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Re: [PATCH v11 4/5] x86/boot: Dig out SRAT table from RSDP and find immovable memory
On Mon, Nov 12, 2018 at 04:51:59PM -0500, Masayoshi Mizuma wrote:
>On Mon, Nov 12, 2018 at 05:46:44PM +0800, Chao Fan wrote:
>> To avoid KASLR extracting kernel on movable memory, slove the
>> conflict between KASLR and movable_node feature, dig the SRAT tables
>> from RSDP pointer. Walk the SRAT tables and store the immovable
>> memory regions in immovable_mem[].
>>
>> There are three methods to get RSDP pointer: KEXEC condition,
>> EFI confition, BIOS condition.
>> If KEXEC add 'acpi_rsdp' to cmdline, use it.
>> Otherwise, parse EFI table for RSDP.
>> Then, search memory for RSDP.
>>
>> Imitate from ACPI code, based on acpi_os_get_root_pointer().
>> Process: RSDP->RSDT/XSDT->ACPI root table->SRAT.
>>
>> Signed-off-by: Chao Fan
>> ---
>> arch/x86/boot/compressed/Makefile | 4 +
>> arch/x86/boot/compressed/acpitb.c | 139 ++
>> arch/x86/boot/compressed/kaslr.c | 4 -
>> arch/x86/boot/compressed/misc.h | 15
>> 4 files changed, 158 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/x86/boot/compressed/Makefile
>> b/arch/x86/boot/compressed/Makefile
>> index 466f66c8a7f8..b51f7629b8ef 100644
>> --- a/arch/x86/boot/compressed/Makefile
>> +++ b/arch/x86/boot/compressed/Makefile
>> @@ -84,6 +84,10 @@ ifdef CONFIG_X86_64
>> vmlinux-objs-y += $(obj)/pgtable_64.o
>> endif
>>
>> +#if (defined CONFIG_MEMORY_HOTREMOVE) && (defined CONFIG_RANDOMIZE_BASE)
>> +vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/acpitb.o
>> +#endif
>
>'#' in Makefile means comment out...
>
>ifdef CONFIG_MEMORY_HOTREMOVE
>vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/acpitb.o
>endif
>
Thanks,
>> +
>> $(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
>>
>> vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o
>> \
>> diff --git a/arch/x86/boot/compressed/acpitb.c
>> b/arch/x86/boot/compressed/acpitb.c
>> index 5cfb4efa5a19..161f21a7fb3b 100644
>> --- a/arch/x86/boot/compressed/acpitb.c
>> +++ b/arch/x86/boot/compressed/acpitb.c
>> @@ -14,6 +14,11 @@
>> #define BOOT_STRING
>> #include "../string.h"
>>
>
>> +#ifdef CONFIG_MEMORY_HOTREMOVE
>> +/* Store the immovable memory regions */
>> +struct mem_vector immovable_mem[MAX_NUMNODES*2];
>> +#endif
>
>This #ifdef isn't needed.
>
>Could you please check the other #ifdef statement as well?
Sure, I will check all the #ifdef.
Thanks,
Chao Fan
>
>Thanks,
>Masa
>
>> +
>> /* Search EFI table for RSDP table. */
>> static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
>> {
>> @@ -226,3 +231,137 @@ static void get_acpi_rsdp(acpi_physical_address
>> *rsdp_addr)
>> }
>> #endif
>> }
>> +
>> +/*
>> + * Used to dig RSDP table from EFI table or BIOS.
>> + * If RSDP table found in EFI table, use it. Or search BIOS.
>> + * Based on acpi_os_get_root_pointer().
>> + */
>> +static acpi_physical_address get_rsdp_addr(void)
>> +{
>> +acpi_physical_address pa = 0;
>> +
>> +get_acpi_rsdp();
>> +
>> +if (!pa)
>> +efi_get_rsdp_addr();
>> +
>> +if (!pa)
>> +bios_get_rsdp_addr();
>> +
>> +return pa;
>> +}
>> +
>> +static struct acpi_table_header *get_acpi_srat_table(void)
>> +{
>> +acpi_physical_address acpi_table;
>> +acpi_physical_address root_table;
>> +struct acpi_table_header *header;
>> +struct acpi_table_rsdp *rsdp;
>> +bool acpi_use_rsdt = false;
>> +char *signature;
>> +char arg[10];
>> +u8 *entry;
>> +u32 count;
>> +u32 size;
>> +int i, j;
>> +int ret;
>> +u32 len;
>> +
>> +rsdp = (struct acpi_table_rsdp *)get_rsdp_addr();
>> +if (!rsdp)
>> +return NULL;
>> +
>> +ret = cmdline_find_option("acpi", arg, sizeof(arg));
>> +if (ret == 4 && !strncmp(arg, "rsdt", 4))
>> +acpi_use_rsdt = true;
>> +
>> +/* Get RSDT or XSDT from RSDP. */
>> +if (!acpi_use_rsdt &&
>> +rsdp->xsdt_physical_address && rsdp->revision > 1) {
>> +root_table = rsdp->xsdt_physical_address;
>> +size = ACPI_XSDT_ENTRY_SIZE;
>> +} else {
>> +root_table = rsdp->rsdt_physical_address;
>> +size = ACPI_RSDT_ENTRY_SIZE;
>> +}
>> +
>> +/* Get ACPI root table from RSDT or XSDT.*/
>> +header = (struct acpi_table_header *)root_table;
>> +len = header->length;
>> +count = (u32)((len - sizeof(struct acpi_table_header)) / size);
>> +entry = ACPI_ADD_PTR(u8, header, sizeof(struct acpi_table_header));
>> +
>> +for (i = 0; i < count; i++) {
>> +u64 address64;
>> +
>> +if (size == ACPI_RSDT_ENTRY_SIZE)
>> +acpi_table = ((acpi_physical_address)
>> + (*ACPI_CAST_PTR(u32, entry)));
>> +else {
>> +*(u64 *)(void *) = *(u64 *)(void *)entry;
>> +acpi_table = (acpi_physical_address) address64;
>> +}
>> +
>> +if (acpi_table) {
>> +header =
Re: [PATCH v11 3/5] x86/boot: Add get_acpi_rsdp() to parse RSDP in cmdlien from kexec
On Mon, Nov 12, 2018 at 12:43:44PM -0500, Masayoshi Mizuma wrote:
>Hi Chao,
>
>On Mon, Nov 12, 2018 at 05:46:43PM +0800, Chao Fan wrote:
>> Imitate setup_acpi_rsdp() for the early_param of 'acpi_rsdp'.
>> KEXEC writes the RSDP pointer to cmdline for EFI booting.
>> So if 'acpi_rsdp' found in cmdline, use it directely.
>>
>
>> Since function kstrtoull() is needed, include it in
>> arch/x86/boot/string.h. To solve the definition conflict
>> problem, set BOOT_STRING tag to expose only kstrtoull() and
>> functions used by it. Other functions in lib/kstrtox.c will
>> be covered.
>
>How about the following get_acpi_rsdp()...? It doesn't use kstrtoull().
>
>static void get_acpi_rsdp(acpi_physical_address *rsdp_addr)
>{
>#ifdef CONFIG_KEXEC
>unsigned long addr;
>char val[32];
>
>if (cmdline_find_option("acpi_rsdp", val, sizeof(val)) > 0) {
>char *e;
>
>if (!strncmp(val, "0x", 2)) {
>addr = simple_strtoull(val + 2, , 16);
>if ((addr == 0) || ((val + 2) == e))
>return;
>*rsdp_addr = (acpi_physical_address)addr;
>}
>}
>#endif
>}
Thanks for the suggestion.
I used this function. In the old version, Boris said simple_strtoull()
is the old function and told me use the new kstrtoull().
Thanks,
Chao Fan
>
>Thanks,
>Masa
>
>>
>> Signed-off-by: Chao Fan
>> ---
>> arch/x86/boot/compressed/acpitb.c | 26 ++
>> arch/x86/boot/string.h| 4
>> lib/kstrtox.c | 4
>> 3 files changed, 34 insertions(+)
>>
>> diff --git a/arch/x86/boot/compressed/acpitb.c
>> b/arch/x86/boot/compressed/acpitb.c
>> index 50fa65cf824d..5cfb4efa5a19 100644
>> --- a/arch/x86/boot/compressed/acpitb.c
>> +++ b/arch/x86/boot/compressed/acpitb.c
>> @@ -8,6 +8,12 @@
>> #include
>> #include
>>
>> +#define STATIC
>> +#include
>> +
>> +#define BOOT_STRING
>> +#include "../string.h"
>> +
>> /* Search EFI table for RSDP table. */
>> static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
>> {
>> @@ -200,3 +206,23 @@ static void bios_get_rsdp_addr(acpi_physical_address
>> *rsdp_addr)
>> *rsdp_addr = (acpi_physical_address)address;
>> }
>> }
>> +
>> +static void get_acpi_rsdp(acpi_physical_address *rsdp_addr)
>> +{
>> +#ifdef CONFIG_KEXEC
>> +unsigned long long res;
>> +int len = 0;
>> +char *val;
>> +
>> +val = malloc(19);
>> +len = cmdline_find_option("acpi_rsdp", val, 19);
>> +
>> +if (len == -1)
>> +return;
>> +
>> +if (len > 0) {
>> +val[len] = 0;
>> +*rsdp_addr = (acpi_physical_address)kstrtoull(val, 16, );
>> +}
>> +#endif
>> +}
>> diff --git a/arch/x86/boot/string.h b/arch/x86/boot/string.h
>> index 3d78e27077f4..0ff3edb888e4 100644
>> --- a/arch/x86/boot/string.h
>> +++ b/arch/x86/boot/string.h
>> @@ -30,3 +30,7 @@ extern unsigned long long simple_strtoull(const char *cp,
>> char **endp,
>>unsigned int base);
>>
>> #endif /* BOOT_STRING_H */
>> +
>> +#ifdef BOOT_STRING
>> +#include "../../../lib/kstrtox.c"
>> +#endif
>> diff --git a/lib/kstrtox.c b/lib/kstrtox.c
>> index 1006bf70bf74..3804db9eed56 100644
>> --- a/lib/kstrtox.c
>> +++ b/lib/kstrtox.c
>> @@ -126,6 +126,8 @@ int kstrtoull(const char *s, unsigned int base, unsigned
>> long long *res)
>> }
>> EXPORT_SYMBOL(kstrtoull);
>>
>> +#ifndef BOOT_STRING
>> +
>> /**
>> * kstrtoll - convert a string to a long long
>> * @s: The start of the string. The string must be null-terminated, and may
>> also
>> @@ -408,3 +410,5 @@ kstrto_from_user(kstrtou16_from_user,kstrtou16,
>> u16);
>> kstrto_from_user(kstrtos16_from_user, kstrtos16, s16);
>> kstrto_from_user(kstrtou8_from_user,kstrtou8, u8);
>> kstrto_from_user(kstrtos8_from_user,kstrtos8, s8);
>> +
>> +#endif
>> --
>> 2.19.1
>>
>>
>>
>
>
Re: [PATCH v11 2/5] x86/boot: Add bios_get_rsdp_addr() to search RSDP in memory
On Mon, Nov 12, 2018 at 04:27:44PM +0100, Borislav Petkov wrote:
>On Mon, Nov 12, 2018 at 05:46:42PM +0800, Chao Fan wrote:
>> Imitate ACPI code to search RSDP pointer from memory.
