From 10ae1a84d0e83a6af8629a1e54d597931591ae67 Mon Sep 17 00:00:00 2001 From: Carl-Daniel Hailfinger Date: Thu, 19 Mar 2009 12:53:57 +0000 Subject: [PATCH] This patch tries to make printk more readable and reliable. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Base 16 number printing used digits[33] instead of the more readable 'x' for the "0x" prefix. That means you have to look up an array just to find out what the code does. Change it. We already write "" if printk gets a NULL pointer as string argument. Introduce "" for string arguments with addresses below 0x400. This error happened in the past when dereferencing a struct member with a string and the struct had the address NULL. Check if all to-be-printed characters in the string are indeed printable. The idea is to catch garbage strings from stray pointers and print "" instead. If a string contains characters outside classic ASCII printable stuff, this will trigger. An example would be characters with diacritic marks like äöüéăçőč. Then again, I don't see localized versions of coreboot on the horizon. Maybe for payloads, but not for coreboot itself. Signed-off-by: Carl-Daniel Hailfinger Acked-by: Peter Stuge git-svn-id: svn://coreboot.org/repository/coreboot-v3@1158 f3766cd6-281f-0410-b1cd-43a5c92072e9 --- lib/vtxprintf.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/lib/vtxprintf.c b/lib/vtxprintf.c index 792d511e8c..bc3621b91b 100644 --- a/lib/vtxprintf.c +++ b/lib/vtxprintf.c @@ -16,6 +16,7 @@ #define isdigit(c) ((c) >= '0' && (c) <= '9') #define is_digit isdigit #define isxdigit(c) (((c) >= '0' && (c) <= '9') || ((c) >= 'a' && (c) <= 'f') || ((c) >= 'A' && (c) <= 'F')) +#define isprint(c) ((c) == '\n' || ((c) >= ' ' && (c) <= '~')) static int skip_atoi(const char **s) { @@ -87,7 +88,7 @@ static int number(void (*tx_byte)(unsigned char byte, void *arg), void *arg, tx_byte('0', arg), count++; else if (base==16) { tx_byte('0', arg), count++; - tx_byte(digits[33], arg), count++; + tx_byte('x', arg), count++; } } if (!(type & LEFT)) @@ -194,9 +195,15 @@ int vtxprintf(void (*tx_byte)(unsigned char byte, void *arg), void *arg, const c s = va_arg(args, char *); if (!s) s = ""; + /* Catch almost-NULL pointers as well */ + if ((size_t)s < 0x400) + s = ""; len = strnlen(s, precision); + for (i = 0; i < len; ++i) + if (!isprint(*s[i])) + s = ""; if (!(flags & LEFT)) while (len < field_width--) tx_byte(' ', arg), count++;