Linus Torvalds c9f016e72b A set of X86 fixes: ... - x2apic_disable() clears x2apic_state and x2apic_mode unconditionally, even when the state is X2APIC_ON_LOCKED, which prevents the kernel to disable it thereby creating inconsistent state. Reorder the logic so it actually works correctly - The XSTATE logic for handling LBR is incorrect as it assumes that XSAVES supports LBR when the CPU supports LBR. In fact both conditions need to be true. Otherwise the enablement of LBR in the IA32_XSS MSR fails and subsequently the machine crashes on the next XRSTORS operation because IA32_XSS is not initialized. Cache the XSTATE support bit during init and make the related functions use this cached information and the LBR CPU feature bit to cure this. - Cure a long standing bug in KASLR KASLR uses the full address space between PAGE_OFFSET and vaddr_end to randomize the starting points of the direct map, vmalloc and vmemmap regions. It thereby limits the size of the direct map by using the installed memory size plus an extra configurable margin for hot-plug memory. This limitation is done to gain more randomization space because otherwise only the holes between the direct map, vmalloc, vmemmap and vaddr_end would be usable for randomizing. The limited direct map size is not exposed to the rest of the kernel, so the memory hot-plug and resource management related code paths still operate under the assumption that the available address space can be determined with MAX_PHYSMEM_BITS. request_free_mem_region() allocates from (1 << MAX_PHYSMEM_BITS) - 1 downwards. That means the first allocation happens past the end of the direct map and if unlucky this address is in the vmalloc space, which causes high_memory to become greater than VMALLOC_START and consequently causes iounmap() to fail for valid ioremap addresses. Cure this by exposing the end of the direct map via PHYSMEM_END and use that for the memory hot-plug and resource management related places instead of relying on MAX_PHYSMEM_BITS. In the KASLR case PHYSMEM_END maps to a variable which is initialized by the KASLR initialization and otherwise it is based on MAX_PHYSMEM_BITS as before. - Prevent a data leak in mmio_read(). The TDVMCALL exposes the value of an initialized variabled on the stack to the VMM. The variable is only required as output value, so it does not have to exposed to the VMM in the first place. - Prevent an array overrun in the resource control code on systems with Sub-NUMA Clustering enabled because the code failed to adjust the index by the number of SNC nodes per L3 cache. -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmbUUu0THHRnbHhAbGlu dXRyb25peC5kZQAKCRCmGPVMDXSYodFsEADFgxq2wjnH+VpuaIhLiQIfUa7iVeUl bwHAakZRMJ+Cb8BsvaRCMdAWWF+cRdLabAHuh7MRJFFzzdwrVTswnxT9baUBBjEe Kd3ZeQOS4AvWxpJNQEDg9r7tYtavmml9ix+Jh0OF+YmXLIweQk5RhDN+ncha07cJ 0DuPt4ngI24iyAyUX+7gZsRZiwoOm0HqImaRiisaspTbGpNwnrwFQCEioCdwnAv0 H5S7WTAlsZURCINLBNT+fV5oPjk2E3Ckj/CCJGoG1LYedGUD/44M1Hj0Xsqm4pHF Zd0+CuFyYpGqkAuBY6moWOheYP8V2U+yhf9Rtvh8/+h3qxZ/yon5i0ycO/2wMjiF 0NBomMeKh4PNyefYq8lHWK3kcXphrXH3yv09wVBDdLMXDy98beuS5NScGgza8148 /nqq0l1uLUyM9TkWg9H+4wW73EzQW1DYIliDU3tC98u+E77kQbyCx+2f0WI2k+ar 3wy7nYzyEJXl38NUTB+La4xXbhsELcaYQ/Q6scIsWAL+6+KlRb3FNBn+HT+KmOmF y702km/28C0uxrLk2OQCjX/zXQtXe2/4aoUzGqFf9atsifa0IBrc8YBzdIDB49Jt zz/MOAZTcz4jfyD3sRfYuG2QhBbdTz3f/kd3OryquitdAGozpoeztMIGs1PU2Y6s zInlLtUwaosadg== =T4i1 -----END PGP SIGNATURE----- Merge tag 'x86-urgent-2024-09-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: - x2apic_disable() clears x2apic_state and x2apic_mode unconditionally, even when the state is X2APIC_ON_LOCKED, which prevents the kernel to disable it thereby creating inconsistent state. Reorder the logic so it actually works correctly - The XSTATE logic for handling LBR is incorrect as it assumes that XSAVES supports LBR when the CPU supports LBR. In fact both conditions need to be true. Otherwise the enablement of LBR in the IA32_XSS MSR fails and subsequently the machine crashes on the next XRSTORS operation because IA32_XSS is not initialized. Cache the XSTATE support bit during init and make the related functions use this cached information and the LBR CPU feature bit to cure this. - Cure a long standing bug in KASLR KASLR uses the full address space between PAGE_OFFSET and vaddr_end to randomize the starting points of the direct map, vmalloc and vmemmap regions. It thereby limits the size of the direct map by using the installed memory size plus an extra configurable margin for hot-plug memory. This limitation is done to gain more randomization space because otherwise only the holes between the direct map, vmalloc, vmemmap and vaddr_end would be usable for randomizing. The limited direct map size is not exposed to the rest of the kernel, so the memory hot-plug and resource management related code paths still operate under the assumption that the available address space can be determined with MAX_PHYSMEM_BITS. request_free_mem_region() allocates from (1 << MAX_PHYSMEM_BITS) - 1 downwards. That means the first allocation happens past the end of the direct map and if unlucky this address is in the vmalloc space, which causes high_memory to become greater than VMALLOC_START and consequently causes iounmap() to fail for valid ioremap addresses. Cure this by exposing the end of the direct map via PHYSMEM_END and use that for the memory hot-plug and resource management related places instead of relying on MAX_PHYSMEM_BITS. In the KASLR case PHYSMEM_END maps to a variable which is initialized by the KASLR initialization and otherwise it is based on MAX_PHYSMEM_BITS as before. - Prevent a data leak in mmio_read(). The TDVMCALL exposes the value of an initialized variabled on the stack to the VMM. The variable is only required as output value, so it does not have to exposed to the VMM in the first place. - Prevent an array overrun in the resource control code on systems with Sub-NUMA Clustering enabled because the code failed to adjust the index by the number of SNC nodes per L3 cache. * tag 'x86-urgent-2024-09-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/resctrl: Fix arch_mbm_* array overrun on SNC x86/tdx: Fix data leak in mmio_read() x86/kaslr: Expose and use the end of the physical memory address space x86/fpu: Avoid writing LBR bit to IA32_XSS unless supported x86/apic: Make x2apic_disable() work correctly		2024-09-01 14:43:08 -07:00
..
asm	A set of X86 fixes:	2024-09-01 14:43:08 -07:00
uapi/asm	ARM:	2024-07-20 12:41:03 -07:00