From e86436ad0ad2a9aaf88802d69b68f02cbd1f04a9 Mon Sep 17 00:00:00 2001 From: Ran Xiaokai Date: Thu, 22 Jan 2026 13:27:40 +0000 Subject: kho: init alloc tags when restoring pages from reserved memory Memblock pages (including reserved memory) should have their allocation tags initialized to CODETAG_EMPTY via clear_page_tag_ref() before being released to the page allocator. When kho restores pages through kho_restore_page(), missing this call causes mismatched allocation/deallocation tracking and below warning message: alloc_tag was not set WARNING: include/linux/alloc_tag.h:164 at ___free_pages+0xb8/0x260, CPU#1: swapper/0/1 RIP: 0010:___free_pages+0xb8/0x260 kho_restore_vmalloc+0x187/0x2e0 kho_test_init+0x3c4/0xa30 do_one_initcall+0x62/0x2b0 kernel_init_freeable+0x25b/0x480 kernel_init+0x1a/0x1c0 ret_from_fork+0x2d1/0x360 Add missing clear_page_tag_ref() annotation in kho_restore_page() to fix this. Link: https://lkml.kernel.org/r/20260122132740.176468-1-ranxiaokai627@163.com Fixes: fc33e4b44b27 ("kexec: enable KHO support for memory preservation") Signed-off-by: Ran Xiaokai Reviewed-by: Pratyush Yadav Reviewed-by: Pasha Tatashin Reviewed-by: Mike Rapoport (Microsoft) Cc: Alexander Graf Cc: Kent Overstreet Cc: Suren Baghdasaryan Cc: Signed-off-by: Andrew Morton --- kernel/liveupdate/kexec_handover.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'kernel') diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c index d4482b6e3cae..96767b106cac 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -255,6 +255,14 @@ static struct page *kho_restore_page(phys_addr_t phys, bool is_folio) if (is_folio && info.order) prep_compound_page(page, info.order); + /* Always mark headpage's codetag as empty to avoid accounting mismatch */ + clear_page_tag_ref(page); + if (!is_folio) { + /* Also do that for the non-compound tail pages */ + for (unsigned int i = 1; i < nr_pages; i++) + clear_page_tag_ref(page + i); + } + adjust_managed_page_count(page, nr_pages); return page; } -- cgit v1.2.3 From 412a32f0e53f4a50062f6f4bc18f8910aa551734 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Wed, 21 Jan 2026 12:36:17 -0800 Subject: kho: kho_preserve_vmalloc(): don't return 0 when ENOMEM kho_preserve_vmalloc() should return -ENOMEM when new_vmalloc_chunk() fails. Reported-by: kernel test robot Reported-by: Dan Carpenter Closes: https://lore.kernel.org/r/202601211636.IRaejjdw-lkp@intel.com/ Reviewed-by: Pasha Tatashin Reviewed-by: Pratyush Yadav Reviewed-by: Mike Rapoport (Microsoft) Cc: Alexander Graf Cc: Jason Gunthorpe Cc: Pasha Tatashin Signed-off-by: Andrew Morton --- kernel/liveupdate/kexec_handover.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c index 96767b106cac..90d411a59f76 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -1014,8 +1014,10 @@ int kho_preserve_vmalloc(void *ptr, struct kho_vmalloc *preservation) chunk->phys[idx++] = phys; if (idx == ARRAY_SIZE(chunk->phys)) { chunk = new_vmalloc_chunk(chunk); - if (!chunk) + if (!chunk) { + err = -ENOMEM; goto err_free; + } idx = 0; } } -- cgit v1.2.3 From bd58782995a2e6a07fd07255f3cc319f40b131c9 Mon Sep 17 00:00:00 2001 From: Breno Leitao Date: Thu, 22 Jan 2026 02:39:36 -0800 Subject: vmcoreinfo: make hwerr_data visible for debugging If the kernel is compiled with LTO, hwerr_data symbol might be lost, and vmcoreinfo doesn't have it dumped. This is currently seen in some production kernels with LTO enabled. Remove the static qualifier from hwerr_data so that the information is still preserved when the kernel is built with LTO. Making hwerr_data a global symbol ensures its debug info survives the LTO link process and appears in kallsyms. Also document it, so it doesn't get removed in the future as suggested by akpm. Link: https://lkml.kernel.org/r/20260122-fix_vmcoreinfo-v2-1-2d6311f9e36c@debian.org Fixes: 3fa805c37dd4 ("vmcoreinfo: track and log recoverable hardware errors") Signed-off-by: Breno Leitao Acked-by: Baoquan He Cc: Dave Young Cc: "Luck, Tony" Cc: Omar Sandoval Cc: Shuai Xue Cc: Vivek Goyal Cc: Zhiquan Li Signed-off-by: Andrew Morton --- kernel/vmcore_info.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/vmcore_info.c b/kernel/vmcore_info.c index fe9bf8db1922..e2784038bbed 100644 --- a/kernel/vmcore_info.c +++ b/kernel/vmcore_info.c @@ -36,7 +36,11 @@ struct hwerr_info { time64_t timestamp; }; -static struct hwerr_info hwerr_data[HWERR_RECOV_MAX]; +/* + * The hwerr_data[] array is declared with global scope so that it remains + * accessible to vmcoreinfo even when Link Time Optimization (LTO) is enabled. + */ +struct hwerr_info hwerr_data[HWERR_RECOV_MAX]; Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type, void *data, size_t data_len) -- cgit v1.2.3