>> Walk memory and check the signature until get the RSDP signature.
>> Based on acpi_tb_scan_memory_for_rsdp() and acpi_find_root_pointer().
>> If didn't get RSDP from EFI table, will run this function.
>
>That's some very strange english. Please improve.
>
>> Used for later patch to dig out SRAT table and get the memory
>> information. And figure out the immovable memory regions
>> to avoid KASLR extracts kernel on movable memory, slove the
> ^^
>
>Please introduce a spellchecker into your patch creation workflow.
>
Thanks.
>> conflict between KASLR and movable_node feature.
>
>Btw, this paragraph could be used for a CONFIG_ item you could define
>for your particular use case. Because right now you have funnies like:
>
>+#if (defined CONFIG_MEMORY_HOTREMOVE) && (defined CONFIG_RANDOMIZE_BASE)
>+vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/acpitb.o
>+#endif
>
>where CONFIG_RANDOMIZE_BASE is repeated for no good reason.
>
>But we'll see - need to get to the end of your patch series first.
>
>> Signed-off-by: Chao Fan
>> ---
>> arch/x86/boot/compressed/acpitb.c | 106 ++
>> 1 file changed, 106 insertions(+)
>>
>> diff --git a/arch/x86/boot/compressed/acpitb.c
>> b/arch/x86/boot/compressed/acpitb.c
>> index 56b54b0e0889..50fa65cf824d 100644
>> --- a/arch/x86/boot/compressed/acpitb.c
>> +++ b/arch/x86/boot/compressed/acpitb.c
>> @@ -94,3 +94,109 @@ static void efi_get_rsdp_addr(acpi_physical_address
>> *rsdp_addr)
>> }
>> #endif
>> }
>> +
>> +static u8 compute_checksum(u8 *buffer, u32 length)
>> +{
>> +u8 sum = 0;
>> +u8 *end = buffer + length;
>> +
>> +while (buffer < end)
>> +sum = (u8)(sum + *(buffer++));
>
>What's that cast for?
>
>Ah, this is the version in acpi_tb_checksum(). Well, I'd write this
>simply as:
>
> sum += *(buffer++);
Thanks for your suggestion.
>
>> +
>> +return sum;
>> +}
>> +
>> +/*
>> + * Used to search a block of memory for the RSDP signature.
>> + * Return Pointer to the RSDP if found, otherwise NULL.
>
> "Returns pointer... "
>
>> + * Based on acpi_tb_scan_memory_for_rsdp().
>> + */
>> +static u8 *scan_mem_for_rsdp(u8 *start, u32 length)
>> +{
>> +struct acpi_table_rsdp *rsdp;
>> +u8 *end;
>> +u8 *rover;
>
>rover?
>
>> +
>> +end = start + length;
>> +
>> +/* Search from given start address for the requested length */
>> +for (rover = start; rover < end; rover += ACPI_RSDP_SCAN_STEP) {
The 'rover' was named as 'mem_rover', but the length of this line is too
long. So shorten it as 'rever' so that they can keep in one line.
>> +/*
>> + * The RSDP signature and checksum must both be correct
>> + * Note: Sometimes there exists more than one RSDP in memory;
>> + * the valid RSDP has a valid checksum, all others have an
>> + * invalid checksum.
>> + */
>> +rsdp = (struct acpi_table_rsdp *)rover;
>> +
>> +/* Nope, BAD Signature */
>> +if (!ACPI_VALIDATE_RSDP_SIG(rsdp->signature))
>> +continue;
>> +
>> +/* Check the standard checksum */
>> +if (compute_checksum((u8 *) rsdp, ACPI_RSDP_CHECKSUM_LENGTH))
>> +continue;
>> +
>> +/* Check extended checksum if table version >= 2 */
>> +if ((rsdp->revision >= 2) &&
>> +(compute_checksum((u8 *) rsdp, ACPI_RSDP_XCHECKSUM_LENGTH)))
>> +continue;
>> +
>> +/* Sig and checksum valid, we have found a real RSDP */
>> +return rover;
>> +}
>> +return NULL;
>> +}
>> +
>> +/*
>> + * Used to search RSDP physical address.
>> + * Based on acpi_find_root_pointer(). Since only use physical address
>> + * in this period, so there is no need to do the memory map jobs.
>
>You mean: "All addresses used here are physical."?
>
>"memory map jobs"?
>
>Please be more careful when writing comments which are going to be read
>by other people. "jobs" means a lot of things and you don't want "jobs"
>in that context here.
OK.
>
>> + */
>> +static void bios_get_rsdp_addr(acpi_physical_address *rsdp_addr)
>
>Same remark as before: the function is void and you're returning through
>its parameter. Make it return acpi_physical_address instead.
>
I will change all these functions.
>> +{
>> +struct acpi_table_rsdp *rsdp;
>> +u8 *table_ptr;
>> +u8 *mem_rover;
>
>rover?
This name came from ACPI driver code, acpi_find_root_pointer().
Used for the loop. If you have a better name, please tell me.
>
>> +u32 address;
>> +
>> +/*
>> + * Get the location of the Extended BIOS Data Area (EBDA)
>> + * Since we use physical address directely, so
>
>It is
Re: [PATCH v11 1/5] x86/boot: Add efi_get_rsdp_addr() to dig out RSDP from EFI table
On Mon, Nov 12, 2018 at 03:54:33PM +0100, Borislav Petkov wrote:
>On Mon, Nov 12, 2018 at 05:46:41PM +0800, Chao Fan wrote:
>> In order to parse SRAT table and get memory information, RSDP pointer
>> should be found. In kernel, there are three methods to get RSDP:
>> EFI condition, BIOS condition and KEXEC condition. The first works
>> for EFI condition.
>
>"condition"?
>
>Also, please explain shortly what all those abbreviations mean: think
>of a person reading your commit message who doesn't have any clue from
>ACPI.
I will try to improve in next version.
>
>> Imitate ACPI code and EFI code to dig RSDP pointer from EFI tables.
>> Process: boot_param->systab->efi_config_table->RSDP.
>> Based on efi_init(), efi_config_init(), efi_config_parse_tables().
>>
>> Signed-off-by: Chao Fan
>> ---
>> arch/x86/boot/compressed/acpitb.c | 96 +++
>> 1 file changed, 96 insertions(+)
>> create mode 100644 arch/x86/boot/compressed/acpitb.c
>>
>> diff --git a/arch/x86/boot/compressed/acpitb.c
>> b/arch/x86/boot/compressed/acpitb.c
>> new file mode 100644
>> index ..56b54b0e0889
>> --- /dev/null
>> +++ b/arch/x86/boot/compressed/acpitb.c
>> @@ -0,0 +1,96 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +#define BOOT_CTYPE_H
>> +#include "misc.h"
>> +#include "error.h"
>> +
>> +#include
>> +#include
>> +#include
>> +#include
>> +
>> +/* Search EFI table for RSDP table. */
>> +static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
>
>This is just silly: the function returns void and has a single parameter
>which is an *output* parameter?!
>
>Why isn't the signature
>
>static acpi_physical_address *efi_get_rsdp_addr(void)
>
>instead?
I will change the function style.
>
>> +{
>> +#ifdef CONFIG_EFI
>> +efi_system_table_t *systab;
>> +bool efi_64 = false;
>
>You're setting it below already, why here too?
I will drop.
>
>> +void *config_tables;
>> +struct efi_info *e;
>> +char *sig;
>> +int size;
>> +int i;
>> +
>> +e = _params->efi_info;
>> +sig = (char *)>efi_loader_signature;
>> +
>> +if (!strncmp(sig, EFI64_LOADER_SIGNATURE, 4))
>> +efi_64 = true;
>> +else if (!strncmp(sig, EFI32_LOADER_SIGNATURE, 4))
>> +efi_64 = false;
>> +else {
>> +debug_putstr("Wrong EFI loader signature.\n");
>> +return;
>> +}
>> +
>> +/* Get systab from boot params. Based on efi_init(). */
>> +#ifdef CONFIG_X86_64
>> +systab = (efi_system_table_t *)(
>> +e->efi_systab | ((__u64)e->efi_systab_hi<<32));
>
>No ugly line breaks with open braces trailing like that, pls - just let
>it stick out.
Thanks for this suggestion.
>
>> +#else
>> +if (e->efi_systab_hi || e->efi_memmap_hi) {
>> +debug_putstr("Table located above 4GB. EFI should be
>> disabled.\n");
>
>You need to say here what really happens here:
>
> debug_putstr("Error getting RSDP address: EFI system table
> located above 4GB.\n");
>
>The same below.
I will change all the all the same message.
>
>> +return;
>> +}
>> +systab = (efi_system_table_t *)e->efi_systab;
>> +#endif
>> +
>> +if (!systab)
>> +return;
>> +
>> +/*
>> + * Get EFI tables from systab. Based on efi_config_init() and
>> + * efi_config_parse_tables(). Only dig out the config_table.
>> + */
>> +size = efi_64 ? sizeof(efi_config_table_64_t) :
>> +sizeof(efi_config_table_32_t);
>> +
>> +for (i = 0; i < systab->nr_tables; i++) {
>> +efi_guid_t guid;
>> +unsigned long table;
>
>Put the void *config_tables declaration here.
OK.
>
>> +
>> +config_tables = (void *)(systab->tables + size * i);
>> +if (efi_64) {
>> +efi_config_table_64_t *tmp_table;
>> +
>> +tmp_table = (efi_config_table_64_t *)config_tables;
>> +guid = tmp_table->guid;
>> +table = tmp_table->table;
>> +#ifndef CONFIG_64BIT
>
>Above you have CONFIG_X86_64, here CONFIG_64BIT. Please use one only.
>
>Also, use IS_ENABLED() instead.
OK.
>
>> +if (table >> 32) {
>> +debug_putstr("Table located above 4G. EFI
>> should be disabled.\n");
>> +return;
>> +}
>> +#endif
>> +} else {
>> +efi_config_table_32_t *tmp_table;
>> +
>> +tmp_table = (efi_config_table_32_t *)config_tables;
>> +guid = tmp_table->guid;
>> +table = tmp_table->table;
>> +}
>> +
>> +/*
>> + * Get RSDP from EFI tables.
>> + * If ACPI20 table found, use it.
