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2025-04-16x86/fpu/apx: Define APX state componentChang S. Bae
Advanced Performance Extensions (APX) is associated with a new state component number 19. To support saving and restoring of the corresponding registers via the XSAVE mechanism, introduce the component definition along with the necessary sanity checks. Define the new component number, state name, and those register data type. Then, extend the size checker to validate the register data type and explicitly list the APX feature flag as a dependency for the new component in xsave_cpuid_features[]. Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Sohil Mehta <sohil.mehta@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20250416021720.12305-3-chang.seok.bae@intel.com
2025-04-16x86/cpufeatures: Add X86_FEATURE_APXChang S. Bae
Intel Advanced Performance Extensions (APX) introduce a new set of general-purpose registers, managed as an extended state component via the xstate management facility. Before enabling this new xstate, define a feature flag to clarify the dependency in xsave_cpuid_features[]. APX is enumerated under CPUID level 7 with EDX=1. Since this CPUID leaf is not yet allocated, place the flag in a scattered feature word. While this feature is intended only for userspace, exposing it via /proc/cpuinfo is unnecessary. Instead, the existing arch_prctl(2) mechanism with the ARCH_GET_XCOMP_SUPP option can be used to query the feature availability. Finally, clarify that APX depends on XSAVE. Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Sohil Mehta <sohil.mehta@intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20250416021720.12305-2-chang.seok.bae@intel.com
2025-04-16Merge branch 'x86/cpu' into x86/fpu, to pick up dependent commitsIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-04-16Merge branch 'linus' into x86/cpu, to resolve conflictsIngo Molnar
Conflicts: tools/arch/x86/include/asm/cpufeatures.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-04-15x86/cpufeatures: Shorten X86_FEATURE_AMD_HETEROGENEOUS_CORESXin Li (Intel)
Shorten X86_FEATURE_AMD_HETEROGENEOUS_CORES to X86_FEATURE_AMD_HTR_CORES to make the last column aligned consistently in the whole file. No functional changes. Suggested-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Xin Li (Intel) <xin@zytor.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250415175410.2944032-4-xin@zytor.com
2025-04-15x86/cpufeatures: Shorten X86_FEATURE_CLEAR_BHB_LOOP_ON_VMEXITXin Li (Intel)
Shorten X86_FEATURE_CLEAR_BHB_LOOP_ON_VMEXIT to X86_FEATURE_CLEAR_BHB_VMEXIT to make the last column aligned consistently in the whole file. There's no need to explain in the name what the mitigation does. No functional changes. Suggested-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Xin Li (Intel) <xin@zytor.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250415175410.2944032-3-xin@zytor.com
2025-04-15x86/cpufeatures: Clean up formattingBorislav Petkov (AMD)
It is a special file with special formatting so remove one whitespace damage and format newer defines like the rest. No functional changes. [ Xin: Do the same to tools/arch/x86/include/asm/cpufeatures.h. ] Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Xin Li (Intel) <xin@zytor.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250415175410.2944032-2-xin@zytor.com
2025-04-15Merge tag 'edac_urgent_for_v6.15_rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras Pull EDAC fixes from Borislav Petkov: "Two fixes to the AMD translation library for the MI300 side of things: - Use the row[13] bit when calculating the memory row to retire - Mask the physical row address in order to avoid creating duplicate error records" * tag 'edac_urgent_for_v6.15_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras: RAS/AMD/FMPM: Get masked address RAS/AMD/ATL: Include row[13] bit in row retirement
2025-04-15Merge tag 'fs_for_v6.15-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull isofs fix from Jan Kara: "Fix a case where isofs could be reading beyond end of the passed file handle if its type was incorrectly set" * tag 'fs_for_v6.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: isofs: Prevent the use of too small fid
2025-04-14Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdmaLinus Torvalds
Pull rdma fixes from Jason Gunthorpe: - Fix hang in bnxt_re due to miscomputing the budget - Avoid a -Wformat-security message in dev_set_name() - Avoid an unused definition warning in fs.c with some kconfigs - Fix error handling in usnic and remove IS_ERR_OR_NULL() usage - Regression in RXE support foudn by blktests due to missing ODP exclusions - Set the dma_segment_size on HNS so it doesn't corrupt DMA when using very large IOs - Move a INIT_WORK to near when the work is allocated in cm.c to fix a racey crash where work in progress was being init'd - Use __GFP_NOWARN to not dump in kvcalloc() if userspace requests a very big MR * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: RDMA/bnxt_re: Remove unusable nq variable RDMA/core: Silence oversized kvmalloc() warning RDMA/cma: Fix workqueue crash in cma_netevent_work_handler RDMA/hns: Fix wrong maximum DMA segment size RDMA/rxe: Fix null pointer dereference in ODP MR check RDMA/mlx5: Fix compilation warning when USER_ACCESS isn't set RDMA/usnic: Fix passing zero to PTR_ERR in usnic_ib_pci_probe() RDMA/ucaps: Avoid format-security warning RDMA/bnxt_re: Fix budget handling of notification queue
