kernel.git/arch/x86/kernel/setup_percpu.c, branch linux-5.8.y

x86/mm/32: Bring back vmalloc faulting on x86_32

2020-09-09T17:14:26Z

[ Upstream commit 4819e15f740ec884a50bdc431d7f1e7638b6f7d9 ] One can not simply remove vmalloc faulting on x86-32. Upstream commit: 7f0a002b5a21 ("x86/mm: remove vmalloc faulting") removed it on x86 alltogether because previously the arch_sync_kernel_mappings() interface was introduced. This interface added synchronization of vmalloc/ioremap page-table updates to all page-tables in the system at creation time and was thought to make vmalloc faulting obsolete. But that assumption was incredibly naive. It turned out that there is a race window between the time the vmalloc or ioremap code establishes a mapping and the time it synchronizes this change to other page-tables in the system. During this race window another CPU or thread can establish a vmalloc mapping which uses the same intermediate page-table entries (e.g. PMD or PUD) and does no synchronization in the end, because it found all necessary mappings already present in the kernel reference page-table. But when these intermediate page-table entries are not yet synchronized, the other CPU or thread will continue with a vmalloc address that is not yet mapped in the page-table it currently uses, causing an unhandled page fault and oops like below: BUG: unable to handle page fault for address: fe80c000 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page *pde = 33183067 *pte = a8648163 Oops: 0002 [#1] SMP CPU: 1 PID: 13514 Comm: cve-2017-17053 Tainted: G ... Call Trace: ldt_dup_context+0x66/0x80 dup_mm+0x2b3/0x480 copy_process+0x133b/0x15c0 _do_fork+0x94/0x3e0 __ia32_sys_clone+0x67/0x80 __do_fast_syscall_32+0x3f/0x70 do_fast_syscall_32+0x29/0x60 do_SYSENTER_32+0x15/0x20 entry_SYSENTER_32+0x9f/0xf2 EIP: 0xb7eef549 So the arch_sync_kernel_mappings() interface is racy, but removing it would mean to re-introduce the vmalloc_sync_all() interface, which is even more awful. Keep arch_sync_kernel_mappings() in place and catch the race condition in the page-fault handler instead. Do a partial revert of above commit to get vmalloc faulting on x86-32 back in place. Fixes: 7f0a002b5a21 ("x86/mm: remove vmalloc faulting") Reported-by: Naresh Kamboju Signed-off-by: Joerg Roedel Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20200902155904.17544-1-joro@8bytes.org [sl: revert 7f0a002b5a21 instead to restore vmalloc faulting for x86-64] Signed-off-by: Sasha Levin

x86/mm: remove vmalloc faulting

2020-06-02T17:59:12Z

Remove fault handling on vmalloc areas, as the vmalloc code now takes care of synchronizing changes to all page-tables in the system. Signed-off-by: Joerg Roedel Signed-off-by: Andrew Morton Acked-by: Andy Lutomirski Acked-by: Peter Zijlstra (Intel) Cc: Arnd Bergmann Cc: Christoph Hellwig Cc: Dave Hansen Cc: "H . Peter Anvin" Cc: Ingo Molnar Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: "Rafael J. Wysocki" Cc: Steven Rostedt (VMware) Cc: Thomas Gleixner Cc: Vlastimil Babka Link: http://lkml.kernel.org/r/20200515140023.25469-8-joro@8bytes.org Signed-off-by: Linus Torvalds

x86: Use pr_warn instead of pr_warning

2019-10-18T13:00:18Z

As said in commit f2c2cbcc35d4 ("powerpc: Use pr_warn instead of pr_warning"), removing pr_warning so all logging messages use a consistent _warn style. Let's do it. Link: http://lkml.kernel.org/r/20191018031850.48498-7-wangkefeng.wang@huawei.com To: linux-kernel@vger.kernel.org Cc: Ingo Molnar Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Robert Richter Cc: Darren Hart Cc: Andy Shevchenko Signed-off-by: Kefeng Wang Reviewed-by: Sergey Senozhatsky Signed-off-by: Petr Mladek