>> + * If ACPI20 table not found, but ACPI table found,
>> + * use the ACPI table.
>> + */
>
>That comment is the opposite of what the code does. Also, why is that
Re: [PATCH v11 4/5] x86/boot: Dig out SRAT table from RSDP and find immovable memory
On Mon, Nov 12, 2018 at 05:46:44PM +0800, Chao Fan wrote:
> To avoid KASLR extracting kernel on movable memory, slove the
> conflict between KASLR and movable_node feature, dig the SRAT tables
> from RSDP pointer. Walk the SRAT tables and store the immovable
> memory regions in immovable_mem[].
>
> There are three methods to get RSDP pointer: KEXEC condition,
> EFI confition, BIOS condition.
> If KEXEC add 'acpi_rsdp' to cmdline, use it.
> Otherwise, parse EFI table for RSDP.
> Then, search memory for RSDP.
>
> Imitate from ACPI code, based on acpi_os_get_root_pointer().
> Process: RSDP->RSDT/XSDT->ACPI root table->SRAT.
>
> Signed-off-by: Chao Fan
> ---
> arch/x86/boot/compressed/Makefile | 4 +
> arch/x86/boot/compressed/acpitb.c | 139 ++
> arch/x86/boot/compressed/kaslr.c | 4 -
> arch/x86/boot/compressed/misc.h | 15
> 4 files changed, 158 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/boot/compressed/Makefile
> b/arch/x86/boot/compressed/Makefile
> index 466f66c8a7f8..b51f7629b8ef 100644
> --- a/arch/x86/boot/compressed/Makefile
> +++ b/arch/x86/boot/compressed/Makefile
> @@ -84,6 +84,10 @@ ifdef CONFIG_X86_64
> vmlinux-objs-y += $(obj)/pgtable_64.o
> endif
>
> +#if (defined CONFIG_MEMORY_HOTREMOVE) && (defined CONFIG_RANDOMIZE_BASE)
> +vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/acpitb.o
> +#endif
'#' in Makefile means comment out...
ifdef CONFIG_MEMORY_HOTREMOVE
vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/acpitb.o
endif
> +
> $(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
>
> vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \
> diff --git a/arch/x86/boot/compressed/acpitb.c
> b/arch/x86/boot/compressed/acpitb.c
> index 5cfb4efa5a19..161f21a7fb3b 100644
> --- a/arch/x86/boot/compressed/acpitb.c
> +++ b/arch/x86/boot/compressed/acpitb.c
> @@ -14,6 +14,11 @@
> #define BOOT_STRING
> #include "../string.h"
>
> +#ifdef CONFIG_MEMORY_HOTREMOVE
> +/* Store the immovable memory regions */
> +struct mem_vector immovable_mem[MAX_NUMNODES*2];
> +#endif
This #ifdef isn't needed.
Could you please check the other #ifdef statement as well?
Thanks,
Masa
> +
> /* Search EFI table for RSDP table. */
> static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
> {
> @@ -226,3 +231,137 @@ static void get_acpi_rsdp(acpi_physical_address
> *rsdp_addr)
> }
> #endif
> }
> +
> +/*
> + * Used to dig RSDP table from EFI table or BIOS.
> + * If RSDP table found in EFI table, use it. Or search BIOS.
> + * Based on acpi_os_get_root_pointer().
> + */
> +static acpi_physical_address get_rsdp_addr(void)
> +{
> + acpi_physical_address pa = 0;
> +
> + get_acpi_rsdp();
> +
> + if (!pa)
> + efi_get_rsdp_addr();
> +
> + if (!pa)
> + bios_get_rsdp_addr();
> +
> + return pa;
> +}
> +
> +static struct acpi_table_header *get_acpi_srat_table(void)
> +{
> + acpi_physical_address acpi_table;
> + acpi_physical_address root_table;
> + struct acpi_table_header *header;
> + struct acpi_table_rsdp *rsdp;
> + bool acpi_use_rsdt = false;
> + char *signature;
> + char arg[10];
> + u8 *entry;
> + u32 count;
> + u32 size;
> + int i, j;
> + int ret;
> + u32 len;
> +
> + rsdp = (struct acpi_table_rsdp *)get_rsdp_addr();
> + if (!rsdp)
> + return NULL;
> +
> + ret = cmdline_find_option("acpi", arg, sizeof(arg));
> + if (ret == 4 && !strncmp(arg, "rsdt", 4))
> + acpi_use_rsdt = true;
> +
> + /* Get RSDT or XSDT from RSDP. */
> + if (!acpi_use_rsdt &&
> + rsdp->xsdt_physical_address && rsdp->revision > 1) {
> + root_table = rsdp->xsdt_physical_address;
> + size = ACPI_XSDT_ENTRY_SIZE;
> + } else {
> + root_table = rsdp->rsdt_physical_address;
> + size = ACPI_RSDT_ENTRY_SIZE;
> + }
> +
> + /* Get ACPI root table from RSDT or XSDT.*/
> + header = (struct acpi_table_header *)root_table;
> + len = header->length;
> + count = (u32)((len - sizeof(struct acpi_table_header)) / size);
> + entry = ACPI_ADD_PTR(u8, header, sizeof(struct acpi_table_header));
> +
> + for (i = 0; i < count; i++) {
> + u64 address64;
> +
> + if (size == ACPI_RSDT_ENTRY_SIZE)
> + acpi_table = ((acpi_physical_address)
> + (*ACPI_CAST_PTR(u32, entry)));
> + else {
> + *(u64 *)(void *) = *(u64 *)(void *)entry;
> + acpi_table = (acpi_physical_address) address64;
> + }
> +
> + if (acpi_table) {
> + header = (struct acpi_table_header *)acpi_table;
> + signature = header->signature;
> +
> + if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_SRAT))
> + return header;
> +
Re: [PATCH v11 4/5] x86/boot: Dig out SRAT table from RSDP and find immovable memory
On Mon, Nov 12, 2018 at 05:46:44PM +0800, Chao Fan wrote:
> To avoid KASLR extracting kernel on movable memory, slove the
> conflict between KASLR and movable_node feature, dig the SRAT tables
> from RSDP pointer. Walk the SRAT tables and store the immovable
> memory regions in immovable_mem[].
>
> There are three methods to get RSDP pointer: KEXEC condition,
> EFI confition, BIOS condition.
> If KEXEC add 'acpi_rsdp' to cmdline, use it.
> Otherwise, parse EFI table for RSDP.
> Then, search memory for RSDP.
>
> Imitate from ACPI code, based on acpi_os_get_root_pointer().
> Process: RSDP->RSDT/XSDT->ACPI root table->SRAT.
>
> Signed-off-by: Chao Fan
> ---
> arch/x86/boot/compressed/Makefile | 4 +
> arch/x86/boot/compressed/acpitb.c | 139 ++
> arch/x86/boot/compressed/kaslr.c | 4 -
> arch/x86/boot/compressed/misc.h | 15
> 4 files changed, 158 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/boot/compressed/Makefile
> b/arch/x86/boot/compressed/Makefile
> index 466f66c8a7f8..b51f7629b8ef 100644
> --- a/arch/x86/boot/compressed/Makefile
> +++ b/arch/x86/boot/compressed/Makefile
> @@ -84,6 +84,10 @@ ifdef CONFIG_X86_64
> vmlinux-objs-y += $(obj)/pgtable_64.o
> endif
>
> +#if (defined CONFIG_MEMORY_HOTREMOVE) && (defined CONFIG_RANDOMIZE_BASE)
> +vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/acpitb.o
> +#endif
> +
> $(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
>
> vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \
> diff --git a/arch/x86/boot/compressed/acpitb.c
> b/arch/x86/boot/compressed/acpitb.c
> index 5cfb4efa5a19..161f21a7fb3b 100644
> --- a/arch/x86/boot/compressed/acpitb.c
> +++ b/arch/x86/boot/compressed/acpitb.c
> @@ -14,6 +14,11 @@
> #define BOOT_STRING
> #include "../string.h"
>
> +#ifdef CONFIG_MEMORY_HOTREMOVE
> +/* Store the immovable memory regions */
> +struct mem_vector immovable_mem[MAX_NUMNODES*2];
> +#endif
> +
> /* Search EFI table for RSDP table. */
> static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
> {
> @@ -226,3 +231,137 @@ static void get_acpi_rsdp(acpi_physical_address
> *rsdp_addr)
> }
> #endif
> }
> +
> +/*
> + * Used to dig RSDP table from EFI table or BIOS.
> + * If RSDP table found in EFI table, use it. Or search BIOS.
> + * Based on acpi_os_get_root_pointer().
> + */
> +static acpi_physical_address get_rsdp_addr(void)
> +{
> + acpi_physical_address pa = 0;
> +
> + get_acpi_rsdp();
> +
> + if (!pa)
> + efi_get_rsdp_addr();
> +
> + if (!pa)
> + bios_get_rsdp_addr();
> +
> + return pa;
> +}
> +
> +static struct acpi_table_header *get_acpi_srat_table(void)
> +{
> + acpi_physical_address acpi_table;
> + acpi_physical_address root_table;
> + struct acpi_table_header *header;
> + struct acpi_table_rsdp *rsdp;
> + bool acpi_use_rsdt = false;
> + char *signature;
> + char arg[10];
> + u8 *entry;
> + u32 count;
> + u32 size;
> + int i, j;
> + int ret;
> + u32 len;
> +
> + rsdp = (struct acpi_table_rsdp *)get_rsdp_addr();
> + if (!rsdp)
> + return NULL;
> +
> + ret = cmdline_find_option("acpi", arg, sizeof(arg));
> + if (ret == 4 && !strncmp(arg, "rsdt", 4))
> + acpi_use_rsdt = true;
All have to do for ret is checking whether it's above 0, right?
So how about the following?
if ((cmdline_find_option("acpi", arg, sizeof(arg)) > 0) &&
!strncmp(arg, "rsdt", 4))
acpi_use_rsdt = true;
> +
> + /* Get RSDT or XSDT from RSDP. */
> + if (!acpi_use_rsdt &&
> + rsdp->xsdt_physical_address && rsdp->revision > 1) {
> + root_table = rsdp->xsdt_physical_address;
> + size = ACPI_XSDT_ENTRY_SIZE;
> + } else {
> + root_table = rsdp->rsdt_physical_address;
> + size = ACPI_RSDT_ENTRY_SIZE;
> + }
> +
> + /* Get ACPI root table from RSDT or XSDT.*/
> + header = (struct acpi_table_header *)root_table;
> + len = header->length;
> + count = (u32)((len - sizeof(struct acpi_table_header)) / size);
> + entry = ACPI_ADD_PTR(u8, header, sizeof(struct acpi_table_header));
> +
> + for (i = 0; i < count; i++) {
> + u64 address64;
> +
> + if (size == ACPI_RSDT_ENTRY_SIZE)
> + acpi_table = ((acpi_physical_address)
> + (*ACPI_CAST_PTR(u32, entry)));
> + else {
> + *(u64 *)(void *) = *(u64 *)(void *)entry;
> + acpi_table = (acpi_physical_address) address64;
> + }
> +
> + if (acpi_table) {
> + header = (struct acpi_table_header *)acpi_table;
> + signature = header->signature;
this isn't needed.
