Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Thu, 25 Feb 2021 10:53:00 +0200
From:   Mike Rapoport <rppt@linux.ibm.com>
To:     George Kennedy <george.kennedy@oracle.com>
Cc:     David Hildenbrand <david@redhat.com>,
        Andrey Konovalov <andreyknvl@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Vincenzo Frascino <vincenzo.frascino@arm.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Konrad Rzeszutek Wilk <konrad@darnok.org>,
        Will Deacon <will.deacon@arm.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Marco Elver <elver@google.com>,
        Peter Collingbourne <pcc@google.com>,
        Evgenii Stepanov <eugenis@google.com>,
        Branislav Rankov <Branislav.Rankov@arm.com>,
        Kevin Brodsky <kevin.brodsky@arm.com>,
        Christoph Hellwig <hch@infradead.org>,
        kasan-dev <kasan-dev@googlegroups.com>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Linux Memory Management List <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Dhaval Giani <dhaval.giani@oracle.com>
Subject: Re: [PATCH] mm, kasan: don't poison boot memory
Message-ID: <20210225085300.GB1854360@linux.ibm.com>
References: <20210223103321.GD1741768@linux.ibm.com>
 <3ef9892f-d657-207f-d4cf-111f98dcb55c@oracle.com>
 <20210223154758.GF1741768@linux.ibm.com>
 <3a56ba38-ce91-63a6-b57c-f1726aa1b76e@oracle.com>
 <20210223200914.GH1741768@linux.ibm.com>
 <af06267d-00cd-d4e0-1985-b06ce7c993a3@oracle.com>
 <20210223213237.GI1741768@linux.ibm.com>
 <450a9895-a2b4-d11b-97ca-1bd33d5308d4@oracle.com>
 <20210224103754.GA1854360@linux.ibm.com>
 <9b7251d1-7b90-db4f-fa5e-80165e1cbb4b@oracle.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <9b7251d1-7b90-db4f-fa5e-80165e1cbb4b@oracle.com>
Precedence: bulk