2025-04-14Merge tag 'vfs-6.15-rc3.fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs fixes from Christian Brauner: - Fix NULL pointer dereference in virtiofs - Fix slab OOB access in hfs/hfsplus - Only create /proc/fs/netfs when CONFIG_PROC_FS is set - Fix getname_flags() to initialize pointer correctly - Convert dentry flags to enum - Don't allow datadir without lowerdir in overlayfs - Use namespace_{lock,unlock} helpers in dissolve_on_fput() instead of plain namespace_sem so unmounted mounts are properly cleaned up - Skip unnecessary ifs_block_is_uptodate check in iomap - Remove an unused forward declaration in overlayfs - Fix devpts uid/gid handling after converting to the new mount api - Fix afs_dynroot_readdir() to not use the RCU read lock - Fix mount_setattr() and open_tree_attr() to not pointlessly do path lookup or walk the mount tree if no mount option change has been requested * tag 'vfs-6.15-rc3.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fs: use namespace_{lock,unlock} in dissolve_on_fput() iomap: skip unnecessary ifs_block_is_uptodate check fs: Fix filename init after recent refactoring netfs: Only create /proc/fs/netfs with CONFIG_PROC_FS mount: ensure we don't pointlessly walk the mount tree dcache: convert dentry flag macros to enum afs: Fix afs_dynroot_readdir() to not use the RCU read lock hfs/hfsplus: fix slab-out-of-bounds in hfs_bnode_read_key virtiofs: add filesystem context source name check devpts: Fix type for uid and gid params ovl: remove unused forward declaration ovl: don't allow datadir only
2025-04-14Merge tag 'perf-tools-fixes-for-v6.15-2025-04-13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools Pull perf tools fixes from Namhyung Kim: "A couple of fixes and the usual tooling header updates: - fix a build error on ARM64 when libunwind is requested - fix an infinite loop with branch stack on AMD Zen3 - sync tooling headers with the kernel source" * tag 'perf-tools-fixes-for-v6.15-2025-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: perf tools: Remove evsel__handle_error_quirks() perf libunwind arm64: Fix missing close parens in an if statement tools headers: Update the arch/x86/lib/memset_64.S copy with the kernel sources tools headers: Update the x86 headers with the kernel sources tools headers: Update the linux/unaligned.h copy with the kernel sources tools headers: Update the uapi/asm-generic/mman-common.h copy with the kernel sources tools headers: Update the uapi/linux/prctl.h copy with the kernel sources tools headers: Update the syscall table with the kernel sources tools headers: Update the VFS headers with the kernel sources tools headers: Update the uapi/linux/perf_event.h copy with the kernel sources tools headers: Update the socket headers with the kernel sources tools headers: Update the KVM headers with the kernel sources
2025-04-14x86/bugs: Remove X86_BUG_MMIO_UNKNOWNBorislav Petkov (AMD)
Whack this thing because: - the "unknown" handling is done only for this vuln and not for the others - it doesn't do anything besides reporting things differently. It doesn't apply any mitigations - it is simply causing unnecessary complications to the code which don't bring anything besides maintenance overhead to what is already a very nasty spaghetti pile - all the currently unaffected CPUs can also be in "unknown" status so there's no need for special handling here so get rid of it. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: David Kaplan <david.kaplan@amd.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Link: https://lore.kernel.org/r/20250414150951.5345-1-bp@kernel.org
2025-04-14x86/cpuid: Align macro linebreaks verticallyBorislav Petkov (AMD)
Align the backspaces vertically again, after recent cleanups. No functional changes. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Ahmed S. Darwish <darwi@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250414094130.6768-1-bp@kernel.org
2025-04-14x86/platform/amd: Move the <asm/amd_node.h> header to <asm/amd/node.h>Ingo Molnar
Collect AMD specific platform header files in <asm/amd/*.h>. Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mario Limonciello <superm1@kernel.org> Link: https://lore.kernel.org/r/20250413084144.3746608-7-mingo@kernel.org
2025-04-14x86/platform/amd: Clean up the <asm/amd/hsmp.h> header guards a bitIngo Molnar
- There's no need for a newline after the SPDX line - But there's a need for one before the closing header guard. Collect AMD specific platform header files in <asm/amd/*.h>. Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: Carlos Bilbao <carlos.bilbao@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mario Limonciello <superm1@kernel.org> Cc: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com> Link: https://lore.kernel.org/r/20250413084144.3746608-6-mingo@kernel.org
2025-04-14x86/platform/amd: Move the <asm/amd_hsmp.h> header to <asm/amd/hsmp.h>Ingo Molnar
Collect AMD specific platform header files in <asm/amd/*.h>. Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: Carlos Bilbao <carlos.bilbao@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mario Limonciello <superm1@kernel.org> Cc: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com> Link: https://lore.kernel.org/r/20250413084144.3746608-5-mingo@kernel.org