> +
> + if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_SRAT))
> + return
Re: [PATCH v11 3/5] x86/boot: Add get_acpi_rsdp() to parse RSDP in cmdlien from kexec
Hi Chao,
On Mon, Nov 12, 2018 at 05:46:43PM +0800, Chao Fan wrote:
> Imitate setup_acpi_rsdp() for the early_param of 'acpi_rsdp'.
> KEXEC writes the RSDP pointer to cmdline for EFI booting.
> So if 'acpi_rsdp' found in cmdline, use it directely.
>
> Since function kstrtoull() is needed, include it in
> arch/x86/boot/string.h. To solve the definition conflict
> problem, set BOOT_STRING tag to expose only kstrtoull() and
> functions used by it. Other functions in lib/kstrtox.c will
> be covered.
How about the following get_acpi_rsdp()...? It doesn't use kstrtoull().
static void get_acpi_rsdp(acpi_physical_address *rsdp_addr)
{
#ifdef CONFIG_KEXEC
unsigned long addr;
char val[32];
if (cmdline_find_option("acpi_rsdp", val, sizeof(val)) > 0) {
char *e;
if (!strncmp(val, "0x", 2)) {
addr = simple_strtoull(val + 2, , 16);
if ((addr == 0) || ((val + 2) == e))
return;
*rsdp_addr = (acpi_physical_address)addr;
}
}
#endif
}
Thanks,
Masa
>
> Signed-off-by: Chao Fan
> ---
> arch/x86/boot/compressed/acpitb.c | 26 ++
> arch/x86/boot/string.h| 4
> lib/kstrtox.c | 4
> 3 files changed, 34 insertions(+)
>
> diff --git a/arch/x86/boot/compressed/acpitb.c
> b/arch/x86/boot/compressed/acpitb.c
> index 50fa65cf824d..5cfb4efa5a19 100644
> --- a/arch/x86/boot/compressed/acpitb.c
> +++ b/arch/x86/boot/compressed/acpitb.c
> @@ -8,6 +8,12 @@
> #include
> #include
>
> +#define STATIC
> +#include
> +
> +#define BOOT_STRING
> +#include "../string.h"
> +
> /* Search EFI table for RSDP table. */
> static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
> {
> @@ -200,3 +206,23 @@ static void bios_get_rsdp_addr(acpi_physical_address
> *rsdp_addr)
> *rsdp_addr = (acpi_physical_address)address;
> }
> }
> +
> +static void get_acpi_rsdp(acpi_physical_address *rsdp_addr)
> +{
> +#ifdef CONFIG_KEXEC
> + unsigned long long res;
> + int len = 0;
> + char *val;
> +
> + val = malloc(19);
> + len = cmdline_find_option("acpi_rsdp", val, 19);
> +
> + if (len == -1)
> + return;
> +
> + if (len > 0) {
> + val[len] = 0;
> + *rsdp_addr = (acpi_physical_address)kstrtoull(val, 16, );
> + }
> +#endif
> +}
> diff --git a/arch/x86/boot/string.h b/arch/x86/boot/string.h
> index 3d78e27077f4..0ff3edb888e4 100644
> --- a/arch/x86/boot/string.h
> +++ b/arch/x86/boot/string.h
> @@ -30,3 +30,7 @@ extern unsigned long long simple_strtoull(const char *cp,
> char **endp,
> unsigned int base);
>
> #endif /* BOOT_STRING_H */
> +
> +#ifdef BOOT_STRING
> +#include "../../../lib/kstrtox.c"
> +#endif
> diff --git a/lib/kstrtox.c b/lib/kstrtox.c
> index 1006bf70bf74..3804db9eed56 100644
> --- a/lib/kstrtox.c
> +++ b/lib/kstrtox.c
> @@ -126,6 +126,8 @@ int kstrtoull(const char *s, unsigned int base, unsigned
> long long *res)
> }
> EXPORT_SYMBOL(kstrtoull);
>
> +#ifndef BOOT_STRING
> +
> /**
> * kstrtoll - convert a string to a long long
> * @s: The start of the string. The string must be null-terminated, and may
> also
> @@ -408,3 +410,5 @@ kstrto_from_user(kstrtou16_from_user, kstrtou16,
> u16);
> kstrto_from_user(kstrtos16_from_user,kstrtos16, s16);
> kstrto_from_user(kstrtou8_from_user, kstrtou8, u8);
> kstrto_from_user(kstrtos8_from_user, kstrtos8, s8);
> +
> +#endif
> --
> 2.19.1
>
>
>
Re: [PATCH v11 2/5] x86/boot: Add bios_get_rsdp_addr() to search RSDP in memory
On Mon, Nov 12, 2018 at 05:46:42PM +0800, Chao Fan wrote:
> Imitate ACPI code to search RSDP pointer from memory.
> Walk memory and check the signature until get the RSDP signature.
> Based on acpi_tb_scan_memory_for_rsdp() and acpi_find_root_pointer().
> If didn't get RSDP from EFI table, will run this function.
That's some very strange english. Please improve.
> Used for later patch to dig out SRAT table and get the memory
> information. And figure out the immovable memory regions
> to avoid KASLR extracts kernel on movable memory, slove the
^^
Please introduce a spellchecker into your patch creation workflow.
> conflict between KASLR and movable_node feature.
Btw, this paragraph could be used for a CONFIG_ item you could define
for your particular use case. Because right now you have funnies like:
+#if (defined CONFIG_MEMORY_HOTREMOVE) && (defined CONFIG_RANDOMIZE_BASE)
+vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/acpitb.o
+#endif
where CONFIG_RANDOMIZE_BASE is repeated for no good reason.
But we'll see - need to get to the end of your patch series first.
> Signed-off-by: Chao Fan
> ---
> arch/x86/boot/compressed/acpitb.c | 106 ++
> 1 file changed, 106 insertions(+)
>
> diff --git a/arch/x86/boot/compressed/acpitb.c
> b/arch/x86/boot/compressed/acpitb.c
> index 56b54b0e0889..50fa65cf824d 100644
> --- a/arch/x86/boot/compressed/acpitb.c
> +++ b/arch/x86/boot/compressed/acpitb.c
> @@ -94,3 +94,109 @@ static void efi_get_rsdp_addr(acpi_physical_address
> *rsdp_addr)
> }
> #endif
> }
> +
> +static u8 compute_checksum(u8 *buffer, u32 length)
> +{
> + u8 sum = 0;
> + u8 *end = buffer + length;
> +
> + while (buffer < end)
> + sum = (u8)(sum + *(buffer++));
What's that cast for?
Ah, this is the version in acpi_tb_checksum(). Well, I'd write this
simply as:
sum += *(buffer++);
> +
> + return sum;
> +}
> +
> +/*
> + * Used to search a block of memory for the RSDP signature.
> + * Return Pointer to the RSDP if found, otherwise NULL.
"Returns pointer... "
> + * Based on acpi_tb_scan_memory_for_rsdp().
> + */
> +static u8 *scan_mem_for_rsdp(u8 *start, u32 length)
> +{
> + struct acpi_table_rsdp *rsdp;
> + u8 *end;
> + u8 *rover;
rover?
> +
> + end = start + length;
> +
> + /* Search from given start address for the requested length */
> + for (rover = start; rover < end; rover += ACPI_RSDP_SCAN_STEP) {
> + /*
> + * The RSDP signature and checksum must both be correct
> + * Note: Sometimes there exists more than one RSDP in memory;
> + * the valid RSDP has a valid checksum, all others have an
> + * invalid checksum.
> + */
> + rsdp = (struct acpi_table_rsdp *)rover;
> +
> + /* Nope, BAD Signature */
> + if (!ACPI_VALIDATE_RSDP_SIG(rsdp->signature))
> + continue;
> +
> + /* Check the standard checksum */
> + if (compute_checksum((u8 *) rsdp, ACPI_RSDP_CHECKSUM_LENGTH))
> + continue;
> +
> + /* Check extended checksum if table version >= 2 */
> + if ((rsdp->revision >= 2) &&
> + (compute_checksum((u8 *) rsdp, ACPI_RSDP_XCHECKSUM_LENGTH)))
> + continue;
> +
> + /* Sig and checksum valid, we have found a real RSDP */
> + return rover;
> + }
> + return NULL;
> +}
> +
> +/*
> + * Used to search RSDP physical address.
> + * Based on acpi_find_root_pointer(). Since only use physical address
> + * in this period, so there is no need to do the memory map jobs.
You mean: "All addresses used here are physical."?
"memory map jobs"?
Please be more careful when writing comments which are going to be read
by other people. "jobs" means a lot of things and you don't want "jobs"
in that context here.
> + */
> +static void bios_get_rsdp_addr(acpi_physical_address *rsdp_addr)
Same remark as before: the function is void and you're returning through
its parameter. Make it return acpi_physical_address instead.
> +{
> + struct acpi_table_rsdp *rsdp;
> + u8 *table_ptr;
> + u8 *mem_rover;
rover?
> + u32 address;
> +
> + /*
> + * Get the location of the Extended BIOS Data Area (EBDA)
> + * Since we use physical address directely, so
It is "directly" - what about that spellchecker?
> + * acpi_os_map_memory() and acpi_os_unmap_memory() are
> + * not needed here.
Why do you even need to say that here?
> + */
> + table_ptr = (u8 *)ACPI_EBDA_PTR_LOCATION;
> + *(u32 *)(void *) = *(u16 *)(void *)table_ptr;
> + address <<= 4;
> + table_ptr = (u8 *)address;
arch/x86/boot/compressed/acpitb.c: In function ‘bios_get_rsdp_addr’:
arch/x86/boot/compressed/acpitb.c:172:14: warning: cast to pointer from integer
of different size
Re: [PATCH v11 1/5] x86/boot: Add efi_get_rsdp_addr() to dig out RSDP from EFI table
On Mon, Nov 12, 2018 at 05:46:41PM +0800, Chao Fan wrote:
> In order to parse SRAT table and get memory information, RSDP pointer
> should be found. In kernel, there are three methods to get RSDP:
> EFI condition, BIOS condition and KEXEC condition. The first works
> for EFI condition.
"condition"?
Also, please explain shortly what all those abbreviations mean: think
of a person reading your commit message who doesn't have any clue from
ACPI.
> Imitate ACPI code and EFI code to dig RSDP pointer from EFI tables.
> Process: boot_param->systab->efi_config_table->RSDP.
> Based on efi_init(), efi_config_init(), efi_config_parse_tables().
