>
> It's kind of a chicken-and-egg situation, where the first readmem()
> needs the virtual address range stuff to be in place, but we need
> something out of the kernel data space to determine the virtual
> address space range data. That being said, it looks possible, at
> least in the case of ppc64, that perhaps we could get away with
> doing a readmem() of a unity-mapped address, since at the
> point where the VM-range decision is made, machdep->kvbase
> has just been set. (Follow the readmem() path, and you'll see
> what I mean...) But you'd have to read raw data and muck
> your way through it because the embedded gdb hasn't been
> invoked yet. Badari had asked the same thing earlier, about
> using the THIS_KERNEL_VERSION macro, but again, the
> underlying crash data to satisfy the macro doesn't get initialized
> until after gdb is alive.
Okay. It looks like we can delay deciding 4-level pagetable layout
till POST_GDB stage. Since THIS_KERNEL_VERSION is set by then, I was
able to use that instead :)
Here is the updated version.
Thanks,
Badari
--- crash-4.0-2.10/defs.h 2005-11-07 07:44:06.000000000 -0800
+++ crash-4.0-2.10.new/defs.h 2005-11-09 10:08:59.000000000 -0800
@@ -2100,6 +2100,24 @@ struct efi_memory_desc_t {
#define PGD_OFFSET(vaddr) ((vaddr >> PGDIR_SHIFT) & 0x7ff)
#define PMD_OFFSET(vaddr) ((vaddr >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
+/* 4-level page table changes */
+#define PGDIR_SHIFT_L4 (PMD_SHIFT + (machdep->pageshift - 5))
+#define L4_SHIFT (PGDIR_SHIFT_L4 + (machdep->pageshift - 5))
+
+#define PTE_SHIFT_L4 17
+
+#define PTE_INDEX_SIZE_L4 9
+#define PMD_INDEX_SIZE_L4 7
+#define PGD_INDEX_SIZE_L4 7
+
+#define PTRS_PER_PTE_L4 (1 << PTE_INDEX_SIZE_L4)
+#define PTRS_PER_PMD_L4 (1 << PMD_INDEX_SIZE_L4)
+#define PTRS_PER_PGD_L4 (1 << PGD_INDEX_SIZE_L4)
+
+#define L4_OFFSET(vaddr) ((vaddr >> L4_SHIFT) & 0x1ff)
+#define PGD_OFFSET_L4(vaddr) ((vaddr >> PGDIR_SHIFT_L4) & (PTRS_PER_PGD_L4 - 1))
+#define PMD_OFFSET_L4(vaddr) ((vaddr >> PMD_SHIFT) & (PTRS_PER_PMD_L4 - 1))
+
#define _PAGE_PRESENT 0x001UL /* software: pte contains a translation */
#define _PAGE_USER 0x002UL /* matches one of the PP bits */
#define _PAGE_RW 0x004UL /* software: user write access allowed */
@@ -3285,13 +3303,26 @@ struct machine_specific {
ulong hwintrstack[NR_CPUS];
char *hwstackbuf;
uint hwstacksize;
+ char *level4;
+ ulong last_level4_read;
};
+#define IS_LAST_L4_READ(l4) ((ulong)(l4) == machdep->machspec->last_level4_read)
+
+#define FILL_L4(L4, TYPE, SIZE) \
+ if (!IS_LAST_L4_READ(L4)) { \
+ readmem((ulonglong)((ulong)(L4)), TYPE, machdep->machspec->level4, \
+ SIZE, "level4 page", FAULT_ON_ERROR); \
+ machdep->machspec->last_level4_read = (ulong)(L4); \
+ }
+
void ppc64_init(int);
void ppc64_dump_machdep_table(ulong);
#define display_idt_table() \
error(FATAL, "-d option is not applicable to PowerPC architecture\n")