Hi George,

> On 2/24/2021 5:37 AM, Mike Rapoport wrote:
> > On Tue, Feb 23, 2021 at 04:46:28PM -0500, George Kennedy wrote:
> > > Mike,
> > > 
> > > Still no luck.
> > > 
> > > [?? 30.193723] iscsi: registered transport (iser)
> > > [?? 30.195970] iBFT detected.
> > > [?? 30.196571] BUG: unable to handle page fault for address: ffffffffff240004
> > Hmm, we cannot set ibft_addr to early pointer to the ACPI table.
> > Let's try something more disruptive and move the reservation back to
> > iscsi_ibft_find.c.
> > 
> > diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
> > index 7bdc0239a943..c118dd54a747 100644
> > --- a/arch/x86/kernel/acpi/boot.c
> > +++ b/arch/x86/kernel/acpi/boot.c
> > @@ -1551,6 +1551,7 @@ void __init acpi_boot_table_init(void)
> >   	if (acpi_disabled)
> >   		return;
> > +#if 0
> >   	/*
> >   	 * Initialize the ACPI boot-time table parser.
> >   	 */
> > @@ -1558,6 +1559,7 @@ void __init acpi_boot_table_init(void)
> >   		disable_acpi();
> >   		return;
> >   	}
> > +#endif
> >   	acpi_table_parse(ACPI_SIG_BOOT, acpi_parse_sbf);
> > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> > index d883176ef2ce..c615ce96c9a2 100644
> > --- a/arch/x86/kernel/setup.c
> > +++ b/arch/x86/kernel/setup.c
> > @@ -570,16 +570,6 @@ void __init reserve_standard_io_resources(void)
> >   }
> > -static __init void reserve_ibft_region(void)
> > -{
> > -	unsigned long addr, size = 0;
> > -
> > -	addr = find_ibft_region(&size);
> > -
> > -	if (size)
> > -		memblock_reserve(addr, size);
> > -}
> > -
> >   static bool __init snb_gfx_workaround_needed(void)
> >   {
> >   #ifdef CONFIG_PCI
> > @@ -1032,6 +1022,12 @@ void __init setup_arch(char **cmdline_p)
> >   	 */
> >   	find_smp_config();
> > +	/*
> > +	 * Initialize the ACPI boot-time table parser.
> > +	 */
> > +	if (acpi_table_init())
> > +		disable_acpi();
> > +
> >   	reserve_ibft_region();
> >   	early_alloc_pgt_buf();
> > diff --git a/drivers/firmware/iscsi_ibft_find.c b/drivers/firmware/iscsi_ibft_find.c
> > index 64bb94523281..01be513843d6 100644
> > --- a/drivers/firmware/iscsi_ibft_find.c
> > +++ b/drivers/firmware/iscsi_ibft_find.c
> > @@ -47,7 +47,25 @@ static const struct {
> >   #define VGA_MEM 0xA0000 /* VGA buffer */
> >   #define VGA_SIZE 0x20000 /* 128kB */
> > -static int __init find_ibft_in_mem(void)
> > +static void __init *acpi_find_ibft_region(void)
> > +{
> > +	int i;
> > +	struct acpi_table_header *table = NULL;
> > +	acpi_status status;
> > +
> > +	if (acpi_disabled)
> > +		return NULL;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(ibft_signs) && !ibft_addr; i++) {
> > +		status = acpi_get_table(ibft_signs[i].sign, 0, &table);
> > +		if (ACPI_SUCCESS(status))
> > +			return table;
> > +	}
> > +
> > +	return NULL;
> > +}
> > +
> > +static void __init *find_ibft_in_mem(void)
> >   {
> >   	unsigned long pos;
> >   	unsigned int len = 0;
> > @@ -70,35 +88,44 @@ static int __init find_ibft_in_mem(void)
> >   				/* if the length of the table extends past 1M,
> >   				 * the table cannot be valid. */
> >   				if (pos + len <= (IBFT_END-1)) {
> > -					ibft_addr = (struct acpi_table_ibft *)virt;
> >   					pr_info("iBFT found at 0x%lx.\n", pos);
> > -					goto done;
> > +					return virt;
> >   				}
> >   			}
> >   		}
> >   	}
> > -done:
> > -	return len;
> > +
> > +	return NULL;
> >   }
> > +
> > +static void __init *find_ibft(void)
> > +{
> > +	/* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
> > +	 * only use ACPI for this */
> > +	if (!efi_enabled(EFI_BOOT))
> > +		return find_ibft_in_mem();
> > +	else
> > +		return acpi_find_ibft_region();
> > +}
> > +
> >   /*
> >    * Routine used to find the iSCSI Boot Format Table. The logical
> >    * kernel address is set in the ibft_addr global variable.
> >    */
> > -unsigned long __init find_ibft_region(unsigned long *sizep)
> > +void __init reserve_ibft_region(void)
> >   {
> > -	ibft_addr = NULL;
> > +	struct acpi_table_ibft *table;
> > +	unsigned long size;
> > -	/* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
> > -	 * only use ACPI for this */
> > +	table = find_ibft();
> > +	if (!table)
> > +		return;
> > -	if (!efi_enabled(EFI_BOOT))
> > -		find_ibft_in_mem();
> > -
> > -	if (ibft_addr) {
> > -		*sizep = PAGE_ALIGN(ibft_addr->header.length);
> > -		return (u64)virt_to_phys(ibft_addr);
> > -	}
> > +	size = PAGE_ALIGN(table->header.length);
> > +	memblock_reserve(virt_to_phys(table), size);
> > -	*sizep = 0;
> > -	return 0;
> > +	if (efi_enabled(EFI_BOOT))
> > +		acpi_put_table(&table->header);
> > +	else
> > +		ibft_addr = table;
> >   }
> > diff --git a/include/linux/iscsi_ibft.h b/include/linux/iscsi_ibft.h
> > index b7b45ca82bea..da813c891990 100644
> > --- a/include/linux/iscsi_ibft.h
> > +++ b/include/linux/iscsi_ibft.h
> > @@ -26,13 +26,9 @@ extern struct acpi_table_ibft *ibft_addr;
> >    * mapped address is set in the ibft_addr variable.
> >    */
> >   #ifdef CONFIG_ISCSI_IBFT_FIND
> > -unsigned long find_ibft_region(unsigned long *sizep);
> > +void reserve_ibft_region(void);
> >   #else
> > -static inline unsigned long find_ibft_region(unsigned long *sizep)
> > -{
> > -	*sizep = 0;
> > -	return 0;
> > -}
> > +static inline void reserve_ibft_region(void) {}
> >   #endif
> >   #endif /* ISCSI_IBFT_H */
> 
> Still no luck Mike,
> 
> We're back to the original problem where the only thing that worked was to
> run "SetPageReserved(page)" before calling "kmap(page)". The page is being
> "freed" before ibft_init() is called as a result of the recent buddy page
> freeing changes.

I keep missing some little details each time :(
Ok, let's try from the different angle.

diff --git a/drivers/acpi/acpica/tbutils.c b/drivers/acpi/acpica/tbutils.c
index 4b9b329a5a92..ec43e1447336 100644
--- a/drivers/acpi/acpica/tbutils.c
+++ b/drivers/acpi/acpica/tbutils.c
@@ -7,6 +7,8 @@
  *
  *****************************************************************************/
 
+#include <linux/memblock.h>
+
 #include <acpi/acpi.h>
 #include "accommon.h"
 #include "actables.h"
@@ -339,6 +341,21 @@ acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
 			acpi_tb_parse_fadt();
 		}
 
+		if (ACPI_SUCCESS(status) &&
+		    ACPI_COMPARE_NAMESEG(&acpi_gbl_root_table_list.
+					 tables[table_index].signature,
+					 ACPI_SIG_IBFT)) {
+			struct acpi_table_header *ibft;
+			struct acpi_table_desc *desc;
+
+			desc = &acpi_gbl_root_table_list.tables[table_index];
+			status = acpi_tb_get_table(desc, &ibft);
+			if (ACPI_SUCCESS(status)) {
+				memblock_reserve(address, ibft->length);
+				acpi_tb_put_table(desc);
+			}
+		}
+
 next_table:
 
 		table_entry += table_entry_size;
 

-- 
Sincerely yours,
Mike.