pmu-backlight.c: In function 'pmu_backlight_curve_lookup': include/linux/compiler.h:168:17: error: '__UNIQUE_ID_x__286' undeclared (first use in this function); did you mean '__UNIQUE_ID_y__287'? 168 | __PASTE(__UNIQUE_ID_, \ | ^~~~~~~~~~~~ drivers/macintosh/via-pmu-backlight.c:45:23: note: in expansion of macro 'max' 45 | max = max((int)bl_curve[i], max); | ^~~ include/linux/minmax.h:71:17: error: first argument to '__builtin_choose_expr' not a constant 71 | (typeof(__builtin_choose_expr(sizeof(ux) > 4, 1LL, 1L)))(ux) >= 0) | ^~~~~~~~~~~~~~~~~~~~~ include/linux/compiler_types.h:577:23: note: in definition of macro '__compiletime_assert' 577 | if (!(condition)) \ | ^~~~~~~~~ drivers/macintosh/via-pmu-backlight.c:45:23: note: in expansion of macro 'max' 45 | max = max((int)bl_curve[i], max); | ^~~ include/linux/minmax.h:71:17: error: first argument to '__builtin_choose_expr' not a constant 71 | (typeof(__builtin_choose_expr(sizeof(ux) > 4, 1LL, 1L)))(ux) >= 0) | ^~~~~~~~~~~~~~~~~~~~~ include/linux/compiler_types.h:577:23: note: in definition of macro '__compiletime_assert' 577 | if (!(condition)) \ | ^~~~~~~~~ include/linux/minmax.h:112:25: note: in expansion of macro '__careful_cmp' 112 | #define max(x, y) __careful_cmp(max, x, y) | ^~~~~~~~~~~~~ drivers/macintosh/via-pmu-backlight.c:45:23: note: in expansion of macro 'max' 45 | max = max((int)bl_curve[i], max); | ^~~ In file included from include/linux/kernel.h:27, from arch/powerpc/include/asm/page.h:11, from arch/powerpc/include/asm/thread_info.h:13, from include/linux/thread_info.h:60, from arch/powerpc/include/asm/ptrace.h:342, from drivers/macintosh/via-pmu-backlight.c:11: include/linux/math.h:162:17: error: first argument to '__builtin_choose_expr' not a constant 162 | __builtin_choose_expr( \ | ^~~~~~~~~~~~~~~~~~~~~ drivers/macintosh/via-pmu-backlight.c: In function 'pmu_backlight_get_level_brightness': drivers/macintosh/via-pmu-backlight.c:63:38: error: 'FB_BACKLIGHT_MAX' undeclared (first use in this function); did you mean 'BACKLIGHT_RAW'? 63 | pmulevel = bl_curve[level] * FB_BACKLIGHT_MAX / MAX_PMU_LEVEL; | ^~~~~~~~~~~~~~~~ | BACKLIGHT_RAW drivers/macintosh/via-pmu-backlight.c:58:51: warning: parameter 'level' set but not used [-Wunused-but-set-parameter] 58 | static int pmu_backlight_get_level_brightness(int level) | ~~~~^~~~~ drivers/macintosh/via-pmu-backlight.c: In function 'pmu_backlight_init': drivers/macintosh/via-pmu-backlight.c:144:17: error: implicit declaration of function 'of_machine_is_compatible' [-Wimplicit-function-declaration] 144 | of_machine_is_compatible("AAPL,3400/2400") || | ^~~~~~~~~~~~~~~~~~~~~~~~ drivers/macintosh/via-pmu-backlight.c: At top level: drivers/macintosh/via-pmu-backlight.c:22:11: warning: 'bl_curve' defined but not used [-Wunused-variable] 22 | static u8 bl_curve[FB_BACKLIGHT_LEVELS]; | ^~~~~~~~ make[5]: *** [scripts/Makefile.build:287: drivers/macintosh/via-pmu-backlight.o] Error 1 make[5]: Target 'drivers/macintosh/' not remade because of errors. ## Source * Kernel version: 6.18.0-rc2-next-20251027 * Git tree: https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next.git * Git describe: next-20251027 * Git commit: 8fec172c82c2b5f6f8e47ab837c1dc91ee3d1b87 * Architectures: powerpc * Toolchains: gcc-14 * Kconfigs: defconfig ## Build * Test log: https://storage.tuxsuite.com/public/linaro/lkft/builds/34dKrlb77LGOQQSoC8FH… * Test details: https://regressions.linaro.org/lkft/linux-next-master/next-20251027/build/g… * Build plan: https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/builds/34dKrlb77… * Build link: https://storage.tuxsuite.com/public/linaro/lkft/builds/34dKrlb77LGOQQSoC8FH… * Kernel config: https://storage.tuxsuite.com/public/linaro/lkft/builds/34dKrlb77LGOQQSoC8FH… -- Linaro LKFT

