Hi,
I totally biffed the previous version of this patch, as it was built
against an experimental tree instead of trunk. Trying again...
Although safe_inc_pos avoids buffer overruns in rs6000-gen-builtins.c,
there are some other routines where we fail to detect the possibility.
Clean those up! (Also, safe_inc_pos is not quite right itself.)
Bootstrapped and tested on powerpc64le-linux-gnu, this time without
some unsubmitted patches in the way. Is this OK for trunk?
Thanks,
Bill
2021-08-19 Bill Schmidt
gcc/
PR target/101830
* config/rs6000/rs6000-gen-builtins.c (consume_whitespace):
Diagnose buffer overrun.
(safe_inc_pos): Fix overrun detection.
(match_identifier): Diagnose buffer overrun.
(match_integer): Likewise.
(match_to_right_bracket): Likewise.
---
gcc/config/rs6000/rs6000-gen-builtins.c | 34 ++---
1 file changed, 30 insertions(+), 4 deletions(-)
diff --git a/gcc/config/rs6000/rs6000-gen-builtins.c
b/gcc/config/rs6000/rs6000-gen-builtins.c
index e5d3b71b622..05b2d2939b5 100644
--- a/gcc/config/rs6000/rs6000-gen-builtins.c
+++ b/gcc/config/rs6000/rs6000-gen-builtins.c
@@ -597,6 +597,13 @@ consume_whitespace (void)
{
while (pos < LINELEN && isspace(linebuf[pos]) && linebuf[pos] != '\n')
pos++;
+
+ if (pos >= LINELEN)
+{
+ diag ("line length overrun at %d.\n", pos);
+ exit (1);
+}
+
return;
}
@@ -623,7 +630,7 @@ advance_line (FILE *file)
static inline void
safe_inc_pos (void)
{
- if (pos++ >= LINELEN)
+ if (++pos >= LINELEN)
{
(*diag) ("line length overrun.\n");
exit (1);
@@ -636,9 +643,16 @@ static char *
match_identifier (void)
{
int lastpos = pos - 1;
- while (isalnum (linebuf[lastpos + 1]) || linebuf[lastpos + 1] == '_')
+ while (lastpos < LINELEN - 1
+&& (isalnum (linebuf[lastpos + 1]) || linebuf[lastpos + 1] == '_'))
++lastpos;
+ if (lastpos >= LINELEN - 1)
+{
+ diag ("line length overrun at %d.\n", lastpos);
+ exit (1);
+}
+
if (lastpos < pos)
return 0;
@@ -660,9 +674,15 @@ match_integer (void)
safe_inc_pos ();
int lastpos = pos - 1;
- while (isdigit (linebuf[lastpos + 1]))
+ while (lastpos < LINELEN - 1 && isdigit (linebuf[lastpos + 1]))
++lastpos;
+ if (lastpos >= LINELEN - 1)
+{
+ diag ("line length overrun at %d.\n", lastpos);
+ exit (1);
+}
+
if (lastpos < pos)
return NULL;
@@ -680,7 +700,7 @@ static const char *
match_to_right_bracket (void)
{
int lastpos = pos - 1;
- while (linebuf[lastpos + 1] != ']')
+ while (lastpos < LINELEN - 1 && linebuf[lastpos + 1] != ']')
{
if (linebuf[lastpos + 1] == '\n')
{
@@ -690,6 +710,12 @@ match_to_right_bracket (void)
++lastpos;
}
+ if (lastpos >= LINELEN - 1)
+{
+ diag ("line length overrun at %d.\n", lastpos);
+ exit (1);
+}
+
if (lastpos < pos)
return 0;
--
2.27.0
