[for-next][PATCH 11/18] vsprintf: Do not preprocess non-dereferenced pointers for bprintf (%px and %pK)

From: Steven Rostedt
Date: Fri Apr 06 2018 - 09:02:45 EST


From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>

Commit 841a915d20c7b2 ("printf: Do not have bprintf dereference pointers")
would preprocess various pointers that are dereferenced in the bprintf()
because the recording and printing are done at two different times. Some
pointers stayed dereferenced in the ring buffer because user space could
handle them (namely "%pS" and friends). Pointers that are not dereferenced
should not be processed immediately but instead just saved directly.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 841a915d20c7b2 ("printf: Do not have bprintf dereference pointers")
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
lib/vsprintf.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index d7a708f82559..89f8a4a4b770 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -2591,6 +2591,8 @@ int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
case 's':
case 'F':
case 'f':
+ case 'x':
+ case 'K':
save_arg(void *);
break;
default:
@@ -2765,6 +2767,8 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
case 's':
case 'F':
case 'f':
+ case 'x':
+ case 'K':
process = true;
break;
default:
--
2.15.1