2 days, 21 hours

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[RFC PATCH v1 00/37] guest_memfd: In-place conversion support

by Ackerley Tng

Hello, IIUC this is the first independent patch series for guest_memfd's in-place conversion series! Happy to finally bring this out on its own. Previous versions of this feature, part of other series, are available at [1][2][3]. Many prior discussions have led up to these main features of this series, and these are the main points I'd like feedback on. 1. Having private/shared status stored in a maple tree (Thanks Michael for your support of using maple trees over xarrays for performance! [4]). 2. Having a new guest_memfd ioctl (not a vm ioctl) that performs conversions. 3. Using ioctls/structs/input attribute similar to the existing vm ioctl KVM_SET_MEMORY_ATTRIBUTES to perform conversions. 4. Storing requested attributes directly in the maple tree. 5. Using a KVM module-wide param to toggle between setting memory attributes via vm and guest_memfd ioctls (making them mututally exclusive - a single loaded KVM module can only do one of the two.) 6. Skipping LRU in guest_memfd folios - make guest_memfd folios not participate in LRU to avoid LRU refcounts from interfering with conversions. This series is based on kvm/next, followed by + v12 of NUMA mempolicy support patches [5] + 3 cleanup patches from Sean [6][7][8] Everything is stitched together here for your convenience https://github.com/googleprodkernel/linux-cc/commits/guest_memfd-inplace-co… Thank you all for helping with this series! If I missed out your comment from a previous series, it's not intentional! Please do raise it again. TODOs: + There might be an issue with memory failure handling because when guest_memfd folios stop participating in LRU. From a preliminary analysis, HWPoisonHandlable() is only true if PageLRU() is true. This needs further investigation. [1] https://lore.kernel.org/all/bd163de3118b626d1005aa88e71ef2fb72f0be0f.172600… [2] https://lore.kernel.org/all/20250117163001.2326672-6-tabba@google.com/ [3] https://lore.kernel.org/all/b784326e9ccae6a08388f1bf39db70a2204bdc51.174726… [4] https://lore.kernel.org/all/20250529054227.hh2f4jmyqf6igd3i@amd.com/ [5] https://lore.kernel.org/all/20251007221420.344669-1-seanjc@google.com/T/ [6] https://lore.kernel.org/all/20250924174255.2141847-1-seanjc@google.com/ [7] https://lore.kernel.org/all/20251007224515.374516-1-seanjc@google.com/ [8] https://lore.kernel.org/all/20251007223625.369939-1-seanjc@google.com/ Ackerley Tng (19): KVM: guest_memfd: Update kvm_gmem_populate() to use gmem attributes KVM: Introduce KVM_SET_MEMORY_ATTRIBUTES2 KVM: guest_memfd: Don't set FGP_ACCESSED when getting folios KVM: guest_memfd: Skip LRU for guest_memfd folios KVM: guest_memfd: Add support for KVM_SET_MEMORY_ATTRIBUTES KVM: selftests: Update framework to use KVM_SET_MEMORY_ATTRIBUTES2 KVM: selftests: guest_memfd: Test basic single-page conversion flow KVM: selftests: guest_memfd: Test conversion flow when INIT_SHARED KVM: selftests: guest_memfd: Test indexing in guest_memfd KVM: selftests: guest_memfd: Test conversion before allocation KVM: selftests: guest_memfd: Convert with allocated folios in different layouts KVM: selftests: guest_memfd: Test precision of conversion KVM: selftests: guest_memfd: Test that truncation does not change shared/private status KVM: selftests: guest_memfd: Test conversion with elevated page refcount KVM: selftests: Reset shared memory after hole-punching KVM: selftests: Provide function to look up guest_memfd details from gpa KVM: selftests: Make TEST_EXPECT_SIGBUS thread-safe KVM: selftests: Update private_mem_conversions_test to mmap() guest_memfd KVM: selftests: Add script to exercise private_mem_conversions_test Sean Christopherson (18): KVM: guest_memfd: Introduce per-gmem attributes, use to guard user mappings KVM: Rename KVM_GENERIC_MEMORY_ATTRIBUTES to KVM_VM_MEMORY_ATTRIBUTES KVM: Enumerate support for PRIVATE memory iff kvm_arch_has_private_mem is defined KVM: Stub in ability to disable per-VM memory attribute tracking KVM: guest_memfd: Wire up kvm_get_memory_attributes() to per-gmem attributes KVM: guest_memfd: Enable INIT_SHARED on guest_memfd for x86 Coco VMs KVM: Move KVM_VM_MEMORY_ATTRIBUTES config definition to x86 KVM: Let userspace disable per-VM mem attributes, enable per-gmem attributes KVM: selftests: Create gmem fd before "regular" fd when adding memslot KVM: selftests: Rename guest_memfd{,_offset} to gmem_{fd,offset} KVM: selftests: Add support for mmap() on guest_memfd in core library KVM: selftests: Add helpers for calling ioctls on guest_memfd KVM: selftests: guest_memfd: Test that shared/private status is consistent across processes KVM: selftests: Add selftests global for guest memory attributes capability KVM: selftests: Provide common function to set memory attributes KVM: selftests: Check fd/flags provided to mmap() when setting up memslot KVM: selftests: Update pre-fault test to work with per-guest_memfd attributes KVM: selftests: Update private memory exits test work with per-gmem attributes Documentation/virt/kvm/api.rst | 72 ++- arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/Kconfig | 15 +- arch/x86/kvm/mmu/mmu.c | 4 +- arch/x86/kvm/x86.c | 13 +- include/linux/kvm_host.h | 44 +- include/trace/events/kvm.h | 4 +- include/uapi/linux/kvm.h | 17 + mm/filemap.c | 1 + mm/memcontrol.c | 2 + tools/testing/selftests/kvm/.gitignore | 1 + tools/testing/selftests/kvm/Makefile.kvm | 1 + .../kvm/guest_memfd_conversions_test.c | 498 ++++++++++++++++++ .../testing/selftests/kvm/include/kvm_util.h | 127 ++++- .../testing/selftests/kvm/include/test_util.h | 29 +- tools/testing/selftests/kvm/lib/kvm_util.c | 128 +++-- tools/testing/selftests/kvm/lib/test_util.c | 7 - .../selftests/kvm/pre_fault_memory_test.c | 2 +- .../kvm/x86/private_mem_conversions_test.c | 55 +- .../kvm/x86/private_mem_conversions_test.py | 159 ++++++ .../kvm/x86/private_mem_kvm_exits_test.c | 36 +- virt/kvm/Kconfig | 4 +- virt/kvm/guest_memfd.c | 414 +++++++++++++-- virt/kvm/kvm_main.c | 104 +++- 24 files changed, 1554 insertions(+), 185 deletions(-) create mode 100644 tools/testing/selftests/kvm/guest_memfd_conversions_test.c create mode 100755 tools/testing/selftests/kvm/x86/private_mem_conversions_test.py -- 2.51.0.858.gf9c4a03a3a-goog