>
> Signed-off-by: Chao Fan
> ---
> arch/x86/boot/compressed/acpitb.c | 96 +++
> 1 file changed, 96 insertions(+)
> create mode 100644 arch/x86/boot/compressed/acpitb.c
>
> diff --git a/arch/x86/boot/compressed/acpitb.c
> b/arch/x86/boot/compressed/acpitb.c
> new file mode 100644
> index ..56b54b0e0889
> --- /dev/null
> +++ b/arch/x86/boot/compressed/acpitb.c
> @@ -0,0 +1,96 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#define BOOT_CTYPE_H
> +#include "misc.h"
> +#include "error.h"
> +
> +#include
> +#include
> +#include
> +#include
> +
> +/* Search EFI table for RSDP table. */
> +static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
This is just silly: the function returns void and has a single parameter
which is an *output* parameter?!
Why isn't the signature
static acpi_physical_address *efi_get_rsdp_addr(void)
instead?
> +{
> +#ifdef CONFIG_EFI
> + efi_system_table_t *systab;
> + bool efi_64 = false;
You're setting it below already, why here too?
> + void *config_tables;
> + struct efi_info *e;
> + char *sig;
> + int size;
> + int i;
> +
> + e = _params->efi_info;
> + sig = (char *)>efi_loader_signature;
> +
> + if (!strncmp(sig, EFI64_LOADER_SIGNATURE, 4))
> + efi_64 = true;
> + else if (!strncmp(sig, EFI32_LOADER_SIGNATURE, 4))
> + efi_64 = false;
> + else {
> + debug_putstr("Wrong EFI loader signature.\n");
> + return;
> + }
> +
> + /* Get systab from boot params. Based on efi_init(). */
> +#ifdef CONFIG_X86_64
> + systab = (efi_system_table_t *)(
> + e->efi_systab | ((__u64)e->efi_systab_hi<<32));
No ugly line breaks with open braces trailing like that, pls - just let
it stick out.
> +#else
> + if (e->efi_systab_hi || e->efi_memmap_hi) {
> + debug_putstr("Table located above 4GB. EFI should be
> disabled.\n");
You need to say here what really happens here:
debug_putstr("Error getting RSDP address: EFI system table
located above 4GB.\n");
The same below.
> + return;
> + }
> + systab = (efi_system_table_t *)e->efi_systab;
> +#endif
> +
> + if (!systab)
> + return;
> +
> + /*
> + * Get EFI tables from systab. Based on efi_config_init() and
> + * efi_config_parse_tables(). Only dig out the config_table.
> + */
> + size = efi_64 ? sizeof(efi_config_table_64_t) :
> + sizeof(efi_config_table_32_t);
> +
> + for (i = 0; i < systab->nr_tables; i++) {
> + efi_guid_t guid;
> + unsigned long table;
Put the void *config_tables declaration here.
> +
> + config_tables = (void *)(systab->tables + size * i);
> + if (efi_64) {
> + efi_config_table_64_t *tmp_table;
> +
> + tmp_table = (efi_config_table_64_t *)config_tables;
> + guid = tmp_table->guid;
> + table = tmp_table->table;
> +#ifndef CONFIG_64BIT
Above you have CONFIG_X86_64, here CONFIG_64BIT. Please use one only.
Also, use IS_ENABLED() instead.
> + if (table >> 32) {
> + debug_putstr("Table located above 4G. EFI
> should be disabled.\n");
> + return;
> + }
> +#endif
> + } else {
> + efi_config_table_32_t *tmp_table;
> +
> + tmp_table = (efi_config_table_32_t *)config_tables;
> + guid = tmp_table->guid;
> + table = tmp_table->table;
> + }
> +
> + /*
> + * Get RSDP from EFI tables.
> + * If ACPI20 table found, use it.
> + * If ACPI20 table not found, but ACPI table found,
> + * use the ACPI table.
> + */
That comment is the opposite of what the code does. Also, why is that
comment needed at all? If anything, it should say *why* ACPI_TABLE_GUID
is preferred and then the fallback to ACPI_20_TABLE_GUID is done - not
*what* it does. That's easily visible in the code.
Thx.
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
Re: [PATCH] efi: permit calling efi_mem_reserve_persistent from atomic context
On 11/12/18 at 3:32 AM, Marc Zyngier wrote:
> On Mon, 12 Nov 2018 02:45:48 +,
> Qian Cai wrote:
> >
> >
> >
> > > On Nov 9, 2018, at 9:45 PM, Qian Cai wrote:
> > >
> > >
> > > On 11/8/18 at 1:05 PM, Ard Biesheuvel wrote:
> > >
> > >> Currently, efi_mem_reserve_persistent() may not be called from atomic
> > >> context, since both the kmalloc() call and the memremap() call may
> > >> sleep.
> > >>
> > >> The kmalloc() call is easy enough to fix, but the memremap() call
> > >> needs to be moved into an init hook since we cannot control the
> > >> memory allocation behavior of memremap() at the call site.
> > >>
> > >> Signed-off-by: Ard Biesheuvel
> > >> ---
> > >> drivers/firmware/efi/efi.c | 31 +++
> > >> 1 file changed, 19 insertions(+), 12 deletions(-)
> > >>
> > >> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> > >> index 249eb70691b0..cfc876e0b67b 100644
> > >> --- a/drivers/firmware/efi/efi.c
> > >> +++ b/drivers/firmware/efi/efi.c
> > >> @@ -963,36 +963,43 @@ bool efi_is_table_address(unsigned long phys_addr)
> > >> }
> > >>
> > >> static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
> > >> +static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;
> > >>
> > >> int efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
> > >> {
> > >> -struct linux_efi_memreserve *rsv, *parent;
> > >> +struct linux_efi_memreserve *rsv;
> > >>
> > >> -if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR)
> > >> +if (!efi_memreserve_root)
> > >> return -ENODEV;
> > >>
> > >> -rsv = kmalloc(sizeof(*rsv), GFP_KERNEL);
> > >> +rsv = kmalloc(sizeof(*rsv), GFP_ATOMIC);
> > >> if (!rsv)
> > >> return -ENOMEM;
> > >>
> > >> -parent = memremap(efi.mem_reserve, sizeof(*rsv), MEMREMAP_WB);
> > >> -if (!parent) {
> > >> -kfree(rsv);
> > >> -return -ENOMEM;
> > >> -}
> > >> -
> > >> rsv->base = addr;
> > >> rsv->size = size;
> > >>
> > >> spin_lock(_mem_reserve_persistent_lock);
> > >> -rsv->next = parent->next;
> > >> -parent->next = __pa(rsv);
> > >> +rsv->next = efi_memreserve_root->next;
> > >> +efi_memreserve_root->next = __pa(rsv);
> > >> spin_unlock(_mem_reserve_persistent_lock);
> > >>
> > >> -memunmap(parent);
> > >> +return 0;
> > >> +}
> > >>
> > >> +static int __init efi_memreserve_root_init(void)
> > >> +{
> > >> +if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR)
> > >> +return -ENODEV;
> > >> +
> > >> +efi_memreserve_root = memremap(efi.mem_reserve,
> > >> + sizeof(*efi_memreserve_root),
> > >> + MEMREMAP_WB);
> > >> +if (!efi_memreserve_root)
> > >> +return -ENOMEM;
> > >> return 0;
> > >> }
> > >> +early_initcall(efi_memreserve_root_init);
> > >>
> > >> #ifdef CONFIG_KEXEC
> > >> static int update_efi_random_seed(struct notifier_block *nb,
> > >> --
> > >> 2.19.1
> > > BTW, I won’t be able to apply this patch on top of this series [1]. After
> > > applied that series, the original BUG sleep from atomic is gone as well
> > > as two other GIC warnings. Do you think a new patch is needed here?
> > >
> > > [1] https://www.spinics.net/lists/arm-kernel/msg685751.html
> > OK, I was able to apply this patch on top of latest mainline (ccda4af0f4b9)
> > which also include one patch (1/6) from the above series,
> >
> > However, the efi-related patches from the series (4/6, 5/6, and 6/6) are no
> > longer able to be cleanly applied.
> >
> > As the results, the above patch did fix the original BUG: sleep from atomic,
> > but it introduces 2 new warnings.
>
> [...]
>
> These are the warnings you've already reported, aren't they? And we've
> established that if you apply the whole series, everything work as
> intended at least on the GIC side (the timer issue is a different
> story altogether).
>
> Or am I missing something?
The problem is that I am not able to apply the whole
series alone on top of the latest mainline (rc2) now to
verify it. Also, I won’t be able to apply the series and
this patch together on top of rc1. There are conflicts
between this patch and 4-6 of the series.
Originally, I said those GIC warnings are gone when
testing rc1 + the series, but I am not sure if it is just
dumb luck that also fix BUG: sleep from atomic. Make
sense?
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Re: [PATCH v11 3/5] x86/boot: Add get_acpi_rsdp() to parse RSDP in cmdlien from kexec
Hi Boris,
I try to include lib/kstrtox.c in arch/x86/boot/string.c and
define the kstrtoull() function in arch/x86/boot/string.h.
But the definition problem is hard to solve, so I include
it in arch/x86/boot/string.c directely.
Then use BOOT_STRING tag to cover other functions and only
kstrtoull() is exposed.
I am not sure whether this is OK.
Thanks,
Chao Fan
On Mon, Nov 12, 2018 at 05:46:43PM +0800, Chao Fan wrote:
>Imitate setup_acpi_rsdp() for the early_param of 'acpi_rsdp'.
>KEXEC writes the RSDP pointer to cmdline for EFI booting.
>So if 'acpi_rsdp' found in cmdline, use it directely.
>
>Since function kstrtoull() is needed, include it in
>arch/x86/boot/string.h. To solve the definition conflict
>problem, set BOOT_STRING tag to expose only kstrtoull() and
>functions used by it. Other functions in lib/kstrtox.c will
>be covered.
