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D21380.1794688743.diff
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Index: sys/amd64/amd64/pmap.c
===================================================================
--- sys/amd64/amd64/pmap.c
+++ sys/amd64/amd64/pmap.c
@@ -124,6 +124,7 @@
#include <sys/proc.h>
#include <sys/rangeset.h>
#include <sys/rwlock.h>
+#include <sys/sbuf.h>
#include <sys/sx.h>
#include <sys/turnstile.h>
#include <sys/vmem.h>
@@ -2097,6 +2098,41 @@
return (mask);
}
+static int
+pmap_pat_index(pmap_t pmap, pt_entry_t pte, bool is_pde)
+{
+ int pat_flag, pat_idx;
+
+ pat_idx = 0;
+ switch (pmap->pm_type) {
+ case PT_X86:
+ case PT_RVI:
+ /* The PAT bit is different for PTE's and PDE's. */
+ pat_flag = is_pde ? X86_PG_PDE_PAT : X86_PG_PTE_PAT;
+
+ if ((pte & pat_flag) != 0)
+ pat_idx |= 0x4;
+ if ((pte & PG_NC_PCD) != 0)
+ pat_idx |= 0x2;
+ if ((pte & PG_NC_PWT) != 0)
+ pat_idx |= 0x1;
+ break;
+ case PT_EPT:
+ if ((pte & EPT_PG_IGNORE_PAT) != 0)
+ panic("EPT PTE %#lx has no PAT memory type", pte);
+ pat_idx = (pte & EPT_PG_MEMORY_TYPE(0x7)) >> 3;
+ break;
+ }
+
+ /* See pmap_init_pat(). */
+ if (pat_idx == 4)
+ pat_idx = 0;
+ if (pat_idx == 7)
+ pat_idx = 3;
+
+ return (pat_idx);
+}
+
bool
pmap_ps_enabled(pmap_t pmap)
{
@@ -9967,6 +10003,260 @@
return (error);
}
+/*
+ * Track a range of the kernel's virtual address space that is contiguous
+ * in various mapping attributes.
+ */
+struct pmap_kernel_map_range {
+ vm_offset_t sva;
+ pt_entry_t attrs;
+ int ptes;
+ int pdes;
+ int pdpes;
+};
+
+static void
+sysctl_kmaps_dump(struct sbuf *sb, struct pmap_kernel_map_range *range,
+ vm_offset_t eva)
+{
+ const char *mode;
+ int i, pat_idx;
+
+ if (eva <= range->sva)
+ return;
+
+ pat_idx = pmap_pat_index(kernel_pmap, range->attrs, true);
+ for (i = 0; i < PAT_INDEX_SIZE; i++)
+ if (pat_index[i] == pat_idx)
+ break;
+
+ switch (i) {
+ case PAT_WRITE_BACK:
+ mode = "WB";
+ break;
+ case PAT_WRITE_THROUGH:
+ mode = "WT";
+ break;
+ case PAT_UNCACHEABLE:
+ mode = "UC";
+ break;
+ case PAT_WRITE_PROTECTED:
+ mode = "WP";
+ break;
+ case PAT_WRITE_COMBINING:
+ mode = "WC";
+ break;
+ default:
+ panic("sysctl_kmaps_dump: unknown PAT mode %d", i);
+ }
+
+ sbuf_printf(sb, "%#016lx-%#016lx r%c%c%c%c %s %d %d %d\n",
+ range->sva, eva,
+ (range->attrs & X86_PG_RW) != 0 ? 'w' : '-',
+ (range->attrs & pg_nx) != 0 ? '-' : 'x',
+ (range->attrs & X86_PG_U) != 0 ? 'u' : 's',
+ (range->attrs & X86_PG_G) != 0 ? 'g' : '-',
+ mode, range->pdpes, range->pdes, range->ptes);
+
+ /* Reset to sentinel value. */
+ range->sva = KVADDR(NPML4EPG - 1, NPDPEPG - 1, NPDEPG - 1, NPTEPG - 1);
+}
+
+/*
+ * Determine whether the attributes specified by a page table entry match those
+ * being tracked by the current range. This is not quite as simple as a direct
+ * flag comparison since some PAT modes have multiple representations.
