@@ -3485,8 +3485,7 @@
difficult since unequal pointers can no longer be
compared. However, if this command-line option is
specified, then all normal pointers will have their true
- value printed. Pointers printed via %pK may still be
- hashed. This option should only be specified when
+ value printed. This option should only be specified when
debugging the kernel. Please do not use on production
kernels.
@@ -53,6 +53,10 @@
#include <linux/string_helpers.h>
#include "kstrtox.h"
+/* Disable pointer hashing if requested */
+bool no_hash_pointers __ro_after_init;
+EXPORT_SYMBOL_GPL(no_hash_pointers);
+
static noinline unsigned long long simple_strntoull(const char *startp, size_t max_chars, char **endp, unsigned int base)
{
const char *cp;
@@ -848,6 +852,19 @@ static char *ptr_to_id(char *buf, char *end, const void *ptr,
return pointer_string(buf, end, (const void *)hashval, spec);
}
+static char *default_pointer(char *buf, char *end, const void *ptr,
+ struct printf_spec spec)
+{
+ /*
+ * default is to _not_ leak addresses, so hash before printing,
+ * unless no_hash_pointers is specified on the command line.
+ */
+ if (unlikely(no_hash_pointers))
+ return pointer_string(buf, end, ptr, spec);
+
+ return ptr_to_id(buf, end, ptr, spec);
+}
+
int kptr_restrict __read_mostly;
static noinline_for_stack
@@ -857,7 +874,7 @@ char *restricted_pointer(char *buf, char *end, const void *ptr,
switch (kptr_restrict) {
case 0:
/* Handle as %p, hash and do _not_ leak addresses. */
- return ptr_to_id(buf, end, ptr, spec);
+ return default_pointer(buf, end, ptr, spec);
case 1: {
const struct cred *cred;
@@ -2223,10 +2240,6 @@ char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
return widen_string(buf, buf - buf_start, end, spec);
}
-/* Disable pointer hashing if requested */
-bool no_hash_pointers __ro_after_init;
-EXPORT_SYMBOL_GPL(no_hash_pointers);
-
int __init no_hash_pointers_enable(char *str)
{
if (no_hash_pointers)
@@ -2455,7 +2468,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
case 'e':
/* %pe with a non-ERR_PTR gets treated as plain %p */
if (!IS_ERR(ptr))
- break;
+ return default_pointer(buf, end, ptr, spec);
return err_ptr(buf, end, ptr, spec);
case 'u':
case 'k':
@@ -2465,16 +2478,9 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
default:
return error_string(buf, end, "(einval)", spec);
}
+ default:
+ return default_pointer(buf, end, ptr, spec);
}
-
- /*
- * default is to _not_ leak addresses, so hash before printing,
- * unless no_hash_pointers is specified on the command line.
- */
- if (unlikely(no_hash_pointers))
- return pointer_string(buf, end, ptr, spec);
- else
- return ptr_to_id(buf, end, ptr, spec);
}
/*
Although kptr_restrict is set to 0 and the kernel is booted with no_hash_pointers parameter, the content of /proc/vmallocinfo is lacking the real addresses. / # cat /proc/vmallocinfo 0x(ptrval)-0x(ptrval) 8192 load_module+0xc0c/0x2c0c pages=1 vmalloc 0x(ptrval)-0x(ptrval) 12288 start_kernel+0x4e0/0x690 pages=2 vmalloc 0x(ptrval)-0x(ptrval) 12288 start_kernel+0x4e0/0x690 pages=2 vmalloc 0x(ptrval)-0x(ptrval) 8192 _mpic_map_mmio.constprop.0+0x20/0x44 phys=0x80041000 ioremap 0x(ptrval)-0x(ptrval) 12288 _mpic_map_mmio.constprop.0+0x20/0x44 phys=0x80041000 ioremap ... According to the documentation for /proc/sys/kernel/, %pK is equivalent to %p when kptr_restrict is set to 0. Fixes: 5ead723a20e0 ("lib/vsprintf: no_hash_pointers prints all addresses as unhashed") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> --- v2: Refactor %p default handling into default_pointer() --- .../admin-guide/kernel-parameters.txt | 3 +- lib/vsprintf.c | 36 +++++++++++-------- 2 files changed, 22 insertions(+), 17 deletions(-)