#define KSYMS_START (0x1)
+#define VM_ORIG (0x2)
+#define VM_4_LEVEL (0x4)
#endif
/*
--- crash-4.0-2.10/ppc64.c 2005-11-07 07:44:06.000000000 -0800
+++ crash-4.0-2.10.new/ppc64.c 2005-11-09 10:07:30.000000000 -0800
@@ -47,6 +47,7 @@ static ulong ppc64_in_irqstack(ulong);
static char * ppc64_check_eframe(struct ppc64_pt_regs *);
static void ppc64_print_eframe(char *, struct ppc64_pt_regs *,
struct bt_info *);
+static void parse_cmdline_arg(void);
struct machine_specific ppc64_machine_specific = { { 0 }, 0, 0 };
@@ -75,12 +76,17 @@ ppc64_init(int when)
error(FATAL, "cannot malloc pmd space.");
if ((machdep->ptbl = (char *)malloc(PAGESIZE())) == NULL)
error(FATAL, "cannot malloc ptbl space.");
+ if ((machdep->machspec->level4 = (char *)malloc(PAGESIZE())) == NULL)
+ error(FATAL, "cannot malloc level4 space.");
machdep->last_pgd_read = 0;
machdep->last_pmd_read = 0;
machdep->last_ptbl_read = 0;
+ machdep->machspec->last_level4_read = 0;
machdep->verify_paddr = generic_verify_paddr;
machdep->ptrs_per_pgd = PTRS_PER_PGD;
machdep->flags |= MACHDEP_BT_TEXT;
+ if (machdep->cmdline_arg)
+ parse_cmdline_arg();
break;
case PRE_GDB:
@@ -109,6 +115,26 @@ ppc64_init(int when)
break;
case POST_GDB:
+ if (!(machdep->flags & (VM_ORIG|VM_4_LEVEL))) {
+ if (THIS_KERNEL_VERSION >= LINUX(2,6,14)) {
+ machdep->flags |= VM_4_LEVEL;
+ } else {
+ machdep->flags |= VM_ORIG;
+ }
+ }
+ switch (machdep->flags & (VM_ORIG|VM_4_LEVEL))
+ {
+ case VM_ORIG:
+ /* pre-2.6.14 layout */
+ free(machdep->machspec->level4);
+ machdep->machspec->level4 = NULL;
+ machdep->ptrs_per_pgd = PTRS_PER_PGD;
+ break;
+ case VM_4_LEVEL:
+ /* 2.6.14 layout */
+ machdep->ptrs_per_pgd = PTRS_PER_PGD_L4;
+ break;
+ }
machdep->vmalloc_start = ppc64_vmalloc_start;
MEMBER_OFFSET_INIT(thread_struct_pg_tables,
"thread_struct", "pg_tables");
@@ -231,6 +257,10 @@ ppc64_dump_machdep_table(ulong arg)
fprintf(fp, "%sKSYMS_START", others++ ? "|" : "");
if (machdep->flags & MACHDEP_BT_TEXT)
fprintf(fp, "%sMACHDEP_BT_TEXT", others++ ? "|" : "");
+ if (machdep->flags & VM_ORIG)
+ fprintf(fp, "%sVM_ORIG", others++ ? "|" : "");
+ if (machdep->flags & VM_4_LEVEL)
+ fprintf(fp, "%sVM_4_LEVEL", others++ ? "|" : "");
fprintf(fp, ")\n");
fprintf(fp, " kvbase: %lx\n", machdep->kvbase);
@@ -340,7 +370,7 @@ ppc64_vtop(ulong vaddr, ulong *pgd, phys
if (!(pte & _PAGE_PRESENT)) {
if (pte && verbose) {
fprintf(fp, "\n");
- ppc64_translate_pte(pte, 0, 0);
+ ppc64_translate_pte(pte, 0, PTE_SHIFT);
}
return FALSE;
}
@@ -352,7 +382,86 @@ ppc64_vtop(ulong vaddr, ulong *pgd, phys
if (verbose) {
fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr));
- ppc64_translate_pte(pte, 0, 0);
+ ppc64_translate_pte(pte, 0, PTE_SHIFT);
+ }
+
+ return TRUE;
+}
+
+/*
+ * Virtual to physical memory translation. This function will be called
+ * by both ppc64_kvtop and ppc64_uvtop.
