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author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-03-04 11:24:47 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-03-04 11:24:47 -0800 |
commit | c5a58f877ca645a3303f7a57476f2de837fdb97a (patch) | |
tree | d2dccb46b1e676027ebeade1891f30313e7b2305 /arch/x86/xen | |
parent | 43df5242af4ed67e8811257ab1bfe6a07e4a5858 (diff) | |
parent | 882213990d32fd224340a4533f6318dd152be4b2 (diff) | |
download | linux-stable-c5a58f877ca645a3303f7a57476f2de837fdb97a.tar.gz linux-stable-c5a58f877ca645a3303f7a57476f2de837fdb97a.tar.bz2 linux-stable-c5a58f877ca645a3303f7a57476f2de837fdb97a.zip |
Merge tag 'for-linus-5.12b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross:
"Two security issues (XSA-367 and XSA-369)"
* tag 'for-linus-5.12b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: fix p2m size in dom0 for disabled memory hotplug case
xen-netback: respect gnttab_map_refs()'s return value
Xen/gnttab: handle p2m update errors on a per-slot basis
Diffstat (limited to 'arch/x86/xen')
-rw-r--r-- | arch/x86/xen/p2m.c | 54 | ||||
-rw-r--r-- | arch/x86/xen/setup.c | 25 |
2 files changed, 50 insertions, 29 deletions
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index b5949e5a83ec..a3cc33091f46 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -416,6 +416,9 @@ void __init xen_vmalloc_p2m_tree(void) xen_p2m_last_pfn = xen_max_p2m_pfn; p2m_limit = (phys_addr_t)P2M_LIMIT * 1024 * 1024 * 1024 / PAGE_SIZE; + if (!p2m_limit && IS_ENABLED(CONFIG_XEN_UNPOPULATED_ALLOC)) + p2m_limit = xen_start_info->nr_pages * XEN_EXTRA_MEM_RATIO; + vm.flags = VM_ALLOC; vm.size = ALIGN(sizeof(unsigned long) * max(xen_max_p2m_pfn, p2m_limit), PMD_SIZE * PMDS_PER_MID_PAGE); @@ -652,10 +655,9 @@ bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn) pte_t *ptep; unsigned int level; - if (unlikely(pfn >= xen_p2m_size)) { - BUG_ON(mfn != INVALID_P2M_ENTRY); - return true; - } + /* Only invalid entries allowed above the highest p2m covered frame. */ + if (unlikely(pfn >= xen_p2m_size)) + return mfn == INVALID_P2M_ENTRY; /* * The interface requires atomic updates on p2m elements. @@ -710,6 +712,8 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, for (i = 0; i < count; i++) { unsigned long mfn, pfn; + struct gnttab_unmap_grant_ref unmap[2]; + int rc; /* Do not add to override if the map failed. */ if (map_ops[i].status != GNTST_okay || @@ -727,10 +731,46 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, WARN(pfn_to_mfn(pfn) != INVALID_P2M_ENTRY, "page must be ballooned"); - if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) { - ret = -ENOMEM; - goto out; + if (likely(set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) + continue; + + /* + * Signal an error for this slot. This in turn requires + * immediate unmapping. + */ + map_ops[i].status = GNTST_general_error; + unmap[0].host_addr = map_ops[i].host_addr, + unmap[0].handle = map_ops[i].handle; + map_ops[i].handle = ~0; + if (map_ops[i].flags & GNTMAP_device_map) + unmap[0].dev_bus_addr = map_ops[i].dev_bus_addr; + else + unmap[0].dev_bus_addr = 0; + + if (kmap_ops) { + kmap_ops[i].status = GNTST_general_error; + unmap[1].host_addr = kmap_ops[i].host_addr, + unmap[1].handle = kmap_ops[i].handle; + kmap_ops[i].handle = ~0; + if (kmap_ops[i].flags & GNTMAP_device_map) + unmap[1].dev_bus_addr = kmap_ops[i].dev_bus_addr; + else + unmap[1].dev_bus_addr = 0; } + + /* + * Pre-populate both status fields, to be recognizable in + * the log message below. + */ + unmap[0].status = 1; + unmap[1].status = 1; + + rc = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, + unmap, 1 + !!kmap_ops); + if (rc || unmap[0].status != GNTST_okay || + unmap[1].status != GNTST_okay) + pr_err_once("gnttab unmap failed: rc=%d st0=%d st1=%d\n", + rc, unmap[0].status, unmap[1].status); } out: diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 7eab14d56369..1a3b75652fa4 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -59,18 +59,6 @@ static struct { } xen_remap_buf __initdata __aligned(PAGE_SIZE); static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY; -/* - * The maximum amount of extra memory compared to the base size. The - * main scaling factor is the size of struct page. At extreme ratios - * of base:extra, all the base memory can be filled with page - * structures for the extra memory, leaving no space for anything - * else. - * - * 10x seems like a reasonable balance between scaling flexibility and - * leaving a practically usable system. - */ -#define EXTRA_MEM_RATIO (10) - static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB); static void __init xen_parse_512gb(void) @@ -790,20 +778,13 @@ char * __init xen_memory_setup(void) extra_pages += max_pages - max_pfn; /* - * Clamp the amount of extra memory to a EXTRA_MEM_RATIO - * factor the base size. On non-highmem systems, the base - * size is the full initial memory allocation; on highmem it - * is limited to the max size of lowmem, so that it doesn't - * get completely filled. + * Clamp the amount of extra memory to a XEN_EXTRA_MEM_RATIO + * factor the base size. * * Make sure we have no memory above max_pages, as this area * isn't handled by the p2m management. - * - * In principle there could be a problem in lowmem systems if - * the initial memory is also very large with respect to - * lowmem, but we won't try to deal with that here. */ - extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)), + extra_pages = min3(XEN_EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)), extra_pages, max_pages - max_pfn); i = 0; addr = xen_e820_table.entries[0].addr; |