GNU C Library master sources branch master updated. glibc-2.26-207-g01b87c6

[azanella at sourceware dot org]

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http://sourceware.org/git/gitweb.cgi?p=glibc.git;a=commitdiff;h=01b87c656f670863ce437421b8e9278200965d38

commit 01b87c656f670863ce437421b8e9278200965d38
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Mon Aug 28 11:24:35 2017 -0300

    ia64: Fix thread stack allocation permission set (BZ #21672)
    
    This patch fixes ia64 failures on thread exit by madvise the required
    area taking in consideration its disjoing stacks
    (NEED_SEPARATE_REGISTER_STACK).  Also the snippet that setup the
    madvise call to advertise kernel the area won't be used anymore in
    near future is reallocated in allocatestack.c (for consistency to
    put all stack management function in one place).
    
    Checked on x86_64-linux-gnu and i686-linux-gnu for sanity (since
    it is not expected code changes for architecture that do not
    define NEED_SEPARATE_REGISTER_STACK) and also got a report that
    it fixes ia64-linux-gnu failures from Sergei Trofimovich
    <slyfox@gentoo.org>.
    
    	[BZ #21672]
    	* nptl/allocatestack.c [_STACK_GROWS_DOWN] (setup_stack_prot):
    	Set to use !NEED_SEPARATE_REGISTER_STACK as well.
    	(advise_stack_range): New function.
    	* nptl/pthread_create.c (START_THREAD_DEFN): Move logic to mark
    	stack non required to advise_stack_range at allocatestack.c

diff --git a/ChangeLog b/ChangeLog
index 07cf8dd..b2016ca 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2017-08-29  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
+
+	[BZ #21672]
+	* nptl/allocatestack.c [_STACK_GROWS_DOWN] (setup_stack_prot):
+	Set to use !NEED_SEPARATE_REGISTER_STACK as well.
+	(advise_stack_range): New function.
+	* nptl/pthread_create.c (START_THREAD_DEFN): Move logic to mark
+	stack non required to advise_stack_range at allocatestack.c
+
 2017-08-29  Szabolcs Nagy  <szabolcs.nagy@arm.com>
 
 	* sysdeps/unix/sysv/linux/aarch64/sys/procfs.h: Use __uint64_t.
diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c
index 6d1bcaa..8766deb 100644
--- a/nptl/allocatestack.c
+++ b/nptl/allocatestack.c
@@ -356,7 +356,7 @@ setup_stack_prot (char *mem, size_t size, char *guard, size_t guardsize,
 		  const int prot)
 {
   char *guardend = guard + guardsize;
-#if _STACK_GROWS_DOWN
+#if _STACK_GROWS_DOWN && !defined(NEED_SEPARATE_REGISTER_STACK)
   /* As defined at guard_position, for architectures with downward stack
      the guard page is always at start of the allocated area.  */
   if (__mprotect (guardend, size - guardsize, prot) != 0)
@@ -372,6 +372,33 @@ setup_stack_prot (char *mem, size_t size, char *guard, size_t guardsize,
   return 0;
 }
 
+/* Mark the memory of the stack as usable to the kernel.  It frees everything
+   except for the space used for the TCB itself.  */
+static inline void
+__always_inline
+advise_stack_range (void *mem, size_t size, uintptr_t pd, size_t guardsize)
+{
+  uintptr_t sp = (uintptr_t) CURRENT_STACK_FRAME;
+  size_t pagesize_m1 = __getpagesize () - 1;
+#if _STACK_GROWS_DOWN && !defined(NEED_SEPARATE_REGISTER_STACK)
+  size_t freesize = (sp - (uintptr_t) mem) & ~pagesize_m1;
+  assert (freesize < size);
+  if (freesize > PTHREAD_STACK_MIN)
+    __madvise (mem, freesize - PTHREAD_STACK_MIN, MADV_DONTNEED);
+#else
+  /* Page aligned start of memory to free (higher than or equal
+     to current sp plus the minimum stack size).  */
+  uintptr_t freeblock = (sp + PTHREAD_STACK_MIN + pagesize_m1) & ~pagesize_m1;
+  uintptr_t free_end = (pd - guardsize) & ~pagesize_m1;
+  if (free_end > freeblock)
+    {
+      size_t freesize = free_end - freeblock;
+      assert (freesize < size);
+      __madvise ((void*) freeblock, freesize, MADV_DONTNEED);
+    }
+#endif
+}
+
 /* Returns a usable stack for a new thread either by allocating a
    new stack or reusing a cached stack of sufficient size.
    ATTR must be non-NULL and point to a valid pthread_attr.
diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
index 2f8ada3..83b88bf 100644
--- a/nptl/pthread_create.c
+++ b/nptl/pthread_create.c
@@ -551,31 +551,8 @@ START_THREAD_DEFN
     }
 #endif
 
-  /* Mark the memory of the stack as usable to the kernel.  We free
-     everything except for the space used for the TCB itself.  */
-  size_t pagesize_m1 = __getpagesize () - 1;
-#ifdef _STACK_GROWS_DOWN
-  char *sp = CURRENT_STACK_FRAME;
-  size_t freesize = (sp - (char *) pd->stackblock) & ~pagesize_m1;
-  assert (freesize < pd->stackblock_size);
-  if (freesize > PTHREAD_STACK_MIN)
-    __madvise (pd->stackblock, freesize - PTHREAD_STACK_MIN, MADV_DONTNEED);
-#else
-  /* Page aligned start of memory to free (higher than or equal
-     to current sp plus the minimum stack size).  */
-  void *freeblock = (void*)((size_t)(CURRENT_STACK_FRAME
-				     + PTHREAD_STACK_MIN
-				     + pagesize_m1)
-				    & ~pagesize_m1);
-  char *free_end = (char *) (((uintptr_t) pd - pd->guardsize) & ~pagesize_m1);
-  /* Is there any space to free?  */
-  if (free_end > (char *)freeblock)
-    {
-      size_t freesize = (size_t)(free_end - (char *)freeblock);
-      assert (freesize < pd->stackblock_size);
-      __madvise (freeblock, freesize, MADV_DONTNEED);
-    }
-#endif
+  advise_stack_range (pd->stackblock, pd->stackblock_size, (uintptr_t) pd,
+		      pd->guardsize);
 
   /* If the thread is detached free the TCB.  */
   if (IS_DETACHED (pd))

-----------------------------------------------------------------------

Summary of changes:
 ChangeLog             |    9 +++++++++
 nptl/allocatestack.c  |   29 ++++++++++++++++++++++++++++-
 nptl/pthread_create.c |   27 ++-------------------------
 3 files changed, 39 insertions(+), 26 deletions(-)


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