lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Mon, 13 Nov 2023 10:03:17 +1000
From:   Gavin Shan <gshan@...hat.com>
To:     "Russell King (Oracle)" <rmk+kernel@...linux.org.uk>,
        linux-pm@...r.kernel.org, loongarch@...ts.linux.dev,
        linux-acpi@...r.kernel.org, linux-arch@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-riscv@...ts.infradead.org, kvmarm@...ts.linux.dev,
        x86@...nel.org, linux-csky@...r.kernel.org,
        linux-doc@...r.kernel.org, linux-ia64@...r.kernel.org,
        linux-parisc@...r.kernel.org
Cc:     Salil Mehta <salil.mehta@...wei.com>,
        Jean-Philippe Brucker <jean-philippe@...aro.org>,
        jianyong.wu@....com, justin.he@....com,
        James Morse <james.morse@....com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        "H. Peter Anvin" <hpa@...or.com>
Subject: Re: [PATCH RFC 02/22] x86: intel_epb: Don't rely on link order

On 11/7/23 20:29, Russell King (Oracle) wrote:
> From: James Morse <james.morse@....com>
> 
> intel_epb_init() is called as a subsys_initcall() to register cpuhp
> callbacks. The callbacks make use of get_cpu_device() which will return
> NULL unless register_cpu() has been called. register_cpu() is called
> from topology_init(), which is also a subsys_initcall().
> 
> This is fragile. Moving the register_cpu() to a different
> subsys_initcall()  leads to a NULL dereference during boot.
> 
> Make intel_epb_init() a late_initcall(), user-space can't provide a
> policy before this point anyway.
> 
> Signed-off-by: James Morse <james.morse@....com>
> Signed-off-by: Russell King (Oracle) <rmk+kernel@...linux.org.uk>
> ---
> subsys_initcall_sync() would be an option, but moving the register_cpu()
> calls into ACPI also means adding a safety net for CPUs that are online
> but not described properly by firmware. This lives in subsys_initcall_sync().
> ---
>   arch/x86/kernel/cpu/intel_epb.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 

Reviewed-by: Gavin Shan <gshan@...hat.com>

Powered by blists - more mailing lists