Re: [PATCH] mm, kasan: don't poison boot memory
From: Mike Rapoport
Date: Tue Feb 23 2021 - 16:34:29 EST
On Tue, Feb 23, 2021 at 04:16:44PM -0500, George Kennedy wrote:
>
>
> On 2/23/2021 3:09 PM, Mike Rapoport wrote:
> > On Tue, Feb 23, 2021 at 01:05:05PM -0500, George Kennedy wrote:
> > > On 2/23/2021 10:47 AM, Mike Rapoport wrote:
> > >
> > > It now crashes here:
> > >
> > > [ 0.051019] ACPI: Early table checksum verification disabled
> > > [ 0.056721] ACPI: RSDP 0x00000000BFBFA014 000024 (v02 BOCHS )
> > > [ 0.057874] ACPI: XSDT 0x00000000BFBF90E8 00004C (v01 BOCHS BXPCFACP
> > > 00000001 01000013)
> > > [ 0.059590] ACPI: FACP 0x00000000BFBF5000 000074 (v01 BOCHS BXPCFACP
> > > 00000001 BXPC 00000001)
> > > [ 0.061306] ACPI: DSDT 0x00000000BFBF6000 00238D (v01 BOCHS BXPCDSDT
> > > 00000001 BXPC 00000001)
> > > [ 0.063006] ACPI: FACS 0x00000000BFBFD000 000040
> > > [ 0.063938] ACPI: APIC 0x00000000BFBF4000 000090 (v01 BOCHS BXPCAPIC
> > > 00000001 BXPC 00000001)
> > > [ 0.065638] ACPI: HPET 0x00000000BFBF3000 000038 (v01 BOCHS BXPCHPET
> > > 00000001 BXPC 00000001)
> > > [ 0.067335] ACPI: BGRT 0x00000000BE49B000 000038 (v01 INTEL EDK2
> > > 00000002 01000013)
> > > [ 0.069030] ACPI: iBFT 0x00000000BE453000 000800 (v01 BOCHS BXPCFACP
> > > 00000000 00000000)
> > > [ 0.070734] XXX acpi_find_ibft_region:
> > > [ 0.071468] XXX iBFT, status=0
> > > [ 0.072073] XXX about to call acpi_put_table()...
> > > ibft_addr=ffffffffff240000
> > > [ 0.073449] XXX acpi_find_ibft_region(EXIT):
> > > PANIC: early exception 0x0e IP 10:ffffffff9259f439 error 0 cr2
> > > 0xffffffffff240004
> > Right, I've missed the dereference of the ibft_addr after
> > acpi_find_ibft_region().
> >
> > With this change to iscsi_ibft_find.c instead of the previous one it should
> > be better:
> >
> > diff --git a/drivers/firmware/iscsi_ibft_find.c b/drivers/firmware/iscsi_ibft_find.c
> > index 64bb94523281..1be7481d5c69 100644
> > --- a/drivers/firmware/iscsi_ibft_find.c
> > +++ b/drivers/firmware/iscsi_ibft_find.c
> > @@ -80,6 +80,27 @@ static int __init find_ibft_in_mem(void)
> > done:
> > return len;
> > }
> > +
> > +static void __init acpi_find_ibft_region(unsigned long *sizep)
> > +{
> > + int i;
> > + struct acpi_table_header *table = NULL;
> > + acpi_status status;
> > +
> > + if (acpi_disabled)
> > + return;
> > +
> > + 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)) {
> > + ibft_addr = (struct acpi_table_ibft *)table;
> > + *sizep = PAGE_ALIGN(ibft_addr->header.length);
> > + acpi_put_table(table);
> > + break;
> > + }
> > + }
> > +}
> > +
> > /*
> > * Routine used to find the iSCSI Boot Format Table. The logical
> > * kernel address is set in the ibft_addr global variable.
> > @@ -91,14 +112,16 @@ unsigned long __init find_ibft_region(unsigned long *sizep)
> > /* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
> > * only use ACPI for this */
> > - if (!efi_enabled(EFI_BOOT))
> > + 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);
> > + } else {
> > + acpi_find_ibft_region(sizep);
> > }
> > + if (ibft_addr)
> > + return (u64)virt_to_phys(ibft_addr);
> > +
> > *sizep = 0;
> > return 0;
> > }
> Mike,
>
> No luck. Back to the original KASAN ibft_init crash.
>
> I ran with only the above patch from you. Was that what you wanted? Your
> previous patch had a section defined out by #if 0. Was that supposed to be
> in there as well?
Sorry, I wasn't clear, but I meant to use the first patch and only replace
changes to iscsi_ibft_find.c with the new patch.
Here's the full patch to be sure we're on the same page:
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..c8a07a7b9577 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1032,6 +1032,14 @@ void __init setup_arch(char **cmdline_p)
*/
find_smp_config();
+ /*
+ * Initialize the ACPI boot-time table parser.
+ */
+ if (acpi_table_init()) {
+ disable_acpi();
+ return;
+ }
+
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..1be7481d5c69 100644
--- a/drivers/firmware/iscsi_ibft_find.c
+++ b/drivers/firmware/iscsi_ibft_find.c
@@ -80,6 +80,27 @@ static int __init find_ibft_in_mem(void)
done:
return len;
}
+
+static void __init acpi_find_ibft_region(unsigned long *sizep)
+{
+ int i;
+ struct acpi_table_header *table = NULL;
+ acpi_status status;
+
+ if (acpi_disabled)
+ return;
+
+ 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)) {
+ ibft_addr = (struct acpi_table_ibft *)table;
+ *sizep = PAGE_ALIGN(ibft_addr->header.length);
+ acpi_put_table(table);
+ break;
+ }
+ }
+}
+
/*
* Routine used to find the iSCSI Boot Format Table. The logical
* kernel address is set in the ibft_addr global variable.
@@ -91,14 +112,16 @@ unsigned long __init find_ibft_region(unsigned long *sizep)
/* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
* only use ACPI for this */
- if (!efi_enabled(EFI_BOOT))
+ 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);
+ } else {
+ acpi_find_ibft_region(sizep);
}
+ if (ibft_addr)
+ return (u64)virt_to_phys(ibft_addr);
+
*sizep = 0;
return 0;
}
--
Sincerely yours,
Mike.