x86, ptrace: Simplify xstateregs_get() (ff7fbc72) · Commits · 戴 / test

48 bytes (bytes 464..511) of the xstateregs payload come from the kernel defined structure (xstate_fx_sw_bytes). Rest comes from the xstate regs structure in the thread struct. Instead of having multiple user_regset_copyout()'s, simplify the xstateregs_get() by first copying the SW bytes into the xstate regs structure in the thread structure and then using one user_regset_copyout() to copyout the xstateregs. Requested-by:

Roland McGrath <roland@redhat.com> Signed-off-by:

Suresh Siddha <suresh.b.siddha@intel.com> LKML-Reference: <20100222225240.494688491@sbs-t61.sc.intel.com> Acked-by:

Roland McGrath <roland@redhat.com> Signed-off-by:

H. Peter Anvin <hpa@zytor.com> Cc: Oleg Nesterov <oleg@redhat.com>

arch/x86/kernel/i387.c

+7 −23

Original line number	Diff line number	Diff line
		@@ -243,34 +243,18 @@ int xstateregs_get(struct task_struct target, const struct user_regset regset,
		return ret;

		/*
		* First copy the fxsave bytes 0..463.
		* Copy the 48bytes defined by the software first into the xstate
		* memory layout in the thread struct, so that we can copy the entire
		* xstateregs to the user using one user_regset_copyout().
		*/
		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
		&target->thread.xstate->xsave, 0,
		offsetof(struct user_xstateregs,
		i387.xstate_fx_sw));
		if (ret)
		return ret;

		/*
		* Copy the 48bytes defined by software.
		*/
		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
		xstate_fx_sw_bytes,
		offsetof(struct user_xstateregs,
		i387.xstate_fx_sw),
		offsetof(struct user_xstateregs,
		xsave_hdr));
		if (ret)
		return ret;
		memcpy(&target->thread.xstate->fxsave.sw_reserved,
		xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes));

		/*
		* Copy the rest of xstate memory layout.
		* Copy the xstate memory layout.
		*/
		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
		&target->thread.xstate->xsave.xsave_hdr,
		offsetof(struct user_xstateregs,
		xsave_hdr), -1);
		&target->thread.xstate->xsave, 0, -1);
		return ret;
		}

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