2 days, 21 hours

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[PATCH v12] exec: Fix dead-lock in de_thread with ptrace_attach

by Bernd Edlinger

This introduces signal->exec_bprm, which is used to fix the case when at least one of the sibling threads is traced, and therefore the trace process may dead-lock in ptrace_attach, but de_thread will need to wait for the tracer to continue execution. The solution is to detect this situation and allow ptrace_attach to continue by temporarily releasing the cred_guard_mutex, while de_thread() is still waiting for traced zombies to be eventually released by the tracer. In the case of the thread group leader we only have to wait for the thread to become a zombie, which may also need co-operation from the tracer due to PTRACE_O_TRACEEXIT. When a tracer wants to ptrace_attach a task that already is in execve, we simply retry the ptrace_may_access check while temporarily installing the new credentials and dumpability which are about to be used after execve completes. If the ptrace_attach happens on a thread that is a sibling-thread of the thread doing execve, it is sufficient to check against the old credentials, as this thread will be waited for, before the new credentials are installed. Other threads die quickly since the cred_guard_mutex is released, but a deadly signal is already pending. In case the mutex_lock_killable misses the signal, the non-zero current->signal->exec_bprm makes sure they release the mutex immediately and return with -ERESTARTNOINTR. This means there is no API change, unlike the previous version of this patch which was discussed here: https://lore.kernel.org/lkml/b6537ae6-31b1-5c50-f32b-8b8332ace882@hotmail.d… See tools/testing/selftests/ptrace/vmaccess.c for a test case that gets fixed by this change. Note that since the test case was originally designed to test the ptrace_attach returning an error in this situation, the test expectation needed to be adjusted, to allow the API to succeed at the first attempt. Signed-off-by: Bernd Edlinger <bernd.edlinger(a)hotmail.de> --- fs/exec.c | 69 ++++++++++++++++------- fs/proc/base.c | 6 ++ include/linux/cred.h | 1 + include/linux/sched/signal.h | 18 ++++++ kernel/cred.c | 28 +++++++-- kernel/ptrace.c | 32 +++++++++++ kernel/seccomp.c | 12 +++- tools/testing/selftests/ptrace/vmaccess.c | 23 +++++--- 8 files changed, 155 insertions(+), 34 deletions(-) v10: Changes to previous version, make the PTRACE_ATTACH retun -EAGAIN, instead of execve return -ERESTARTSYS. Added some lessions learned to the description. v11: Check old and new credentials in PTRACE_ATTACH again without changing the API. Note: I got actually one response from an automatic checker to the v11 patch, https://lore.kernel.org/lkml/202107121344.wu68hEPF-lkp@intel.com/ which is complaining about: >> kernel/ptrace.c:425:26: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct cred const *old_cred @@ got struct cred const [noderef] __rcu *real_cred @@ 417 struct linux_binprm *bprm = task->signal->exec_bprm; 418 const struct cred *old_cred; 419 struct mm_struct *old_mm; 420 421 retval = down_write_killable(&task->signal->exec_update_lock); 422 if (retval) 423 goto unlock_creds; 424 task_lock(task); > 425 old_cred = task->real_cred; v12: Essentially identical to v11. - Fixed a minor merge conflict in linux v5.17, and fixed the above mentioned nit by adding __rcu to the declaration. - re-tested the patch with all linux versions from v5.11 to v6.6 v10 was an alternative approach which did imply an API change. But I would prefer to avoid such an API change. The difficult part is getting the right dumpability flags assigned before de_thread starts, hope you like this version. If not, the v10 is of course also acceptable. Thanks Bernd. diff --git a/fs/exec.c b/fs/exec.c index 2f2b0acec4f0..902d3b230485 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1041,11 +1041,13 @@ static int exec_mmap(struct mm_struct *mm) return 0; } -static int de_thread(struct task_struct *tsk) +static int de_thread(struct task_struct *tsk, struct linux_binprm *bprm) { struct signal_struct *sig = tsk->signal; struct sighand_struct *oldsighand = tsk->sighand; spinlock_t *lock = &oldsighand->siglock; + struct task_struct *t = tsk; + bool unsafe_execve_in_progress = false; if (thread_group_empty(tsk)) goto no_thread_group; @@ -1068,6 +1070,19 @@ static int de_thread(struct task_struct *tsk) if (!thread_group_leader(tsk)) sig->notify_count--; + while_each_thread(tsk, t) { + if (unlikely(t->ptrace) + && (t != tsk->group_leader || !t->exit_state)) + unsafe_execve_in_progress = true; + } + + if (unlikely(unsafe_execve_in_progress)) { + spin_unlock_irq(lock); + sig->exec_bprm = bprm; + mutex_unlock(&sig->cred_guard_mutex); + spin_lock_irq(lock); + } + while (sig->notify_count) { __set_current_state(TASK_KILLABLE); spin_unlock_irq(lock); @@ -1158,6 +1173,11 @@ static int de_thread(struct task_struct *tsk) release_task(leader); } + if (unlikely(unsafe_execve_in_progress)) { + mutex_lock(&sig->cred_guard_mutex); + sig->exec_bprm = NULL; + } + sig->group_exec_task = NULL; sig->notify_count = 0; @@ -1169,6 +1189,11 @@ static int de_thread(struct task_struct *tsk) return 0; killed: + if (unlikely(unsafe_execve_in_progress)) { + mutex_lock(&sig->cred_guard_mutex); + sig->exec_bprm = NULL; + } + /* protects against exit_notify() and __exit_signal() */ read_lock(&tasklist_lock); sig->group_exec_task = NULL; @@ -1253,6 +1278,24 @@ int begin_new_exec(struct linux_binprm * bprm) if (retval) return retval; + /* If the binary is not readable then enforce mm->dumpable=0 */ + would_dump(bprm, bprm->file); + if (bprm->have_execfd) + would_dump(bprm, bprm->executable); + + /* + * Figure out dumpability. Note that this checking only of current + * is wrong, but userspace depends on it. This should be testing + * bprm->secureexec instead. + */ + if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP || + is_dumpability_changed(current_cred(), bprm->cred) || + !(uid_eq(current_euid(), current_uid()) && + gid_eq(current_egid(), current_gid()))) + set_dumpable(bprm->mm, suid_dumpable); + else + set_dumpable(bprm->mm, SUID_DUMP_USER); + /* * Ensure all future errors are fatal. */ @@ -1261,7 +1304,7 @@ int begin_new_exec(struct linux_binprm * bprm) /* * Make this the only thread in the thread group. */ - retval = de_thread(me); + retval = de_thread(me, bprm); if (retval) goto out; @@ -1284,11 +1327,6 @@ int begin_new_exec(struct linux_binprm * bprm) if (retval) goto out; - /* If the binary is not readable then enforce mm->dumpable=0 */ - would_dump(bprm, bprm->file); - if (bprm->have_execfd) - would_dump(bprm, bprm->executable); - /* * Release all of the old mmap stuff */ @@ -1350,18 +1388,6 @@ int begin_new_exec(struct linux_binprm * bprm) me->sas_ss_sp = me->sas_ss_size = 0; - /* - * Figure out dumpability. Note that this checking only of current - * is wrong, but userspace depends on it. This should be testing - * bprm->secureexec instead. - */ - if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP || - !(uid_eq(current_euid(), current_uid()) && - gid_eq(current_egid(), current_gid()))) - set_dumpable(current->mm, suid_dumpable); - else - set_dumpable(current->mm, SUID_DUMP_USER); - perf_event_exec(); __set_task_comm(me, kbasename(bprm->filename), true); @@ -1480,6 +1506,11 @@ static int prepare_bprm_creds(struct linux_binprm *bprm) if (mutex_lock_interruptible(&current->signal->cred_guard_mutex)) return -ERESTARTNOINTR; + if (unlikely(current->signal->exec_bprm)) { + mutex_unlock(&current->signal->cred_guard_mutex); + return -ERESTARTNOINTR; + } + bprm->cred = prepare_exec_creds(); if (likely(bprm->cred)) return 0; diff --git a/fs/proc/base.c b/fs/proc/base.c index ffd54617c354..0da9adfadb48 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2788,6 +2788,12 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf, if (rv < 0) goto out_free; + if (unlikely(current->signal->exec_bprm)) { + mutex_unlock(&current->signal->cred_guard_mutex); + rv = -ERESTARTNOINTR; + goto out_free; + } + rv = security_setprocattr(PROC_I(inode)->op.lsm, file->f_path.dentry->d_name.name, page, count); diff --git a/include/linux/cred.h b/include/linux/cred.h index f923528d5cc4..b01e309f5686 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -159,6 +159,7 @@ extern const struct cred *get_task_cred(struct task_struct *); extern struct cred *cred_alloc_blank(void); extern struct cred *prepare_creds(void); extern struct cred *prepare_exec_creds(void); +extern bool is_dumpability_changed(const struct cred *, const struct cred *); extern int commit_creds(struct cred *); extern void abort_creds(struct cred *); extern const struct cred *override_creds(const struct cred *); diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index 0014d3adaf84..14df7073a0a8 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -234,9 +234,27 @@ struct signal_struct { struct mm_struct *oom_mm; /* recorded mm when the thread group got * killed by the oom killer */ + struct linux_binprm *exec_bprm; /* Used to check ptrace_may_access + * against new credentials while + * de_thread is waiting for other + * traced threads to terminate. + * Set while de_thread is executing. + * The cred_guard_mutex is released + * after de_thread() has called + * zap_other_threads(), therefore + * a fatal signal is guaranteed to be + * already pending in the unlikely + * event, that + * current->signal->exec_bprm happens + * to be non-zero after the + * cred_guard_mutex was acquired. + */ + struct mutex cred_guard_mutex; /* guard against foreign influences on * credential calculations * (notably. ptrace) + * Held while execve runs, except when + * a sibling thread is being traced. * Deprecated do not use in new code. * Use exec_update_lock instead. */ diff --git a/kernel/cred.c b/kernel/cred.c index 98cb4eca23fb..586cb6c7cf6b 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -433,6 +433,28 @@ static bool cred_cap_issubset(const struct cred *set, const struct cred *subset) return