From: Anthony Yznaga <anthony.yznaga@oracle.com>
To: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Cc: willy@infradead.org, corbet@lwn.net, tglx@linutronix.de,
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kexec@lists.infradead.org
Subject: [RFC v2 21/43] x86/KASLR: PKRAM: support physical kaslr
Date: Tue, 30 Mar 2021 14:35:56 -0700 [thread overview]
Message-ID: <1617140178-8773-22-git-send-email-anthony.yznaga@oracle.com> (raw)
In-Reply-To: <1617140178-8773-1-git-send-email-anthony.yznaga@oracle.com>
Avoid regions of memory that contain preserved pages when computing
slots used to select where to put the decompressed kernel.
Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com>
---
arch/x86/boot/compressed/Makefile | 3 ++
arch/x86/boot/compressed/kaslr.c | 10 +++-
arch/x86/boot/compressed/misc.h | 10 ++++
arch/x86/boot/compressed/pkram.c | 109 ++++++++++++++++++++++++++++++++++++++
4 files changed, 130 insertions(+), 2 deletions(-)
create mode 100644 arch/x86/boot/compressed/pkram.c
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index e0bc3988c3fa..ef27d411b641 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -93,6 +93,9 @@ ifdef CONFIG_X86_64
vmlinux-objs-y += $(obj)/mem_encrypt.o
vmlinux-objs-y += $(obj)/pgtable_64.o
vmlinux-objs-$(CONFIG_AMD_MEM_ENCRYPT) += $(obj)/sev-es.o
+ifdef CONFIG_RANDOMIZE_BASE
+ vmlinux-objs-$(CONFIG_PKRAM) += $(obj)/pkram.o
+endif
endif
vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index b92fffbe761f..a007363a7698 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -440,6 +440,7 @@ static bool mem_avoid_overlap(struct mem_vector *img,
struct setup_data *ptr;
u64 earliest = img->start + img->size;
bool is_overlapping = false;
+ struct mem_vector avoid;
for (i = 0; i < MEM_AVOID_MAX; i++) {
if (mem_overlaps(img, &mem_avoid[i]) &&
@@ -453,8 +454,6 @@ static bool mem_avoid_overlap(struct mem_vector *img,
/* Avoid all entries in the setup_data linked list. */
ptr = (struct setup_data *)(unsigned long)boot_params->hdr.setup_data;
while (ptr) {
- struct mem_vector avoid;
-
avoid.start = (unsigned long)ptr;
avoid.size = sizeof(*ptr) + ptr->len;
@@ -479,6 +478,12 @@ static bool mem_avoid_overlap(struct mem_vector *img,
ptr = (struct setup_data *)(unsigned long)ptr->next;
}
+ if (pkram_has_overlap(img, &avoid) && (avoid.start < earliest)) {
+ *overlap = avoid;
+ earliest = overlap->start;
+ is_overlapping = true;
+ }
+
return is_overlapping;
}
@@ -840,6 +845,7 @@ void choose_random_location(unsigned long input,
return;
}
+ pkram_init();
boot_params->hdr.loadflags |= KASLR_FLAG;
if (IS_ENABLED(CONFIG_X86_32))
diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
index 901ea5ebec22..f8232ffd8141 100644
--- a/arch/x86/boot/compressed/misc.h
+++ b/arch/x86/boot/compressed/misc.h
@@ -116,6 +116,16 @@ static inline void console_init(void)
{ }
#endif
+#ifdef CONFIG_PKRAM
+void pkram_init(void);
+int pkram_has_overlap(struct mem_vector *entry, struct mem_vector *overlap);
+#else
+static inline void pkram_init(void) { }
+static inline int pkram_has_overlap(struct mem_vector *entry,
+ struct mem_vector *overlap);
+{ return 0; }
+#endif
+
void set_sev_encryption_mask(void);
#ifdef CONFIG_AMD_MEM_ENCRYPT
diff --git a/arch/x86/boot/compressed/pkram.c b/arch/x86/boot/compressed/pkram.c
new file mode 100644
index 000000000000..60380f074c3f
--- /dev/null
+++ b/arch/x86/boot/compressed/pkram.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "misc.h"
+
+#define PKRAM_MAGIC 0x706B726D
+
+struct pkram_super_block {
+ __u32 magic;
+
+ __u64 node_pfn;
+ __u64 region_list_pfn;
+ __u64 nr_regions;
+};
+
+struct pkram_region {
+ phys_addr_t base;
+ phys_addr_t size;
+};
+
+struct pkram_region_list {
+ __u64 prev_pfn;
+ __u64 next_pfn;
+
+ struct pkram_region regions[0];
+};
+
+#define PKRAM_REGIONS_LIST_MAX \
+ ((PAGE_SIZE-sizeof(struct pkram_region_list))/sizeof(struct pkram_region))
+
+static u64 pkram_sb_pfn;
+static struct pkram_super_block *pkram_sb;
+
+void pkram_init(void)
+{
+ struct pkram_super_block *sb;
+ char arg[32];
+
+ if (cmdline_find_option("pkram", arg, sizeof(arg)) > 0) {
+ if (kstrtoull(arg, 16, &pkram_sb_pfn) != 0)
+ return;
+ } else
+ return;
+
+ sb = (struct pkram_super_block *)(pkram_sb_pfn << PAGE_SHIFT);
+ if (sb->magic != PKRAM_MAGIC) {
+ debug_putstr("PKRAM: invalid super block\n");
+ return;
+ }
+
+ pkram_sb = sb;
+}
+
+static struct pkram_region *pkram_first_region(struct pkram_super_block *sb, struct pkram_region_list **rlp, int *idx)
+{
+ if (!sb || !sb->region_list_pfn)
+ return NULL;
+
+ *rlp = (struct pkram_region_list *)(sb->region_list_pfn << PAGE_SHIFT);
+ *idx = 0;
+
+ return &(*rlp)->regions[0];
+}
+
+static struct pkram_region *pkram_next_region(struct pkram_region_list **rlp, int *idx)
+{
+ struct pkram_region_list *rl = *rlp;
+ int i = *idx;
+
+ i++;
+ if (i >= PKRAM_REGIONS_LIST_MAX) {
+ if (!rl->next_pfn) {
+ debug_putstr("PKRAM: no more pkram_region_list pages\n");
+ return NULL;
+ }
+ rl = (struct pkram_region_list *)(rl->next_pfn << PAGE_SHIFT);
+ *rlp = rl;
+ i = 0;
+ }
+ *idx = i;
+
+ if (rl->regions[i].size == 0)
+ return NULL;
+
+ return &rl->regions[i];
+}
+
+int pkram_has_overlap(struct mem_vector *entry, struct mem_vector *overlap)
+{
+ struct pkram_region_list *rl;
+ struct pkram_region *r;
+ int idx;
+
+ r = pkram_first_region(pkram_sb, &rl, &idx);
