[Guile-commits] 362/437: Avoid problems if JIT_INSTR_MAX is miscalculated

[Andy Wingo]

wingo pushed a commit to branch lightning
in repository guile.

commit fb21cf9f3806845ec3f3da704432a3759618a7b5
Author: pcpa <address@hidden>
Date:   Sat Feb 7 17:08:43 2015 -0200

    Avoid problems if JIT_INSTR_MAX is miscalculated
    
        * lib/jit_size.c: Preventively use at least 144 bytes
        if JIT_INSTR_MAX is less than it. The logic is not
        guaranteed to be 100% precise, it is mostly heuristics
        to allocate a buffer with as close as possible size,
        but a wrong value may cause code generation to write
        past the end of the buffer.
---
 ChangeLog      | 9 +++++++++
 lib/jit_size.c | 2 +-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 0a6fa04..336bf07 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2015-02-07 Paulo Andrade <address@hidden>
+
+       * lib/jit_size.c: Preventively use at least 144 bytes
+       if JIT_INSTR_MAX is less than it. The logic is not
+       guaranteed to be 100% precise, it is mostly heuristics
+       to allocate a buffer with as close as possible size,
+       but a wrong value may cause code generation to write
+       past the end of the buffer.
+
 2015-02-03 Paulo Andrade <address@hidden>
 
        * lib/lightning.c: Correct the reason the bug in
diff --git a/lib/jit_size.c b/lib/jit_size.c
index ae4c633..612417e 100644
--- a/lib/jit_size.c
+++ b/lib/jit_size.c
@@ -110,7 +110,7 @@ _jit_get_size(jit_state_t *_jit)
 jit_word_t
 jit_get_max_instr(void)
 {
-    return (JIT_INSTR_MAX);
+    return (JIT_INSTR_MAX >= 144 ? JIT_INSTR_MAX : 144);
 }
 
 void