false; } +/** + * is_dumpability_changed - Will changing creds from old to new + * affect the dumpability in commit_creds? + * + * Return: false - dumpability will not be changed in commit_creds. + * Return: true - dumpability will be changed to non-dumpable. + * + * @old: The old credentials + * @new: The new credentials + */ +bool is_dumpability_changed(const struct cred *old, const struct cred *new) +{ + if (!uid_eq(old->euid, new->euid) || + !gid_eq(old->egid, new->egid) || + !uid_eq(old->fsuid, new->fsuid) || + !gid_eq(old->fsgid, new->fsgid) || + !cred_cap_issubset(old, new)) + return true; + + return false; +} + /** * commit_creds - Install new credentials upon the current task * @new: The credentials to be assigned @@ -467,11 +489,7 @@ int commit_creds(struct cred *new) get_cred(new); /* we will require a ref for the subj creds too */ /* dumpability changes */ - if (!uid_eq(old->euid, new->euid) || - !gid_eq(old->egid, new->egid) || - !uid_eq(old->fsuid, new->fsuid) || - !gid_eq(old->fsgid, new->fsgid) || - !cred_cap_issubset(old, new)) { + if (is_dumpability_changed(old, new)) { if (task->mm) set_dumpable(task->mm, suid_dumpable); task->pdeath_signal = 0; diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 443057bee87c..eb1c450bb7d7 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -20,6 +20,7 @@ #include <linux/pagemap.h> #include <linux/ptrace.h> #include <linux/security.h> +#include <linux/binfmts.h> #include <linux/signal.h> #include <linux/uio.h> #include <linux/audit.h> @@ -435,6 +436,28 @@ static int ptrace_attach(struct task_struct *task, long request, if (retval) goto unlock_creds; + if (unlikely(task->in_execve)) { + struct linux_binprm *bprm = task->signal->exec_bprm; + const struct cred __rcu *old_cred; + struct mm_struct *old_mm; + + retval = down_write_killable(&task->signal->exec_update_lock); + if (retval) + goto unlock_creds; + task_lock(task); + old_cred = task->real_cred; + old_mm = task->mm; + rcu_assign_pointer(task->real_cred, bprm->cred); + task->mm = bprm->mm; + retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS); + rcu_assign_pointer(task->real_cred, old_cred); + task->mm = old_mm; + task_unlock(task); + up_write(&task->signal->exec_update_lock); + if (retval) + goto unlock_creds; + } + write_lock_irq(&tasklist_lock); retval = -EPERM; if (unlikely(task->exit_state)) @@ -508,6 +531,14 @@ static int ptrace_traceme(void) { int ret = -EPERM; + if (mutex_lock_interruptible(&current->signal->cred_guard_mutex)) + return -ERESTARTNOINTR; + + if (unlikely(current->signal->exec_bprm)) { + mutex_unlock(&current->signal->cred_guard_mutex); + return -ERESTARTNOINTR; + } + write_lock_irq(&tasklist_lock); /* Are we already being traced? */ if (!current->ptrace) { @@ -523,6 +554,7 @@ static int ptrace_traceme(void) } } write_unlock_irq(&tasklist_lock); + mutex_unlock(&current->signal->cred_guard_mutex); return ret; } diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 255999ba9190..b29bbfa0b044 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -1955,9 +1955,15 @@ static long seccomp_set_mode_filter(unsigned int flags, * Make sure we cannot change seccomp or nnp state via TSYNC * while another thread is in the middle of calling exec. */ - if (flags & SECCOMP_FILTER_FLAG_TSYNC && - mutex_lock_killable(&current->signal->cred_guard_mutex)) - goto out_put_fd; + if (flags & SECCOMP_FILTER_FLAG_TSYNC) { + if (mutex_lock_killable(&current->signal->cred_guard_mutex)) + goto out_put_fd; + + if (unlikely(current->signal->exec_bprm)) { + mutex_unlock(&current->signal->cred_guard_mutex); + goto out_put_fd; + } + } spin_lock_irq(&current->sighand->siglock); diff --git a/tools/testing/selftests/ptrace/vmaccess.c b/tools/testing/selftests/ptrace/vmaccess.c index 4db327b44586..3b7d81fb99bb 100644 --- a/tools/testing/selftests/ptrace/vmaccess.c +++ b/tools/testing/selftests/ptrace/vmaccess.c @@ -39,8 +39,15 @@ TEST(vmaccess) f = open(mm, O_RDONLY); ASSERT_GE(f, 0); close(f); - f = kill(pid, SIGCONT); - ASSERT_EQ(f, 0); + f = waitpid(-1, NULL, 0); + ASSERT_NE(f, -1); + ASSERT_NE(f, 0); + ASSERT_NE(f, pid); + f = waitpid(-1, NULL, 0); + ASSERT_EQ(f, pid); + f = waitpid(-1, NULL, 0); + ASSERT_EQ(f, -1); + ASSERT_EQ(errno, ECHILD); } TEST(attach) @@ -57,22 +64,24 @@ TEST(attach) sleep(1); k = ptrace(PTRACE_ATTACH, pid, 0L, 0L); - ASSERT_EQ(errno, EAGAIN); - ASSERT_EQ(k, -1); + ASSERT_EQ(k, 0); k = waitpid(-1, &s, WNOHANG); ASSERT_NE(k, -1); ASSERT_NE(k, 0); ASSERT_NE(k, pid); ASSERT_EQ(WIFEXITED(s), 1); ASSERT_EQ(WEXITSTATUS(s), 0); - sleep(1); - k = ptrace(PTRACE_ATTACH, pid, 0L, 0L); + k = waitpid(-1, &s, 0); + ASSERT_EQ(k, pid); + ASSERT_EQ(WIFSTOPPED(s), 1); + ASSERT_EQ(WSTOPSIG(s), SIGTRAP); + k = ptrace(PTRACE_CONT, pid, 0L, 0L); ASSERT_EQ(k, 0); k = waitpid(-1, &s, 0); ASSERT_EQ(k, pid); ASSERT_EQ(WIFSTOPPED(s), 1); ASSERT_EQ(WSTOPSIG(s), SIGSTOP); - k = ptrace(PTRACE_DETACH, pid, 0L, 0L); + k = ptrace(PTRACE_CONT, pid, 0L, 0L); ASSERT_EQ(k, 0); k = waitpid(-1, &s, 0); ASSERT_EQ(k, pid); -- 2.39.2

