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| author |   Peter Zijlstra <peterz@infradead.org> | 2019-03-06 19:09:08 +0100 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2019-04-03 09:39:46 +0200 |
| commit | 4fc0f0e9471ec573ab2d44e7f462d996d614536e (patch) | |
| tree | 3c973eefcbf1cde7b61fb5aec5d2a1c4673218bb /arch/x86/include/asm/xen/hypercall.h | |
| parent | x86/nospec, objtool: Introduce ANNOTATE_IGNORE_ALTERNATIVE (diff) | |
| download | linux-dev-4fc0f0e9471ec573ab2d44e7f462d996d614536e.tar.xz linux-dev-4fc0f0e9471ec573ab2d44e7f462d996d614536e.zip | |
x86/uaccess, xen: Suppress SMAP warnings
drivers/xen/privcmd.o: warning: objtool: privcmd_ioctl()+0x1414: call to hypercall_page() with UACCESS enabled
Some Xen hypercalls allow parameter buffers in user land, so they need
to set AC=1. Avoid the warning for those cases.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: andrew.cooper3@citrix.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to '')
| -rw-r--r-- | arch/x86/include/asm/xen/hypercall.h | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h index de6f0d59a24f..580a909afad4 100644 --- a/arch/x86/include/asm/xen/hypercall.h +++ b/arch/x86/include/asm/xen/hypercall.h @@ -214,6 +214,22 @@ xen_single_call(unsigned int call, return (long)__res; } +static __always_inline void __xen_stac(void) +{ + /* + * Suppress objtool seeing the STAC/CLAC and getting confused about it + * calling random code with AC=1. + */ + asm volatile(ANNOTATE_IGNORE_ALTERNATIVE + ASM_STAC ::: "memory", "flags"); +} + +static __always_inline void __xen_clac(void) +{ + asm volatile(ANNOTATE_IGNORE_ALTERNATIVE + ASM_CLAC ::: "memory", "flags"); +} + static inline long privcmd_call(unsigned int call, unsigned long a1, unsigned long a2, @@ -222,9 +238,9 @@ privcmd_call(unsigned int call, { long res; - stac(); + __xen_stac(); res = xen_single_call(call, a1, a2, a3, a4, a5); - clac(); + __xen_clac(); return res; } @@ -421,9 +437,9 @@ HYPERVISOR_dm_op( domid_t dom, unsigned int nr_bufs, struct xen_dm_op_buf *bufs) { int ret; - stac(); + __xen_stac(); ret = _hypercall3(int, dm_op, dom, nr_bufs, bufs); - clac(); + __xen_clac(); return ret; } |