diff options
| author |  Maxime Dénès <mail@maximedenes.fr> | 2016-10-19 14:48:14 +0200 |
|---|---|---|
| committer | Maxime Dénès <mail@maximedenes.fr> | 2016-10-24 18:04:26 +0200 |
| commit | 897ce077f11940adce406a20ad7d5c128e90cc28 (patch) | |
| tree | db359323a84ed17d180e01ffb6af67885a3ecbfc /kernel/byterun/coq_fix_code.c | |
| parent | 1d769e02b3baba54246c942fe116abaf850892db (diff) | |
Fix #5127 Memory corruption with the VM
The bytecode interpreter ensures that the stack space available at some
points is above a static threshold. However, arbitrary large stack space
can be needed between two check points, leading to segmentation faults
in some cases.
We track the use of stack space at compilation time and add
an instruction to ensure greater stack capacity when required. This is
inspired from OCaml's PR#339 and PR#7168.
Patch written with Benjamin Grégoire.
Diffstat (limited to 'kernel/byterun/coq_fix_code.c')
| -rw-r--r-- | kernel/byterun/coq_fix_code.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/kernel/byterun/coq_fix_code.c b/kernel/byterun/coq_fix_code.c index 29e33d349..d5feafbf9 100644 --- a/kernel/byterun/coq_fix_code.c +++ b/kernel/byterun/coq_fix_code.c @@ -57,7 +57,7 @@ void init_arity () { arity[MAKEBLOCK1]=arity[MAKEBLOCK2]=arity[MAKEBLOCK3]=arity[MAKEBLOCK4]= arity[MAKEACCU]=arity[CONSTINT]=arity[PUSHCONSTINT]=arity[GRABREC]= arity[PUSHFIELDS]=arity[GETFIELD]=arity[SETFIELD]= - arity[BRANCH]=arity[ISCONST]= 1; + arity[BRANCH]=arity[ISCONST]=arity[ENSURESTACKCAPACITY]=1; /* instruction with two operands */ arity[APPTERM]=arity[MAKEBLOCK]=arity[CLOSURE]= arity[ARECONST]=arity[PROJ]=2; @@ -79,7 +79,7 @@ void * coq_stat_alloc (asize_t sz) value coq_makeaccu (value i) { code_t q; - code_t res = coq_stat_alloc(8); + code_t res = coq_stat_alloc(2 * sizeof(opcode_t)); q = res; *q++ = VALINSTR(MAKEACCU); *q = (opcode_t)Int_val(i); @@ -91,13 +91,13 @@ value coq_pushpop (value i) { int n; n = Int_val(i); if (n == 0) { - res = coq_stat_alloc(4); + res = coq_stat_alloc(sizeof(opcode_t)); *res = VALINSTR(STOP); return (value)res; } else { code_t q; - res = coq_stat_alloc(12); + res = coq_stat_alloc(3 * sizeof(opcode_t)); q = res; *q++ = VALINSTR(POP); *q++ = (opcode_t)n; |