+ */
+static bool
+sysctl_kmaps_match(struct pmap_kernel_map_range *range, pt_entry_t attrs,
+ pt_entry_t mask)
+{
+ pt_entry_t diff;
+
+ diff = (range->attrs ^ attrs) & mask;
+ if (diff == 0)
+ return (true);
+ if ((diff & ~X86_PG_PDE_PAT) == 0 &&
+ pmap_pat_index(kernel_pmap, range->attrs, true) ==
+ pmap_pat_index(kernel_pmap, attrs, true))
+ return (true);
+ return (false);
+}
+
+static void
+sysctl_kmaps_reinit(struct pmap_kernel_map_range *range, vm_offset_t va,
+ pt_entry_t attrs)
+{
+
+ memset(range, 0, sizeof(*range));
+ range->sva = va;
+ range->attrs = attrs;
+}
+
+/*
+ * Called for every kernel page table entry. Maintain a range of kernel virtual
+ * addresses that is contiguous with respect to access permissions and cache
+ * mode.
+ */
+static bool
+sysctl_kmaps_update(struct sbuf *sb, struct pmap_kernel_map_range *range,
+ vm_offset_t va, pml4_entry_t *pml4, pdp_entry_t *pdp, pd_entry_t *pd,
+ pt_entry_t *pt)
+{
+ pt_entry_t attrs, mask;
+
+ if ((*pml4 & X86_PG_V) == 0) {
+ sysctl_kmaps_dump(sb, range, va);
+ return (false);
+ }
+ attrs = *pml4 & (X86_PG_RW | X86_PG_U | pg_nx);
+ mask = X86_PG_RW | X86_PG_U | pg_nx;
+
+ if (pdp == NULL)
+ return (true);
+ if ((*pdp & X86_PG_V) == 0) {
+ sysctl_kmaps_dump(sb, range, va);
+ return (false);
+ }
+ attrs |= *pdp & pg_nx;
+ attrs &= pg_nx | (*pdp & (X86_PG_RW | X86_PG_U));
+ if ((*pdp & X86_PG_PS) != 0) {
+ attrs |= *pdp & (X86_PG_G | X86_PG_PDE_CACHE);
+ mask |= X86_PG_G | X86_PG_PDE_CACHE;
+
+ if (range->sva > va ||
+ !sysctl_kmaps_match(range, attrs, mask)) {
+ sysctl_kmaps_dump(sb, range, va);
+ sysctl_kmaps_reinit(range, va, attrs);
+ }
+ range->pdpes++;
+ return (false);
+ }
+
+ if (pd == NULL)
+ return (true);
+ if ((*pd & X86_PG_V) == 0) {
+ sysctl_kmaps_dump(sb, range, va);
+ return (false);
+ }
+ attrs |= *pd & pg_nx;
+ attrs &= pg_nx | (*pd & (X86_PG_RW | X86_PG_U));
+ if ((*pd & X86_PG_PS) != 0) {
+ attrs |= *pd & (X86_PG_G | X86_PG_PDE_CACHE);
+ mask |= X86_PG_G | X86_PG_PDE_CACHE;
+
+ if (range->sva > va ||
+ !sysctl_kmaps_match(range, attrs, mask)) {
+ sysctl_kmaps_dump(sb, range, va);
+ sysctl_kmaps_reinit(range, va, attrs);
+ }
+ range->pdes++;
+ return (false);
+ }
+
+ if (pt == NULL)
+ return (true);
+ if ((*pt & X86_PG_V) == 0) {
+ sysctl_kmaps_dump(sb, range, va);
+ return (false);
+ }
+ attrs |= *pt & pg_nx;
+ attrs &= pg_nx | (*pt & (X86_PG_RW | X86_PG_U));
+ attrs |= (*pt & (X86_PG_G | X86_PG_PTE_CACHE));
+
+ /*
+ * PTEs use different bits for the PAT index; canonicalize by using the
+ * PDE format.
+ */
+ if ((*pt & X86_PG_PTE_PAT) != 0) {
+ attrs &= ~X86_PG_PTE_PAT;
+ attrs |= X86_PG_PDE_PAT;
+ }
+ mask |= X86_PG_G | X86_PG_PDE_CACHE;
+
+ if (range->sva > va || !sysctl_kmaps_match(range, attrs, mask)) {
+ sysctl_kmaps_dump(sb, range, va);
+ sysctl_kmaps_reinit(range, va, attrs);
+ }
+ range->ptes++;
+
+ return (true);
+}
+
+static int
+sysctl_kmaps(SYSCTL_HANDLER_ARGS)
+{
+ struct pmap_kernel_map_range range;
+ struct sbuf sbuf, *sb;
+ pml4_entry_t *pml4;
+ pdp_entry_t *pdp;
+ pd_entry_t *pd;
+ pt_entry_t *pt;
+ vm_offset_t va;
+ int error, i, j, k, l;
+
+ error = sysctl_wire_old_buffer(req, 0);
+ if (error != 0)
+ return (error);
+ sb = &sbuf;
+ sbuf_new_for_sysctl(sb, NULL, PAGE_SIZE, req);
+
+ range.sva = KVADDR(NPML4EPG - 1, NPDPEPG - 1, NPDEPG - 1, NPTEPG - 1);
+
+ PMAP_LOCK(kernel_pmap);
+ for (i = 0; i < NPML4EPG; i++) {
+ switch (i) {
+ case PML4PML4I:
+ sbuf_printf(sb, "\nRecursive map:\n");
+ break;
+ case DMPML4I:
+ sbuf_printf(sb, "\nDirect map:\n");
+ break;
+ case KPML4BASE:
+ sbuf_printf(sb, "\nKernel map:\n");
+ break;
+ case LMSPML4I:
+ sbuf_printf(sb, "\nLarge map:\n");
+ break;
+ }
+
+ va = KVADDR(i, 0, 0, 0);
+ pml4 = &kernel_pmap->pm_pml4[i];
+ if (!sysctl_kmaps_update(sb, &range, va, pml4, NULL, NULL,
+ NULL))
+ continue;
+ for (j = 0; j < NPDPEPG; j++) {
+ va = KVADDR(i, j, 0, 0);
+ pdp = pmap_pml4e_to_pdpe(pml4, va);
+ if (!sysctl_kmaps_update(sb, &range, va, pml4, pdp,
+ NULL, NULL))
+ continue;
+ for (k = 0; k < NPDEPG; k++) {
+ va = KVADDR(i, j, k, 0);
+ pd = pmap_pdpe_to_pde(pdp, va);
+ if (!sysctl_kmaps_update(sb, &range, va, pml4,
+ pdp, pd, NULL))
+ continue;
+ for (l = 0; l < NPTEPG; l++) {
+ va = KVADDR(i, j, k, l);
+ pt = pmap_pde_to_pte(pd, va);
+ (void)sysctl_kmaps_update(sb, &range,
+ va, pml4, pdp, pd, pt);
+ }
+ }
+ }
+ }
+ PMAP_UNLOCK(kernel_pmap);
+
+ error = sbuf_finish(sb);
+ sbuf_delete(sb);
+ return (error);
+}
+SYSCTL_OID(_vm_pmap, OID_AUTO, kernel_maps,
+ CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
+ NULL, 0, sysctl_kmaps, "A",
+ "Dump kernel address layout");
+
#ifdef DDB
DB_SHOW_COMMAND(pte, pmap_print_pte)
{

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