2025-04-14x86/platform/amd: Move the <asm/amd_nb.h> header to <asm/amd/nb.h>Ingo Molnar
Collect AMD specific platform header files in <asm/amd/*.h>. Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mario Limonciello <superm1@kernel.org> Link: https://lore.kernel.org/r/20250413084144.3746608-4-mingo@kernel.org
2025-04-14x86/platform/amd: Add standard header guards to <asm/amd/ibs.h>Ingo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mario Limonciello <superm1@kernel.org> Link: https://lore.kernel.org/r/20250413084144.3746608-3-mingo@kernel.org
2025-04-14x86/platform/amd: Move the <asm/amd-ibs.h> header to <asm/amd/ibs.h>Ingo Molnar
Collect AMD specific platform header files in <asm/amd/*.h>. Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mario Limonciello <superm1@kernel.org> Link: https://lore.kernel.org/r/20250413084144.3746608-2-mingo@kernel.org
2025-04-14x86/fpu: Clarify FPU context cacheline alignmentIngo Molnar
Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Chang S. Bae <chang.seok.bae@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/Z_ejggklB5-IWB5W@gmail.com
2025-04-14x86/fpu: Use 'fpstate' variable names consistentlyIngo Molnar
A few uses of 'fps' snuck in, which is rather confusing (to me) as it suggests frames-per-second. ;-) Rename them to the canonical 'fpstate' name. No change in functionality. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chang S. Bae <chang.seok.bae@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20250409211127.3544993-9-mingo@kernel.org
2025-04-14x86/fpu: Remove init_task FPU state dependencies, add debugging warning for ↵Ingo Molnar
PF_KTHREAD tasks init_task's FPU state initialization was a bit of a hack: __x86_init_fpu_begin = .; . = __x86_init_fpu_begin + 128*PAGE_SIZE; __x86_init_fpu_end = .; But the init task isn't supposed to be using the FPU context in any case, so remove the hack and add in some debug warnings. As Linus noted in the discussion, the init task (and other PF_KTHREAD tasks) *can* use the FPU via kernel_fpu_begin()/_end(), but they don't need the context area because their FPU use is not preemptible or reentrant, and they don't return to user-space. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chang S. Bae <chang.seok.bae@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Uros Bizjak <ubizjak@gmail.com> Link: https://lore.kernel.org/r/20250409211127.3544993-8-mingo@kernel.org
2025-04-14x86/fpu: Make sure x86_task_fpu() doesn't get called for ↵Ingo Molnar
PF_KTHREAD|PF_USER_WORKER tasks during exit fpu__drop() and arch_release_task_struct() calls x86_task_fpu() unconditionally, while the FPU context area will not be present if it's the init task, and should not be in use when it's some other type of kthread. Return early for PF_KTHREAD or PF_USER_WORKER tasks. The debug warning in x86_task_fpu() will catch any kthreads attempting to use the FPU save area. Fixed-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20250409211127.3544993-7-mingo@kernel.org
2025-04-14x86/fpu: Push 'fpu' pointer calculation into the fpu__drop() callIngo Molnar
This encapsulates the fpu__drop() functionality better, and it will also enable other changes that want to check a task for PF_KTHREAD before calling x86_task_fpu(). Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chang S. Bae <chang.seok.bae@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20250409211127.3544993-6-mingo@kernel.org
2025-04-14x86/fpu: Remove the thread::fpu pointerIngo Molnar
As suggested by Oleg, remove the thread::fpu pointer, as we can calculate it via x86_task_fpu() at compile-time. This improves code generation a bit: kepler:~/tip> size vmlinux.before vmlinux.after text data bss dec hex filename 26475405 10435342 1740804 38651551 24dc69f vmlinux.before 26475339 10959630 1216516 38651485 24dc65d vmlinux.after Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chang S. Bae <chang.seok.bae@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Uros Bizjak <ubizjak@gmail.com> Link: https://lore.kernel.org/r/20250409211127.3544993-5-mingo@kernel.org
2025-04-14x86/fpu: Make task_struct::thread constant sizeIngo Molnar
Turn thread.fpu into a pointer. Since most FPU code internals work by passing around the FPU pointer already, the code generation impact is small. This allows us to remove the old kludge of task_struct being variable size: struct task_struct { ... /* * New fields for task_struct should be added above here, so that * they are included in the randomized portion of task_struct. */ randomized_struct_fields_end /* CPU-specific state of this task: */ struct thread_struct thread; /* * WARNING: on x86, 'thread_struct' contains a variable-sized * structure. It *MUST* be at the end of 'task_struct'. * * Do not put anything below here! */ }; ... which creates a number of problems, such as requiring thread_struct to be the last member of the struct - not allowing it to be struct-randomized, etc. But the primary motivation is to allow the decoupling of task_struct from hardware details (<asm/processor.h> in particular), and to eventually allow the per-task infrastructure: DECLARE_PER_TASK(type, name); ... per_task(current, name) = val; ... which requires task_struct to be a constant size struct. The fpu_thread_struct_whitelist() quirk to hardened usercopy can be removed, now that the FPU structure is not embedded in the task struct anymore, which reduces text footprint a bit. Fixed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chang S. Bae <chang.seok.bae@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250409211127.3544993-4-mingo@kernel.org
