There is a print_vma_addr function used several places
that requires KERN_CONT use.
Add a %pv mechanism to avoid the need for KERN_CONT.
An example conversion is arch/x86/kernel/signal.c
from:
if (show_unhandled_signals && printk_ratelimit()) {
printk("%s"
"%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
me->comm, me->pid, where, frame,
regs->ip, regs->sp, regs->orig_ax);
print_vma_addr(KERN_CONT " in ", regs->ip);
pr_cont("\n");
to:
printk("%s"
"%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx
in %pv\n",
task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
me->comm, me->pid, where, frame,
regs->ip, regs->sp, regs->orig_ax, (void *)regs->ip);
---
lib/vsprintf.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 52 insertions(+)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index c155769559ab..654402c43f8d 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -995,6 +995,12 @@ static const struct printf_spec default_dec_spec = {
.precision = -1,
};
+static const struct printf_spec default_hex_spec = {
+ .base = 16,
+ .precision = -1,
+ .flags = SMALL,
+};
+
static const struct printf_spec default_dec02_spec = {
.base = 10,
.field_width = 2,
@@ -2089,6 +2095,50 @@ char *fwnode_string(char *buf, char *end, struct
fwnode_handle *fwnode,
return widen_string(buf, buf - buf_start, end, spec);
}
+static noinline_for_stack
+char *vma_addr(char *buf, char *end, void *ip,
+ struct printf_spec spec, const char *fmt)
+{
+#ifdef CONFIG_MMU
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+
+ /*
+ * we might be running from an atomic context so we cannot sleep
+ */
+ if (!mmap_read_trylock(mm))
+ return buf;
+
+ vma = find_vma(mm, (unsigned long)ip);
+ if (vma && vma->vm_file) {
+ char *p;
+ struct file *f = vma->vm_file;
+ char *page = (char *)__get_free_page(GFP_NOWAIT);
+
+ if (page) {
+ p = file_path(f, page, PAGE_SIZE);
+ if (IS_ERR(p))
+ p = "?";
+ buf = string(buf, end, kbasename(p), default_str_spec);
+ buf = string_nocheck(buf, end, "[", default_str_spec);
+ buf = pointer_string(buf, end,
+ (void *)vma->vm_start,
+ default_hex_spec);
+ buf = string_nocheck(buf, end, "+", default_str_spec);
+ buf = pointer_string(buf, end,
+ (void *)(vma->vm_end -
vma->vm_start),
+ default_hex_spec);
+ buf = string_nocheck(buf, end, "]", default_str_spec);
+ free_page((unsigned long)page);
+ }
+ }
+ mmap_read_unlock(mm);
+#else
+ buf = string_nocheck(buf, end, "CONFIG_MMU=n", default_str_spec);
+#endif
+ return buf;
+}
+
/*
* Show a '%p' thing. A kernel extension is that the '%p' is followed
* by an extra set of alphanumeric characters that are extended format
@@ -2254,6 +2304,8 @@ char *pointer(const char *fmt, char *buf, char *end, void
*ptr,
return uuid_string(buf, end, ptr, spec, fmt);
case 'V':
return va_format(buf, end, ptr, spec, fmt);
+ case 'v':
+ return vma_addr(buf, end, ptr, spec, fmt);
case 'K':
return restricted_pointer(buf, end, ptr, spec);
case 'N':
