xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

x86/fpu/xstate: Define and use 'fpu_user_xstate_size'

Browse Source 
The kernel xstate area can be in standard or compacted format;
it is always in standard format for user mode. When XSAVES is
enabled, the kernel uses the compacted format and it is necessary
to use a separate fpu_user_xstate_size for signal/ptrace frames.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
[ Rebased the patch and cleaned up the naming. ]
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/8756ec34dabddfc727cda5743195eb81e8caf91c.1463760376.git.yu-cheng.yu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Fenghua Yu
2016-05-20 10:47:05 -07:00
committed by Ingo Molnar
parent d1898b7336
commit a1141e0b5c
5 changed files with 73 additions and 37 deletions
Download Patch File Download Diff File Expand all files Collapse all files

27
arch/x86/kernel/fpu/signal.c
View File

@@ -32,7 +32,7 @@ static inline int check_for_xstate(struct fxregs_state __user *buf,
/* Check for the first magic field and other error scenarios. */
if (fx_sw->magic1 != FP_XSTATE_MAGIC1 ||
fx_sw->xstate_size < min_xstate_size ||
fx_sw->xstate_size > xstate_size ||
fx_sw->xstate_size > fpu_user_xstate_size ||
fx_sw->xstate_size > fx_sw->extended_size)
return -1;
@@ -89,7 +89,8 @@ static inline int save_xstate_epilog(void __user *buf, int ia32_frame)
if (!use_xsave())
return err;
err |= __put_user(FP_XSTATE_MAGIC2, (__u32 *)(buf + xstate_size));
err |= __put_user(FP_XSTATE_MAGIC2,
(__u32 *)(buf + fpu_user_xstate_size));
/*
* Read the xfeatures which we copied (directly from the cpu or
@@ -126,7 +127,7 @@ static inline int copy_fpregs_to_sigframe(struct xregs_state __user *buf)
else
err = copy_fregs_to_user((struct fregs_state __user *) buf);
if (unlikely(err) && __clear_user(buf, xstate_size))
if (unlikely(err) && __clear_user(buf, fpu_user_xstate_size))
err = -EFAULT;
return err;
}
@@ -176,8 +177,19 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
if (ia32_fxstate)
copy_fxregs_to_kernel(&tsk->thread.fpu);
} else {
/*
* It is a *bug* if kernel uses compacted-format for xsave
* area and we copy it out directly to a signal frame. It
* should have been handled above by saving the registers
* directly.
*/
if (boot_cpu_has(X86_FEATURE_XSAVES)) {
WARN_ONCE(1, "x86/fpu: saving compacted-format xsave area to a signal frame!\n");
return -1;
}
fpstate_sanitize_xstate(&tsk->thread.fpu);
if (__copy_to_user(buf_fx, xsave, xstate_size))
if (__copy_to_user(buf_fx, xsave, fpu_user_xstate_size))
return -1;
}
@@ -344,7 +356,8 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
static inline int xstate_sigframe_size(void)
{
return use_xsave() ? xstate_size + FP_XSTATE_MAGIC2_SIZE : xstate_size;
return use_xsave() ? fpu_user_xstate_size + FP_XSTATE_MAGIC2_SIZE :
fpu_user_xstate_size;
}
/*
@@ -388,12 +401,12 @@ fpu__alloc_mathframe(unsigned long sp, int ia32_frame,
*/
void fpu__init_prepare_fx_sw_frame(void)
{
int size = xstate_size + FP_XSTATE_MAGIC2_SIZE;
int size = fpu_user_xstate_size + FP_XSTATE_MAGIC2_SIZE;
fx_sw_reserved.magic1 = FP_XSTATE_MAGIC1;
fx_sw_reserved.extended_size = size;
fx_sw_reserved.xfeatures = xfeatures_mask;
fx_sw_reserved.xstate_size = xstate_size;
fx_sw_reserved.xstate_size = fpu_user_xstate_size;
if (config_enabled(CONFIG_IA32_EMULATION) ||
config_enabled(CONFIG_X86_32)) {