>
>Signed-off-by: Chao Fan
>---
> arch/x86/boot/compressed/acpitb.c | 26 ++
> arch/x86/boot/string.h| 4
> lib/kstrtox.c | 4
> 3 files changed, 34 insertions(+)
>
>diff --git a/arch/x86/boot/compressed/acpitb.c
>b/arch/x86/boot/compressed/acpitb.c
>index 50fa65cf824d..5cfb4efa5a19 100644
>--- a/arch/x86/boot/compressed/acpitb.c
>+++ b/arch/x86/boot/compressed/acpitb.c
>@@ -8,6 +8,12 @@
> #include
> #include
>
>+#define STATIC
>+#include
>+
>+#define BOOT_STRING
>+#include "../string.h"
>+
> /* Search EFI table for RSDP table. */
> static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
> {
>@@ -200,3 +206,23 @@ static void bios_get_rsdp_addr(acpi_physical_address
>*rsdp_addr)
> *rsdp_addr = (acpi_physical_address)address;
> }
> }
>+
>+static void get_acpi_rsdp(acpi_physical_address *rsdp_addr)
>+{
>+#ifdef CONFIG_KEXEC
>+ unsigned long long res;
>+ int len = 0;
>+ char *val;
>+
>+ val = malloc(19);
>+ len = cmdline_find_option("acpi_rsdp", val, 19);
>+
>+ if (len == -1)
>+ return;
>+
>+ if (len > 0) {
>+ val[len] = 0;
>+ *rsdp_addr = (acpi_physical_address)kstrtoull(val, 16, );
>+ }
>+#endif
>+}
>diff --git a/arch/x86/boot/string.h b/arch/x86/boot/string.h
>index 3d78e27077f4..0ff3edb888e4 100644
>--- a/arch/x86/boot/string.h
>+++ b/arch/x86/boot/string.h
>@@ -30,3 +30,7 @@ extern unsigned long long simple_strtoull(const char *cp,
>char **endp,
> unsigned int base);
>
> #endif /* BOOT_STRING_H */
>+
>+#ifdef BOOT_STRING
>+#include "../../../lib/kstrtox.c"
>+#endif
>diff --git a/lib/kstrtox.c b/lib/kstrtox.c
>index 1006bf70bf74..3804db9eed56 100644
>--- a/lib/kstrtox.c
>+++ b/lib/kstrtox.c
>@@ -126,6 +126,8 @@ int kstrtoull(const char *s, unsigned int base, unsigned
>long long *res)
> }
> EXPORT_SYMBOL(kstrtoull);
>
>+#ifndef BOOT_STRING
>+
> /**
> * kstrtoll - convert a string to a long long
> * @s: The start of the string. The string must be null-terminated, and may
> also
>@@ -408,3 +410,5 @@ kstrto_from_user(kstrtou16_from_user, kstrtou16,
>u16);
> kstrto_from_user(kstrtos16_from_user, kstrtos16, s16);
> kstrto_from_user(kstrtou8_from_user, kstrtou8, u8);
> kstrto_from_user(kstrtos8_from_user, kstrtos8, s8);
>+
>+#endif
>--
>2.19.1
>
[PATCH v11 0/5] x86/boot/KASLR: Parse ACPI table and limit kaslr in immovable memory
***Background: People reported that kaslr may randomly chooses some positions which are located in movable memory regions. This will break memory hotplug feature and make the movable memory chosen by KASLR can't be removed. ***Solutions: There should be a method to limit kaslr to choosing immovable memory regions, so there are 2 solutions: 1) Add a kernel parameter to specify the memory regions. 2) Get the information of memory hot-remove, then kaslr will know the right regions. In method 2, information about memory hot-remove is in ACPI tables, which will be parsed after start_kernel(), kaslr can't get the information. In method 1, users should know the regions address and specify in kernel parameter. In the earliest time, I tried to dig ACPI tabls to solve this problem. But I didn't splite the code in 'compressed/' and ACPI code, so the patch is hard to follow so refused by community. Somebody suggest to add a kernel parameter to specify the immovable memory so that limit kaslr in these regions. Then I make a new patchset. After several versions, Ingo gave a suggestion: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1634024.html Follow Ingo's suggestion, imitate the ACPI code to parse the acpi tables, so that the kaslr can get necessary memory information in ACPI tables. I think ACPI code is an independent part, so imitate the codes and functions to 'compressed/' directory, so that kaslr won't influence the initialization of ACPI. PATCH 1/7 Add efi_get_rsdp_addr() to dig out RSDP from EFI table when booting from EFI. PATCH 2/7 Add bios_get_rsdp_addr() to search RSDP in memory when EFI table not found. PATCH 3/7 Add get_acpi_rsdp() to parse RSDP in cmdline from kexec PATCH 4/7 Dig out SRAT table from RSDP and walk SRAT table to store the immovable memory regions. PATCH 5/7 Calculate the intersection between memory regions from e820/efi memory table and immovable memory regions. Limit KASLR choose these regions for randomization. v1->v2: - Simplify some code. Follow Baoquan He's suggestion: - Reuse the head file of acpi code. v2->v3: - Test in more conditions, so remove the 'RFC' tag. - Change some comments. v3->v4: Follow Thomas Gleixner's suggetsion: - Put the whole efi related function into #define CONFIG_EFI and return false in the other stub. v4->v5: Follow Dou Liyang's suggestion: - Add more comments about some functions based on kernel code. - Change some typo in comments. - Clean useless variable. - Add check for the boundary of array. - Add check for 'movable_node' parameter v5->v6: Follow Baoquan He's suggestion: - Change some log. - Add the check for acpi_rsdp - Change some code logical to make code clear v6->v7: Follow Rafael's suggestion: - Add more comments and patch log. Follow test robot's suggestion: - Add "static" tag for function v7-v8: Follow Kees Cook's suggestion: - Use mem_overlaps() to check memory region. - Use #ifdef in the definition of function. v8-v9: Follow Boris' suggestion: - Change code style. - Splite PATCH 1/3 to more path. - Introduce some new function - Use existing function to rework some code Follow Masayoshi's suggetion: - Make code more readable v9->v10: Follow Baoquan's suggestion: - Change some log - Merge last two patch together. v10->v11: Follow Boris' suggestion: - Link kstrtoull() instead of copying it. - Drop the useless wraped function. Any comments will be welcome. Chao Fan (5): x86/boot: Add efi_get_rsdp_addr() to dig out RSDP from EFI table x86/boot: Add bios_get_rsdp_addr() to search RSDP in memory x86/boot: Add get_acpi_rsdp() to parse RSDP in cmdlien from kexec x86/boot: Dig out SRAT table from RSDP and find immovable memory x86/boot/KASLR: Walk srat tables to filter immovable memory arch/x86/boot/compressed/Makefile | 4 + arch/x86/boot/compressed/acpitb.c | 367 ++ arch/x86/boot/compressed/kaslr.c | 81 +-- arch/x86/boot/compressed/misc.h | 15 ++ arch/x86/boot/string.h| 4 + lib/kstrtox.c | 4 + 6 files changed, 460 insertions(+), 15 deletions(-) create mode 100644 arch/x86/boot/compressed/acpitb.c -- 2.19.1
[PATCH v11 5/5] x86/boot/KASLR: Walk srat tables to filter immovable memory
KASLR may randomly chooses some positions which are located in movable
memory regions. This will break memory hotplug feature and make the
movable memory chosen by KASLR can't be removed.
The solution is limite KASLR to choose memory regions in immovable
node according to SRAT tables.
If CONFIG_MEMORY_HOTREMOVE enabled, walk through the SRAT memory
tables and store those immovable memory regions so that KASLR can get
where to choose for randomization.
If the amount of immovable memory regions is not zero, which
means the immovable memory regions existing. Calculate the intersection
between memory regions from e820/efi memory table and immovable memory
regions.
Signed-off-by: Chao Fan
---
arch/x86/boot/compressed/kaslr.c | 77 +++-
1 file changed, 66 insertions(+), 11 deletions(-)
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index b251572e77af..174d2114045e 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -97,6 +97,11 @@ static bool memmap_too_large;
/* Store memory limit specified by "mem=nn[KMG]" or "memmap=nn[KMG]" */
static unsigned long long mem_limit = ULLONG_MAX;
+#ifdef CONFIG_MEMORY_HOTREMOVE
+/* Store the immovable memory regions */
+extern struct mem_vector immovable_mem[MAX_NUMNODES*2];
+#endif
+
enum mem_avoid_index {
MEM_AVOID_ZO_RANGE = 0,
@@ -413,6 +418,11 @@ static void mem_avoid_init(unsigned long input, unsigned
long input_size,
/* Mark the memmap regions we need to avoid */
handle_mem_options();
+#ifdef CONFIG_MEMORY_HOTREMOVE
+ /* Mark the immovable regions we need to choose */
+ get_immovable_mem();
+#endif
+
#ifdef CONFIG_X86_VERBOSE_BOOTUP
/* Make sure video RAM can be used. */
add_identity_map(0, PMD_SIZE);
@@ -568,9 +578,9 @@ static unsigned long slots_fetch_random(void)
return 0;
}
-static void process_mem_region(struct mem_vector *entry,
- unsigned long minimum,
- unsigned long image_size)
+static void slots_count(struct mem_vector *entry,
+ unsigned long minimum,
+ unsigned long image_size)
{
struct mem_vector region, overlap;
unsigned long start_orig, end;
@@ -646,6 +656,57 @@ static void process_mem_region(struct mem_vector *entry,
}
}
+static bool process_mem_region(struct mem_vector *region,
+ unsigned long long minimum,
+ unsigned long long image_size)
+{
+ int i;
+ /*
+* If no immovable memory found, or MEMORY_HOTREMOVE disabled,
+* walk all the regions, so use region directely.
+*/
+ if (num_immovable_mem == 0) {
+ slots_count(region, minimum, image_size);
+
+ if (slot_area_index == MAX_SLOT_AREA) {
+ debug_putstr("Aborted e820/efi memmap scan (slot_areas
full)!\n");
+ return 1;
+ }
+ return 0;
+ }
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+ /*
+* If immovable memory found, filter the intersection between
+* immovable memory and region to slots_count.
+* Otherwise, go on old code.
+*/
+ for (i = 0; i < num_immovable_mem; i++) {
+ struct mem_vector entry;
+ unsigned long long start, end, entry_end, region_end;
+
+ if (!mem_overlaps(region, _mem[i]))
+ continue;
+
+ start = immovable_mem[i].start;
+ end = start + immovable_mem[i].size;
+ region_end = region->start + region->size;
+
+ entry.start = clamp(region->start, start, end);
+ entry_end = clamp(region_end, start, end);
+ entry.size = entry_end - entry.start;
+
+ slots_count(, minimum, image_size);
+
+ if (slot_area_index == MAX_SLOT_AREA) {
+ debug_putstr("Aborted e820/efi memmap scan (slot_areas
full)!\n");
+ return 1;
+ }
+ }
+ return 0;
+#endif
+}
+
#ifdef CONFIG_EFI
/*
* Returns true if mirror region found (and must have been processed
@@ -711,11 +772,8 @@ process_efi_entries(unsigned long minimum, unsigned long
image_size)
region.start = md->phys_addr;
region.size = md->num_pages << EFI_PAGE_SHIFT;
- process_mem_region(, minimum, image_size);
- if (slot_area_index == MAX_SLOT_AREA) {
- debug_putstr("Aborted EFI scan (slot_areas full)!\n");
+ if (process_mem_region(, minimum, image_size))
break;
- }
}
return true;
}
@@ -742,11 +800,8 @@ static void process_e820_entries(unsigned long minimum,
continue;
region.start = entry->addr;
[PATCH v11 3/5] x86/boot: Add get_acpi_rsdp() to parse RSDP in cmdlien from kexec
Imitate setup_acpi_rsdp() for the early_param of 'acpi_rsdp'.
