#include <linux/stacktrace.h>
#include <linux/uaccess.h>
#include <linux/mmzone.h>
+#include <linux/dcache.h>
+#include <linux/fs.h>
#include <asm/backtrace.h>
#include <asm/page.h>
-#include <asm/tlbflush.h>
#include <asm/ucontext.h>
#include <asm/sigframe.h>
#include <asm/stack.h>
return sp >= kstack_base && sp < kstack_base + THREAD_SIZE;
}
-/* Is address valid for reading? */
-static int valid_address(struct KBacktraceIterator *kbt, unsigned long address)
-{
- HV_PTE *l1_pgtable = kbt->pgtable;
- HV_PTE *l2_pgtable;
- unsigned long pfn;
- HV_PTE pte;
- struct page *page;
-
- if (l1_pgtable == NULL)
- return 0; /* can't read user space in other tasks */
-
- pte = l1_pgtable[PGD_INDEX(address)];
-#ifdef CONFIG_64BIT
- /* Find the real l1_pgtable by looking in the l0_pgtable. */
- if (!hv_pte_get_present(pte))
- return 0;
- pfn = pte_pfn(pte);
- if (pte_huge(pte)) {
- if (!pfn_valid(pfn)) {
- pr_err("L0 huge page has bad pfn %#lx\n", pfn);
- return 0;
- }
- return hv_pte_get_present(pte) && hv_pte_get_readable(pte);
- }
- page = pfn_to_page(pfn);
- BUG_ON(PageHighMem(page)); /* No HIGHMEM on 64-bit. */
- l1_pgtable = (HV_PTE *)pfn_to_kaddr(pfn);
- pte = l1_pgtable[PMD_INDEX(address)];
-#endif
- if (!hv_pte_get_present(pte))
- return 0;
- pfn = pte_pfn(pte);
- if (pte_huge(pte)) {
- if (!pfn_valid(pfn)) {
- pr_err("huge page has bad pfn %#lx\n", pfn);
- return 0;
- }
- return hv_pte_get_present(pte) && hv_pte_get_readable(pte);
- }
-
- page = pfn_to_page(pfn);
- if (PageHighMem(page)) {
- pr_err("L2 page table not in LOWMEM (%#llx)\n", PFN_PHYS(pfn));
- return 0;
- }
- l2_pgtable = (HV_PTE *)pfn_to_kaddr(pfn);
- pte = l2_pgtable[PTE_INDEX(address)];
- return hv_pte_get_present(pte) && hv_pte_get_readable(pte);
-}
-
/* Callback for backtracer; basically a glorified memcpy */
static bool read_memory_func(void *result, unsigned long address,
unsigned int size, void *vkbt)
{
int retval;
struct KBacktraceIterator *kbt = (struct KBacktraceIterator *)vkbt;
+
+ if (address == 0)
+ return 0;
if (__kernel_text_address(address)) {
/* OK to read kernel code. */
} else if (address >= PAGE_OFFSET) {
/* We only tolerate kernel-space reads of this task's stack */
if (!in_kernel_stack(kbt, address))
return 0;
- } else if (!valid_address(kbt, address)) {
- return 0; /* invalid user-space address */
+ } else if (!kbt->is_current) {
+ return 0; /* can't read from other user address spaces */
}
pagefault_disable();
retval = __copy_from_user_inatomic(result,
unsigned long sp = kbt->it.sp;
struct pt_regs *p;
+ if (sp % sizeof(long) != 0)
+ return NULL;
if (!in_kernel_stack(kbt, sp))
return NULL;
if (!in_kernel_stack(kbt, sp + C_ABI_SAVE_AREA_SIZE + PTREGS_SIZE-1))
}
/* Return a pt_regs pointer for a valid signal handler frame */
-static struct pt_regs *valid_sigframe(struct KBacktraceIterator* kbt)
+static struct pt_regs *valid_sigframe(struct KBacktraceIterator* kbt,
+ struct rt_sigframe* kframe)
{
BacktraceIterator *b = &kbt->it;
- if (b->pc == VDSO_BASE) {
- struct rt_sigframe *frame;
