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eina - mmap safety handler - fix to only handle sigbus's from io 

@fix

this fixes the eina mmap safety handler to only  handle what comes
from actual i/o errors (not actual corrupt/hw memory faults or invalid
objects), and if it's not a sigbus eina mmap should handle then pass
it onto the previous handler before eina mmap took over.
This commit is contained in:
Carsten Haitzler 2015-01-13 19:26:55 +09:00
parent 43a60f7718
commit 615456aae8
1 changed files with 36 additions and 7 deletions
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43
src/lib/eina/eina_mmap.c
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@ -65,6 +65,7 @@ static Eina_Bool mmap_safe = EINA_FALSE;
static int _eina_mmap_log_dom = -1;
static int _eina_mmap_zero_fd = -1;
static long _eina_mmap_pagesize = -1;
static struct sigaction _eina_mmap_prev_sigaction;
#ifdef ERR
#undef ERR
@ -77,9 +78,7 @@ static long _eina_mmap_pagesize = -1;
#define DBG(...) EINA_LOG_DOM_DBG(_eina_mmap_log_dom, __VA_ARGS__)
static void
_eina_mmap_safe_sigbus(int sig EINA_UNUSED,
siginfo_t *siginfo,
void *ptr EINA_UNUSED)
_eina_mmap_safe_sigbus(int sig, siginfo_t *siginfo, void *ptr)
{
unsigned char *addr = (unsigned char *)(siginfo->si_addr);
int perrno;
@ -87,11 +86,41 @@ _eina_mmap_safe_sigbus(int sig EINA_UNUSED,
/* save previous errno */
perrno = errno;
/* if problems was an unaligned access - complain accordingly and abort */
if (siginfo->si_code == BUS_ADRALN)
if (siginfo->si_code != BUS_ADRERR)
{
ERR("Unaligned memory access. SIGBUS!!!");
if (siginfo->si_code == BUS_ADRALN)
ERR("Unaligned memory access - BUS_ADRALN. SIGBUS!!!");
else if (siginfo->si_code == BUS_OBJERR)
ERR("Invalid object - BUS_OBJERR. SIGBUS!!!");
else if (siginfo->si_code == BUS_MCEERR_AR)
ERR("Memory Fault - BUS_MCEERR_AR. SIGBUS!!!");
else if (siginfo->si_code == BUS_MCEERR_AO)
ERR("Memory Fault - BUS_MCEERR_AO. SIGBUS!!!");
errno = perrno;
abort();
if (_eina_mmap_prev_sigaction.sa_flags & SA_SIGINFO)
{
if (_eina_mmap_prev_sigaction.sa_sigaction)
{
_eina_mmap_prev_sigaction.sa_sigaction(sig, siginfo, ptr);
if (_eina_mmap_prev_sigaction.sa_flags & SA_RESETHAND)
_eina_mmap_prev_sigaction.sa_sigaction = NULL;
if (_eina_mmap_prev_sigaction.sa_flags & SA_RESTART)
return;
}
abort();
}
else
{
if (_eina_mmap_prev_sigaction.sa_handler == SIG_IGN)
return;
else if (_eina_mmap_prev_sigaction.sa_handler == SIG_DFL)
abort();
else if (_eina_mmap_prev_sigaction.sa_handler)
{
_eina_mmap_prev_sigaction.sa_handler(sig);
abort();
}
}
}
/* send this to stderr - not eina_log. Specifically want this on stderr */
fprintf(stderr,
@ -171,7 +200,7 @@ eina_mmap_safety_enabled_set(Eina_Bool enabled)
sa.sa_sigaction = _eina_mmap_safe_sigbus;
sa.sa_flags = SA_RESTART | SA_SIGINFO;
sigemptyset(&sa.sa_mask);
if (sigaction(SIGBUS, &sa, NULL) == 0) goto done;
if (sigaction(SIGBUS, &sa, &_eina_mmap_prev_sigaction) == 0) goto done;
/* setup of SIGBUS handler failed, lets close zero page dev and fail */
close(_eina_mmap_zero_fd);
_eina_mmap_zero_fd = -1;