x86/irq/64: Split the IRQ stack into its own pages

2019-04-17T13:37:02Z

Currently, the IRQ stack is hardcoded as the first page of the percpu area, and the stack canary lives on the IRQ stack. The former gets in the way of adding an IRQ stack guard page, and the latter is a potential weakness in the stack canary mechanism. Split the IRQ stack into its own private percpu pages. [ tglx: Make 64 and 32 bit share struct irq_stack ] Signed-off-by: Andy Lutomirski Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Ard Biesheuvel Cc: Boris Ostrovsky Cc: Brijesh Singh Cc: "Chang S. Bae" Cc: Dominik Brodowski Cc: Feng Tang Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jan Beulich Cc: Jiri Kosina Cc: Joerg Roedel Cc: Jordan Borgner Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Konrad Rzeszutek Wilk Cc: Maran Wilson Cc: Masahiro Yamada Cc: Michal Hocko Cc: Mike Rapoport Cc: Nick Desaulniers Cc: Nicolai Stange Cc: Peter Zijlstra Cc: Pu Wen Cc: "Rafael Ávila de Espíndola" Cc: Sean Christopherson Cc: Stefano Stabellini Cc: Vlastimil Babka Cc: x86-ml Cc: xen-devel@lists.xenproject.org Link: https://lkml.kernel.org/r/20190414160146.267376656@linutronix.de

x86/irq/64: Rename irq_stack_ptr to hardirq_stack_ptr

2019-04-17T13:27:10Z

Preparatory patch to share code with 32bit. No functional changes. Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Cc: Alexey Dobriyan Cc: Andrew Morton Cc: Andy Lutomirski Cc: "Chang S. Bae" Cc: Dominik Brodowski Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jiri Kosina Cc: Josh Poimboeuf Cc: Konrad Rzeszutek Wilk Cc: Michal Hocko Cc: Mike Rapoport Cc: Nick Desaulniers Cc: Nicolai Stange Cc: Peter Zijlstra Cc: Pingfan Liu Cc: Sean Christopherson Cc: Stephen Rothwell Cc: Vlastimil Babka Cc: x86-ml Link: https://lkml.kernel.org/r/20190414160145.912584074@linutronix.de

memblock: drop memblock_alloc_*_nopanic() variants

2019-03-12T17:04:02Z

As all the memblock allocation functions return NULL in case of error rather than panic(), the duplicates with _nopanic suffix can be removed. Link: http://lkml.kernel.org/r/1548057848-15136-22-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport Acked-by: Greg Kroah-Hartman Reviewed-by: Petr Mladek [printk] Cc: Catalin Marinas Cc: Christophe Leroy Cc: Christoph Hellwig Cc: "David S. Miller" Cc: Dennis Zhou Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Guan Xuetao Cc: Guo Ren Cc: Guo Ren [c-sky] Cc: Heiko Carstens Cc: Juergen Gross [Xen] Cc: Mark Salter Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Paul Burton Cc: Richard Weinberger Cc: Rich Felker Cc: Rob Herring Cc: Rob Herring Cc: Russell King Cc: Stafford Horne Cc: Tony Luck Cc: Vineet Gupta Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

