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* mm/mmap: Add shadow stack pages to memory accountingRick Edgecombe2023-07-111-2/+2
| | | | | | | | | | | | | | | | | | | | The x86 Control-flow Enforcement Technology (CET) feature includes a new type of memory called shadow stack. This shadow stack memory has some unusual properties, which requires some core mm changes to function properly. Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/20230613001108.3040476-20-rick.p.edgecombe%40intel.com
* x86/mm: Warn if create Write=0,Dirty=1 with raw protRick Edgecombe2023-07-111-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | When user shadow stack is in use, Write=0,Dirty=1 is treated by the CPU as shadow stack memory. So for shadow stack memory this bit combination is valid, but when Dirty=1,Write=1 (conventionally writable) memory is being write protected, the kernel has been taught to transition the Dirty=1 bit to SavedDirty=1, to avoid inadvertently creating shadow stack memory. It does this inside pte_wrprotect() because it knows the PTE is not intended to be a writable shadow stack entry, it is supposed to be write protected. However, when a PTE is created by a raw prot using mk_pte(), mk_pte() can't know whether to adjust Dirty=1 to SavedDirty=1. It can't distinguish between the caller intending to create a shadow stack PTE or needing the SavedDirty shift. The kernel has been updated to not do this, and so Write=0,Dirty=1 memory should only be created by the pte_mkfoo() helpers. Add a warning to make sure no new mk_pte() start doing this, like, for example, set_memory_rox() did. Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/20230613001108.3040476-19-rick.p.edgecombe%40intel.com
* mm: Warn on shadow stack memory in wrong vmaRick Edgecombe2023-07-115-0/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The x86 Control-flow Enforcement Technology (CET) feature includes a new type of memory called shadow stack. This shadow stack memory has some unusual properties, which requires some core mm changes to function properly. One sharp edge is that PTEs that are both Write=0 and Dirty=1 are treated as shadow by the CPU, but this combination used to be created by the kernel on x86. Previous patches have changed the kernel to now avoid creating these PTEs unless they are for shadow stack memory. In case any missed corners of the kernel are still creating PTEs like this for non-shadow stack memory, and to catch any re-introductions of the logic, warn if any shadow stack PTEs (Write=0, Dirty=1) are found in non-shadow stack VMAs when they are being zapped. This won't catch transient cases but should have decent coverage. In order to check if a PTE is shadow stack in core mm code, add two arch breakouts arch_check_zapped_pte/pmd(). This will allow shadow stack specific code to be kept in arch/x86. Only do the check if shadow stack is supported by the CPU and configured because in rare cases older CPUs may write Dirty=1 to a Write=0 CPU on older CPUs. This check is handled in pte_shstk()/pmd_shstk(). Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Mark Brown <broonie@kernel.org> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/20230613001108.3040476-18-rick.p.edgecombe%40intel.com
* mm: Add guard pages around a shadow stack.Rick Edgecombe2023-07-112-8/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The x86 Control-flow Enforcement Technology (CET) feature includes a new type of memory called shadow stack. This shadow stack memory has some unusual properties, which requires some core mm changes to function properly. The architecture of shadow stack constrains the ability of userspace to move the shadow stack pointer (SSP) in order to prevent corrupting or switching to other shadow stacks. The RSTORSSP instruction can move the SSP to different shadow stacks, but it requires a specially placed token in order to do this. However, the architecture does not prevent incrementing the stack pointer to wander onto an adjacent shadow stack. To prevent this in software, enforce guard pages at the beginning of shadow stack VMAs, such that there will always be a gap between adjacent shadow stacks. Make the gap big enough so that no userspace SSP changing operations (besides RSTORSSP), can move the SSP from one stack to the next. The SSP can be incremented or decremented by CALL, RET and INCSSP. CALL and RET can move the SSP by a maximum of 8 bytes, at which point the shadow stack would be accessed. The INCSSP instruction can also increment the shadow stack pointer. It is the shadow stack analog of an instruction like: addq $0x80, %rsp However, there is one important difference between an ADD on %rsp and INCSSP. In addition to modifying SSP, INCSSP also reads from the memory of the first and last elements that were "popped". It can be thought of as acting like this: READ_ONCE(ssp); // read+discard top element on stack ssp += nr_to_pop * 8; // move the shadow stack READ_ONCE(ssp-8); // read+discard last popped stack element The maximum distance INCSSP can move the SSP is 2040 bytes, before it would read the memory. Therefore, a single page gap will be enough to prevent any operation from shifting the SSP to an adjacent stack, since it would have to land in the gap at least once, causing a fault. This could be accomplished by using VM_GROWSDOWN, but this has a downside. The behavior would allow shadow stacks to grow, which is unneeded and adds a strange difference to how most regular stacks work. In the maple tree code, there is some logic for retrying the unmapped area search if a guard gap is violated. This retry should happen for shadow stack guard gap violations as well. This logic currently only checks for VM_GROWSDOWN for start gaps. Since shadow stacks also have a start gap as well, create an new define VM_STARTGAP_FLAGS to hold all the VM flag bits that have start gaps, and make mmap use it. Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mark Brown <broonie@kernel.org> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/20230613001108.3040476-17-rick.p.edgecombe%40intel.com