+ */
+static int
+ppc64_vtop_level4(ulong vaddr, ulong *level4, physaddr_t *paddr, int verbose)
+{
+ ulong *level4_dir;
+ ulong *page_dir;
+ ulong *page_middle;
+ ulong *page_table;
+ ulong level4_pte, pgd_pte, pmd_pte;
+ ulong pte;
+
+ if (verbose)
+ fprintf(fp, "PAGE DIRECTORY: %lx\n", (ulong)level4);
+
+ level4_dir = (ulong *)((ulong *)level4 + L4_OFFSET(vaddr));
+ FILL_L4(PAGEBASE(level4), KVADDR, PAGESIZE());
+ level4_pte = ULONG(machdep->machspec->level4 + PAGEOFFSET(level4_dir));
+ if (verbose)
+ fprintf(fp, " L4: %lx => %lx\n", (ulong)level4_dir, level4_pte);
+ if (!level4_pte)
+ return FALSE;
+
+ page_dir = (ulong *)((ulong *)level4_pte + PGD_OFFSET_L4(vaddr));
+ FILL_PGD(PAGEBASE(level4_pte), KVADDR, PAGESIZE());
+ pgd_pte = ULONG(machdep->pgd + PAGEOFFSET(page_dir));
+
+ if (verbose)
+ fprintf(fp, " PGD: %lx => %lx\n", (ulong)page_dir, pgd_pte);
+
+ if (!pgd_pte)
+ return FALSE;
+
+ page_middle = (ulong *)((ulong *)pgd_pte + PMD_OFFSET_L4(vaddr));
+ FILL_PMD(PAGEBASE(pgd_pte), KVADDR, PAGESIZE());
+ pmd_pte = ULONG(machdep->pmd + PAGEOFFSET(page_middle));
+
+ if (verbose)
+ fprintf(fp, " PMD: %lx => %lx\n", (ulong)page_middle, pmd_pte);
+
+ if (!(pmd_pte))
+ return FALSE;
+
+ page_table = (ulong *)pmd_pte + (BTOP(vaddr) & (PTRS_PER_PTE_L4 - 1));
+ if (verbose)
+ fprintf(fp, " vaddr %lx BTOP %lx PTRS_PER_PTE_L4 %lx\n", vaddr, BTOP(vaddr), PTRS_PER_PTE_L4);
+ if (verbose)
+ fprintf(fp, " PMD: %lx => %lx\n",(ulong)page_middle,
+ (ulong)page_table);
+
+ FILL_PTBL(PAGEBASE(pmd_pte), KVADDR, PAGESIZE());
+ pte = ULONG(machdep->ptbl + PAGEOFFSET(page_table));
+
+ if (verbose)
+ fprintf(fp, " PTE: %lx => %lx\n", (ulong)page_table, pte);
+
+ if (!(pte & _PAGE_PRESENT)) {
+ if (pte && verbose) {
+ fprintf(fp, "\n");
+ ppc64_translate_pte(pte, 0, PTE_SHIFT_L4);
+ }
+ return FALSE;
+ }
+
+ if (!pte)
+ return FALSE;
+
+ *paddr = PAGEBASE(PTOB(pte >> PTE_SHIFT_L4)) + PAGEOFFSET(vaddr);
+
+ if (verbose) {
+ fprintf(fp, " PAGE: %lx\n\n", PAGEBASE(*paddr));
+ ppc64_translate_pte(pte, 0, PTE_SHIFT_L4);
}
return TRUE;
@@ -409,7 +518,10 @@ ppc64_uvtop(struct task_context *tc, ulo
FAULT_ON_ERROR);
}
- return ppc64_vtop(vaddr, pgd, paddr, verbose);
+ if (machdep->flags & VM_4_LEVEL)
+ return ppc64_vtop_level4(vaddr, pgd, paddr, verbose);
+ else
+ return ppc64_vtop(vaddr, pgd, paddr, verbose);
}
/*
@@ -434,7 +546,10 @@ ppc64_kvtop(struct task_context *tc, ulo
return TRUE;
}
- return ppc64_vtop(kvaddr, (ulong *)vt->kernel_pgd[0], paddr, verbose);
+ if (machdep->flags & VM_4_LEVEL)
+ return ppc64_vtop_level4(kvaddr, (ulong *)vt->kernel_pgd[0], paddr, verbose);
+ else
+ return ppc64_vtop(kvaddr, (ulong *)vt->kernel_pgd[0], paddr, verbose);
}
/*
@@ -655,7 +770,7 @@ ppc64_get_task_pgd(ulong task)
* If a physaddr pointer is passed in, don't print anything.