numa: make "nr_node_ids" unsigned int

2019-03-06T05:07:19Z

Number of NUMA nodes can't be negative. This saves a few bytes on x86_64: add/remove: 0/0 grow/shrink: 4/21 up/down: 27/-265 (-238) Function old new delta hv_synic_alloc.cold 88 110 +22 prealloc_shrinker 260 262 +2 bootstrap 249 251 +2 sched_init_numa 1566 1567 +1 show_slab_objects 778 777 -1 s_show 1201 1200 -1 kmem_cache_init 346 345 -1 __alloc_workqueue_key 1146 1145 -1 mem_cgroup_css_alloc 1614 1612 -2 __do_sys_swapon 4702 4699 -3 __list_lru_init 655 651 -4 nic_probe 2379 2374 -5 store_user_store 118 111 -7 red_zone_store 106 99 -7 poison_store 106 99 -7 wq_numa_init 348 338 -10 __kmem_cache_empty 75 65 -10 task_numa_free 186 173 -13 merge_across_nodes_store 351 336 -15 irq_create_affinity_masks 1261 1246 -15 do_numa_crng_init 343 321 -22 task_numa_fault 4760 4737 -23 swapfile_init 179 156 -23 hv_synic_alloc 536 492 -44 apply_wqattrs_prepare 746 695 -51 Link: http://lkml.kernel.org/r/20190201223029.GA15820@avx2 Signed-off-by: Alexey Dobriyan Reviewed-by: Andrew Morton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: remove include/linux/bootmem.h

2018-10-31T15:54:16Z

Move remaining definitions and declarations from include/linux/bootmem.h into include/linux/memblock.h and remove the redundant header. The includes were replaced with the semantic patch below and then semi-automated removal of duplicated '#include @@ @@ - #include + #include [sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au [sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au [sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal] Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport Signed-off-by: Stephen Rothwell Acked-by: Michal Hocko Cc: Catalin Marinas Cc: Chris Zankel Cc: "David S. Miller" Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Greg Kroah-Hartman Cc: Guan Xuetao Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Jonas Bonn Cc: Jonathan Corbet Cc: Ley Foon Tan Cc: Mark Salter Cc: Martin Schwidefsky Cc: Matt Turner Cc: Michael Ellerman Cc: Michal Simek Cc: Palmer Dabbelt Cc: Paul Burton Cc: Richard Kuo Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Serge Semin Cc: Thomas Gleixner Cc: Tony Luck Cc: Vineet Gupta Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memblock: replace BOOTMEM_ALLOC_* with MEMBLOCK variants

2018-10-31T15:54:16Z

Drop BOOTMEM_ALLOC_ACCESSIBLE and BOOTMEM_ALLOC_ANYWHERE in favor of identical MEMBLOCK definitions. Link: http://lkml.kernel.org/r/1536927045-23536-29-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport Acked-by: Michal Hocko Cc: Catalin Marinas Cc: Chris Zankel Cc: "David S. Miller" Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Greg Kroah-Hartman Cc: Guan Xuetao Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Jonas Bonn Cc: Jonathan Corbet Cc: Ley Foon Tan Cc: Mark Salter Cc: Martin Schwidefsky Cc: Matt Turner Cc: Michael Ellerman Cc: Michal Simek Cc: Palmer Dabbelt Cc: Paul Burton Cc: Richard Kuo Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Serge Semin Cc: Thomas Gleixner Cc: Tony Luck Cc: Vineet Gupta Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memblock: replace free_bootmem{_node} with memblock_free

2018-10-31T15:54:16Z

The free_bootmem and free_bootmem_node are merely wrappers for memblock_free. Replace their usage with a call to memblock_free using the following semantic patch: @@ expression e1, e2, e3; @@ ( - free_bootmem(e1, e2) + memblock_free(e1, e2) | - free_bootmem_node(e1, e2, e3) + memblock_free(e2, e3) ) Link: http://lkml.kernel.org/r/1536927045-23536-24-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport Acked-by: Michal Hocko Cc: Catalin Marinas Cc: Chris Zankel Cc: "David S. Miller" Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Greg Kroah-Hartman Cc: Guan Xuetao Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Jonas Bonn Cc: Jonathan Corbet Cc: Ley Foon Tan Cc: Mark Salter Cc: Martin Schwidefsky Cc: Matt Turner Cc: Michael Ellerman Cc: Michal Simek Cc: Palmer Dabbelt Cc: Paul Burton Cc: Richard Kuo Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Serge Semin Cc: Thomas Gleixner Cc: Tony Luck Cc: Vineet Gupta Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds