[PATCH 02/41] x86: copy_fpstate_to_sigframe(): have fpregs_soft_get() use kernel buffer

From: Al Viro
Date: Mon Jun 29 2020 - 17:28:15 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

... then copy_to_user() the results

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/fpu/signal.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index 9393a445d73c..e0b832df7404 100644
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -170,14 +170,14 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
ia32_fxstate &= (IS_ENABLED(CONFIG_X86_32) ||
IS_ENABLED(CONFIG_IA32_EMULATION));

+ if (!static_cpu_has(X86_FEATURE_FPU)) {
+ struct user_i387_ia32_struct fp;
+ fpregs_soft_get(current, NULL, 0, sizeof(fp), &fp, NULL);
+ return copy_to_user(buf, &fp, sizeof(fp)) ? -EFAULT : 0;
+ }
+
if (!access_ok(buf, size))
return -EACCES;
-
- if (!static_cpu_has(X86_FEATURE_FPU))
- return fpregs_soft_get(current, NULL, 0,
- sizeof(struct user_i387_ia32_struct), NULL,
- (struct _fpstate_32 __user *) buf) ? -1 : 1;
-
retry:
/*
* Load the FPU registers if they are not valid for the current task.
--
2.11.0