[PATCH 11/15] x86/headers: Make sigcontext pointers bit independent

From: Ingo Molnar
Date: Sat Sep 05 2015 - 03:35:06 EST


Before we can eliminate the duplication between 'struct sigcontext_32'
and 'struct sigcontext_ia32', make the 'fpstate' pointer field in
'struct sigcontext_32' bit independent.

Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mikko Rapeli <mikko.rapeli@xxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/uapi/asm/sigcontext.h | 4 ++--
arch/x86/kernel/signal.c | 4 +++-
2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/uapi/asm/sigcontext.h b/arch/x86/include/uapi/asm/sigcontext.h
index 3591cef6d7d2..d0def259d545 100644
--- a/arch/x86/include/uapi/asm/sigcontext.h
+++ b/arch/x86/include/uapi/asm/sigcontext.h
@@ -218,7 +218,7 @@ struct sigcontext_32 {
* of extended memory layout. See comments at the definition of
* (struct _fpx_sw_bytes)
*/
- void __user *fpstate; /* Zero when no FPU/extended context */
+ __u32 fpstate; /* Zero when no FPU/extended context */
__u32 oldmask;
__u32 cr2;
};
@@ -258,7 +258,7 @@ struct sigcontext_64 {
* of extended memory layout. See comments at the definition of
* (struct _fpx_sw_bytes)
*/
- void __user *fpstate; /* Zero when no FPU/extended context */
+ __u64 fpstate; /* Zero when no FPU/extended context */
__u64 reserved1[8];
};

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 71820c42b6ce..373f87cbbdf5 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -63,6 +63,7 @@

int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
{
+ unsigned long buf_val;
void __user *buf;
unsigned int tmpflags;
unsigned int err = 0;
@@ -107,7 +108,8 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
regs->orig_ax = -1; /* disable syscall checks */

- get_user_ex(buf, &sc->fpstate);
+ get_user_ex(buf_val, &sc->fpstate);
+ buf = (void __user *)buf_val;
} get_user_catch(err);

err |= fpu__restore_sig(buf, config_enabled(CONFIG_X86_32));
--
2.1.4

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