* x86/mm: Check shadow stack page fault errorsRick Edgecombe2023-07-112-0/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The CPU performs "shadow stack accesses" when it expects to encounter shadow stack mappings. These accesses can be implicit (via CALL/RET instructions) or explicit (instructions like WRSS). Shadow stack accesses to shadow-stack mappings can result in faults in normal, valid operation just like regular accesses to regular mappings. Shadow stacks need some of the same features like delayed allocation, swap and copy-on-write. The kernel needs to use faults to implement those features. The architecture has concepts of both shadow stack reads and shadow stack writes. Any shadow stack access to non-shadow stack memory will generate a fault with the shadow stack error code bit set. This means that, unlike normal write protection, the fault handler needs to create a type of memory that can be written to (with instructions that generate shadow stack writes), even to fulfill a read access. So in the case of COW memory, the COW needs to take place even with a shadow stack read. Otherwise the page will be left (shadow stack) writable in userspace. So to trigger the appropriate behavior, set FAULT_FLAG_WRITE for shadow stack accesses, even if the access was a shadow stack read. For the purpose of making this clearer, consider the following example. If a process has a shadow stack, and forks, the shadow stack PTEs will become read-only due to COW. If the CPU in one process performs a shadow stack read access to the shadow stack, for example executing a RET and causing the CPU to read the shadow stack copy of the return address, then in order for the fault to be resolved the PTE will need to be set with shadow stack permissions. But then the memory would be changeable from userspace (from CALL, RET, WRSS, etc). So this scenario needs to trigger COW, otherwise the shared page would be changeable from both processes. Shadow stack accesses can also result in errors, such as when a shadow stack overflows, or if a shadow stack access occurs to a non-shadow-stack mapping. Also, generate the errors for invalid shadow stack accesses. Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/20230613001108.3040476-16-rick.p.edgecombe%40intel.com
* mm: Introduce VM_SHADOW_STACK for shadow stack memoryYu-cheng Yu2023-07-113-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | New hardware extensions implement support for shadow stack memory, such as x86 Control-flow Enforcement Technology (CET). Add a new VM flag to identify these areas, for example, to be used to properly indicate shadow stack PTEs to the hardware. Shadow stack VMA creation will be tightly controlled and limited to anonymous memory to make the implementation simpler and since that is all that is required. The solution will rely on pte_mkwrite() to create the shadow stack PTEs, so it will not be required for vm_get_page_prot() to learn how to create shadow stack memory. For this reason document that VM_SHADOW_STACK should not be mixed with VM_SHARED. Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Mark Brown <broonie@kernel.org> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: Mark Brown <broonie@kernel.org> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/20230613001108.3040476-15-rick.p.edgecombe%40intel.com
* x86/mm: Remove _PAGE_DIRTY from kernel RO pagesRick Edgecombe2023-07-112-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | New processors that support Shadow Stack regard Write=0,Dirty=1 PTEs as shadow stack pages. In normal cases, it can be helpful to create Write=1 PTEs as also Dirty=1 if HW dirty tracking is not needed, because if the Dirty bit is not already set the CPU has to set Dirty=1 when the memory gets written to. This creates additional work for the CPU. So traditional wisdom was to simply set the Dirty bit whenever you didn't care about it. However, it was never really very helpful for read-only kernel memory. When CR4.CET=1 and IA32_S_CET.SH_STK_EN=1, some instructions can write to such supervisor memory. The kernel does not set IA32_S_CET.SH_STK_EN, so avoiding kernel Write=0,Dirty=1 memory is not strictly needed for any functional reason. But having Write=0,Dirty=1 kernel memory doesn't have any functional benefit either, so to reduce ambiguity between shadow stack and regular Write=0 pages, remove Dirty=1 from any kernel Write=0 PTEs. Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/20230613001108.3040476-14-rick.p.edgecombe%40intel.com
* x86/mm: Start actually marking _PAGE_SAVED_DIRTYRick Edgecombe2023-07-112-21/+144
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recently introduced _PAGE_SAVED_DIRTY should be used instead of the HW Dirty bit whenever a PTE is Write=0, in order to not inadvertently create shadow stack PTEs. Update pte_mk*() helpers to do this, and apply the same changes to pmd and pud. Since there is no x86 version of pte_mkwrite() to hold this arch specific logic, create one. Add it to x86/mm/pgtable.c instead of x86/asm/include/pgtable.h as future patches will require it to live in pgtable.c and it will make the diff easier for reviewers. Since CPUs without shadow stack support could create Write=0,Dirty=1 PTEs, only return true for pte_shstk() if the CPU also supports shadow stack. This will prevent these HW creates PTEs as showing as true for pte_write(). For pte_modify() this is a bit trickier. It takes a "raw" pgprot_t which was not necessarily created with any of the existing PTE bit helpers. That means that it can return a pte_t with Write=0,Dirty=1, a shadow stack PTE, when it did not intend to create one. Modify it to also move _PAGE_DIRTY to _PAGE_SAVED_DIRTY. To avoid creating Write=0,Dirty=1 PTEs, pte_modify() needs to avoid: 1. Marking Write=0 PTEs Dirty=1 2. Marking Dirty=1 PTEs Write=0 The first case cannot happen as the existing behavior of pte_modify() is to filter out any Dirty bit passed in newprot. Handle the second case by shifting _PAGE_DIRTY=1 to _PAGE_SAVED_DIRTY=1 if the PTE was write protected by the pte_modify() call. Apply the same changes to pmd_modify(). Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/20230613001108.3040476-13-rick.p.edgecombe%40intel.com
