x86/asm: Replace access to desc_struct:a/b fields (9a98e778) · Commits · 戴 / test

The union inside of desc_struct which allows access to the raw u32 parts of the descriptors. This raw access part is about to go away. Replace the few code parts which access those fields. Signed-off-by:

Thomas Gleixner <tglx@linutronix.de> Reviewed-by:

Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170828064958.120214366@linutronix.de Signed-off-by:

Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/xen/hypercall.h

+4 −2

Original line number	Diff line number	Diff line
		@@ -552,6 +552,8 @@ static inline void
		MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr,
		struct desc_struct desc)
		{
		u32 p = (u32 ) &desc;

		mcl->op = __HYPERVISOR_update_descriptor;
		if (sizeof(maddr) == sizeof(long)) {
		mcl->args[0] = maddr;
		@@ -559,8 +561,8 @@ MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr,
		} else {
		mcl->args[0] = maddr;
		mcl->args[1] = maddr >> 32;
		mcl->args[2] = desc.a;
		mcl->args[3] = desc.b;
		mcl->args[2] = *p++;
		mcl->args[3] = *p;
		}

		trace_xen_mc_entry(mcl, sizeof(maddr) == sizeof(long) ? 2 : 4);

arch/x86/kernel/tls.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -93,7 +93,7 @@ static void set_tls_desc(struct task_struct *p, int idx,

		while (n-- > 0) {
		if (LDT_empty(info) \|\| LDT_zero(info)) {
		desc->a = desc->b = 0;
		memset(desc, 0, sizeof(*desc));
		} else {
		fill_ldt(desc, info);

arch/x86/xen/enlighten_pv.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -494,7 +494,7 @@ static void __init xen_load_gdt_boot(const struct desc_ptr *dtr)
		static inline bool desc_equal(const struct desc_struct *d1,
		const struct desc_struct *d2)
		{
		return d1->a == d2->a && d1->b == d2->b;
		return !memcmp(d1, d2, sizeof(*d1));
		}

		static void load_TLS_descriptor(struct thread_struct *t,

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