KEXEC writes the RSDP pointer to cmdline for EFI booting.
So if 'acpi_rsdp' found in cmdline, use it directely.
Since function kstrtoull() is needed, include it in
arch/x86/boot/string.h. To solve the definition conflict
problem, set BOOT_STRING tag to expose only kstrtoull() and
functions used by it. Other functions in lib/kstrtox.c will
be covered.
Signed-off-by: Chao Fan
---
arch/x86/boot/compressed/acpitb.c | 26 ++
arch/x86/boot/string.h| 4
lib/kstrtox.c | 4
3 files changed, 34 insertions(+)
diff --git a/arch/x86/boot/compressed/acpitb.c
b/arch/x86/boot/compressed/acpitb.c
index 50fa65cf824d..5cfb4efa5a19 100644
--- a/arch/x86/boot/compressed/acpitb.c
+++ b/arch/x86/boot/compressed/acpitb.c
@@ -8,6 +8,12 @@
#include
#include
+#define STATIC
+#include
+
+#define BOOT_STRING
+#include "../string.h"
+
/* Search EFI table for RSDP table. */
static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
{
@@ -200,3 +206,23 @@ static void bios_get_rsdp_addr(acpi_physical_address
*rsdp_addr)
*rsdp_addr = (acpi_physical_address)address;
}
}
+
+static void get_acpi_rsdp(acpi_physical_address *rsdp_addr)
+{
+#ifdef CONFIG_KEXEC
+ unsigned long long res;
+ int len = 0;
+ char *val;
+
+ val = malloc(19);
+ len = cmdline_find_option("acpi_rsdp", val, 19);
+
+ if (len == -1)
+ return;
+
+ if (len > 0) {
+ val[len] = 0;
+ *rsdp_addr = (acpi_physical_address)kstrtoull(val, 16, );
+ }
+#endif
+}
diff --git a/arch/x86/boot/string.h b/arch/x86/boot/string.h
index 3d78e27077f4..0ff3edb888e4 100644
--- a/arch/x86/boot/string.h
+++ b/arch/x86/boot/string.h
@@ -30,3 +30,7 @@ extern unsigned long long simple_strtoull(const char *cp,
char **endp,
unsigned int base);
#endif /* BOOT_STRING_H */
+
+#ifdef BOOT_STRING
+#include "../../../lib/kstrtox.c"
+#endif
diff --git a/lib/kstrtox.c b/lib/kstrtox.c
index 1006bf70bf74..3804db9eed56 100644
--- a/lib/kstrtox.c
+++ b/lib/kstrtox.c
@@ -126,6 +126,8 @@ int kstrtoull(const char *s, unsigned int base, unsigned
long long *res)
}
EXPORT_SYMBOL(kstrtoull);
+#ifndef BOOT_STRING
+
/**
* kstrtoll - convert a string to a long long
* @s: The start of the string. The string must be null-terminated, and may
also
@@ -408,3 +410,5 @@ kstrto_from_user(kstrtou16_from_user, kstrtou16,
u16);
kstrto_from_user(kstrtos16_from_user, kstrtos16, s16);
kstrto_from_user(kstrtou8_from_user, kstrtou8, u8);
kstrto_from_user(kstrtos8_from_user, kstrtos8, s8);
+
+#endif
--
2.19.1
[PATCH v11 1/5] x86/boot: Add efi_get_rsdp_addr() to dig out RSDP from EFI table
In order to parse SRAT table and get memory information, RSDP pointer
should be found. In kernel, there are three methods to get RSDP:
EFI condition, BIOS condition and KEXEC condition. The first works
for EFI condition.
Imitate ACPI code and EFI code to dig RSDP pointer from EFI tables.
Process: boot_param->systab->efi_config_table->RSDP.
Based on efi_init(), efi_config_init(), efi_config_parse_tables().
Signed-off-by: Chao Fan
---
arch/x86/boot/compressed/acpitb.c | 96 +++
1 file changed, 96 insertions(+)
create mode 100644 arch/x86/boot/compressed/acpitb.c
diff --git a/arch/x86/boot/compressed/acpitb.c
b/arch/x86/boot/compressed/acpitb.c
new file mode 100644
index ..56b54b0e0889
--- /dev/null
+++ b/arch/x86/boot/compressed/acpitb.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0
+#define BOOT_CTYPE_H
+#include "misc.h"
+#include "error.h"
+
+#include
+#include
+#include
+#include
+
+/* Search EFI table for RSDP table. */
+static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
+{
+#ifdef CONFIG_EFI
+ efi_system_table_t *systab;
+ bool efi_64 = false;
+ void *config_tables;
+ struct efi_info *e;
+ char *sig;
+ int size;
+ int i;
+
+ e = _params->efi_info;
+ sig = (char *)>efi_loader_signature;
+
+ if (!strncmp(sig, EFI64_LOADER_SIGNATURE, 4))
+ efi_64 = true;
+ else if (!strncmp(sig, EFI32_LOADER_SIGNATURE, 4))
+ efi_64 = false;
+ else {
+ debug_putstr("Wrong EFI loader signature.\n");
+ return;
+ }
+
+ /* Get systab from boot params. Based on efi_init(). */
+#ifdef CONFIG_X86_64
+ systab = (efi_system_table_t *)(
+ e->efi_systab | ((__u64)e->efi_systab_hi<<32));
+#else
+ if (e->efi_systab_hi || e->efi_memmap_hi) {
+ debug_putstr("Table located above 4GB. EFI should be
disabled.\n");
+ return;
+ }
+ systab = (efi_system_table_t *)e->efi_systab;
+#endif
+
+ if (!systab)
+ return;
+
+ /*
+* Get EFI tables from systab. Based on efi_config_init() and
+* efi_config_parse_tables(). Only dig out the config_table.
+*/
+ size = efi_64 ? sizeof(efi_config_table_64_t) :
+ sizeof(efi_config_table_32_t);
+
+ for (i = 0; i < systab->nr_tables; i++) {
+ efi_guid_t guid;
+ unsigned long table;
+
+ config_tables = (void *)(systab->tables + size * i);
+ if (efi_64) {
+ efi_config_table_64_t *tmp_table;
+
+ tmp_table = (efi_config_table_64_t *)config_tables;
+ guid = tmp_table->guid;
+ table = tmp_table->table;
+#ifndef CONFIG_64BIT
+ if (table >> 32) {
+ debug_putstr("Table located above 4G. EFI
should be disabled.\n");
+ return;
+ }
+#endif
+ } else {
+ efi_config_table_32_t *tmp_table;
+
+ tmp_table = (efi_config_table_32_t *)config_tables;
+ guid = tmp_table->guid;
+ table = tmp_table->table;
+ }
+
+ /*
+* Get RSDP from EFI tables.
+* If ACPI20 table found, use it.
+* If ACPI20 table not found, but ACPI table found,
+* use the ACPI table.
+*/
+ if (!(efi_guidcmp(guid, ACPI_TABLE_GUID))) {
+ *rsdp_addr = (acpi_physical_address)table;
+ } else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID))) {
+ *rsdp_addr = (acpi_physical_address)table;
+ return;
+ }
+ }
+#endif
+}
--
2.19.1
[PATCH v11 4/5] x86/boot: Dig out SRAT table from RSDP and find immovable memory
To avoid KASLR extracting kernel on movable memory, slove the
conflict between KASLR and movable_node feature, dig the SRAT tables
from RSDP pointer. Walk the SRAT tables and store the immovable
memory regions in immovable_mem[].
There are three methods to get RSDP pointer: KEXEC condition,
EFI confition, BIOS condition.
If KEXEC add 'acpi_rsdp' to cmdline, use it.
Otherwise, parse EFI table for RSDP.
Then, search memory for RSDP.
Imitate from ACPI code, based on acpi_os_get_root_pointer().
Process: RSDP->RSDT/XSDT->ACPI root table->SRAT.
Signed-off-by: Chao Fan
---
arch/x86/boot/compressed/Makefile | 4 +
arch/x86/boot/compressed/acpitb.c | 139 ++
arch/x86/boot/compressed/kaslr.c | 4 -
arch/x86/boot/compressed/misc.h | 15
4 files changed, 158 insertions(+), 4 deletions(-)
diff --git a/arch/x86/boot/compressed/Makefile
b/arch/x86/boot/compressed/Makefile
index 466f66c8a7f8..b51f7629b8ef 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -84,6 +84,10 @@ ifdef CONFIG_X86_64
vmlinux-objs-y += $(obj)/pgtable_64.o
endif
+#if (defined CONFIG_MEMORY_HOTREMOVE) && (defined CONFIG_RANDOMIZE_BASE)
+vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/acpitb.o
+#endif
+
$(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \
diff --git a/arch/x86/boot/compressed/acpitb.c
b/arch/x86/boot/compressed/acpitb.c
index 5cfb4efa5a19..161f21a7fb3b 100644
--- a/arch/x86/boot/compressed/acpitb.c
+++ b/arch/x86/boot/compressed/acpitb.c
@@ -14,6 +14,11 @@
#define BOOT_STRING
#include "../string.h"
+#ifdef CONFIG_MEMORY_HOTREMOVE
+/* Store the immovable memory regions */
+struct mem_vector immovable_mem[MAX_NUMNODES*2];
+#endif
+
/* Search EFI table for RSDP table. */
static void efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
{
@@ -226,3 +231,137 @@ static void get_acpi_rsdp(acpi_physical_address
*rsdp_addr)
}
#endif
}
+
+/*
+ * Used to dig RSDP table from EFI table or BIOS.
+ * If RSDP table found in EFI table, use it. Or search BIOS.
+ * Based on acpi_os_get_root_pointer().