* x86/mm: Update ptep/pmdp_set_wrprotect() for _PAGE_SAVED_DIRTYRick Edgecombe2023-07-111-2/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When shadow stack is in use, Write=0,Dirty=1 PTE are preserved for shadow stack. Copy-on-write PTEs then have Write=0,SavedDirty=1. When a PTE goes from Write=1,Dirty=1 to Write=0,SavedDirty=1, it could become a transient shadow stack PTE in two cases: 1. Some processors can start a write but end up seeing a Write=0 PTE by the time they get to the Dirty bit, creating a transient shadow stack PTE. However, this will not occur on processors supporting shadow stack, and a TLB flush is not necessary. 2. When _PAGE_DIRTY is replaced with _PAGE_SAVED_DIRTY non-atomically, a transient shadow stack PTE can be created as a result. Prevent the second case when doing a write protection and Dirty->SavedDirty shift at the same time with a CMPXCHG loop. The first case Note, in the PAE case CMPXCHG will need to operate on 8 byte, but try_cmpxchg() will not use CMPXCHG8B, so it cannot operate on a full PAE PTE. However the exiting logic is not operating on a full 8 byte region either, and relies on the fact that the Write bit is in the first 4 bytes when doing the clear_bit(). Since both the Dirty, SavedDirty and Write bits are in the first 4 bytes, casting to a long will be similar to the existing behavior which also casts to a long. Dave Hansen, Jann Horn, Andy Lutomirski, and Peter Zijlstra provided many insights to the issue. Jann Horn provided the CMPXCHG solution. Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/20230613001108.3040476-12-rick.p.edgecombe%40intel.com
* x86/mm: Introduce _PAGE_SAVED_DIRTYRick Edgecombe2023-07-113-5/+115
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some OSes have a greater dependence on software available bits in PTEs than Linux. That left the hardware architects looking for a way to represent a new memory type (shadow stack) within the existing bits. They chose to repurpose a lightly-used state: Write=0,Dirty=1. So in order to support shadow stack memory, Linux should avoid creating memory with this PTE bit combination unless it intends for it to be shadow stack. The reason it's lightly used is that Dirty=1 is normally set by HW _before_ a write. A write with a Write=0 PTE would typically only generate a fault, not set Dirty=1. Hardware can (rarely) both set Dirty=1 *and* generate the fault, resulting in a Write=0,Dirty=1 PTE. Hardware which supports shadow stacks will no longer exhibit this oddity. So that leaves Write=0,Dirty=1 PTEs created in software. To avoid inadvertently created shadow stack memory, in places where Linux normally creates Write=0,Dirty=1, it can use the software-defined _PAGE_SAVED_DIRTY in place of the hardware _PAGE_DIRTY. In other words, whenever Linux needs to create Write=0,Dirty=1, it instead creates Write=0,SavedDirty=1 except for shadow stack, which is Write=0,Dirty=1. There are six bits left available to software in the 64-bit PTE after consuming a bit for _PAGE_SAVED_DIRTY. For 32 bit, the same bit as _PAGE_BIT_UFFD_WP is used, since user fault fd is not supported on 32 bit. This leaves one unused software bit on 32 bit (_PAGE_BIT_SOFT_DIRTY, as this is also not supported on 32 bit). Implement only the infrastructure for _PAGE_SAVED_DIRTY. Changes to actually begin creating _PAGE_SAVED_DIRTY PTEs will follow once other pieces are in place. Since this SavedDirty shifting is done for all x86 CPUs, this leaves the possibility for the hardware oddity to still create Write=0,Dirty=1 PTEs in rare cases. Since these CPUs also don't support shadow stack, this will be harmless as it was before the introduction of SavedDirty. Implement the shifting logic to be branchless. Embed the logic of whether to do the shifting (including checking the Write bits) so that it can be called by future callers that would otherwise need additional branching logic. This efficiency allows the logic of when to do the shifting to be centralized, making the code easier to reason about. Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/20230613001108.3040476-11-rick.p.edgecombe%40intel.com
* x86/mm: Move pmd_write(), pud_write() up in the fileRick Edgecombe2023-07-111-12/+12
| | | | | | | | | | | | | | | | | | | To prepare the introduction of _PAGE_SAVED_DIRTY, move pmd_write() and pud_write() up in the file, so that they can be used by other helpers below. No functional changes. Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/20230613001108.3040476-10-rick.p.edgecombe%40intel.com
* x86/cpufeatures: Add CPU feature flags for shadow stacksRick Edgecombe2023-07-113-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Control-Flow Enforcement Technology contains two related features, one of which is Shadow Stacks. Future patches will utilize this feature for shadow stack support in KVM, so add a CPU feature flags for Shadow Stacks (CPUID.(EAX=7,ECX=0):ECX[bit 7]). To protect shadow stack state from malicious modification, the registers are only accessible in supervisor mode. This implementation context-switches the registers with XSAVES. Make X86_FEATURE_SHSTK depend on XSAVES. The shadow stack feature, enumerated by the CPUID bit described above, encompasses both supervisor and userspace support for shadow stack. In near future patches, only userspace shadow stack will be enabled. In expectation of future supervisor shadow stack support, create a software CPU capability to enumerate kernel utilization of userspace shadow stack support. This user shadow stack bit should depend on the HW "shstk" capability and that logic will be implemented in future patches. Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/20230613001108.3040476-9-rick.p.edgecombe%40intel.com
* x86/traps: Move control protection handler to separate fileRick Edgecombe2023-07-113-75/+78
| | | | | | | | | | | | | | | | | | | Today the control protection handler is defined in traps.c and used only for the kernel IBT feature. To reduce ifdeffery, move it to it's own file. In future patches, functionality will be added to make this handler also handle user shadow stack faults. So name the file cet.c. No functional change. Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/20230613001108.3040476-8-rick.p.edgecombe%40intel.com
* x86/shstk: Add Kconfig option for shadow stackRick Edgecombe2023-07-112-0/+29
