lwn.git/arch/x86/kernel/machine_kexec_64.c, branch docs-6.10

x86, crash: wrap crash dumping code into crash related ifdefs

2024-02-24T01:48:23+00:00

Now crash codes under kernel/ folder has been split out from kexec code, crash dumping can be separated from kexec reboot in config items on x86 with some adjustments. Here, also change some ifdefs or IS_ENABLED() check to more appropriate ones, e,g - #ifdef CONFIG_KEXEC_CORE -> #ifdef CONFIG_CRASH_DUMP - (!IS_ENABLED(CONFIG_KEXEC_CORE)) - > (!IS_ENABLED(CONFIG_CRASH_RESERVE)) [bhe@redhat.com: don't nest CONFIG_CRASH_DUMP ifdef inside CONFIG_KEXEC_CODE ifdef scope] Link: https://lore.kernel.org/all/SN6PR02MB4157931105FA68D72E3D3DB8D47B2@SN6PR02MB4157.namprd02.prod.outlook.com/T/#u Link: https://lkml.kernel.org/r/20240124051254.67105-7-bhe@redhat.com Signed-off-by: Baoquan He Cc: Al Viro Cc: Eric W. Biederman Cc: Hari Bathini Cc: Pingfan Liu Cc: Klara Modin Cc: Michael Kelley Cc: Nathan Chancellor Cc: Stephen Rothwell Cc: Yang Li Signed-off-by: Andrew Morton

x86/kexec: fix incorrect end address passed to kernel_ident_mapping_init()

2023-12-29T20:22:29+00:00

kernel_ident_mapping_init() takes an exclusive memory range [pstart, pend) where pend is not included in the range, while res represents an inclusive memory range [start, end] where end is considered part of the range. Passing [start, end] rather than [start, end+1) to kernel_ident_mapping_init() may result in the identity mapping for the end address not being set up. For example, when res->start is equal to res->end, kernel_ident_mapping_init() will not establish any identity mapping. Similarly, when the value of res->end is a multiple of 2M and the page table maps 2M pages, kernel_ident_mapping_init() will also not set up identity mapping for res->end. Therefore, passing res->end directly to kernel_ident_mapping_init() is incorrect, the correct end address should be `res->end + 1`. Link: https://lkml.kernel.org/r/20231221101702.20956-1-ytcoode@gmail.com Signed-off-by: Yuntao Wang Cc: Baoquan He Cc: Bjorn Helgaas Cc: Borislav Petkov (AMD) Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Simon Horman Cc: Thomas Gleixner Signed-off-by: Andrew Morton

x86/kexec: simplify the logic of mem_region_callback()

2023-12-20T23:02:58+00:00

The expression `mstart + resource_size(res) - 1` is actually equivalent to `res->end`, simplify the logic of this function to improve readability. Link: https://lkml.kernel.org/r/20231212150506.31711-1-ytcoode@gmail.com Signed-off-by: Yuntao Wang Acked-by: Baoquan He Cc: Bjorn Helgaas Cc: Borislav Petkov Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Simon Horman Cc: Thomas Gleixner Signed-off-by: Andrew Morton

x86/kexec: remove unnecessary arch_kexec_kernel_image_load()

2023-04-08T20:45:38+00:00

Patch series "kexec: Remove unnecessary arch hook", v2. There are no arch-specific things in arch_kexec_kernel_image_load(), so remove it and just use the generic version. This patch (of 2): The x86 implementation of arch_kexec_kernel_image_load() is functionally identical to the generic arch_kexec_kernel_image_load(): arch_kexec_kernel_image_load # x86 if (!image->fops || !image->fops->load) return ERR_PTR(-ENOEXEC); return image->fops->load(image, image->kernel_buf, ...) arch_kexec_kernel_image_load # generic kexec_image_load_default if (!image->fops || !image->fops->load) return ERR_PTR(-ENOEXEC); return image->fops->load(image, image->kernel_buf, ...) Remove the x86-specific version and use the generic arch_kexec_kernel_image_load(). No functional change intended. Link: https://lkml.kernel.org/r/20230307224416.907040-1-helgaas@kernel.org Link: https://lkml.kernel.org/r/20230307224416.907040-2-helgaas@kernel.org Signed-off-by: Bjorn Helgaas Reviewed-by: Simon Horman Acked-by: Baoquan He Cc: Borislav Petkov (AMD) Cc: Dave Hansen Cc: Eric Biederman Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: Andrew Morton

