In perl.git, the branch blead has been updated
<https://perl5.git.perl.org/perl.git/commitdiff/35ad0133df9b65a4e32f2f07a2a05b387bd79591?hp=d586c8db9528182f19e2cca28ca3e6a38c65b9a8>
- Log -----------------------------------------------------------------
commit 35ad0133df9b65a4e32f2f07a2a05b387bd79591
Author: Tony Cook <t...@develop-help.com>
Date: Thu Jan 3 10:48:05 2019 +1100
(perl #133575) prevent set/longjmp clobbering locals in S_fold_constants
My original approach moved the whole switch into the new function,
but that was a lot messier, and I don't think it's necessary.
pad_swipe() can throw, but only for panics, and in DESTROY if
refadjust is true, which isn't the case here.
CLEAR_ERRSV() might throw if the code called by CALLRUNOPS()
puts an object that dies in DESTROY in $@, but I think that
might cause an infinite loop in the original code.
-----------------------------------------------------------------------
Summary of changes:
op.c | 32 ++++++++++++++++++++++++--------
1 file changed, 24 insertions(+), 8 deletions(-)
diff --git a/op.c b/op.c
index 146407ba70..0b46b348cb 100644
--- a/op.c
+++ b/op.c
@@ -5464,15 +5464,34 @@ S_op_integerize(pTHX_ OP *o)
return o;
}
+/* This function exists solely to provide a scope to limit
+ setjmp/longjmp() messing with auto variables.
+ */
+PERL_STATIC_INLINE int
+S_fold_constants_eval(pTHX) {
+ int ret = 0;
+ dJMPENV;
+
+ JMPENV_PUSH(ret);
+
+ if (ret == 0) {
+ CALLRUNOPS(aTHX);
+ }
+
+ JMPENV_POP;
+
+ return ret;
+}
+
static OP *
S_fold_constants(pTHX_ OP *const o)
{
dVAR;
- OP * volatile curop;
+ OP *curop;
OP *newop;
- volatile I32 type = o->op_type;
+ I32 type = o->op_type;
bool is_stringify;
- SV * volatile sv = NULL;
+ SV *sv = NULL;
int ret = 0;
OP *old_next;
SV * const oldwarnhook = PL_warnhook;
@@ -5480,7 +5499,6 @@ S_fold_constants(pTHX_ OP *const o)
COP not_compiling;
U8 oldwarn = PL_dowarn;
I32 old_cxix;
- dJMPENV;
PERL_ARGS_ASSERT_FOLD_CONSTANTS;
@@ -5582,15 +5600,15 @@ S_fold_constants(pTHX_ OP *const o)
assert(IN_PERL_RUNTIME);
PL_warnhook = PERL_WARNHOOK_FATAL;
PL_diehook = NULL;
- JMPENV_PUSH(ret);
/* Effective $^W=1. */
if ( ! (PL_dowarn & G_WARN_ALL_MASK))
PL_dowarn |= G_WARN_ON;
+ ret = S_fold_constants_eval(aTHX);
+
switch (ret) {
case 0:
- CALLRUNOPS(aTHX);
sv = *(PL_stack_sp--);
if (o->op_targ && sv == PAD_SV(o->op_targ)) { /* grab pad temp? */
pad_swipe(o->op_targ, FALSE);
@@ -5608,7 +5626,6 @@ S_fold_constants(pTHX_ OP *const o)
o->op_next = old_next;
break;
default:
- JMPENV_POP;
/* Don't expect 1 (setjmp failed) or 2 (something called my_exit) */
PL_warnhook = oldwarnhook;
PL_diehook = olddiehook;
@@ -5616,7 +5633,6 @@ S_fold_constants(pTHX_ OP *const o)
* the stack - eg any nested evals */
Perl_croak(aTHX_ "panic: fold_constants JMPENV_PUSH returned %d", ret);
}
- JMPENV_POP;
PL_dowarn = oldwarn;
PL_warnhook = oldwarnhook;
PL_diehook = olddiehook;
--
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