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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /fs/proc/page.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'fs/proc/page.c')
-rw-r--r--fs/proc/page.c289
1 files changed, 289 insertions, 0 deletions
diff --git a/fs/proc/page.c b/fs/proc/page.c
new file mode 100644
index 000000000..260772b20
--- /dev/null
+++ b/fs/proc/page.c
@@ -0,0 +1,289 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/memblock.h>
+#include <linux/compiler.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/ksm.h>
+#include <linux/mm.h>
+#include <linux/mmzone.h>
+#include <linux/huge_mm.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/hugetlb.h>
+#include <linux/memremap.h>
+#include <linux/memcontrol.h>
+#include <linux/mmu_notifier.h>
+#include <linux/page_idle.h>
+#include <linux/kernel-page-flags.h>
+#include <linux/uaccess.h>
+#include "internal.h"
+
+#define KPMSIZE sizeof(u64)
+#define KPMMASK (KPMSIZE - 1)
+
+enum kpage_operation {
+ KPAGE_FLAGS,
+ KPAGE_COUNT,
+ KPAGE_CGROUP,
+};
+
+static inline unsigned long get_max_dump_pfn(void)
+{
+#ifdef CONFIG_SPARSEMEM
+ /*
+ * The memmap of early sections is completely populated and marked
+ * online even if max_pfn does not fall on a section boundary -
+ * pfn_to_online_page() will succeed on all pages. Allow inspecting
+ * these memmaps.
+ */
+ return round_up(max_pfn, PAGES_PER_SECTION);
+#else
+ return max_pfn;
+#endif
+}
+
+static u64 get_kpage_count(const struct page *page)
+{
+ struct page_snapshot ps;
+ u64 ret;
+
+ snapshot_page(&ps, page);
+
+ if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT))
+ ret = folio_precise_page_mapcount(&ps.folio_snapshot,
+ &ps.page_snapshot);
+ else
+ ret = folio_average_page_mapcount(&ps.folio_snapshot);
+
+ return ret;
+}
+
+static ssize_t kpage_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos,
+ enum kpage_operation op)
+{
+ const unsigned long max_dump_pfn = get_max_dump_pfn();
+ u64 __user *out = (u64 __user *)buf;
+ struct page *page;
+ unsigned long src = *ppos;
+ unsigned long pfn;
+ ssize_t ret = 0;
+ u64 info;
+
+ pfn = src / KPMSIZE;
+ if (src & KPMMASK || count & KPMMASK)
+ return -EINVAL;
+ if (src >= max_dump_pfn * KPMSIZE)
+ return 0;
+ count = min_t(unsigned long, count, (max_dump_pfn * KPMSIZE) - src);
+
+ while (count > 0) {
+ /*
+ * TODO: ZONE_DEVICE support requires to identify
+ * memmaps that were actually initialized.
+ */
+ page = pfn_to_online_page(pfn);
+
+ if (page) {
+ switch (op) {
+ case KPAGE_FLAGS:
+ info = stable_page_flags(page);
+ break;
+ case KPAGE_COUNT:
+ info = get_kpage_count(page);
+ break;
+ case KPAGE_CGROUP:
+ info = page_cgroup_ino(page);
+ break;
+ default:
+ info = 0;
+ break;
+ }
+ } else
+ info = 0;
+
+ if (put_user(info, out)) {
+ ret = -EFAULT;
+ break;
+ }
+
+ pfn++;
+ out++;
+ count -= KPMSIZE;
+
+ cond_resched();
+ }
+
+ *ppos += (char __user *)out - buf;
+ if (!ret)
+ ret = (char __user *)out - buf;
+ return ret;
+}
+
+/* /proc/kpagecount - an array exposing page mapcounts
+ *
+ * Each entry is a u64 representing the corresponding
+ * physical page mapcount.