2 days, 23 hours

8
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[PATCH] selftests/seccomp: fix pointer type mismatch in UPROBE test

by Nirbhay Sharma

Fix compilation error in UPROBE_setup caused by pointer type mismatch in ternary expression. The probed_uretprobe and probed_uprobe function pointers have different type attributes (__attribute__((nocf_check))), which causes the conditional operator to fail with: seccomp_bpf.c:5175:74: error: pointer type mismatch in conditional expression [-Wincompatible-pointer-types] Cast both function pointers to 'const void *' to match the expected parameter type of get_uprobe_offset(), resolving the type mismatch while preserving the function selection logic. Signed-off-by: Nirbhay Sharma <nirbhay.lkd(a)gmail.com> --- tools/testing/selftests/seccomp/seccomp_bpf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c index 874f17763536..e13ffe18ef95 100644 --- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -5172,7 +5172,8 @@ FIXTURE_SETUP(UPROBE) ASSERT_GE(bit, 0); } - offset = get_uprobe_offset(variant->uretprobe ? probed_uretprobe : probed_uprobe); + offset = get_uprobe_offset(variant->uretprobe ? + (const void *)probed_uretprobe : (const void *)probed_uprobe); ASSERT_GE(offset, 0); if (variant->uretprobe) -- 2.48.1

