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authorPaul Mundt <lethal@linux-sh.org>2008-10-15 22:04:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-16 11:21:46 -0700
commitc7637941d16ae426a94058fe3b5460a31f68f61b (patch)
tree61ae6860d2e58acf17ca2c3c774b99db6994a5a4
parentec23847d6cfe445ba9a1a5ec513297f4cc0ada53 (diff)
binfmt_elf_fdpic: convert initial stack alignment to arch_align_stack()
binfmt_elf_fdpic seems to have grabbed a hard-coded hack from an ancient version of binfmt_elf in order to try and fix up initial stack alignment on multi-threaded x86, which while in addition to being unused, was also pushed down beyond the first set of operations on the stack pointer, negating the entire purpose. These days, we have an architecture independent arch_align_stack(), so we switch to using that instead. Move the initial alignment up before the initial stores while we're at it. Signed-off-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/binfmt_elf_fdpic.c25
1 files changed, 8 insertions, 17 deletions
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index e4eb472558c..9eee649449a 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -466,7 +466,8 @@ error_kill:
#endif
/*
- * present useful information to the program
+ * present useful information to the program by shovelling it onto the new
+ * process's stack
*/
static int create_elf_fdpic_tables(struct linux_binprm *bprm,
struct mm_struct *mm,
@@ -482,9 +483,13 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
int loop;
int nr; /* reset for each csp adjustment */
- /* we're going to shovel a whole load of stuff onto the stack */
#ifdef CONFIG_MMU
- sp = bprm->p;
+ /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
+ * by the processes running on the same package. One thing we can do is
+ * to shuffle the initial stack for them, so we give the architecture
+ * an opportunity to do so here.
+ */
+ sp = arch_align_stack(bprm->p);
#else
sp = mm->start_stack;
@@ -527,20 +532,6 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
return -EFAULT;
}
-#if defined(__i386__) && defined(CONFIG_SMP)
- /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
- * by the processes running on the same package. One thing we can do is
- * to shuffle the initial stack for them.
- *
- * the conditionals here are unneeded, but kept in to make the code
- * behaviour the same as pre change unless we have hyperthreaded
- * processors. This keeps Mr Marcelo Person happier but should be
- * removed for 2.5
- */
- if (smp_num_siblings > 1)
- sp = sp - ((current->pid % 64) << 7);
-#endif
-
sp &= ~7UL;
/* stack the load map(s) */