- unsigned long sigframe_top =
- b->sp + sizeof(struct rt_sigframe) - 1;
- if (!valid_address(kbt, b->sp) ||
- !valid_address(kbt, sigframe_top)) {
- if (kbt->verbose)
- pr_err(" (odd signal: sp %#lx?)\n",
- (unsigned long)(b->sp));
+ if (b->pc == VDSO_BASE && b->sp < PAGE_OFFSET &&
+ b->sp % sizeof(long) == 0) {
+ int retval;
+ pagefault_disable();
+ retval = __copy_from_user_inatomic(
+ kframe, (void __user __force *)b->sp,
+ sizeof(*kframe));
+ pagefault_enable();
+ if (retval != 0 ||
+ (unsigned int)(kframe->info.si_signo) >= _NSIG)
return NULL;
- }
- frame = (struct rt_sigframe *)b->sp;
if (kbt->verbose) {
pr_err(" <received signal %d>\n",
- frame->info.si_signo);
+ kframe->info.si_signo);
}
- return (struct pt_regs *)&frame->uc.uc_mcontext;
+ return (struct pt_regs *)&kframe->uc.uc_mcontext;
}
return NULL;
}
static int KBacktraceIterator_restart(struct KBacktraceIterator *kbt)
{
struct pt_regs *p;
+ struct rt_sigframe kframe;
p = valid_fault_handler(kbt);
if (p == NULL)
- p = valid_sigframe(kbt);
+ p = valid_sigframe(kbt, &kframe);
if (p == NULL)
return 0;
backtrace_init(&kbt->it, read_memory_func, kbt,
/*
* Set up callback information. We grab the kernel stack base
- * so we will allow reads of that address range, and if we're
- * asking about the current process we grab the page table
- * so we can check user accesses before trying to read them.
- * We flush the TLB to avoid any weird skew issues.
+ * so we will allow reads of that address range.
*/
- is_current = (t == NULL);
+ is_current = (t == NULL || t == current);
kbt->is_current = is_current;
if (is_current)
t = validate_current();
kbt->task = t;
- kbt->pgtable = NULL;
kbt->verbose = 0; /* override in caller if desired */
kbt->profile = 0; /* override in caller if desired */
kbt->end = KBT_ONGOING;
- kbt->new_context = 0;
- if (is_current) {
- HV_PhysAddr pgdir_pa = hv_inquire_context().page_table;
- if (pgdir_pa == (unsigned long)swapper_pg_dir - PAGE_OFFSET) {
- /*
- * Not just an optimization: this also allows
- * this to work at all before va/pa mappings
- * are set up.
- */
- kbt->pgtable = swapper_pg_dir;
- } else {
- struct page *page = pfn_to_page(PFN_DOWN(pgdir_pa));
- if (!PageHighMem(page))
- kbt->pgtable = __va(pgdir_pa);
- else
- pr_err("page table not in LOWMEM"
- " (%#llx)\n", pgdir_pa);
- }
- local_flush_tlb_all();
+ kbt->new_context = 1;
+ if (is_current)
validate_stack(regs);
- }
if (regs == NULL) {
if (is_current || t->state == TASK_RUNNING) {
}
EXPORT_SYMBOL(KBacktraceIterator_next);
+static void describe_addr(struct KBacktraceIterator *kbt,
+ unsigned long address,
+ int have_mmap_sem, char *buf, size_t bufsize)
+{
+ struct vm_area_struct *vma;
+ size_t namelen, remaining;
+ unsigned long size, offset, adjust;
+ char *p, *modname;
+ const char *name;
+ int rc;
+
+ /*
+ * Look one byte back for every caller frame (i.e. those that
+ * aren't a new context) so we look up symbol data for the
+ * call itself, not the following instruction, which may be on
+ * a different line (or in a different function).
