Merge revisions 14216,14591,14593 from the BUF_REMOVAL branch to trunk.

Chang the semantics of VG_(getgroups) to support querying the number
of supplementary group IDs which simplifies obtaining them and gets
rid of fixed size buffers.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14594

diff --git a/coregrind/m_libcfile.c b/coregrind/m_libcfile.c
index ceb6bdc1efa72a7a63de69f57ad00cb91e09f0a9..06a4461676995db9eae91e49fa6cd37f97b9d061 100644 (file)
--- a/coregrind/m_libcfile.c
+++ b/coregrind/m_libcfile.c
@@ -615,9 +615,17 @@ Int VG_(check_executable)(/*OUT*/Bool* is_setuid,
       if (VG_(getegid)() == st.gid)
         grpmatch = 1;
       else {
-        UInt groups[32];
-        Int ngrp = VG_(getgroups)(32, groups);
-        Int i;
+         UInt *groups = NULL;
+         Int   ngrp;
+
+         /* Find out # groups, allocate large enough array and fetch groups */
+         ngrp = VG_(getgroups)(0, NULL);
+         if (ngrp != -1) {
+            groups = VG_(malloc)("check_executable", ngrp * sizeof *groups);
+            ngrp   = VG_(getgroups)(ngrp, groups);
+         }
+
+         Int i;
          /* ngrp will be -1 if VG_(getgroups) failed. */
          for (i = 0; i < ngrp; i++) {
            if (groups[i] == st.gid) {
@@ -625,6 +633,7 @@ Int VG_(check_executable)(/*OUT*/Bool* is_setuid,
               break;
            }
          }
+         VG_(free)(groups);
       }
 
       if (grpmatch) {

diff --git a/coregrind/m_libcproc.c b/coregrind/m_libcproc.c
index 98c625f1de70583e50d0bb3866aed169d425c87d..cc285c437a841f408325567791e89baef6dfd9d9 100644 (file)
--- a/coregrind/m_libcproc.c
+++ b/coregrind/m_libcproc.c
@@ -532,23 +532,25 @@ Int VG_(getegid) ( void )
 /* Get supplementary groups into list[0 .. size-1].  Returns the
    number of groups written, or -1 if error.  Note that in order to be
    portable, the groups are 32-bit unsigned ints regardless of the
-   platform. */
+   platform. 
+   As a special case, if size == 0 the function returns the number of
+   groups leaving list untouched. */
 Int VG_(getgroups)( Int size, UInt* list )
 {
+   if (size < 0) return -1;
+
 #  if defined(VGP_x86_linux) || defined(VGP_ppc32_linux) \
       || defined(VGP_mips64_linux)
    Int    i;
    SysRes sres;
-   UShort list16[64];
-   if (size < 0) return -1;
-   if (size > 64) size = 64;
+   UShort list16[size];
    sres = VG_(do_syscall2)(__NR_getgroups, size, (Addr)list16);
    if (sr_isError(sres))
       return -1;
-   if (sr_Res(sres) > size)
-      return -1;
-   for (i = 0; i < sr_Res(sres); i++)
-      list[i] = (UInt)list16[i];
+   if (size != 0) {
+      for (i = 0; i < sr_Res(sres); i++)
+         list[i] = (UInt)list16[i];
+   }
    return sr_Res(sres);
 
 #  elif defined(VGP_amd64_linux) || defined(VGP_arm_linux) \