diff options
author | David Hildenbrand <david@redhat.com> | 2021-11-08 18:31:48 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-09 10:02:48 -0800 |
commit | cc5f2704c93456e6f1c671c5cf7b582a55df5484 (patch) | |
tree | f407b00013ea6cf043f9c3bfea7b2e262bb5d833 /arch | |
parent | 2c9feeaedfe1f34c4e327cb6f9b8b90052edced1 (diff) |
proc/vmcore: convert oldmem_pfn_is_ram callback to more generic vmcore callbacks
Let's support multiple registered callbacks, making sure that
registering vmcore callbacks cannot fail. Make the callback return a
bool instead of an int, handling how to deal with errors internally.
Drop unused HAVE_OLDMEM_PFN_IS_RAM.
We soon want to make use of this infrastructure from other drivers:
virtio-mem, registering one callback for each virtio-mem device, to
prevent reading unplugged virtio-mem memory.
Handle it via a generic vmcore_cb structure, prepared for future
extensions: for example, once we support virtio-mem on s390x where the
vmcore is completely constructed in the second kernel, we want to detect
and add plugged virtio-mem memory ranges to the vmcore in order for them
to get dumped properly.
Handle corner cases that are unexpected and shouldn't happen in sane
setups: registering a callback after the vmcore has already been opened
(warn only) and unregistering a callback after the vmcore has already been
opened (warn and essentially read only zeroes from that point on).
Link: https://lkml.kernel.org/r/20211005121430.30136-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/kernel/aperture_64.c | 13 | ||||
-rw-r--r-- | arch/x86/xen/mmu_hvm.c | 11 |
2 files changed, 19 insertions, 5 deletions
diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c index 10562885f5fc..af3ba08b684b 100644 --- a/arch/x86/kernel/aperture_64.c +++ b/arch/x86/kernel/aperture_64.c @@ -73,12 +73,23 @@ static int gart_mem_pfn_is_ram(unsigned long pfn) (pfn >= aperture_pfn_start + aperture_page_count)); } +#ifdef CONFIG_PROC_VMCORE +static bool gart_oldmem_pfn_is_ram(struct vmcore_cb *cb, unsigned long pfn) +{ + return !!gart_mem_pfn_is_ram(pfn); +} + +static struct vmcore_cb gart_vmcore_cb = { + .pfn_is_ram = gart_oldmem_pfn_is_ram, +}; +#endif + static void __init exclude_from_core(u64 aper_base, u32 aper_order) { aperture_pfn_start = aper_base >> PAGE_SHIFT; aperture_page_count = (32 * 1024 * 1024) << aper_order >> PAGE_SHIFT; #ifdef CONFIG_PROC_VMCORE - WARN_ON(register_oldmem_pfn_is_ram(&gart_mem_pfn_is_ram)); + register_vmcore_cb(&gart_vmcore_cb); #endif #ifdef CONFIG_PROC_KCORE WARN_ON(register_mem_pfn_is_ram(&gart_mem_pfn_is_ram)); diff --git a/arch/x86/xen/mmu_hvm.c b/arch/x86/xen/mmu_hvm.c index 6ba8826dcdcc..509bdee3ab90 100644 --- a/arch/x86/xen/mmu_hvm.c +++ b/arch/x86/xen/mmu_hvm.c @@ -12,10 +12,10 @@ * The kdump kernel has to check whether a pfn of the crashed kernel * was a ballooned page. vmcore is using this function to decide * whether to access a pfn of the crashed kernel. - * Returns 0 if the pfn is not backed by a RAM page, the caller may + * Returns "false" if the pfn is not backed by a RAM page, the caller may * handle the pfn special in this case. */ -static int xen_oldmem_pfn_is_ram(unsigned long pfn) +static bool xen_vmcore_pfn_is_ram(struct vmcore_cb *cb, unsigned long pfn) { struct xen_hvm_get_mem_type a = { .domid = DOMID_SELF, @@ -24,10 +24,13 @@ static int xen_oldmem_pfn_is_ram(unsigned long pfn) if (HYPERVISOR_hvm_op(HVMOP_get_mem_type, &a)) { pr_warn_once("Unexpected HVMOP_get_mem_type failure\n"); - return -ENXIO; + return true; } return a.mem_type != HVMMEM_mmio_dm; } +static struct vmcore_cb xen_vmcore_cb = { + .pfn_is_ram = xen_vmcore_pfn_is_ram, +}; #endif static void xen_hvm_exit_mmap(struct mm_struct *mm) @@ -61,6 +64,6 @@ void __init xen_hvm_init_mmu_ops(void) if (is_pagetable_dying_supported()) pv_ops.mmu.exit_mmap = xen_hvm_exit_mmap; #ifdef CONFIG_PROC_VMCORE - WARN_ON(register_oldmem_pfn_is_ram(&xen_oldmem_pfn_is_ram)); + register_vmcore_cb(&xen_vmcore_cb); #endif } |