Re: linux-next: manual merge of the tip tree with Linus' tree

From: Ingo Molnar
Date: Wed Feb 15 2023 - 06:15:24 EST



* Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:

> Hi all,
>
> Today's linux-next merge of the tip tree got a conflict in:
>
> arch/x86/kernel/cpu/common.c
>
> between commit:
>
> be8de49bea50 ("x86/speculation: Identify processors vulnerable to SMT RSB predictions")
>
> from Linus' tree and commit:
>
> e7862eda309e ("x86/cpu: Support AMD Automatic IBRS")
>
> from the tip tree.
>
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging. You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.
>
> --
> Cheers,
> Stephen Rothwell
>
> diff --cc arch/x86/kernel/cpu/common.c
> index f3cc7699e1e1,38646f1b5f14..000000000000
> --- a/arch/x86/kernel/cpu/common.c
> +++ b/arch/x86/kernel/cpu/common.c
> @@@ -1403,14 -1412,6 +1414,9 @@@ static void __init cpu_set_bug_bits(str
> setup_force_cpu_bug(X86_BUG_RETBLEED);
> }
>
> - if (cpu_has(c, X86_FEATURE_IBRS_ENHANCED) &&
> - !cpu_matches(cpu_vuln_whitelist, NO_EIBRS_PBRSB) &&
> - !(ia32_cap & ARCH_CAP_PBRSB_NO))
> - setup_force_cpu_bug(X86_BUG_EIBRS_PBRSB);
> -
> + if (cpu_matches(cpu_vuln_blacklist, SMT_RSB))
> + setup_force_cpu_bug(X86_BUG_SMT_RSB);
> +
> if (cpu_matches(cpu_vuln_whitelist, NO_MELTDOWN))
> return;

Looks good, thanks Stephen!

A similar resolution will show up in tomorrow's -next as well, via:

e067248949e3 Merge branch 'linus' into x86/cpu, to resolve conflict

... so the conflict should go away in the next -next.

Thanks,

Ingo