| | | | | | | | | | | | | | | | | | | | | | | | | Shadow stack provides protection for applications against function return address corruption. It is active when the processor supports it, the kernel has CONFIG_X86_SHADOW_STACK enabled, and the application is built for the feature. This is only implemented for the 64-bit kernel. When it is enabled, legacy non-shadow stack applications continue to work, but without protection. Since there is another feature that utilizes CET (Kernel IBT) that will share implementation with shadow stacks, create CONFIG_CET to signify that at least one CET feature is configured. Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/20230613001108.3040476-7-rick.p.edgecombe%40intel.com
* mm: Move VM_UFFD_MINOR_BIT from 37 to 38Yu-cheng Yu2023-07-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The x86 Control-flow Enforcement Technology (CET) feature includes a new type of memory called shadow stack. This shadow stack memory has some unusual properties, which requires some core mm changes to function properly. Future patches will introduce a new VM flag VM_SHADOW_STACK that will be VM_HIGH_ARCH_BIT_5. VM_HIGH_ARCH_BIT_1 through VM_HIGH_ARCH_BIT_4 are bits 32-36, and bit 37 is the unrelated VM_UFFD_MINOR_BIT. For the sake of order, make all VM_HIGH_ARCH_BITs stay together by moving VM_UFFD_MINOR_BIT from 37 to 38. This will allow VM_SHADOW_STACK to be introduced as 37. Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Axel Rasmussen <axelrasmussen@google.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Peter Xu <peterx@redhat.com> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/all/20230613001108.3040476-6-rick.p.edgecombe%40intel.com
* mm: Re-introduce vm_flags to do_mmap()Yu-cheng Yu2023-07-116-11/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | There was no more caller passing vm_flags to do_mmap(), and vm_flags was removed from the function's input by: commit 45e55300f114 ("mm: remove unnecessary wrapper function do_mmap_pgoff()"). There is a new user now. Shadow stack allocation passes VM_SHADOW_STACK to do_mmap(). Thus, re-introduce vm_flags to do_mmap(). Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Peter Collingbourne <pcc@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Mark Brown <broonie@kernel.org> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: Pengfei Xu <pengfei.xu@intel.com> Tested-by: John Allen <john.allen@amd.com> Tested-by: Kees Cook <keescook@chromium.org> Tested-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/all/20230613001108.3040476-5-rick.p.edgecombe%40intel.com
* mm: Make pte_mkwrite() take a VMARick Edgecombe2023-07-1110-22/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The x86 Shadow stack feature includes a new type of memory called shadow stack. This shadow stack memory has some unusual properties, which requires some core mm changes to function properly. One of these unusual properties is that shadow stack memory is writable, but only in limited ways. These limits are applied via a specific PTE bit combination. Nevertheless, the memory is writable, and core mm code will need to apply the writable permissions in the typical paths that call pte_mkwrite(). Future patches will make pte_mkwrite() take a VMA, so that the x86 implementation of it can know whether to create regular writable or shadow stack mappings. But there are a couple of challenges to this. Modifying the signatures of each arch pte_mkwrite() implementation would be error prone because some are generated with macros and would need to be re-implemented. Also, some pte_mkwrite() callers operate on kernel memory without a VMA. So this can be done in a three step process. First pte_mkwrite() can be renamed to pte_mkwrite_novma() in each arch, with a generic pte_mkwrite() added that just calls pte_mkwrite_novma(). Next callers without a VMA can be moved to pte_mkwrite_novma(). And lastly, pte_mkwrite() and all callers can be changed to take/pass a VMA. Previous work pte_mkwrite() renamed pte_mkwrite_novma() and converted callers that don't have a VMA were to use pte_mkwrite_novma(). So now change pte_mkwrite() to take a VMA and change the remaining callers to pass a VMA. Apply the same changes for pmd_mkwrite(). No functional change. Suggested-by: David Hildenbrand <david@redhat.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/all/20230613001108.3040476-4-rick.p.edgecombe%40intel.com
* mm: Move pte/pmd_mkwrite() callers with no VMA to _novma()Rick Edgecombe2023-07-113-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The x86 Shadow stack feature includes a new type of memory called shadow stack. This shadow stack memory has some unusual properties, which requires some core mm changes to function properly. One of these unusual properties is that shadow stack memory is writable, but only in limited ways. These limits are applied via a specific PTE bit combination. Nevertheless, the memory is writable, and core mm code will need to apply the writable permissions in the typical paths that call pte_mkwrite(). Future patches will make pte_mkwrite() take a VMA, so that the x86 implementation of it can know whether to create regular writable or shadow stack mappings. But there are a couple of challenges to this. Modifying the signatures of each arch pte_mkwrite() implementation would be error prone because some are generated with macros and would need to be re-implemented. Also, some pte_mkwrite() callers operate on kernel memory without a VMA. So this can be done in a three step process. First pte_mkwrite() can be renamed to pte_mkwrite_novma() in each arch, with a generic pte_mkwrite() added that just calls pte_mkwrite_novma(). Next callers without a VMA can be moved to pte_mkwrite_novma(). And lastly, pte_mkwrite() and all callers can be changed to take/pass a VMA. Earlier work did the first step, so next move the callers that don't have a VMA to pte_mkwrite_novma(). Also do the same for pmd_mkwrite(). This will be ok for the shadow stack feature, as these callers are on kernel memory which will not need to be made shadow stack, and the other architectures only currently support one type of memory in pte_mkwrite() Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/all/20230613001108.3040476-3-rick.p.edgecombe%40intel.com
* mm: Rename arch pte_mkwrite()'s to pte_mkwrite_novma()Rick Edgecombe2023-07-1137-47/+76