x86/kexec: fix memory leak of elf header buffer

2022-06-01T22:57:16+00:00

This is reported by kmemleak detector: unreferenced object 0xffffc900002a9000 (size 4096): comm "kexec", pid 14950, jiffies 4295110793 (age 373.951s) hex dump (first 32 bytes): 7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00 .ELF............ 04 00 3e 00 01 00 00 00 00 00 00 00 00 00 00 00 ..>............. backtrace: [<0000000016a8ef9f>] __vmalloc_node_range+0x101/0x170 [<000000002b66b6c0>] __vmalloc_node+0xb4/0x160 [<00000000ad40107d>] crash_prepare_elf64_headers+0x8e/0xcd0 [<0000000019afff23>] crash_load_segments+0x260/0x470 [<0000000019ebe95c>] bzImage64_load+0x814/0xad0 [<0000000093e16b05>] arch_kexec_kernel_image_load+0x1be/0x2a0 [<000000009ef2fc88>] kimage_file_alloc_init+0x2ec/0x5a0 [<0000000038f5a97a>] __do_sys_kexec_file_load+0x28d/0x530 [<0000000087c19992>] do_syscall_64+0x3b/0x90 [<0000000066e063a4>] entry_SYSCALL_64_after_hwframe+0x44/0xae In crash_prepare_elf64_headers(), a buffer is allocated via vmalloc() to store elf headers. While it's not freed back to system correctly when kdump kernel is reloaded or unloaded. Then memory leak is caused. Fix it by introducing x86 specific function arch_kimage_file_post_load_cleanup(), and freeing the buffer there. And also remove the incorrect elf header buffer freeing code. Before calling arch specific kexec_file loading function, the image instance has been initialized. So 'image->elf_headers' must be NULL. It doesn't make sense to free the elf header buffer in the place. Three different people have reported three bugs about the memory leak on x86_64 inside Redhat. Link: https://lkml.kernel.org/r/20220223113225.63106-2-bhe@redhat.com Signed-off-by: Baoquan He Acked-by: Dave Young Cc: Signed-off-by: Andrew Morton

x86/ibt,kexec: Disable CET on kexec

2022-03-15T09:32:39+00:00

Signed-off-by: Peter Zijlstra (Intel) Acked-by: Josh Poimboeuf Link: https://lore.kernel.org/r/20220308154318.641454603@infradead.org

x86/sev: Replace occurrences of sev_active() with cc_platform_has()

2021-10-04T09:46:58+00:00

Replace uses of sev_active() with the more generic cc_platform_has() using CC_ATTR_GUEST_MEM_ENCRYPT. If future support is added for other memory encryption technologies, the use of CC_ATTR_GUEST_MEM_ENCRYPT can be updated, as required. Signed-off-by: Tom Lendacky Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20210928191009.32551-7-bp@alien8.de

x86/sme: Replace occurrences of sme_active() with cc_platform_has()

2021-10-04T09:46:46+00:00

Replace uses of sme_active() with the more generic cc_platform_has() using CC_ATTR_HOST_MEM_ENCRYPT. If future support is added for other memory encryption technologies, the use of CC_ATTR_HOST_MEM_ENCRYPT can be updated, as required. This also replaces two usages of sev_active() that are really geared towards detecting if SME is active. Signed-off-by: Tom Lendacky Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20210928191009.32551-6-bp@alien8.de

x86/kexec: Set_[gi]dt() -> native_[gi]dt_invalidate() in machine_kexec_*.c

2021-05-21T10:36:45+00:00

These files contain private set_gdt() functions which are only used to invalid the gdt; machine_kexec_64.c also contains a set_idt() function to invalidate the idt. phys_to_virt(0) *really* doesn't make any sense for creating an invalid GDT. A NULL pointer (virtual 0) makes a lot more sense; although neither will allow any actual memory reference, a NULL pointer stands out more. Replace these calls with native_[gi]dt_invalidate(). Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20210519212154.511983-7-hpa@zytor.com

Merge tag 'devicetree-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

2021-04-28T22:50:24+00:00

Pull devicetree updates from Rob Herring: - Refactor powerpc and arm64 kexec DT handling to common code. This enables IMA on arm64. - Add kbuild support for applying DT overlays at build time. The first user are the DT unittests. - Fix kerneldoc formatting and W=1 warnings in drivers/of/ - Fix handling 64-bit flag on PCI resources - Bump dtschema version required to v2021.2.1 - Enable undocumented compatible checks for dtbs_check. This allows tracking of missing binding schemas. - DT docs improvements. Regroup the DT docs and add the example schema and DT kernel ABI docs to the doc build. - Convert Broadcom Bluetooth and video-mux bindings to schema - Add QCom sm8250 Venus video codec binding schema - Add vendor prefixes for AESOP, YIC System Co., Ltd, and Siliconfile Technologies Inc. - Cleanup of DT schema type references on common properties and standard unit properties * tag 'devicetree-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (64 commits) powerpc: If kexec_build_elf_info() fails return immediately from elf64_load() powerpc: Free fdt on error in elf64_load() of: overlay: Fix kerneldoc warning in of_overlay_remove() of: linux/of.h: fix kernel-doc warnings of/pci: Add IORESOURCE_MEM_64 to resource flags for 64-bit memory addresses dt-bindings: bcm4329-fmac: add optional brcm,ccode-map docs: dt: update writing-schema.rst references dt-bindings: media: venus: Add sm8250 dt schema of: base: Fix spelling issue with function param 'prop' docs: dt: Add DT API documentation of: Add missing 'Return' section in kerneldoc comments of: Fix kerneldoc output formatting docs: dt: Group DT docs into relevant sub-sections docs: dt: Make 'Devicetree' wording more consistent docs: dt: writing-schema: Include the example schema in the doc build docs: dt: writing-schema: Remove spurious indentation dt-bindings: Fix reference in submitting-patches.rst to the DT ABI doc dt-bindings: ddr: Add optional manufacturer and revision ID to LPDDR3 dt-bindings: media: video-interfaces: Drop the example devicetree: bindings: clock: Minor typo fix in the file armada3700-tbg-clock.txt ...