2025-04-14x86/fpu: Convert task_struct::thread.fpu accesses to use x86_task_fpu()Ingo Molnar
This will make the removal of the task_struct::thread.fpu array easier. No change in functionality - code generated before and after this commit is identical on x86-defconfig: kepler:~/tip> diff -up vmlinux.before.asm vmlinux.after.asm kepler:~/tip> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chang S. Bae <chang.seok.bae@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20250409211127.3544993-3-mingo@kernel.org
2025-04-14x86/fpu: Introduce the x86_task_fpu() helper methodIngo Molnar
The per-task FPU context/save area is allocated right next to task_struct, currently in a variable-size array via task_struct::thread.fpu[], but we plan to fully hide it from the C type scope. Introduce the x86_task_fpu() accessor that gets to the FPU context pointer explicitly from the task pointer. Right now this is a simple (task)->thread.fpu wrapper. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chang S. Bae <chang.seok.bae@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20250409211127.3544993-2-mingo@kernel.org
2025-04-14x86/fpu/xstate: Adjust xstate copying logic for user ABIChang S. Bae
== Background == As feature positions in the userspace XSAVE buffer do not always align with their feature numbers, the XSAVE format conversion needs to be reconsidered to align with the revised xstate size calculation logic. * For signal handling, XSAVE and XRSTOR are used directly to save and restore extended registers. * For ptrace, KVM, and signal returns (for 32-bit frame), the kernel copies data between its internal buffer and the userspace XSAVE buffer. If memcpy() were used for these cases, existing offset helpers — such as __raw_xsave_addr() or xstate_offsets[] — would be sufficient to handle the format conversion. == Problem == When copying data from the compacted in-kernel buffer to the non-compacted userspace buffer, the function follows the user_regset_get2_fn() prototype. This means it utilizes struct membuf helpers for the destination buffer. As defined in regset.h, these helpers update the memory pointer during the copy process, enforcing sequential writes within the loop. Since xstate components are processed sequentially, any component whose buffer position does not align with its feature number has an issue. == Solution == Replace for_each_extended_xfeature() with the newly introduced for_each_extended_xfeature_in_order(). This macro ensures xstate components are handled in the correct order based on their actual positions in the destination buffer, rather than their feature numbers. Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20250320234301.8342-5-chang.seok.bae@intel.com
2025-04-14x86/fpu/xstate: Adjust XSAVE buffer size calculationChang S. Bae
The current xstate size calculation assumes that the highest-numbered xstate feature has the highest offset in the buffer, determining the size based on the topmost bit in the feature mask. However, this assumption is not architecturally guaranteed -- higher-numbered features may have lower offsets. With the introduction of the xfeature order table and its helper macro, xstate components can now be traversed in their positional order. Update the non-compacted format handling to iterate through the table to determine the last-positioned feature. Then, set the offset accordingly. Since size calculation primarily occurs during initialization or in non-critical paths, looping to find the last feature is not expected to have a meaningful performance impact. Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20250320234301.8342-4-chang.seok.bae@intel.com
2025-04-14x86/fpu/xstate: Introduce xfeature order table and accessor macroChang S. Bae
The kernel has largely assumed that higher xstate component numbers correspond to later offsets in the buffer. However, this assumption no longer holds for the non-compacted format, where a newer state component may have a lower offset. When iterating over xstate components in offset order, using the feature number as an index may be misleading. At the same time, the CPU exposes each component’s size and offset based on its feature number, making it a key for state information. To provide flexibility in handling xstate ordering, introduce a mapping table: feature order -> feature number. The table is dynamically populated based on the CPU-exposed features and is sorted in offset order at boot time. Additionally, add an accessor macro to facilitate sequential traversal of xstate components based on their actual buffer positions, given a feature bitmask. This accessor macro will be particularly useful for computing custom non-compacted format sizes and iterating over xstate offsets in non-compacted buffers. Suggested-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20250320234301.8342-3-chang.seok.bae@intel.com