+ */
+static ssize_t kpagecount_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ return kpage_read(file, buf, count, ppos, KPAGE_COUNT);
+}
+
+static const struct proc_ops kpagecount_proc_ops = {
+ .proc_flags = PROC_ENTRY_PERMANENT,
+ .proc_lseek = mem_lseek,
+ .proc_read = kpagecount_read,
+};
+
+
+static inline u64 kpf_copy_bit(u64 kflags, int ubit, int kbit)
+{
+ return ((kflags >> kbit) & 1) << ubit;
+}
+
+u64 stable_page_flags(const struct page *page)
+{
+ const struct folio *folio;
+ struct page_snapshot ps;
+ unsigned long k;
+ u64 u = 0;
+
+ /*
+ * pseudo flag: KPF_NOPAGE
+ * it differentiates a memory hole from a page with no flags
+ */
+ if (!page)
+ return BIT_ULL(KPF_NOPAGE);
+
+ snapshot_page(&ps, page);
+ folio = &ps.folio_snapshot;
+ k = folio->flags.f;
+
+ /*
+ * pseudo flags for the well known (anonymous) memory mapped pages
+ */
+ if (folio_mapped(folio))
+ u |= BIT_ULL(KPF_MMAP);
+ if (folio_test_anon(folio)) {
+ u |= BIT_ULL(KPF_ANON);
+ if (folio_test_ksm(folio))
+ u |= BIT_ULL(KPF_KSM);
+ }
+
+ /*
+ * compound pages: export both head/tail info
+ * they together define a compound page's start/end pos and order
+ */
+ if (ps.idx == 0)
+ u |= kpf_copy_bit(k, KPF_COMPOUND_HEAD, PG_head);
+ else
+ u |= BIT_ULL(KPF_COMPOUND_TAIL);
+ if (folio_test_hugetlb(folio))
+ u |= BIT_ULL(KPF_HUGE);
+ else if (folio_test_large(folio) &&
+ folio_test_large_rmappable(folio)) {
+ /* Note: we indicate any THPs here, not just PMD-sized ones */
+ u |= BIT_ULL(KPF_THP);
+ } else if (is_huge_zero_pfn(ps.pfn)) {
+ u |= BIT_ULL(KPF_ZERO_PAGE);
+ u |= BIT_ULL(KPF_THP);
+ } else if (is_zero_pfn(ps.pfn)) {
+ u |= BIT_ULL(KPF_ZERO_PAGE);
+ }
+
+ if (ps.flags & PAGE_SNAPSHOT_PG_BUDDY)
+ u |= BIT_ULL(KPF_BUDDY);
+
+ if (ps.flags & PAGE_SNAPSHOT_PG_IDLE)
+ u |= BIT_ULL(KPF_IDLE);
+
+ if (folio_test_offline(folio))
+ u |= BIT_ULL(KPF_OFFLINE);
+ if (folio_test_pgtable(folio))
+ u |= BIT_ULL(KPF_PGTABLE);
+ if (folio_test_slab(folio))
+ u |= BIT_ULL(KPF_SLAB);
+
+ u |= kpf_copy_bit(k, KPF_LOCKED, PG_locked);
+ u |= kpf_copy_bit(k, KPF_DIRTY, PG_dirty);
+ u |= kpf_copy_bit(k, KPF_UPTODATE, PG_uptodate);
+ u |= kpf_copy_bit(k, KPF_WRITEBACK, PG_writeback);
+
+ u |= kpf_copy_bit(k, KPF_LRU, PG_lru);
+ u |= kpf_copy_bit(k, KPF_REFERENCED, PG_referenced);
+ u |= kpf_copy_bit(k, KPF_ACTIVE, PG_active);
+ u |= kpf_copy_bit(k, KPF_RECLAIM, PG_reclaim);
+
+ if (folio_test_swapcache(folio))
+ u |= BIT_ULL(KPF_SWAPCACHE);
+
+ u |= kpf_copy_bit(k, KPF_SWAPBACKED, PG_swapbacked);
+ u |= kpf_copy_bit(k, KPF_UNEVICTABLE, PG_unevictable);
+ u |= kpf_copy_bit(k, KPF_MLOCKED, PG_mlocked);
+
+#ifdef CONFIG_MEMORY_FAILURE
+ if (u & BIT_ULL(KPF_HUGE))
+ u |= kpf_copy_bit(k, KPF_HWPOISON, PG_hwpoison);
+ else
+ u |= kpf_copy_bit(ps.page_snapshot.flags.f, KPF_HWPOISON, PG_hwpoison);
+#endif
+
+ u |= kpf_copy_bit(k, KPF_RESERVED, PG_reserved);
+ u |= kpf_copy_bit(k, KPF_OWNER_2, PG_owner_2);
+ u |= kpf_copy_bit(k, KPF_PRIVATE, PG_private);
+ u |= kpf_copy_bit(k, KPF_PRIVATE_2, PG_private_2);
+ u |= kpf_copy_bit(k, KPF_OWNER_PRIVATE, PG_owner_priv_1);
+ u |= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
+#ifdef CONFIG_ARCH_USES_PG_ARCH_2
+ u |= kpf_copy_bit(k, KPF_ARCH_2, PG_arch_2);
+#endif
+#ifdef CONFIG_ARCH_USES_PG_ARCH_3
+ u |= kpf_copy_bit(k, KPF_ARCH_3, PG_arch_3);
+#endif
+
+ return u;
+}
+EXPORT_SYMBOL_GPL(stable_page_flags);
+
+/* /proc/kpageflags - an array exposing page flags
+ *
+ * Each entry is a u64 representing the corresponding
+ * physical page flags.
+ */
+static ssize_t kpageflags_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ return kpage_read(file, buf, count, ppos, KPAGE_FLAGS);
+}
+
+static const struct proc_ops kpageflags_proc_ops = {
+ .proc_flags = PROC_ENTRY_PERMANENT,
+ .proc_lseek = mem_lseek,
+ .proc_read = kpageflags_read,
+};
+
+#ifdef CONFIG_MEMCG
+static ssize_t kpagecgroup_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ return kpage_read(file, buf, count, ppos, KPAGE_CGROUP);
+}
+static const struct proc_ops kpagecgroup_proc_ops = {
+ .proc_flags = PROC_ENTRY_PERMANENT,
+ .proc_lseek = mem_lseek,
+ .proc_read = kpagecgroup_read,
+};
+#endif /* CONFIG_MEMCG */
+
+static int __init proc_page_init(void)
+{
+ proc_create("kpagecount", S_IRUSR, NULL, &kpagecount_proc_ops);
+ proc_create("kpageflags", S_IRUSR, NULL, &kpageflags_proc_ops);
+#ifdef CONFIG_MEMCG
+ proc_create("kpagecgroup", S_IRUSR, NULL, &kpagecgroup_proc_ops);
+#endif
+ return 0;
+}
+fs_initcall(proc_page_init);