FreeBSD sigwait syscall: fixes for unusual return codes

sigwait doesn't follow the usual syscall convention of
returning -1 on error and setting errno. Instead it
returns errno and 0 means success.

Previously the POST was getting called on failure, potentially
resulting in memory getting incorrectly marked as accessible and
initialized.

Also only flag 'may block' if the first sigset argument is
accessible.

diff --git a/coregrind/m_syswrap/syswrap-freebsd.c b/coregrind/m_syswrap/syswrap-freebsd.c
index 787581b86006b2bdc33c447e13209227be2de129..685eb6be076c5e610575bce0d32e1770f9ed554f 100644 (file)
--- a/coregrind/m_syswrap/syswrap-freebsd.c
+++ b/coregrind/m_syswrap/syswrap-freebsd.c
@@ -4010,13 +4010,16 @@ PRE(sys___acl_aclcheck_link)
 // int sigwait(const sigset_t * restrict set, int * restrict sig);
 PRE(sys_sigwait)
 {
-   *flags |= SfMayBlock;
    PRINT("sys_sigwait ( %#" FMT_REGWORD "x, %#" FMT_REGWORD "x )",
          ARG1,ARG2);
    PRE_REG_READ2(int, "sigwait",
                  const vki_sigset_t *, set, int *, sig);
    if (ARG1 != 0) {
       PRE_MEM_READ(  "sigwait(set)",  ARG1, sizeof(vki_sigset_t));
+      vki_sigset_t* set = (vki_sigset_t*)ARG1;
+      if (ML_(safe_to_deref)(set, sizeof(vki_sigset_t))) {
+         *flags |= SfMayBlock;
+      }
    }
    if (ARG2 != 0) {
       PRE_MEM_WRITE( "sigwait(sig)", ARG2, sizeof(int));
@@ -4025,7 +4028,7 @@ PRE(sys_sigwait)
 
 POST(sys_sigwait)
 {
-   if (ARG2 != 0) {
+   if (RES == 0 && ARG2 != 0) {
       POST_MEM_WRITE( ARG2, sizeof(int));
    }
 }

diff --git a/memcheck/tests/freebsd/scalar.c b/memcheck/tests/freebsd/scalar.c
index ef6649040848763124450006522088f626c83b1c..a7dd23947bbe053cb21e39a70c92f58f5f75a7ad 100644 (file)
--- a/memcheck/tests/freebsd/scalar.c
+++ b/memcheck/tests/freebsd/scalar.c
@@ -1547,6 +1547,7 @@ int main(void)
    /* SYS_sigwait                 429 */
    GO(SYS_sigwait, "2s 2m");
    SY(SYS_sigwait, x0+1, x0+2); SUCC;
+   assert(res == EFAULT);
 
    // thr_create                  430
 
@@ -2166,6 +2167,36 @@ int main(void)
    GO(SYS___sysctlbyname, "(putnew) 4s 2m");
    SY(SYS___sysctlbyname, x0, x0+1, NULL, NULL, x0+1, x0+2); FAIL;
 
+#if 0 // for later
+   // FreeBSD 13 (and any backports)
+   /* SYS_shm_open2                      571 */
+   GO(SYS_shm_open2, " 5s 2m");
+   SY(SYS_shm_open2, x0+0xf00c, x0+1, x0+2, x0+3, x0+4); FAIL;
+
+   GO(SYS_shm_open2, " 5s 1m");
+   SY(SYS_shm_open2, x0+SHM_ANON, x0+1, x0+2, x0+3, x0+4); FAIL;
+
+   /* SYS___realpathat                   574 */
+   GO(SYS___realpathat, " 5s 2m");
+   SY(SYS___realpathat, x0+0xffff, x0, x0, x0+100, x0+2); FAIL;
+
+   /* SYS_close_range                    575 */
+   GO(SYS_close_range, "3s 0m");
+   SY(SYS_close_range, x0+5, x0+10, x0); SUCC;
+
+   /* SYS___specialfd                    577 */
+   GO(SYS___specialfd, "3s 1m");
+   SY(SYS___specialfd, x0+0xf000, x0+1, x0+10); FAIL;
+
+   /* SYS_aio_writev                     578 */
+   GO(SYS_aio_writev, "1s 1m");
+   SY(SYS_aio_writev, x0+1); FAIL;
+
+   /* SYS_aio_readv                      579 */
+   GO(SYS_aio_readv, "1s 1m");
+   SY(SYS_aio_readv, x0+1); FAIL;
+#endif
+
    /* SYS_exit                    1 */
    GO(SYS_exit, "1s 0m");
    SY(SYS_exit, x0); FAIL;

diff --git a/memcheck/tests/freebsd/scalar.stderr.exp b/memcheck/tests/freebsd/scalar.stderr.exp
index 681bb8f2add72389e4481991ad88ba204a446b98..5c61947a153357fa6ef0b3e4cf31504a630ffd7c 100644 (file)
--- a/memcheck/tests/freebsd/scalar.stderr.exp
+++ b/memcheck/tests/freebsd/scalar.stderr.exp
@@ -3605,6 +3605,10 @@ Syscall param mq_timedreceive(msg_prio) contains uninitialised byte(s)
 Syscall param mq_timedreceive(abs_timeout) contains uninitialised byte(s)
    ...
 
+Syscall param mq_timedreceive(msg_ptr) points to unaddressable byte(s)
+   ...
+ Address 0x........ is not stack'd, malloc'd or (recently) free'd
+
 Syscall param mq_timedreceive(msg_prio) points to unaddressable byte(s)
    ...
  Address 0x........ is not stack'd, malloc'd or (recently) free'd
@@ -3631,6 +3635,10 @@ Syscall param mq_timedsend(msg_prio) contains uninitialised byte(s)
 Syscall param mq_timedsend(abs_timeout) contains uninitialised byte(s)
    ...
 
+Syscall param mq_timedsend(msg_ptr) points to unaddressable byte(s)
+   ...
+ Address 0x........ is not stack'd, malloc'd or (recently) free'd
+
 Syscall param mq_timedsend(abs_timeout) points to unaddressable byte(s)
    ...
  Address 0x........ is not stack'd, malloc'd or (recently) free'd
@@ -3714,6 +3722,14 @@ Syscall param sctp_generic_sendmsg(sinfo) contains uninitialised byte(s)
 Syscall param sctp_generic_sendmsg(flags) contains uninitialised byte(s)
    ...
 
+Syscall param sctp_generic_sendmsg(msg) points to unaddressable byte(s)
+   ...
+ Address 0x........ is not stack'd, malloc'd or (recently) free'd
+
+Syscall param sctp_generic_sendmsg(to) points to unaddressable byte(s)
+   ...
+ Address 0x........ is not stack'd, malloc'd or (recently) free'd
+
 Syscall param sctp_generic_sendmsg(sinfo) points to unaddressable byte(s)
    ...
  Address 0x........ is not stack'd, malloc'd or (recently) free'd