2025-04-14x86/fpu/xstate: Remove xstate offset checkChang S. Bae
Traditionally, new xstate components have been assigned sequentially, aligning feature numbers with their offsets in the XSAVE buffer. However, this ordering is not architecturally mandated in the non-compacted format, where a component's offset may not correspond to its feature number. The kernel caches CPUID-reported xstate component details, including size and offset in the non-compacted format. As part of this process, a sanity check is also conducted to ensure alignment between feature numbers and offsets. This check was likely intended as a general guideline rather than a strict requirement. Upcoming changes will support out-of-order offsets. Remove the check as becoming obsolete. Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Link: https://lore.kernel.org/r/20250320234301.8342-2-chang.seok.bae@intel.com
2025-04-13Linux 6.15-rc2v6.15-rc2Linus Torvalds
2025-04-13Merge tag 'erofs-for-6.15-rc2-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs Pull erofs fixes from Gao Xiang: - Properly handle errors when file-backed I/O fails - Fix compilation issues on ARM platform (arm-linux-gnueabi) - Fix parsing of encoded extents - Minor cleanup * tag 'erofs-for-6.15-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs: erofs: remove duplicate code erofs: fix encoded extents handling erofs: add __packed annotation to union(__le16..) erofs: set error to bio if file-backed IO fails
2025-04-13Merge tag 'ext4_for_linus-6.15-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 fixes from Ted Ts'o: "A few more miscellaneous ext4 bug fixes and cleanups including some syzbot failures and fixing a stale file handing refeencing an inode previously used as a regular file, but which has been deleted and reused as an ea_inode would result in ext4 erroneously considering this a case of fs corruption" * tag 'ext4_for_linus-6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: fix off-by-one error in do_split ext4: make block validity check resistent to sb bh corruption ext4: avoid -Wflex-array-member-not-at-end warning Documentation: ext4: Add fields to ext4_super_block documentation ext4: don't treat fhandle lookup of ea_inode as FS corruption
2025-04-13Merge tag 'fixes-2025-04-13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock Pull memblock fix from Mike Rapoport: "Fix build of memblock test. Add missing stubs for mutex and free_reserved_area() to memblock tests" * tag 'fixes-2025-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock: memblock tests: Fix mutex related build error
2025-04-12ext4: fix off-by-one error in do_splitArtem Sadovnikov
Syzkaller detected a use-after-free issue in ext4_insert_dentry that was caused by out-of-bounds access due to incorrect splitting in do_split. BUG: KASAN: use-after-free in ext4_insert_dentry+0x36a/0x6d0 fs/ext4/namei.c:2109 Write of size 251 at addr ffff888074572f14 by task syz-executor335/5847 CPU: 0 UID: 0 PID: 5847 Comm: syz-executor335 Not tainted 6.12.0-rc6-syzkaller-00318-ga9cda7c0ffed #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189 __asan_memcpy+0x40/0x70 mm/kasan/shadow.c:106 ext4_insert_dentry+0x36a/0x6d0 fs/ext4/namei.c:2109 add_dirent_to_buf+0x3d9/0x750 fs/ext4/namei.c:2154 make_indexed_dir+0xf98/0x1600 fs/ext4/namei.c:2351 ext4_add_entry+0x222a/0x25d0 fs/ext4/namei.c:2455 ext4_add_nondir+0x8d/0x290 fs/ext4/namei.c:2796 ext4_symlink+0x920/0xb50 fs/ext4/namei.c:3431 vfs_symlink+0x137/0x2e0 fs/namei.c:4615 do_symlinkat+0x222/0x3a0 fs/namei.c:4641 __do_sys_symlink fs/namei.c:4662 [inline] __se_sys_symlink fs/namei.c:4660 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4660 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> The following loop is located right above 'if' statement. for (i = count-1; i >= 0; i--) { /* is more than half of this entry in 2nd half of the block? */ if (size + map[i].size/2 > blocksize/2) break; size += map[i].size; move++; } 'i' in this case could go down to -1, in which case sum of active entries wouldn't exceed half the block size, but previous behaviour would also do split in half if sum would exceed at the very last block, which in case of having too many long name files in a single block could lead to out-of-bounds access and following use-after-free. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Cc: stable@vger.kernel.org Fixes: 5872331b3d91 ("ext4: fix potential negative array index in do_split()") Signed-off-by: Artem Sadovnikov <a.sadovnikov@ispras.ru> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20250404082804.2567-3-a.sadovnikov@ispras.ru Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-04-12ext4: make block validity check resistent to sb bh corruptionOjaswin Mujoo