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The x86 Shadow stack feature includes a new type of memory called shadow stack. This shadow stack memory has some unusual properties, which requires some core mm changes to function properly. One of these unusual properties is that shadow stack memory is writable, but only in limited ways. These limits are applied via a specific PTE bit combination. Nevertheless, the memory is writable, and core mm code will need to apply the writable permissions in the typical paths that call pte_mkwrite(). The goal is to make pte_mkwrite() take a VMA, so that the x86 implementation of it can know whether to create regular writable or shadow stack mappings. But there are a couple of challenges to this. Modifying the signatures of each arch pte_mkwrite() implementation would be error prone because some are generated with macros and would need to be re-implemented. Also, some pte_mkwrite() callers operate on kernel memory without a VMA. So this can be done in a three step process. First pte_mkwrite() can be renamed to pte_mkwrite_novma() in each arch, with a generic pte_mkwrite() added that just calls pte_mkwrite_novma(). Next callers without a VMA can be moved to pte_mkwrite_novma(). And lastly, pte_mkwrite() and all callers can be changed to take/pass a VMA. Start the process by renaming pte_mkwrite() to pte_mkwrite_novma() and adding the pte_mkwrite() wrapper in linux/pgtable.h. Apply the same pattern for pmd_mkwrite(). Since not all archs have a pmd_mkwrite_novma(), create a new arch config HAS_HUGE_PAGE that can be used to tell if pmd_mkwrite() should be defined. Otherwise in the !HAS_HUGE_PAGE cases the compiler would not be able to find pmd_mkwrite_novma(). No functional change. Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/lkml/CAHk-=wiZjSu7c9sFYZb3q04108stgHff2wfbokGCCgW7riz+8Q@mail.gmail.com/ Link: https://lore.kernel.org/all/20230613001108.3040476-2-rick.p.edgecombe%40intel.com
* Linux 6.5-rc1v6.5-rc1Linus Torvalds2023-07-091-2/+2
|
* MAINTAINERS 2: Electric BoogalooLinus Torvalds2023-07-091-46/+46
| | | | | | | | | | | | | | | | | | | We just sorted the entries and fields last release, so just out of a perverse sense of curiosity, I decided to see if we can keep things ordered for even just one release. The answer is "No. No we cannot". I suggest that all kernel developers will need weekly training sessions, involving a lot of Big Bird and Sesame Street. And at the yearly maintainer summit, we will all sing the alphabet song together. I doubt I will keep doing this. At some point "perverse sense of curiosity" turns into just a cold dark place filled with sadness and despair. Repeats: 80e62bc8487b ("MAINTAINERS: re-sort all entries and fields") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'dma-mapping-6.5-2023-07-09' of ↵Linus Torvalds2023-07-091-11/+35
|\ | | | | | | | | | | | | | | | | | | | | | | git://git.infradead.org/users/hch/dma-mapping Pull dma-mapping fixes from Christoph Hellwig: - swiotlb area sizing fixes (Petr Tesarik) * tag 'dma-mapping-6.5-2023-07-09' of git://git.infradead.org/users/hch/dma-mapping: swiotlb: reduce the number of areas to match actual memory pool size swiotlb: always set the number of areas before allocating the pool
| * swiotlb: reduce the number of areas to match actual memory pool sizePetr Tesarik2023-06-291-3/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Although the desired size of the SWIOTLB memory pool is increased in swiotlb_adjust_nareas() to match the number of areas, the actual allocation may be smaller, which may require reducing the number of areas. For example, Xen uses swiotlb_init_late(), which in turn uses the page allocator. On x86, page size is 4 KiB and MAX_ORDER is 10 (1024 pages), resulting in a maximum memory pool size of 4 MiB. This corresponds to 2048 slots of 2 KiB each. The minimum area size is 128 (IO_TLB_SEGSIZE), allowing at most 2048 / 128 = 16 areas. If num_possible_cpus() is greater than the maximum number of areas, areas are smaller than IO_TLB_SEGSIZE and contiguous groups of free slots will span multiple areas. When allocating and freeing slots, only one area will be properly locked, causing race conditions on the unlocked slots and ultimately data corruption, kernel hangs and crashes. Fixes: 20347fca71a3 ("swiotlb: split up the global swiotlb lock") Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
| * swiotlb: always set the number of areas before allocating the poolPetr Tesarik2023-06-291-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The number of areas defaults to the number of possible CPUs. However, the total number of slots may have to be increased after adjusting the number of areas. Consequently, the number of areas must be determined before allocating the memory pool. This is even explained with a comment in swiotlb_init_remap(), but swiotlb_init_late() adjusts the number of areas after slots are already allocated. The areas may end up being smaller than IO_TLB_SEGSIZE, which breaks per-area locking. While fixing swiotlb_init_late(), move all relevant comments before the definition of swiotlb_adjust_nareas() and convert them to kernel-doc. Fixes: 20347fca71a3 ("swiotlb: split up the global swiotlb lock") Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com> Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
* | Merge tag 'irq_urgent_for_v6.5_rc1' of ↵Linus Torvalds2023-07-091-3/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq update from Borislav Petkov: - Optimize IRQ domain's name assignment * tag 'irq_urgent_for_v6.5_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqdomain: Use return value of strreplace()
| * | irqdomain: Use return value of strreplace()Andy Shevchenko2023-06-301-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since strreplace() returns the pointer to the string itself, use it directly. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230628150251.17832-1-andriy.shevchenko@linux.intel.com
* | | Merge tag 'x86_urgent_for_v6.5_rc1' of ↵Linus Torvalds2023-07-091-0/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fpu fix from Borislav Petkov: - Do FPU AP initialization on Xen PV too which got missed by the recent boot reordering work * tag 'x86_urgent_for_v6.5_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/xen: Fix secondary processors' FPU initialization
