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.