Block validity checks need to be skipped in case they are called for journal blocks since they are part of system's protected zone. Currently, this is done by checking inode->ino against sbi->s_es->s_journal_inum, which is a direct read from the ext4 sb buffer head. If someone modifies this underneath us then the s_journal_inum field might get corrupted. To prevent against this, change the check to directly compare the inode with journal->j_inode. **Slight change in behavior**: During journal init path, check_block_validity etc might be called for journal inode when sbi->s_journal is not set yet. In this case we now proceed with ext4_inode_block_valid() instead of returning early. Since systems zones have not been set yet, it is okay to proceed so we can perform basic checks on the blocks. Suggested-by: Baokun Li <libaokun1@huawei.com> Reviewed-by: Baokun Li <libaokun1@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/0c06bc9ebfcd6ccfed84a36e79147bf45ff5adc1.1743142920.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-04-12ext4: avoid -Wflex-array-member-not-at-end warningGustavo A. R. Silva
-Wflex-array-member-not-at-end was introduced in GCC-14, and we are getting ready to enable it, globally. Use the `DEFINE_RAW_FLEX()` helper for an on-stack definition of a flexible structure where the size of the flexible-array member is known at compile-time, and refactor the rest of the code, accordingly. So, with these changes, fix the following warning: fs/ext4/mballoc.c:3041:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/Z-SF97N3AxcIMlSi@kspp Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-04-12Documentation: ext4: Add fields to ext4_super_block documentationTom Vierjahn
Documentation and implementation of the ext4 super block have slightly diverged: Padding has been removed in order to make room for new fields that are still missing in the documentation. Add the new fields s_encryption_level, s_first_error_errorcode, s_last_error_errorcode to the documentation of the ext4 super block. Fixes: f542fbe8d5e8 ("ext4 crypto: reserve codepoints used by the ext4 encryption feature") Fixes: 878520ac45f9 ("ext4: save the error code which triggered an ext4_error() in the superblock") Signed-off-by: Tom Vierjahn <tom.vierjahn@acm.org> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/20250324221004.5268-1-tom.vierjahn@acm.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-04-12Merge tag 'trace-v6.15-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Hide get_vm_area() from MMUless builds The function get_vm_area() is not defined when CONFIG_MMU is not defined. Hide that function within #ifdef CONFIG_MMU. - Fix output of synthetic events when they have dynamic strings The print fmt of the synthetic event's format file use to have "%.*s" for dynamic size strings even though the user space exported arguments had only __get_str() macro that provided just a nul terminated string. This was fixed so that user space could parse this properly. But the reason that it had "%.*s" was because internally it provided the maximum size of the string as one of the arguments. The fix that replaced "%.*s" with "%s" caused the trace output (when the kernel reads the event) to write "(efault)" as it would now read the length of the string as "%s". As the string provided is always nul terminated, there's no reason for the internal code to use "%.*s" anyway. Just remove the length argument to match the "%s" that is now in the format. - Fix the ftrace subops hash logic of the manager ops hash The function_graph uses the ftrace subops code. The subops code is a way to have a single ftrace_ops registered with ftrace to determine what functions will call the ftrace_ops callback. More than one user of function graph can register a ftrace_ops with it. The function graph infrastructure will then add this ftrace_ops as a subops with the main ftrace_ops it registers with ftrace. This is because the functions will always call the function graph callback which in turn calls the subops ftrace_ops callbacks. The main ftrace_ops must add a callback to all the functions that the subops want a callback from. When a subops is registered, it will update the main ftrace_ops hash to include the functions it wants. This is the logic that was broken. The ftrace_ops hash has a "filter_hash" and a "notrace_hash" where all the functions in the filter_hash but not in the notrace_hash are attached by ftrace. The original logic would have the main ftrace_ops filter_hash be a union of all the subops filter_hashes and the main notrace_hash would be a intersect of all the subops filter hashes. But this was incorrect because the notrace hash depends on the filter_hash it is associated to and not the union of all filter_hashes. Instead, when a subops is added, just include all the functions of the subops hash that are in its filter_hash but not in its notrace_hash. The main subops hash should not use its notrace hash, unless all of its subops hashes have an empty filter_hash (which means to attach to all functions), and then, and only then, the main ftrace_ops notrace hash can be the intersect of all the subops hashes. This not only fixes the bug, but also simplifies the code. - Add a selftest to better test the subops filtering Add a selftest that would catch the bug fixed by the above change. - Fix extra newline printed in function tracing with retval The function parameter code changed the output logic slightly and called print_graph_retval() and also printed a newline. The print_graph_retval() also prints a newline which caused blank lines to be printed in the function graph tracer when retval was added. This caused one of the selftests to fail if retvals were enabled. Instead remove the new line output from print_graph_retval() and