| * | | x86/xen: Fix secondary processors' FPU initializationJuergen Gross2023-07-051-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Moving the call of fpu__init_cpu() from cpu_init() to start_secondary() broke Xen PV guests, as those don't call start_secondary() for APs. Call fpu__init_cpu() in Xen's cpu_bringup(), which is the Xen PV replacement of start_secondary(). Fixes: b81fac906a8f ("x86/fpu: Move FPU initialization into arch_cpu_finalize_init()") Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230703130032.22916-1-jgross@suse.com
* | | | Merge tag 'x86-core-2023-07-09' of ↵Linus Torvalds2023-07-091-0/+8
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fix from Thomas Gleixner: "A single fix for the mechanism to park CPUs with an INIT IPI. On shutdown or kexec, the kernel tries to park the non-boot CPUs with an INIT IPI. But the same code path is also used by the crash utility. If the CPU which panics is not the boot CPU then it sends an INIT IPI to the boot CPU which resets the machine. Prevent this by validating that the CPU which runs the stop mechanism is the boot CPU. If not, leave the other CPUs in HLT" * tag 'x86-core-2023-07-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/smp: Don't send INIT to boot CPU
| * | | | x86/smp: Don't send INIT to boot CPUThomas Gleixner2023-07-071-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Parking CPUs in INIT works well, except for the crash case when the CPU which invokes smp_park_other_cpus_in_init() is not the boot CPU. Sending INIT to the boot CPU resets the whole machine. Prevent this by validating that this runs on the boot CPU. If not fall back and let CPUs hang in HLT. Fixes: 45e34c8af58f ("x86/smp: Put CPUs into INIT on shutdown if possible") Reported-by: Baokun Li <libaokun1@huawei.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Baokun Li <libaokun1@huawei.com> Link: https://lore.kernel.org/r/87ttui91jo.ffs@tglx
* | | | | Merge tag 'mips_6.5_1' of ↵Linus Torvalds2023-07-0910-53/+46
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux Pull MIPS fixes from Thomas Bogendoerfer: - fixes for KVM - fix for loongson build and cpu probing - DT fixes * tag 'mips_6.5_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: MIPS: kvm: Fix build error with KVM_MIPS_DEBUG_COP0_COUNTERS enabled MIPS: dts: add missing space before { MIPS: Loongson: Fix build error when make modules_install MIPS: KVM: Fix NULL pointer dereference MIPS: Loongson: Fix cpu_probe_loongson() again
| * | | | | MIPS: kvm: Fix build error with KVM_MIPS_DEBUG_COP0_COUNTERS enabledThomas Bogendoerfer2023-07-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit e4de20576986 ("MIPS: KVM: Fix NULL pointer dereference") missed converting one place accessing cop0 registers, which results in a build error, if KVM_MIPS_DEBUG_COP0_COUNTERS is enabled. Fixes: e4de20576986 ("MIPS: KVM: Fix NULL pointer dereference") Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
| * | | | | MIPS: dts: add missing space before {Krzysztof Kozlowski2023-07-062-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add missing whitespace between node name/label and opening {. Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
| * | | | | MIPS: Loongson: Fix build error when make modules_installHuacai Chen2023-07-031-7/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After commit 0e96ea5c3eb5904e5dc2f ("MIPS: Loongson64: Clean up use of cc-ifversion") we get a build error when make modules_install: cc1: error: '-mloongson-mmi' must be used with '-mhard-float' The reason is when make modules_install, 'call cc-option' doesn't work in $(KBUILD_CFLAGS) of 'CHECKFLAGS'. Then there is no -mno-loongson-mmi applied and -march=loongson3a enable MMI instructions. To be detail, the error message comes from the CHECKFLAGS invocation of $(CC) but it has no impact on the final result of make modules_install, it is purely a cosmetic issue. The error occurs because cc-option is defined in scripts/Makefile.compiler, which is not included in Makefile when running 'make modules_install', as install targets are not supposed to require the compiler; see commit 805b2e1d427aab4b ("kbuild: include Makefile.compiler only when compiler is needed"). As a result, the call to check for '-mno-loongson-mmi' just never happens. Fix this by partially reverting to the old logic, use 'call cc-option' to conditionally apply -march=loongson3a and -march=mips64r2. By the way, Loongson-2E/2F is also broken in commit 13ceb48bc19c563e05f4 ("MIPS: Loongson2ef: Remove unnecessary {as,cc}-option calls") so fix it together. Fixes: 13ceb48bc19c563e05f4 ("MIPS: Loongson2ef: Remove unnecessary {as,cc}-option calls") Fixes: 0e96ea5c3eb5904e5dc2 ("MIPS: Loongson64: Clean up use of cc-ifversion") Cc: stable@vger.kernel.org Cc: Feiyang Chen <chenfeiyang@loongson.cn> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
| * | | | | MIPS: KVM: Fix NULL pointer dereferenceHuacai Chen2023-07-035-36/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After commit 45c7e8af4a5e3f0bea4ac209 ("MIPS: Remove KVM_TE support") we get a NULL pointer dereference when creating a KVM guest: [ 146.243409] Starting KVM with MIPS VZ extensions [ 149.849151] CPU 3 Unable to handle kernel paging request at virtual address 0000000000000300, epc == ffffffffc06356ec, ra == ffffffffc063568c [ 149.849177] Oops[#1]: [ 149.849182] CPU: 3 PID: 2265 Comm: qemu-system-mip Not tainted 6.4.0-rc3+ #1671 [ 149.849188] Hardware name: THTF CX TL630 Series/THTF-LS3A4000-7A1000-ML4A, BIOS KL4.1F.TF.D.166.201225.R 12/25/2020 [ 149.849192] $ 0 : 0000000000000000 000000007400cce0 0000000000400004 ffffffff8119c740 [ 149.849209] $ 4 : 000000007400cce1 000000007400cce1 0000000000000000 0000000000000000 [ 149.849221] $ 8 : 000000240058bb36 ffffffff81421ac0 0000000000000000 0000000000400dc0 [ 149.849233] $12 : 9800000102a07cc8 ffffffff80e40e38 0000000000000001 0000000000400dc0 [ 149.849245] $16 : 0000000000000000 9800000106cd0000 9800000106cd0000 9800000100cce000 [ 149.849257] $20 : ffffffffc0632b28 ffffffffc05b31b0 9800000100ccca00 0000000000400000 [ 149.849269] $24 : 9800000106cd09ce ffffffff802f69d0 [ 149.849281] $28 : 9800000102a04000 9800000102a07cd0 98000001106a8000 ffffffffc063568c [ 149.849293] Hi : 00000335b2111e66 [ 149.849295] Lo : 6668d90061ae0ae9 [ 149.849298] epc : ffffffffc06356ec