Re: [PATCH] mm, kasan: don't poison boot memory
From: Mike Rapoport
Date: Thu Feb 25 2021 - 03:54:33 EST
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.