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[Qemu-devel] [PATCH] linux-user/flatload: fix initial stack pointer alig
From: |
Max Filippov |
Subject: |
[Qemu-devel] [PATCH] linux-user/flatload: fix initial stack pointer alignment |
Date: |
Tue, 23 Oct 2018 19:38:31 -0700 |
Stack pointer alignment code incorrectly adds stack_size to sp instead
of subtracting it. It also does not take flat_argvp_envp_on_stack() into
account when calculating stack_size. This results in initial stack
pointer misalignment with certain set of command line arguments and
environment variables and correct alignment for the same binary with a
different set of arguments. This misalignment causes failures in the
following tests in the testsuite of gcc built for xtensa uclinux:
gcc.dg/torture/vshuf-v64qi.c
gcc.dg/torture/vshuf-v8sf.c
gcc.dg/torture/vshuf-v8si.c
Signed-off-by: Max Filippov <address@hidden>
---
linux-user/flatload.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/linux-user/flatload.c b/linux-user/flatload.c
index 2eefe55e5000..1893966b5b30 100644
--- a/linux-user/flatload.c
+++ b/linux-user/flatload.c
@@ -771,10 +771,12 @@ int load_flt_binary(struct linux_binprm *bprm, struct
image_info *info)
/* Enforce final stack alignment of 16 bytes. This is sufficient
for all current targets, and excess alignment is harmless. */
stack_len = bprm->envc + bprm->argc + 2;
- stack_len += 3; /* argc, arvg, argp */
+ stack_len += flat_argvp_envp_on_stack() ? 2 : 0; /* arvg, argp */
+ stack_len += 1; /* argc */
stack_len *= sizeof(abi_ulong);
- if ((sp + stack_len) & 15)
- sp -= 16 - ((sp + stack_len) & 15);
+ if ((sp - stack_len) & 15) {
+ sp -= ((sp - stack_len) & 15);
+ }
sp = loader_build_argptr(bprm->envc, bprm->argc, sp, p,
flat_argvp_envp_on_stack());
--
2.11.0
- [Qemu-devel] [PATCH] linux-user/flatload: fix initial stack pointer alignment,
Max Filippov <=