+ */
+ adjust = !kbt->new_context;
+ address -= adjust;
+
+ if (address >= PAGE_OFFSET) {
+ /* Handle kernel symbols. */
+ BUG_ON(bufsize < KSYM_NAME_LEN);
+ name = kallsyms_lookup(address, &size, &offset,
+ &modname, buf);
+ if (name == NULL) {
+ buf[0] = '\0';
+ return;
+ }
+ namelen = strlen(buf);
+ remaining = (bufsize - 1) - namelen;
+ p = buf + namelen;
+ rc = snprintf(p, remaining, "+%#lx/%#lx ",
+ offset + adjust, size);
+ if (modname && rc < remaining)
+ snprintf(p + rc, remaining - rc, "[%s] ", modname);
+ buf[bufsize-1] = '\0';
+ return;
+ }
+
+ /* If we don't have the mmap_sem, we can't show any more info. */
+ buf[0] = '\0';
+ if (!have_mmap_sem)
+ return;
+
+ /* Find vma info. */
+ vma = find_vma(kbt->task->mm, address);
+ if (vma == NULL || address < vma->vm_start) {
+ snprintf(buf, bufsize, "[unmapped address] ");
+ return;
+ }
+
+ if (vma->vm_file) {
+ char *s;
+ p = d_path(&vma->vm_file->f_path, buf, bufsize);
+ if (IS_ERR(p))
+ p = "?";
+ s = strrchr(p, '/');
+ if (s)
+ p = s+1;
+ } else {
+ p = "anon";
+ }
+
+ /* Generate a string description of the vma info. */
+ namelen = strlen(p);
+ remaining = (bufsize - 1) - namelen;
+ memmove(buf, p, namelen);
+ snprintf(buf + namelen, remaining, "[%lx+%lx] ",
+ vma->vm_start, vma->vm_end - vma->vm_start);
+}
+
/*
* This method wraps the backtracer's more generic support.
* It is only invoked from the architecture-specific code; show_stack()
void tile_show_stack(struct KBacktraceIterator *kbt, int headers)
{
int i;
+ int have_mmap_sem = 0;
if (headers) {
/*
kbt->verbose = 1;
i = 0;
for (; !KBacktraceIterator_end(kbt); KBacktraceIterator_next(kbt)) {
- char *modname;
- const char *name;
- unsigned long address = kbt->it.pc;
- unsigned long offset, size;
char namebuf[KSYM_NAME_LEN+100];
+ unsigned long address = kbt->it.pc;
- if (address >= PAGE_OFFSET)
- name = kallsyms_lookup(address, &size, &offset,
- &modname, namebuf);
- else
- name = NULL;
-
- if (!name)
- namebuf[0] = '\0';
- else {
- size_t namelen = strlen(namebuf);
- size_t remaining = (sizeof(namebuf) - 1) - namelen;
- char *p = namebuf + namelen;
- int rc = snprintf(p, remaining, "+%#lx/%#lx ",
- offset, size);
- if (modname && rc < remaining)
- snprintf(p + rc, remaining - rc,
- "[%s] ", modname);
- namebuf[sizeof(namebuf)-1] = '\0';
- }
+ /* Try to acquire the mmap_sem as we pass into userspace. */
+ if (address < PAGE_OFFSET && !have_mmap_sem && kbt->task->mm)
+ have_mmap_sem =
+ down_read_trylock(&kbt->task->mm->mmap_sem);
+
+ describe_addr(kbt, address, have_mmap_sem,
+ namebuf, sizeof(namebuf));
pr_err(" frame %d: 0x%lx %s(sp 0x%lx)\n",
i++, address, namebuf, (unsigned long)(kbt->it.sp));
pr_err("Stack dump stopped; next frame identical to this one\n");
if (headers)
pr_err("Stack dump complete\n");
+ if (have_mmap_sem)
+ up_read(&kbt->task->mm->mmap_sem);
}
EXPORT_SYMBOL(tile_show_stack);
projects / karo-tx-linux.git / commitdiff