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authorEli Cooper <elicooper@gmx.com>2016-03-19 19:58:39 +0300
committerRichard Weinberger <richard@nod.at>2016-05-22 00:37:16 +0300
commit6de5a8a5001687df720b36729c799991cc0faff5 (patch)
tree542d6b18724e71912a73c5bdc9f220404506e6e4 /arch/x86/um
parent44549e8f5eea4e0a41b487b63e616cb089922b99 (diff)
downloadlinux-6de5a8a5001687df720b36729c799991cc0faff5.tar.xz
um: fix FPU state preservation around signal handlers
This patch makes UML saves/restores FPU state from/to the fpstate in pt_regs when setting up or returning from a signal stack, rather than calling ptrace directly. This ensures that FPU state is correctly preserved around signal handlers in a multi-threaded scenario. Signed-off-by: Eli Cooper <elicooper@gmx.com>
Diffstat (limited to 'arch/x86/um')
-rw-r--r--arch/x86/um/signal.c18
1 files changed, 3 insertions, 15 deletions
diff --git a/arch/x86/um/signal.c b/arch/x86/um/signal.c
index 14fcd01ed992..dac23ee4e5a1 100644
--- a/arch/x86/um/signal.c
+++ b/arch/x86/um/signal.c
@@ -225,20 +225,10 @@ static int copy_sc_from_user(struct pt_regs *regs,
} else
#endif
{
- struct user_i387_struct fp;
-
- err = copy_from_user(&fp, (void *)sc.fpstate,
+ err = copy_from_user(regs->regs.fp, (void *)sc.fpstate,
sizeof(struct user_i387_struct));
if (err)
return 1;
-
- err = restore_fp_registers(pid, (unsigned long *) &fp);
- if (err < 0) {
- printk(KERN_ERR "copy_sc_from_user - "
- "restore_fp_registers failed, errno = %d\n",
- -err);
- return 1;
- }
}
return 0;
}
@@ -325,10 +315,8 @@ static int copy_sc_to_user(struct sigcontext __user *to,
} else
#endif
{
- struct user_i387_struct fp;
-
- err = save_fp_registers(pid, (unsigned long *) &fp);
- if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct)))
+ if (copy_to_user(to_fp, regs->regs.fp,
+ sizeof(struct user_i387_struct)))
return 1;
}