+
+ while (r) {
+ if (r->base + r->size <= entry->start) {
+ r = pkram_next_region(&rl, &idx);
+ continue;
+ }
+ if (r->base >= entry->start + entry->size)
+ return 0;
+
+ overlap->start = r->base;
+ overlap->size = r->size;
+ return 1;
+ }
+
+ return 0;
+}
--
1.8.3.1
next prev parent reply other threads:[~2021-03-30 21:27 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-30 21:35 [RFC v2 00/43] PKRAM: Preserved-over-Kexec RAM Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 01/43] mm: add PKRAM API stubs and Kconfig Anthony Yznaga
2021-03-31 18:43 ` Randy Dunlap
2021-03-31 20:28 ` Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 02/43] mm: PKRAM: implement node load and save functions Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 03/43] mm: PKRAM: implement object " Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 04/43] mm: PKRAM: implement page stream operations Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 05/43] mm: PKRAM: support preserving transparent hugepages Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 06/43] mm: PKRAM: implement byte stream operations Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 07/43] mm: PKRAM: link nodes by pfn before reboot Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 08/43] mm: PKRAM: introduce super block Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 09/43] PKRAM: track preserved pages in a physical mapping pagetable Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 10/43] PKRAM: pass a list of preserved ranges to the next kernel Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 11/43] PKRAM: prepare for adding preserved ranges to memblock reserved Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 12/43] mm: PKRAM: reserve preserved memory at boot Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 13/43] PKRAM: free the preserved ranges list Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 14/43] PKRAM: prevent inadvertent use of a stale superblock Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 15/43] PKRAM: provide a way to ban pages from use by PKRAM Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 16/43] kexec: PKRAM: prevent kexec clobbering preserved pages in some cases Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 17/43] PKRAM: provide a way to check if a memory range has preserved pages Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 18/43] kexec: PKRAM: avoid clobbering already " Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 19/43] mm: PKRAM: allow preserved memory to be freed from userspace Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 20/43] PKRAM: disable feature when running the kdump kernel Anthony Yznaga
2021-03-30 21:35 ` Anthony Yznaga [this message]
2021-03-30 21:35 ` [RFC v2 22/43] x86/boot/compressed/64: use 1GB pages for mappings Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 23/43] mm: shmem: introduce shmem_insert_page Anthony Yznaga
2021-03-30 21:35 ` [RFC v2 24/43] mm: shmem: enable saving to PKRAM Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 25/43] mm: shmem: prevent swapping of PKRAM-enabled tmpfs pages Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 26/43] mm: shmem: specify the mm to use when inserting pages Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 27/43] mm: shmem: when inserting, handle pages already charged to a memcg Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 28/43] x86/mm/numa: add numa_isolate_memblocks() Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 29/43] PKRAM: ensure memblocks with preserved pages init'd for numa Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 30/43] memblock: PKRAM: mark memblocks that contain preserved pages Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 31/43] memblock, mm: defer initialization of " Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 32/43] shmem: preserve shmem files a chunk at a time Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 33/43] PKRAM: atomically add and remove link pages Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 34/43] shmem: PKRAM: multithread preserving and restoring shmem pages Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 35/43] shmem: introduce shmem_insert_pages() Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 36/43] PKRAM: add support for loading pages in bulk Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 37/43] shmem: PKRAM: enable bulk loading of preserved pages into shmem Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 38/43] mm: implement splicing a list of pages to the LRU Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 39/43] shmem: optimize adding pages to the LRU in shmem_insert_pages() Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 40/43] shmem: initial support for adding multiple pages to pagecache Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 41/43] XArray: add xas_export_node() and xas_import_node() Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 42/43] shmem: reduce time holding xa_lock when inserting pages Anthony Yznaga
2021-03-30 21:36 ` [RFC v2 43/43] PKRAM: improve index alignment of pkram_link entries Anthony Yznaga
2021-06-05 13:39 ` [RFC v2 00/43] PKRAM: Preserved-over-Kexec RAM Pavel Tatashin
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