[PATCH, v6] x86-64: Emulate legacy vsyscalls

[Ingo Molnar]

* Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:

> On Jun 7, 2011 6:46 AM, "Ingo Molnar" <mingo@xxxxxxx> wrote:
> >
> > Do you think x86/vdso is worth rebasing at this stage? Right now 
> > it has:
> 
> Yes, I'd rebase it. By now, much of what the initial patches are 
> adding is then removed in the final result, so the patch series 
> ends up first adding things, then changing the things it adds, and 
> then removing three quarters of it all.

Ok - the rebase was easy and kept much of the existing commits:

64b0e3256b8a: x86-64: Emulate legacy vsyscalls
5dfcea629a08: x86-64: Fill unused parts of the vsyscall page with 0xcc
bb5fe2f78ead: x86-64: Remove vsyscall number 3 (venosys)
d319bb79afa4: x86-64: Map the HPET NX
0d7b8547fb67: x86-64: Remove kernel.vsyscall64 sysctl
9fd67b4ed071: x86-64: Give vvars their own page
8b4777a4b50c: x86-64: Document some of entry_64.S
6879eb2deed7: x86-64: Fix alignment of jiffies variable

The 64b0e3256b8a commit (attached below) is the only rebased one - it 
merges all these commits:

d1a70649f49b: x86-64: Remove LEGACY_VTIME
feba7e97df8c: x86-64: Rename COMPAT_VSYSCALLS to LEGACY_VTIME and clarify documentation
7dc0452808b7: x86-64: Clean up vsyscall emulation and remove fixed-address ret
8d6316596441: x86-64: Fix outdated comments in vsyscall_64.c
1593843e2ada: x86-64, vsyscalls: Rename UNSAFE_VSYSCALLS to COMPAT_VSYSCALLS
764611c8dfb5: x86-64, vdso, seccomp: Fix !CONFIG_SECCOMP build
38172403a978: x86-64: Add CONFIG_UNSAFE_VSYSCALLS to feature-removal-schedule
d55ed1d30b82: x86-64: Emulate legacy vsyscalls

and does a few obvious cleanups to the code.

I've added your Acked-by to this commit because you seemed to agree 
with the commit.

I removed this portion:

+	if (__ratelimit(&rs)) {
+		printk(KERN_INFO "%s[%d] emulated legacy vsyscall %s(); "
+		       "upgrade your code to avoid a performance hit. "
+		       "ip:%lx sp:%lx caller:%lx",
+		       tsk->comm, task_pid_nr(tsk), vsyscall_name,
+		       regs->ip - 2, regs->sp, caller);
+		if (caller)
+			print_vma_addr(" in ", caller);
+		printk("\n");
+	}

as it would now needlessly annoy everyone.

Thanks,

	Ingo

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