diff options
Diffstat (limited to 'lib/vsprintf.c')
| -rw-r--r-- | lib/vsprintf.c | 51 |
1 files changed, 42 insertions, 9 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 14c9a6af1b23..41ddc353ebb8 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -1265,7 +1265,7 @@ char *mac_address_string(char *buf, char *end, u8 *addr, case 'R': reversed = true; - /* fall through */ + fallthrough; default: separator = ':'; @@ -1682,7 +1682,7 @@ char *uuid_string(char *buf, char *end, const u8 *addr, switch (*(++fmt)) { case 'L': uc = true; - /* fall through */ + fallthrough; case 'l': index = guid_index; break; @@ -2090,6 +2090,32 @@ 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); + +static int __init no_hash_pointers_enable(char *str) +{ + no_hash_pointers = true; + + pr_warn("**********************************************************\n"); + pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); + pr_warn("** **\n"); + pr_warn("** This system shows unhashed kernel memory addresses **\n"); + pr_warn("** via the console, logs, and other interfaces. This **\n"); + pr_warn("** might reduce the security of your system. **\n"); + pr_warn("** **\n"); + pr_warn("** If you see this message and you are not debugging **\n"); + pr_warn("** the kernel, report this immediately to your system **\n"); + pr_warn("** administrator! **\n"); + pr_warn("** **\n"); + pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); + pr_warn("**********************************************************\n"); + + return 0; +} +early_param("no_hash_pointers", no_hash_pointers_enable); + /* * Show a '%p' thing. A kernel extension is that the '%p' is followed * by an extra set of alphanumeric characters that are extended format @@ -2219,7 +2245,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, case 'S': case 's': ptr = dereference_symbol_descriptor(ptr); - /* fall through */ + fallthrough; case 'B': return symbol_string(buf, end, ptr, spec, fmt); case 'R': @@ -2297,8 +2323,14 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, } } - /* default is to _not_ leak addresses, hash before printing */ - return ptr_to_id(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); } /* @@ -2450,7 +2482,7 @@ qualifier: case 'x': spec->flags |= SMALL; - /* fall through */ + fallthrough; case 'X': spec->base = 16; @@ -2459,6 +2491,7 @@ qualifier: case 'd': case 'i': spec->flags |= SIGN; + break; case 'u': break; @@ -2468,7 +2501,7 @@ qualifier: * utility, treat it as any other invalid or * unsupported format specifier. */ - /* fall through */ + fallthrough; default: WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt); @@ -3411,10 +3444,10 @@ int vsscanf(const char *buf, const char *fmt, va_list args) break; case 'i': base = 0; - /* fall through */ + fallthrough; case 'd': is_sign = true; - /* fall through */ + fallthrough; case 'u': break; case '%': |