3 days, 3 hours

3
6
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[PATCH v8 0/8] liveupdate: Rework KHO for in-kernel users

by Pasha Tatashin

Changelog: v8: Added review-bys and addressed comments from Mike Rapoport and Pratyush Yadav. Added "memblock: Unpreserve memory in case of error" to handle rollback if preserve fails half way through. This series refactors the KHO framework to better support in-kernel users like the upcoming LUO. The current design, which relies on a notifier chain and debugfs for control, is too restrictive for direct programmatic use. The core of this rework is the removal of the notifier chain in favor of a direct registration API. This decouples clients from the shutdown-time finalization sequence, allowing them to manage their preserved state more flexibly and at any time. In support of this new model, this series also: - Exports kho_finalize() and kho_abort() for programmatic control. - Makes the debugfs interface optional. - Introduces APIs to unpreserve memory and fixes a bug in the abort path where client state was being incorrectly discarded. Note that this is an interim step, as a more comprehensive fix is planned as part of the stateless KHO work [1]. - Moves all KHO code into a new kernel/liveupdate/ directory to consolidate live update components. [1] https://lore.kernel.org/all/20251020100306.2709352-1-jasonmiu@google.com Mike Rapoport (Microsoft) (1): kho: drop notifiers Pasha Tatashin (7): kho: allow to drive kho from within kernel kho: make debugfs interface optional kho: add interfaces to unpreserve folios and page ranges kho: don't unpreserve memory during abort liveupdate: kho: move to kernel/liveupdate liveupdate: kho: move kho debugfs directory to liveupdate memblock: Unpreserve memory in case of error Documentation/core-api/kho/concepts.rst | 2 +- MAINTAINERS | 3 +- include/linux/kexec_handover.h | 53 +- init/Kconfig | 2 + kernel/Kconfig.kexec | 24 - kernel/Makefile | 3 +- kernel/kexec_handover_internal.h | 16 - kernel/liveupdate/Kconfig | 39 ++ kernel/liveupdate/Makefile | 5 + kernel/{ => liveupdate}/kexec_handover.c | 508 +++++++----------- .../{ => liveupdate}/kexec_handover_debug.c | 0 kernel/liveupdate/kexec_handover_debugfs.c | 219 ++++++++ kernel/liveupdate/kexec_handover_internal.h | 56 ++ lib/test_kho.c | 33 +- mm/memblock.c | 82 ++- tools/testing/selftests/kho/init.c | 2 +- tools/testing/selftests/kho/vmtest.sh | 1 + 17 files changed, 590 insertions(+), 458 deletions(-) delete mode 100644 kernel/kexec_handover_internal.h create mode 100644 kernel/liveupdate/Kconfig create mode 100644 kernel/liveupdate/Makefile rename kernel/{ => liveupdate}/kexec_handover.c (80%) rename kernel/{ => liveupdate}/kexec_handover_debug.c (100%) create mode 100644 kernel/liveupdate/kexec_handover_debugfs.c create mode 100644 kernel/liveupdate/kexec_handover_internal.h base-commit: 72fb0170ef1f45addf726319c52a0562b6913707 -- 2.51.1.821.gb6fe4d2222-goog

3 days, 4 hours

4
18
0 0

[PATCH 0/4] SBI MPXY support for KVM Guest

by Anup Patel

This series adds SBI MPXY support for KVM Guest/VM which will enable QEMU-KVM or KVMTOOL to emulate RPMI MPXY channels for the Guest/VM. These patches can also be found in riscv_kvm_sbi_mpxy_v1 branch at: https://github.com/avpatel/linux.git Anup Patel (4): RISC-V: KVM: Convert kvm_riscv_vcpu_sbi_forward() into extension handler RISC-V: KVM: Add separate source for forwarded SBI extensions RISC-V: KVM: Add SBI MPXY extension support for Guest KVM: riscv: selftests: Add SBI MPXY extension to get-reg-list arch/riscv/include/asm/kvm_vcpu_sbi.h | 5 ++- arch/riscv/include/uapi/asm/kvm.h | 1 + arch/riscv/kvm/Makefile | 1 + arch/riscv/kvm/vcpu_sbi.c | 10 +++++- arch/riscv/kvm/vcpu_sbi_base.c | 28 +-------------- arch/riscv/kvm/vcpu_sbi_forward.c | 34 +++++++++++++++++++ arch/riscv/kvm/vcpu_sbi_replace.c | 32 ----------------- arch/riscv/kvm/vcpu_sbi_system.c | 4 +-- arch/riscv/kvm/vcpu_sbi_v01.c | 3 +- .../selftests/kvm/riscv/get-reg-list.c | 4 +++ 10 files changed, 56 insertions(+), 66 deletions(-) create mode 100644 arch/riscv/kvm/vcpu_sbi_forward.c -- 2.43.0

3 days, 8 hours

3
9
0 0

[PATCH] selftests: tty: add tty_tiocsti_test to .gitignore

by Gopi Krishna Menon

Add the tty_tiocsti_test binary to .gitignore to avoid accidentally staging the build artifact. Signed-off-by: Gopi Krishna Menon <krishnagopi487(a)gmail.com> --- tools/testing/selftests/tty/.gitignore | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/testing/selftests/tty/.gitignore b/tools/testing/selftests/tty/.gitignore index fe70462a4aad..2453685d2493 100644 --- a/tools/testing/selftests/tty/.gitignore +++ b/tools/testing/selftests/tty/.gitignore @@ -1,2 +1,3 @@ # SPDX-License-Identifier: GPL-2.0-only +tty_tiocsti_test tty_tstamp_update -- 2.43.0