have the callers always print the new line so that it doesn't have to do special logic if it calls print_graph_retval() or not. - Fix out-of-bound memory access in the runtime verifier When rv_is_container_monitor() is called on the last entry on the link list it references the next entry, which is the list head and causes an out-of-bound memory access. * tag 'trace-v6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: rv: Fix out-of-bound memory access in rv_is_container_monitor() ftrace: Do not have print_graph_retval() add a newline tracing/selftest: Add test to better test subops filtering of function graph ftrace: Fix accounting of subop hashes ftrace: Properly merge notrace hashes tracing: Do not add length to print format in synthetic events tracing: Hide get_vm_area() from MMUless builds
2025-04-12Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfLinus Torvalds
Pull bpf fixes from Alexei Starovoitov: - Followup fixes for resilient spinlock (Kumar Kartikeya Dwivedi): - Make res_spin_lock test less verbose, since it was spamming BPF CI on failure, and make the check for AA deadlock stronger - Fix rebasing mistake and use architecture provided res_smp_cond_load_acquire - Convert BPF maps (queue_stack and ringbuf) to resilient spinlock to address long standing syzbot reports - Make sure that classic BPF load instruction from SKF_[NET|LL]_OFF offsets works when skb is fragmeneted (Willem de Bruijn) * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: bpf: Convert ringbuf map to rqspinlock bpf: Convert queue_stack map to rqspinlock bpf: Use architecture provided res_smp_cond_load_acquire selftests/bpf: Make res_spin_lock AA test condition stronger selftests/net: test sk_filter support for SKF_NET_OFF on frags bpf: support SKF_NET_OFF and SKF_LL_OFF on skb frags selftests/bpf: Make res_spin_lock test less verbose
2025-04-12rv: Fix out-of-bound memory access in rv_is_container_monitor()Nam Cao
When rv_is_container_monitor() is called on the last monitor in rv_monitors_list, KASAN yells: BUG: KASAN: global-out-of-bounds in rv_is_container_monitor+0x101/0x110 Read of size 8 at addr ffffffff97c7c798 by task setup/221 The buggy address belongs to the variable: rv_monitors_list+0x18/0x40 This is due to list_next_entry() is called on the last entry in the list. It wraps around to the first list_head, and the first list_head is not embedded in struct rv_monitor_def. Fix it by checking if the monitor is last in the list. Cc: stable@vger.kernel.org Cc: Gabriele Monaco <gmonaco@redhat.com> Fixes: cb85c660fcd4 ("rv: Add option for nested monitors and include sched") Link: https://lore.kernel.org/e85b5eeb7228bfc23b8d7d4ab5411472c54ae91b.1744355018.git.namcao@linutronix.de Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-04-12ftrace: Do not have print_graph_retval() add a newlineSteven Rostedt
The retval and retaddr options for function_graph tracer will add a comment at the end of a function for both leaf and non leaf functions that looks like: __wake_up_common(); /* ret=0x1 */ } /* pick_next_task_fair ret=0x0 */ The function print_graph_retval() adds a newline after the "*/". But if that's not called, the caller function needs to make sure there's a newline added. This is confusing and when the function parameters code was added, it added a newline even when calling print_graph_retval() as the fact that the print_graph_retval() function prints a newline isn't obvious. This caused an extra newline to be printed and that made it fail the selftests when the retval option was set, as the selftests were not expecting blank lines being injected into the trace. Instead of having print_graph_retval() print a newline, just have the caller always print the newline regardless if it calls print_graph_retval() or not. This not only fixes this bug, but it also simplifies the code. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20250411133015.015ca393@gandalf.local.home Reported-by: Mark Brown <broonie@kernel.org> Tested-by: Mark Brown <broonie@kernel.org> Closes: https://lore.kernel.org/all/ccc40f2b-4b9e-4abd-8daf-d22fce2a86f0@sirena.org.uk/ Fixes: ff5c9c576e754 ("ftrace: Add support for function argument to graph tracer") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-04-12Merge tag 'pwm/for-6.15-rc2-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux Pull pwm fixes from Uwe Kleine-König: "A set of fixes for pwm core and various drivers The first three patches handle clk_get_rate() returning 0 (which might happen for example if the CCF is disabled). The first of these was found because this triggered a warning with clang, the two others by looking for similar issues in other drivers. The remaining three fixes address issues in the new waveform pwm API. Now that I worked on this a bit more, the finer details and corner cases are better understood and the code is fixed accordingly" * tag 'pwm/for-6.15-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux: pwm: axi-pwmgen: Let .round_waveform_tohw() signal when request was rounded up pwm: stm32: Search an appropriate duty_cycle if period cannot be modified pwm: Let pwm_set_waveform() succeed even if lowlevel driver rounded up pwm: fsl-ftm: Handle clk_get_rate() returning 0 pwm: rcar: Improve register calculation pwm: mediatek: Prevent divide-by-zero in pwm_mediatek_config()
