libvx32/FreeBSD: better handling of segmentation fault, breakpoint - vx32 - Local 9vx git repository for patches.
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---
(DIR) commit c82f48a95967c71d4f81debf6ae9c15a3b60ebe9
(DIR) parent d2d43ccb6890cbd0afaaa45a24db7b8d6b05129c
(HTM) Author: Russ Cox <rsc@swtch.com>
Date: Sun, 29 Jun 2008 21:46:25 -0400
libvx32/FreeBSD: better handling of segmentation fault, breakpoint
Diffstat:
src/libvx32/freebsd.c | 41 +++++++++++++++++--------------
1 file changed, 22 insertions(+), 19 deletions(-)
---
(DIR) diff --git a/src/libvx32/freebsd.c b/src/libvx32/freebsd.c
@@ -157,13 +157,10 @@ int vx32_sighandler(int signo, siginfo_t *si, void *v)
vxemu *emu;
ucontext_t *uc;
mcontext_t *mc;
- uint32_t cr2;
uc = v;
mc = &uc->uc_mcontext;
- cr2 = (uint32_t)si->si_addr;
-
// We can't be sure that vxemu is running,
// and thus that %VSEG is actually mapped to a
// valid vxemu. The only way to tell is to look at %VSEG.
@@ -207,39 +204,45 @@ int vx32_sighandler(int signo, siginfo_t *si, void *v)
// so that thread-local storage and such works.
vxrun_cleanup(emu);
- // dumpmcontext(mc, cr2);
+ // dumpmcontext(mc, (uint32_t)si->si_addr);
+ uint32_t addr;
int newtrap;
+ addr = 0;
switch(signo){
case SIGSEGV:
+ newtrap = VXTRAP_PAGEFAULT;
+ addr = (uint32_t)si->si_addr;
+ break;
case SIGBUS:
+ /*
+ * On FreeBSD, SIGBUS means segmentation limit fault.
+ * The supplied address is bogus.
+ */
newtrap = VXTRAP_PAGEFAULT;
+ addr = 0;
break;
case SIGFPE:
- // iprint("fpe %d\n", si->si_code);
+ // vxprint("fpe %d\n", si->si_code);
newtrap = VXTRAP_FLOAT;
+ addr = 0;
break;
case SIGVTALRM:
newtrap = VXTRAP_IRQ + VXIRQ_TIMER;
+ addr = 0;
break;
case SIGTRAP:
-#warning "FreeBSD: need to test single-stepping"
- // Linux sends SIGTRAP when it gets a processor
+ // FreeBSD sends SIGTRAP when it gets a processor
// debug exception, which is caused by single-stepping
- // with the TF bit, among other things. The processor
- // turns off the TF bit before generating the trap, but
- // it appears that Linux turns it back on for us.
- // Let's use it to confirm that this is a single-step trap.
- if (mc->mc_eflags & EFLAGS_TF){
- newtrap = VXTRAP_SINGLESTEP;
- mc->mc_eflags &= ~EFLAGS_TF;
- }else{
- vxprint("Unexpected sigtrap eflags=%#x\n", mc->mc_eflags);
- newtrap = VXTRAP_SIGNAL + signo;
- }
+ // with the TF bit, among other things.
+ // It appears that FreeBSD does not turn the flag back on
+ // before entering the signal handler.
+ addr = 0;
+ newtrap = VXTRAP_SINGLESTEP;
+ mc->mc_eflags &= ~EFLAGS_TF; // Just in case.
break;
default:
@@ -323,7 +326,7 @@ int vx32_sighandler(int signo, siginfo_t *si, void *v)
if (emu->trapenv == NULL)
return 0;
emu->cpu.traperr = mc->mc_err;
- emu->cpu.trapva = cr2;
+ emu->cpu.trapva = addr;
memmove(&mc->mc_gs, &emu->trapenv->mc_gs, 19*4);
return 1;
}