*/
static int
-ppc64_translate_pte(ulong pte, void *physaddr, ulonglong unused)
+ppc64_translate_pte(ulong pte, void *physaddr, ulonglong pte_shift)
{
int c, len1, len2, len3, others, page_present;
char buf[BUFSIZE];
@@ -666,7 +781,7 @@ ppc64_translate_pte(ulong pte, void *phy
char *arglist[MAXARGS];
ulong paddr;
- paddr = PTOB(pte >> PTE_SHIFT);
+ paddr = PTOB(pte >> pte_shift);
page_present = (pte & _PAGE_PRESENT);
if (physaddr) {
@@ -1999,4 +2114,78 @@ ppc64_compiler_warning_stub(void)
ppc64_dump_line_number(0);
}
+/*
+ * Force the VM address-range selection via:
+ *
+ * --machdep vm=orig
+ * --machdep vm=2.6.14
+ */
+
+void
+parse_cmdline_arg(void)
+{
+ int i, c, errflag;
+ char *p;
+ char buf[BUFSIZE];
+ char *arglist[MAXARGS];
+ int lines = 0;
+
+ if (!strstr(machdep->cmdline_arg, "=")) {
+ error(WARNING, "ignoring --machdep option: %s\n\n",
+ machdep->cmdline_arg);
+ return;
+ }
+
+ strcpy(buf, machdep->cmdline_arg);
+
+ for (p = buf; *p; p++) {
+ if (*p == ',')
+ *p = ' ';
+ }
+
+ c = parse_line(buf, arglist);
+
+ for (i = 0; i < c; i++) {
+ errflag = 0;
+
+ if (STRNEQ(arglist[i], "vm=")) {
+ p = arglist[i] + strlen("vm=");
+ if (strlen(p)) {
+ if (STREQ(p, "orig")) {
+ machdep->flags |= VM_ORIG;
+ continue;
+ } else if (STREQ(p, "2.6.14")) {
+ machdep->flags |= VM_4_LEVEL;
+ continue;
+ }
+ }
+ }
+
+ error(WARNING, "ignoring --machdep option: %s\n", arglist[i]);
+ lines++;
+ }
+
+ switch (machdep->flags & (VM_ORIG|VM_4_LEVEL))
+ {
+ case VM_ORIG:
+ error(NOTE, "using original PPC64 VM address ranges\n");
+ lines++;
+ break;
+
+ case VM_4_LEVEL:
+ error(NOTE, "using 4-level pagetable PPC64 VM address ranges\n");
+ lines++;
+ break;
+
+ case (VM_ORIG|VM_4_LEVEL):
+ error(WARNING, "cannot set both vm=orig and vm=2.6.14\n");
+ lines++;
+ machdep->flags &= ~(VM_ORIG|VM_4_LEVEL);
+ break;
+ }
+
+ if (lines)
+ fprintf(fp, "\n");
+}
+
#endif /* PPC64 */
