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Bugfix: 32-bit vs 64-bit bug in x86_64-gen.c:gcall_or_jmp

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Verify an immediate value fits into 32 bits before jumping to it/calling
it with a 32-bit immediate operand. Without this fix, code along the
lines of

  ((int (*)(const char *, ...))140244834372944LL)("hi\n");

will fail mysteriously, even if that decimal constant is the correct
address for printf.

See https://github.com/pipcet/tinycc/tree/bugfix-1
This commit is contained in:
Philip 2015-04-23 17:30:16 +00:00
parent b08ce88082
commit aacf65bbfa
1 changed files with 2 additions and 1 deletions
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3
x86_64-gen.c
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@ -600,7 +600,8 @@ void store(int r, SValue *v)
static void gcall_or_jmp(int is_jmp) static void gcall_or_jmp(int is_jmp)
{ {
int r; int r;
if ((vtop->r & (VT_VALMASK | VT_LVAL)) == VT_CONST) { if ((vtop->r & (VT_VALMASK | VT_LVAL)) == VT_CONST &&
((vtop->r & VT_SYM) || (vtop->c.ll-4) == (int)(vtop->c.ll-4))) {
/* constant case */ /* constant case */
if (vtop->r & VT_SYM) { if (vtop->r & VT_SYM) {
/* relocation case */ /* relocation case */