4 days, 1 hour

3
6
0 0

[PATCH v3 0/9] riscv: vector: misc ptrace fixes for debug use-cases

by Sergey Matyukevich

This patch series suggests fixes for several corner cases in the RISC-V vector ptrace implementation: - init vector context with proper vlenb, to avoid reading zero vlenb by an early attached debugger - follow gdbserver expectations and return ENODATA instead of EINVAL if vector extension is supported but not yet activated for the traced process - validate input vector csr registers in ptrace, to maintain an accurate view of the tracee's vector context across multiple halt/resume debug cycles For detailed description see the appropriate commit messages. A new test suite v_ptrace is added into the tools/testing/selftests/riscv/vector to verify some of the vector ptrace functionality and corner cases. Previous versions: - v2: https://lore.kernel.org/linux-riscv/20250821173957.563472-1-geomatsi@gmail.… - v1: https://lore.kernel.org/linux-riscv/20251007115840.2320557-1-geomatsi@gmail… Changes in v3: Address the review comments by Andy Chiu and rework the approach: - drop forced vector context save entirely - perform strict validation of vector csr regs in ptrace Changes in v2: - add thread_info flag to allow to force vector context save - force vector context save after vector ptrace to ensure valid vector context in the next ptrace operations - force vector context save on the first context switch after vector context init to get proper vlenb --- Ilya Mamay (1): riscv: ptrace: return ENODATA for inactive vector extension Sergey Matyukevich (8): selftests: riscv: test ptrace vector interface selftests: riscv: verify initial vector state with ptrace riscv: vector: init vector context with proper vlenb riscv: csr: define vector registers elements riscv: ptrace: validate input vector csr registers selftests: riscv: verify ptrace rejects invalid vector csr inputs selftests: riscv: verify ptrace accepts valid vector csr values selftests: riscv: verify syscalls discard vector context arch/riscv/include/asm/csr.h | 11 + arch/riscv/kernel/ptrace.c | 72 +- arch/riscv/kernel/vector.c | 12 +- .../testing/selftests/riscv/vector/.gitignore | 1 + tools/testing/selftests/riscv/vector/Makefile | 5 +- .../testing/selftests/riscv/vector/v_ptrace.c | 737 ++++++++++++++++++ 6 files changed, 830 insertions(+), 8 deletions(-) create mode 100644 tools/testing/selftests/riscv/vector/v_ptrace.c base-commit: 72761a7e31225971d0b29d9195e0ffa986b77867 -- 2.51.0

4 days, 14 hours

1
9
0 0

[PATCH AUTOSEL 6.17-5.4] selftests/Makefile: include $(INSTALL_DEP_TARGETS) in clean target to clean net/lib dependency

by Sasha Levin

From: Nai-Chen Cheng <bleach1827(a)gmail.com> [ Upstream commit d3f7457da7b9527a06dbcbfaf666aa51ac2eeb53 ] The selftests 'make clean' does not clean the net/lib because it only processes $(TARGETS) and ignores $(INSTALL_DEP_TARGETS). This leaves compiled objects in net/lib after cleaning, requiring manual cleanup. Include $(INSTALL_DEP_TARGETS) in clean target to ensure net/lib dependency is properly cleaned. Signed-off-by: Nai-Chen Cheng <bleach1827(a)gmail.com> Reviewed-by: Simon Horman <horms(a)kernel.org> Tested-by: Simon Horman <horms(a)kernel.org> # build-tested Acked-by: Shuah Khan <skhan(a)linuxfoundation.org> Link: https://patch.msgid.link/20250910-selftests-makefile-clean-v1-1-29e7f496cd8… Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- LLM Generated explanations, may be completely bogus: YES – updating `tools/testing/selftests/Makefile:319` to iterate over `$(TARGETS) $(INSTALL_DEP_TARGETS)` brings the `clean` recipe in line with the existing `all` and `install` loops (`tools/testing/selftests/Makefile:211` and `:276`), so the implicit net/lib helper that gets built for networking selftests is now removed during `make clean`. This fixes a real annoyance where stale objects remain under `net/lib/` after cleaning, forcing manual removal and risking rebuild flakiness if headers or tooling change. The change is tiny, selftests-only, and mirrors logic already exercised in other targets, so regression risk is negligible. Just make sure the stable branch you target already carries the dependency hook that introduced `INSTALL_DEP_TARGETS` (commit b86761ff6374813cdf64ffd6b95ddd1813c435d8 or equivalent); older branches without that infrastructure don’t need this patch. Natural follow-up: once backported, run `make -C tools/testing/selftests clean` after building the net tests to confirm the stale net/lib objects are cleared. tools/testing/selftests/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 030da61dbff3a..a2d8e1093b005 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -314,7 +314,7 @@ gen_tar: install @echo "Created ${TAR_PATH}" clean: - @for TARGET in $(TARGETS); do \ + @for TARGET in $(TARGETS) $(INSTALL_DEP_TARGETS); do \ BUILD_TARGET=$$BUILD/$$TARGET; \ $(MAKE) OUTPUT=$$BUILD_TARGET -C $$TARGET clean;\ done; -- 2.51.0

4 days, 19 hours

1
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