From 5c76d652ab567a230f2ef0022b7ea5acb693e19c Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Tue, 23 Oct 2018 19:30:02 -0700 Subject: [PATCH] linux-user/flatload: fix initial stack pointer alignment 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 Reviewed-by: Laurent Vivier Signed-off-by: Max Filippov --- linux-user/flatload.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/linux-user/flatload.c b/linux-user/flatload.c index 2eefe55e50..0122ab3afe 100644 --- a/linux-user/flatload.c +++ b/linux-user/flatload.c @@ -771,10 +771,10 @@ 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); + sp -= (sp - stack_len) & 15; sp = loader_build_argptr(bprm->envc, bprm->argc, sp, p, flat_argvp_envp_on_stack()); -- 2.11.4.GIT