kvm_vz_vcpu_setup+0xc4/0x328 [kvm] [ 149.849324] ra : ffffffffc063568c kvm_vz_vcpu_setup+0x64/0x328 [kvm] [ 149.849336] Status: 7400cce3 KX SX UX KERNEL EXL IE [ 149.849351] Cause : 1000000c (ExcCode 03) [ 149.849354] BadVA : 0000000000000300 [ 149.849357] PrId : 0014c004 (ICT Loongson-3) [ 149.849360] Modules linked in: kvm nfnetlink_queue nfnetlink_log nfnetlink fuse sha256_generic libsha256 cfg80211 rfkill binfmt_misc vfat fat snd_hda_codec_hdmi input_leds led_class snd_hda_intel snd_intel_dspcfg snd_hda_codec snd_hda_core snd_pcm snd_timer snd serio_raw xhci_pci radeon drm_suballoc_helper drm_display_helper xhci_hcd ip_tables x_tables [ 149.849432] Process qemu-system-mip (pid: 2265, threadinfo=00000000ae2982d2, task=0000000038e09ad4, tls=000000ffeba16030) [ 149.849439] Stack : 9800000000000003 9800000100ccca00 9800000100ccc000 ffffffffc062cef4 [ 149.849453] 9800000102a07d18 c89b63a7ab338e00 0000000000000000 ffffffff811a0000 [ 149.849465] 0000000000000000 9800000106cd0000 ffffffff80e59938 98000001106a8920 [ 149.849476] ffffffff80e57f30 ffffffffc062854c ffffffff811a0000 9800000102bf4240 [ 149.849488] ffffffffc05b0000 ffffffff80e3a798 000000ff78000000 000000ff78000010 [ 149.849500] 0000000000000255 98000001021f7de0 98000001023f0078 ffffffff81434000 [ 149.849511] 0000000000000000 0000000000000000 9800000102ae0000 980000025e92ae28 [ 149.849523] 0000000000000000 c89b63a7ab338e00 0000000000000001 ffffffff8119dce0 [ 149.849535] 000000ff78000010 ffffffff804f3d3c 9800000102a07eb0 0000000000000255 [ 149.849546] 0000000000000000 ffffffff8049460c 000000ff78000010 0000000000000255 [ 149.849558] ... [ 149.849565] Call Trace: [ 149.849567] [<ffffffffc06356ec>] kvm_vz_vcpu_setup+0xc4/0x328 [kvm] [ 149.849586] [<ffffffffc062cef4>] kvm_arch_vcpu_create+0x184/0x228 [kvm] [ 149.849605] [<ffffffffc062854c>] kvm_vm_ioctl+0x64c/0xf28 [kvm] [ 149.849623] [<ffffffff805209c0>] sys_ioctl+0xc8/0x118 [ 149.849631] [<ffffffff80219eb0>] syscall_common+0x34/0x58 The root cause is the deletion of kvm_mips_commpage_init() leaves vcpu ->arch.cop0 NULL. So fix it by making cop0 from a pointer to an embedded object. Fixes: 45c7e8af4a5e3f0bea4ac209 ("MIPS: Remove KVM_TE support") Cc: stable@vger.kernel.org Reported-by: Yu Zhao <yuzhao@google.com> Suggested-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
| * | | | | MIPS: Loongson: Fix cpu_probe_loongson() againHuacai Chen2023-07-031-6/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 7db5e9e9e5e6c10d7d ("MIPS: loongson64: fix FTLB configuration") move decode_configs() from the beginning of cpu_probe_loongson() to the end in order to fix FTLB configuration. However, it breaks the CPUCFG decoding because decode_configs() use "c->options = xxxx" rather than "c->options |= xxxx", all information get from CPUCFG by decode_cpucfg() is lost. This causes error when creating a KVM guest on Loongson-3A4000: Exception Code: 4 not handled @ PC: 0000000087ad5981, inst: 0xcb7a1898 BadVaddr: 0x0 Status: 0x0 Fix this by moving the c->cputype setting to the beginning and moving decode_configs() after that. Fixes: 7db5e9e9e5e6c10d7d ("MIPS: loongson64: fix FTLB configuration") Cc: stable@vger.kernel.org Cc: Huang Pei <huangpei@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
* | | | | | Merge tag 'xfs-6.5-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds2023-07-091-1/+1
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull xfs fix from Darrick Wong: "Nothing exciting here, just getting rid of a gcc warning that I got tired of seeing when I turn on gcov" * tag 'xfs-6.5-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: fix uninit warning in xfs_growfs_data
| * | | | | | xfs: fix uninit warning in xfs_growfs_dataDarrick J. Wong2023-07-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Quiet down this gcc warning: fs/xfs/xfs_fsops.c: In function ‘xfs_growfs_data’: fs/xfs/xfs_fsops.c:219:21: error: ‘lastag_extended’ may be used uninitialized in this function [-Werror=maybe-uninitialized] 219 | if (lastag_extended) { | ^~~~~~~~~~~~~~~ fs/xfs/xfs_fsops.c:100:33: note: ‘lastag_extended’ was declared here 100 | bool lastag_extended; | ^~~~~~~~~~~~~~~ By setting its value explicitly. From code analysis I don't think this is a real problem, but I have better things to do than analyse this closely. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com>
* | | | | | | Merge tag '6.5-rc-smb3-client-fixes-part2' of ↵Linus Torvalds2023-07-094-5/+72
|\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.samba.org/sfrench/cifs-2.6 Pull more smb client updates from Steve French: - fix potential use after free in unmount - minor cleanup - add worker to cleanup stale directory leases * tag '6.5-rc-smb3-client-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6: cifs: Add a laundromat thread for cached directories smb: client: remove redundant pointer 'server' cifs: fix session state transition to avoid use-after-free issue
| * | | | | | | cifs: Add a laundromat thread for cached directoriesRonnie Sahlberg2023-07-052-0/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | and drop cached directories after 30 seconds Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * | | | | | | smb: client: remove redundant pointer 'server'Colin Ian King2023-07-011-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The pointer 'server' is assigned but never read, the pointer is redundant and can be removed. Cleans up clang scan build warning: fs/smb/client/dfs.c:217:3: warning: Value stored to 'server' is never read [deadcode.DeadStores] Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * | | | | | | cifs: fix session state transition to avoid use-after-free issueWinston Wen2023-07-011-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We switch session state to SES_EXITING without cifs_tcp_ses_lock now, it may lead to potential use-after-free issue. Consider the following execution processes: Thread 1: __cifs_put_smb_ses() spin_lock(&cifs_tcp_ses_lock) if (--ses->ses_count > 0) spin_unlock(&cifs_tcp_ses_lock) return spin_unlock(&cifs_tcp_ses_lock) ---> **GAP** spin_lock(&ses->ses_lock) if (ses->ses_status == SES_GOOD) ses->ses_status = SES_EXITING spin_unlock(&ses->ses_lock) Thread 2: cifs_find_smb_ses() spin_lock(&cifs_tcp_ses_lock) list_for_each_entry(ses, ...) spin_lock(&ses->ses_lock) if (ses->ses_status == SES_EXITING) spin_unlock(&ses->ses_lock) continue ... spin_unlock(&ses->ses_lock) if (ret) cifs_smb_ses_inc_refcount(ret) spin_unlock(&cifs_tcp_ses_lock) If thread 1 is preempted in the gap and thread 2 start executing, thread 2 will get the session, and soon thread 1 will switch the session state to SES_EXITING and start releasing it, even though thread 1 had increased the session's refcount and still uses it. So switch session state under cifs_tcp_ses_lock to eliminate this gap. Signed-off-by: Winston Wen <wentao@uniontech.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* | | | | | | | Merge tag 'ntb-6.5' of https://github.com/jonmason/ntbLinus Torvalds2023-07-0910-33/+36
