[1/2] os: fix vararg length calculation

Submitted by Peter Hutterer on June 29, 2012, 5:30 a.m.

Details

Message ID 20120629053051.GA31436@yabbi.bne.redhat.com
State Not Applicable
Headers show

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Commit Message

Peter Hutterer June 29, 2012, 5:30 a.m. 
Make %u and %x sizeof(unsigned int), %p sizeof(void*). This is printf
behaviour and we can't guarantee that void* is uint64_t anyway.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
---
This needs to be squashed into:
  Add LogMessageVerbSigSafe() for logging messages while in signal context

Fixes the test/input crash on 32-bit userspace

 os/log.c |   15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

Patch hide | download patch | download mbox 

diff --git a/os/log.c b/os/log.c
index 3ae8fd4..6399eba 100644
--- a/os/log.c
+++ b/os/log.c
@@ -289,6 +289,7 @@  pnprintf(char *string, size_t size, const char *f, va_list args)
     char number[21];
     int p_len;
     int i;
+    uint64_t ui;
 
     for (; f_idx < f_len && s_idx < size - 1; f_idx++) {
         if (f[f_idx] != '%') {
@@ -306,7 +307,8 @@  pnprintf(char *string, size_t size, const char *f, va_list args)
             break;
 
         case 'u':
-            FormatUInt64(va_arg(args, uint64_t), number);
+            ui = va_arg(args, unsigned);
+            FormatUInt64(ui, number);
             p_len = strlen_sigsafe(number);
 
             for (i = 0; i < p_len && s_idx < size - 1; i++)
@@ -317,10 +319,17 @@  pnprintf(char *string, size_t size, const char *f, va_list args)
             string[s_idx++] = '0';
             if (s_idx < size - 1)
                 string[s_idx++] = 'x';
-            /* Intentional fall-through */
+            ui = (uint64_t)va_arg(args, void*);
+            FormatUInt64Hex(ui, number);
+            p_len = strlen_sigsafe(number);
+
+            for (i = 0; i < p_len && s_idx < size - 1; i++)
+                string[s_idx++] = number[i];
+            break;
 
         case 'x':
-            FormatUInt64Hex(va_arg(args, uint64_t), number);
+            ui = va_arg(args, unsigned);
+            FormatUInt64Hex(ui, number);
             p_len = strlen_sigsafe(number);
 
             for (i = 0; i < p_len && s_idx < size - 1; i++)

Comments

Chase Douglas July 2, 2012, 6:13 p.m. 
On 06/28/2012 10:30 PM, Peter Hutterer wrote:
> Make %u and %x sizeof(unsigned int), %p sizeof(void*). This is printf
> behaviour and we can't guarantee that void* is uint64_t anyway.
>
> Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
> ---
> This needs to be squashed into:
>    Add LogMessageVerbSigSafe() for logging messages while in signal context
>
> Fixes the test/input crash on 32-bit userspace

This looks correct to me. For both patches:

Reviewed-by: Chase Douglas <chase.douglas@!canonical.com>