From: Tom Hughes <tom@compton.nu>
Date: Wed, 17 Apr 2013 10:08:04 +0000 (+0000)
Subject: Pay attention to PT_GNU_STACK when deciding what permissions to
X-Git-Tag: svn/VALGRIND_3_9_0~316
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=11234a940796a250cd3eaf70667940ce99463409;p=thirdparty%2Fvalgrind.git

Pay attention to PT_GNU_STACK when deciding what permissions to
use for the client stack.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13368
---

diff --git a/coregrind/m_initimg/initimg-linux.c b/coregrind/m_initimg/initimg-linux.c
index f9a68a6715..653ce1a9e8 100644
--- a/coregrind/m_initimg/initimg-linux.c
+++ b/coregrind/m_initimg/initimg-linux.c
@@ -557,7 +557,7 @@ Addr setup_client_stack( void*  init_sp,
         res = VG_(am_mmap_anon_fixed_client)(
                  anon_start -inner_HACK,
                  anon_size +inner_HACK,
-	         VKI_PROT_READ|VKI_PROT_WRITE|VKI_PROT_EXEC
+	         info->stack_prot
 	      );
      }
      if ((!ok) || sr_isError(res)) {
diff --git a/coregrind/m_ume/elf.c b/coregrind/m_ume/elf.c
index 3fae44390b..03b0102d59 100644
--- a/coregrind/m_ume/elf.c
+++ b/coregrind/m_ume/elf.c
@@ -354,6 +354,7 @@ Int VG_(load_ELF)(Int fd, const HChar* name, /*MOD*/ExeInfo* info)
    info->phnum = e->e.e_phnum;
    info->entry = e->e.e_entry + ebase;
    info->phdr = 0;
+   info->stack_prot = VKI_PROT_READ|VKI_PROT_WRITE|VKI_PROT_EXEC;
 
    for (i = 0; i < e->e.e_phnum; i++) {
       ESZ(Phdr) *ph = &e->p[i];
@@ -416,6 +417,12 @@ Int VG_(load_ELF)(Int fd, const HChar* name, /*MOD*/ExeInfo* info)
          }
          break;
 
+      case PT_GNU_STACK:
+         if ((ph->p_flags & PF_X) == 0) info->stack_prot &= ~VKI_PROT_EXEC;
+         if ((ph->p_flags & PF_W) == 0) info->stack_prot &= ~VKI_PROT_WRITE;
+         if ((ph->p_flags & PF_R) == 0) info->stack_prot &= ~VKI_PROT_READ;
+         break;
+
       default:
          // do nothing
          break;
diff --git a/coregrind/pub_core_ume.h b/coregrind/pub_core_ume.h
index e1ab47ba28..2ac4600324 100644
--- a/coregrind/pub_core_ume.h
+++ b/coregrind/pub_core_ume.h
@@ -52,6 +52,7 @@ typedef
 #if !defined(VGO_darwin)
       Addr phdr;         // OUT: address phdr was mapped at
       Int  phnum;        // OUT: number of phdrs
+      UInt stack_prot;   // OUT: stack permissions
       Addr interp_base;  // OUT: where interpreter (ld.so) was mapped
 #else
       Addr  stack_start;      // OUT: address of start of stack segment (hot)