|\ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull NTB updates from Jon Mason: "Fixes for pci_clean_master, error handling in driver inits, and various other issues/bugs" * tag 'ntb-6.5' of https://github.com/jonmason/ntb: ntb: hw: amd: Fix debugfs_create_dir error checking ntb.rst: Fix copy and paste error ntb_netdev: Fix module_init problem ntb: intel: Remove redundant pci_clear_master ntb: epf: Remove redundant pci_clear_master ntb_hw_amd: Remove redundant pci_clear_master ntb: idt: drop redundant pci_enable_pcie_error_reporting() MAINTAINERS: git://github -> https://github.com for jonmason NTB: EPF: fix possible memory leak in pci_vntb_probe() NTB: ntb_tool: Add check for devm_kcalloc NTB: ntb_transport: fix possible memory leak while device_register() fails ntb: intel: Fix error handling in intel_ntb_pci_driver_init() NTB: amd: Fix error handling in amd_ntb_pci_driver_init() ntb: idt: Fix error handling in idt_pci_driver_init()
| * | | | | | | | ntb: hw: amd: Fix debugfs_create_dir error checkingAnup Sharma2023-07-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The debugfs_create_dir function returns ERR_PTR in case of error, and the only correct way to check if an error occurred is 'IS_ERR' inline function. This patch will replace the null-comparison with IS_ERR. Signed-off-by: Anup Sharma <anupnewsmail@gmail.com> Suggested-by: Ivan Orlov <ivan.orlov0322@gmail.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
| * | | | | | | | ntb.rst: Fix copy and paste errorGeoff Levand2023-07-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It seems the text for the NTB MSI Test Client section was copied from the NTB Tool Test Client, but was not updated for the new section. Corrects the NTB MSI Test Client section text. Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Geoff Levand <geoff@infradead.org> Signed-off-by: Jon Mason <jdmason@kudzu.us>
| * | | | | | | | ntb_netdev: Fix module_init problemGeoff Levand2023-07-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With both the ntb_transport_init and the ntb_netdev_init_module routines in the module_init init group, the ntb_netdev_init_module routine can be called before the ntb_transport_init routine that it depends on is called. To assure the proper initialization order put ntb_netdev_init_module in the late_initcall group. Fixes runtime errors where the ntb_netdev_init_module call fails with ENODEV. Signed-off-by: Geoff Levand <geoff@infradead.org> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
| * | | | | | | | ntb: intel: Remove redundant pci_clear_masterCai Huoqing2023-07-081-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove pci_clear_master to simplify the code, the bus-mastering is also cleared in do_pci_disable_device, like this: ./drivers/pci/pci.c:2197 static void do_pci_disable_device(struct pci_dev *dev) { u16 pci_command; pci_read_config_word(dev, PCI_COMMAND, &pci_command); if (pci_command & PCI_COMMAND_MASTER) { pci_command &= ~PCI_COMMAND_MASTER; pci_write_config_word(dev, PCI_COMMAND, pci_command); } pcibios_disable_device(dev); }. And dev->is_busmaster is set to 0 in pci_disable_device. Signed-off-by: Cai Huoqing <cai.huoqing@linux.dev> Acked-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
| * | | | | | | | ntb: epf: Remove redundant pci_clear_masterCai Huoqing2023-07-081-8/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove pci_clear_master to simplify the code, the bus-mastering is also cleared in do_pci_disable_device, like this: ./drivers/pci/pci.c:2197 static void do_pci_disable_device(struct pci_dev *dev) { u16 pci_command; pci_read_config_word(dev, PCI_COMMAND, &pci_command); if (pci_command & PCI_COMMAND_MASTER) { pci_command &= ~PCI_COMMAND_MASTER; pci_write_config_word(dev, PCI_COMMAND, pci_command); } pcibios_disable_device(dev); }. And dev->is_busmaster is set to 0 in pci_disable_device. Signed-off-by: Cai Huoqing <cai.huoqing@linux.dev> Signed-off-by: Jon Mason <jdmason@kudzu.us>
| * | | | | | | | ntb_hw_amd: Remove redundant pci_clear_masterCai Huoqing2023-07-081-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove pci_clear_master to simplify the code, the bus-mastering is also cleared in do_pci_disable_device, like this: ./drivers/pci/pci.c:2197 static void do_pci_disable_device(struct pci_dev *dev) { u16 pci_command; pci_read_config_word(dev, PCI_COMMAND, &pci_command); if (pci_command & PCI_COMMAND_MASTER) { pci_command &= ~PCI_COMMAND_MASTER; pci_write_config_word(dev, PCI_COMMAND, pci_command); } pcibios_disable_device(dev); }. And dev->is_busmaster is set to 0 in pci_disable_device. Signed-off-by: Cai Huoqing <cai.huoqing@linux.dev> Signed-off-by: Jon Mason <jdmason@kudzu.us>
| * | | | | | | | ntb: idt: drop redundant pci_enable_pcie_error_reporting()Bjorn Helgaas2023-07-081-12/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pci_enable_pcie_error_reporting() enables the device to send ERR_* Messages. Since f26e58bf6f54 ("PCI/AER: Enable error reporting when AER is native"), the PCI core does this for all devices during enumeration, so the driver doesn't need to do it itself. Remove the redundant pci_enable_pcie_error_reporting() call from the driver. Also remove the corresponding pci_disable_pcie_error_reporting() from the driver .remove() path. Note that this only controls ERR_* Messages from the device. An ERR_* Message may cause the Root Port to generate an interrupt, depending on the AER Root Error Command register managed by the AER service driver. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
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