diff options
Diffstat (limited to 'common/printf.c')
| -rw-r--r-- | common/printf.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/common/printf.c b/common/printf.c index 1f6733e552..dd66d3630a 100644 --- a/common/printf.c +++ b/common/printf.c @@ -225,7 +225,7 @@ int vfnprintf(int (*addchar)(void *context, int c), void *context, /* * Handle length: - * %l - long + * %l - DEPRECATED (see below) * %ll - long long * %z - size_t */ @@ -239,6 +239,22 @@ int vfnprintf(int (*addchar)(void *context, int c), void *context, c = *format++; } + /* + * %l on 32-bit systems is deliberately + * deprecated. It was originally used as + * shorthand for 64-bit values. When + * compile-time printf format checking was + * enabled, it had to be cleaned up to be + * sizeof(long), which is 32 bits on today's + * ECs. This presents a mismatch which can be + * dangerous if a new-style printf call is + * cherry-picked into an old firmware branch. + * See crbug.com/984041 for more context. + */ + if (!(flags & PF_64BIT)) { + format = error_str; + continue; + } } else if (c == 'z') { if (sizeof(size_t) == sizeof(uint64_t)) flags |= PF_64BIT; |