linux-kernel - Re: [regression, bisected] x86: efi: Pass boot services variable info to runtime code

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <alpine.LNX.2.00.1305300048520.30576@pobox.suse.cz>
Date:	Thu, 30 May 2013 00:53:17 +0200 (CEST)
From:	Jiri Kosina <jkosina@...e.cz>
To:	Russ Anderson <rja@....com>
Cc:	Matt Fleming <matt@...sole-pimps.org>,
	Matthew Garrett <matthew.garrett@...ula.com>,
	matt.fleming@...el.com, linux-efi@...r.kernel.org, x86@...nel.org,
	linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	"H. Peter Anvin" <hpa@...ux.intel.com>,
	Borislav Petkov <bp@...en8.de>
Subject: Re: [regression, bisected] x86: efi: Pass boot services variable
 info to runtime code

On Wed, 29 May 2013, Russ Anderson wrote:

> > Yes, but this call is clearly happening way before ExitBootServices() -- 
> > see the surrounding code, see for example this in efi_main():
> > 
> > [ ... snip ... ]
> > 	setup_efi_vars(boot_params);
> > 
> > 	setup_efi_pci(boot_params);
> > 
> > 	status = efi_call_phys3(sys_table->boottime->allocate_pool,
> > 				EFI_LOADER_DATA, sizeof(*gdt),
> > 				(void **)&gdt);
> > 	if (status != EFI_SUCCESS) {
> > 		efi_printk("Failed to alloc mem for gdt structure\n");
> > 		goto fail;
> > 	}
> > [ ... snip ... ]
> 
> Yes.  Note the failing call is sys_table->runtime while all the
> other calls are sys_table->boottime and seem to work.  Not sure
> why the sys_table->runtime call has a problem but it may be
> a clue.  Could something in the runtime path not be set up???

That was my original idea early today as well. My understanding of the 
UEFI spec is admittedly limited, but afaics calling runtime method from 
boot environment should be a valid thing to do ... ?

> > We are calling QueryVariableInfo() in setup_efi_vars(), and later on 
> > AllocatePool is being called (through boot table).
> 
> On my system the QueryVariableInfo() call fails, so AllocatePool()
> is not called in setup_efi_vars().

But it's being called later on coming back to efi_main(). That was just a 
poor man's demonstration attempt why this code is running before 
ExitBootServices() has been called.

-- 
Jiri Kosina
SUSE Labs
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/