+ */
+static acpi_physical_address get_rsdp_addr(void)
+{
+ acpi_physical_address pa = 0;
+
+ get_acpi_rsdp();
+
+ if (!pa)
+ efi_get_rsdp_addr();
+
+ if (!pa)
+ bios_get_rsdp_addr();
+
+ return pa;
+}
+
+static struct acpi_table_header *get_acpi_srat_table(void)
+{
+ acpi_physical_address acpi_table;
+ acpi_physical_address root_table;
+ struct acpi_table_header *header;
+ struct acpi_table_rsdp *rsdp;
+ bool acpi_use_rsdt = false;
+ char *signature;
+ char arg[10];
+ u8 *entry;
+ u32 count;
+ u32 size;
+ int i, j;
+ int ret;
+ u32 len;
+
+ rsdp = (struct acpi_table_rsdp *)get_rsdp_addr();
+ if (!rsdp)
+ return NULL;
+
+ ret = cmdline_find_option("acpi", arg, sizeof(arg));
+ if (ret == 4 && !strncmp(arg, "rsdt", 4))
+ acpi_use_rsdt = true;
+
+ /* Get RSDT or XSDT from RSDP. */
+ if (!acpi_use_rsdt &&
+ rsdp->xsdt_physical_address && rsdp->revision > 1) {
+ root_table = rsdp->xsdt_physical_address;
+ size = ACPI_XSDT_ENTRY_SIZE;
+ } else {
+ root_table = rsdp->rsdt_physical_address;
+ size = ACPI_RSDT_ENTRY_SIZE;
+ }
+
+ /* Get ACPI root table from RSDT or XSDT.*/
+ header = (struct acpi_table_header *)root_table;
+ len = header->length;
+ count = (u32)((len - sizeof(struct acpi_table_header)) / size);
+ entry = ACPI_ADD_PTR(u8, header, sizeof(struct acpi_table_header));
+
+ for (i = 0; i < count; i++) {
+ u64 address64;
+
+ if (size == ACPI_RSDT_ENTRY_SIZE)
+ acpi_table = ((acpi_physical_address)
+ (*ACPI_CAST_PTR(u32, entry)));
+ else {
+ *(u64 *)(void *) = *(u64 *)(void *)entry;
+ acpi_table = (acpi_physical_address) address64;
+ }
+
+ if (acpi_table) {
+ header = (struct acpi_table_header *)acpi_table;
+ signature = header->signature;
+
+ if (ACPI_COMPARE_NAME(header->signature, ACPI_SIG_SRAT))
+ return header;
+ }
+ entry += size;
+ }
+ return NULL;
+}
+
+/*
+ * According to ACPI table, filter the immvoable memory regions
+ * and store them in immovable_mem[].
+ */
+void get_immovable_mem(void)
+{
+ struct acpi_table_header *table_header;
+ struct acpi_subtable_header *table;
+ struct acpi_srat_mem_affinity *ma;
+ unsigned long table_end;
+ char arg[10];
+ int i = 0;
+ int ret;
+
+ ret =
[PATCH v11 2/5] x86/boot: Add bios_get_rsdp_addr() to search RSDP in memory
Imitate ACPI code to search RSDP pointer from memory.
Walk memory and check the signature until get the RSDP signature.
Based on acpi_tb_scan_memory_for_rsdp() and acpi_find_root_pointer().
If didn't get RSDP from EFI table, will run this function.
Used for later patch to dig out SRAT table and get the memory
information. And figure out the immovable memory regions
to avoid KASLR extracts kernel on movable memory, slove the
conflict between KASLR and movable_node feature.
Signed-off-by: Chao Fan
---
arch/x86/boot/compressed/acpitb.c | 106 ++
1 file changed, 106 insertions(+)
diff --git a/arch/x86/boot/compressed/acpitb.c
b/arch/x86/boot/compressed/acpitb.c
index 56b54b0e0889..50fa65cf824d 100644
--- a/arch/x86/boot/compressed/acpitb.c
+++ b/arch/x86/boot/compressed/acpitb.c
@@ -94,3 +94,109 @@ static void efi_get_rsdp_addr(acpi_physical_address
*rsdp_addr)
}
#endif
}
+
+static u8 compute_checksum(u8 *buffer, u32 length)
+{
+ u8 sum = 0;
+ u8 *end = buffer + length;
+
+ while (buffer < end)
+ sum = (u8)(sum + *(buffer++));
+
+ return sum;
+}
+
+/*
+ * Used to search a block of memory for the RSDP signature.
+ * Return Pointer to the RSDP if found, otherwise NULL.
+ * Based on acpi_tb_scan_memory_for_rsdp().
+ */
+static u8 *scan_mem_for_rsdp(u8 *start, u32 length)
+{
+ struct acpi_table_rsdp *rsdp;
+ u8 *end;
+ u8 *rover;
+
+ end = start + length;
+
+ /* Search from given start address for the requested length */
+ for (rover = start; rover < end; rover += ACPI_RSDP_SCAN_STEP) {
+ /*
+* The RSDP signature and checksum must both be correct
+* Note: Sometimes there exists more than one RSDP in memory;
+* the valid RSDP has a valid checksum, all others have an
+* invalid checksum.
+*/
+ rsdp = (struct acpi_table_rsdp *)rover;
+
+ /* Nope, BAD Signature */
+ if (!ACPI_VALIDATE_RSDP_SIG(rsdp->signature))
+ continue;
+
+ /* Check the standard checksum */
+ if (compute_checksum((u8 *) rsdp, ACPI_RSDP_CHECKSUM_LENGTH))
+ continue;
+
+ /* Check extended checksum if table version >= 2 */
+ if ((rsdp->revision >= 2) &&
+ (compute_checksum((u8 *) rsdp, ACPI_RSDP_XCHECKSUM_LENGTH)))
+ continue;
+
+ /* Sig and checksum valid, we have found a real RSDP */
+ return rover;
+ }
+ return NULL;
+}
+
+/*
+ * Used to search RSDP physical address.
+ * Based on acpi_find_root_pointer(). Since only use physical address
+ * in this period, so there is no need to do the memory map jobs.
+ */
+static void bios_get_rsdp_addr(acpi_physical_address *rsdp_addr)
+{
+ struct acpi_table_rsdp *rsdp;
+ u8 *table_ptr;
+ u8 *mem_rover;
+ u32 address;
+
+ /*
+* Get the location of the Extended BIOS Data Area (EBDA)
+* Since we use physical address directely, so
+* acpi_os_map_memory() and acpi_os_unmap_memory() are
+* not needed here.
+*/
+ table_ptr = (u8 *)ACPI_EBDA_PTR_LOCATION;
+ *(u32 *)(void *) = *(u16 *)(void *)table_ptr;
+ address <<= 4;
+ table_ptr = (u8 *)address;
+
+ /*
+* Search EBDA paragraphs (EBDA is required to be a minimum of
+* 1K length)
+*/
+ if (address > 0x400) {
+ mem_rover = scan_mem_for_rsdp(table_ptr, ACPI_EBDA_WINDOW_SIZE);
+
+ if (mem_rover) {
+ address += (u32)ACPI_PTR_DIFF(mem_rover, table_ptr);
+ *rsdp_addr = (acpi_physical_address)address;
+ return;
+ }
+ }
+
+ table_ptr = (u8 *)ACPI_HI_RSDP_WINDOW_BASE;
+ mem_rover = scan_mem_for_rsdp(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);
+
+ /*
+* Search upper memory: 16-byte boundaries in Eh-Fh
+* Since we use physical address directely, so
+* acpi_os_map_memory() and acpi_os_unmap_memory() are
+* not needed here.
+*/
+ if (mem_rover) {
+ address = (u32)(ACPI_HI_RSDP_WINDOW_BASE +
+ ACPI_PTR_DIFF(mem_rover, table_ptr));
+ *rsdp_addr = (acpi_physical_address)address;
+ }
+}
--
2.19.1
Re: [PATCH] efi: permit calling efi_mem_reserve_persistent from atomic context
On Mon, 12 Nov 2018 02:45:48 +,
Qian Cai wrote:
>
>
>
> > On Nov 9, 2018, at 9:45 PM, Qian Cai wrote:
> >
> >
> > On 11/8/18 at 1:05 PM, Ard Biesheuvel wrote:
> >
> >> Currently, efi_mem_reserve_persistent() may not be called from atomic
> >> context, since both the kmalloc() call and the memremap() call may
> >> sleep.
> >>
> >> The kmalloc() call is easy enough to fix, but the memremap() call
> >> needs to be moved into an init hook since we cannot control the
> >> memory allocation behavior of memremap() at the call site.
> >>
> >> Signed-off-by: Ard Biesheuvel
> >> ---
> >> drivers/firmware/efi/efi.c | 31 +++
> >> 1 file changed, 19 insertions(+), 12 deletions(-)
> >>
> >> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> >> index 249eb70691b0..cfc876e0b67b 100644
> >> --- a/drivers/firmware/efi/efi.c
> >> +++ b/drivers/firmware/efi/efi.c
> >> @@ -963,36 +963,43 @@ bool efi_is_table_address(unsigned long phys_addr)
> >> }
> >>
> >> static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
> >> +static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init;
> >>
> >> int efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
> >> {
> >> - struct linux_efi_memreserve *rsv, *parent;
> >> + struct linux_efi_memreserve *rsv;
> >>
> >> - if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR)
> >> + if (!efi_memreserve_root)
> >>return -ENODEV;
> >>
> >> - rsv = kmalloc(sizeof(*rsv), GFP_KERNEL);
> >> + rsv = kmalloc(sizeof(*rsv), GFP_ATOMIC);
> >>if (!rsv)
> >>return -ENOMEM;
> >>
> >> - parent = memremap(efi.mem_reserve, sizeof(*rsv), MEMREMAP_WB);
> >> - if (!parent) {
> >> - kfree(rsv);
> >> - return -ENOMEM;
> >> - }
> >> -
> >>rsv->base = addr;
> >>rsv->size = size;
> >>
> >>spin_lock(_mem_reserve_persistent_lock);
> >> - rsv->next = parent->next;
> >> - parent->next = __pa(rsv);
> >> + rsv->next = efi_memreserve_root->next;
> >> + efi_memreserve_root->next = __pa(rsv);
> >>spin_unlock(_mem_reserve_persistent_lock);
> >>
> >> - memunmap(parent);
> >> + return 0;
> >> +}
> >>
> >> +static int __init efi_memreserve_root_init(void)
> >> +{
> >> + if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR)
> >> + return -ENODEV;
> >> +
> >> + efi_memreserve_root = memremap(efi.mem_reserve,
> >> + sizeof(*efi_memreserve_root),
> >> + MEMREMAP_WB);
> >> + if (!efi_memreserve_root)
> >> + return -ENOMEM;
> >>return 0;
> >> }
> >> +early_initcall(efi_memreserve_root_init);
> >>
> >> #ifdef CONFIG_KEXEC
> >> static int update_efi_random_seed(struct notifier_block *nb,
> >> --
> >> 2.19.1
> > BTW, I won’t be able to apply this patch on top of this series [1]. After
> > applied that series, the original BUG sleep from atomic is gone as well as
> > two other GIC warnings. Do you think a new patch is needed here?
> >
> > [1] https://www.spinics.net/lists/arm-kernel/msg685751.html
> OK, I was able to apply this patch on top of latest mainline (ccda4af0f4b9)
> which also include one patch (1/6) from the above series,
>
> However, the efi-related patches from the series (4/6, 5/6, and 6/6) are no
> longer able to be cleanly applied.
>
> As the results, the above patch did fix the original BUG: sleep from atomic,
> but it introduces 2 new warnings.
[...]
These are the warnings you've already reported, aren't they? And we've
established that if you apply the whole series, everything work as
intended at least on the GIC side (the timer issue is a different
story altogether).
Or am I missing something?
Thanks,
M.
--
Jazz is not dead, it just smell funny.