2025-04-11Merge tag 'v6.15-rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds
Pull smb client fixes from Steve French: - Fix multichannel decryption UAF - Fix regression mounting to onedrive shares - Fix missing mount option check for posix vs. noposix - Fix version field in WSL symlinks - Three minor cleanup to reparse point handling - SMB1 fix for WSL special files - SMB1 Kerberos fix - Add SMB3 defines for two new FS attributes * tag 'v6.15-rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6: smb3: Add defines for two new FileSystemAttributes cifs: Fix querying of WSL CHR and BLK reparse points over SMB1 cifs: Split parse_reparse_point callback to functions: get buffer and parse buffer cifs: Improve handling of name surrogate reparse points in reparse.c cifs: Remove explicit handling of IO_REPARSE_TAG_MOUNT_POINT in inode.c cifs: Fix encoding of SMB1 Session Setup Kerberos Request in non-UNICODE mode smb: client: fix UAF in decryption with multichannel cifs: Fix support for WSL-style symlinks smb311 client: fix missing tcon check when mounting with linux/posix extensions cifs: Ensure that all non-client-specific reparse points are processed by the server
2025-04-11Merge tag 'pci-v6.15-fixes-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci Pull pci fix from Bjorn Helgaas: - Run quirk_huawei_pcie_sva() before arm_smmu_probe_device(), which depends on the quirk, to avoid IOMMU initialization failures (Zhangfei Gao) * tag 'pci-v6.15-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: PCI: Run quirk_huawei_pcie_sva() before arm_smmu_probe_device()
2025-04-11tracing/selftest: Add test to better test subops filtering of function graphSteven Rostedt
A bug was discovered that showed the accounting of the subops of the ftrace_ops filtering was incorrect. Add a new test to better test the filtering. This test creates two instances, where it will add various filters to both the set_ftrace_filter and the set_ftrace_notrace files and enable function_graph. Then it looks into the enabled_functions file to make sure that the filters are behaving correctly. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Andy Chiu <andybnac@gmail.com> Link: https://lore.kernel.org/20250409152720.380778379@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-04-11ftrace: Fix accounting of subop hashesSteven Rostedt
The function graph infrastructure uses ftrace to hook to functions. It has a single ftrace_ops to manage all the users of function graph. Each individual user (tracing, bpf, fprobes, etc) has its own ftrace_ops to track the functions it will have its callback called from. These ftrace_ops are "subops" to the main ftrace_ops of the function graph infrastructure. Each ftrace_ops has a filter_hash and a notrace_hash that is defined as: Only trace functions that are in the filter_hash but not in the notrace_hash. If the filter_hash is empty, it means to trace all functions. If the notrace_hash is empty, it means do not disable any function. The function graph main ftrace_ops needs to be a superset containing all the functions to be traced by all the subops it has. The algorithm to perform this merge was incorrect. When the first subops was added to the main ops, it simply made the main ops a copy of the subops (same filter_hash and notrace_hash). When a second ops was added, it joined the new subops filter_hash with the main ops filter_hash as a union of the two sets. The intersect between the new subops notrace_hash and the main ops notrace_hash was created as the new notrace_hash of the main ops. The issue here is that it would then start tracing functions than no subops were tracing. For example if you had two subops that had: subops 1: filter_hash = '*sched*' # trace all functions with "sched" in it notrace_hash = '*time*' # except do not trace functions with "time" subops 2: filter_hash = '*lock*' # trace all functions with "lock" in it notrace_hash = '*clock*' # except do not trace functions with "clock" The intersect of '*time*' functions with '*clock*' functions could be the empty set. That means the main ops will be tracing all functions with '*time*' and all "*clock*" in it! Instead, modify the algorithm to be a bit simpler and correct. First, when adding a new subops, even if it's the first one, do not add the notrace_hash if the filter_hash is not empty. Instead, just add the functions that are in the filter_hash of the subops but not in the notrace_hash of the subops into the main ops filter_hash. There's no reason to add anything to the main ops notrace_hash. The notrace_hash of the main ops should only be non empty iff all subops filter_hashes are empty (meaning to trace all functions) and all subops notrace_hashes include the same functions. That is, the main ops notrace_hash is empty if any subops filter_hash is non empty. The main ops notrace_hash only has content in it if all subops filter_hashes are empty, and the content are only functions that intersect all the subops notrace_hashes. If any subops notrace_hash is empty, then so is the main ops notrace_hash. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Andy Chiu <andybnac@gmail.com> Link: https://lore.kernel.org/20250409152720.216356767@goodmis.org Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>