--- /dev/null
+From 2b3d89b402b085b08498e896c65267a145bed486 Mon Sep 17 00:00:00 2001
+From: Jerry Hoemann <jerry.hoemann@hpe.com>
+Date: Sun, 25 Feb 2018 20:22:20 -0700
+Subject: watchdog: hpwdt: Remove legacy NMI sourcing.
+
+From: Jerry Hoemann <jerry.hoemann@hpe.com>
+
+commit 2b3d89b402b085b08498e896c65267a145bed486 upstream.
+
+Gen8 and prior Proliant systems supported the "CRU" interface
+to firmware. This interfaces allows linux to "call back" into firmware
+to source the cause of an NMI. This feature isn't fully utilized
+as the actual source of the NMI isn't printed, the driver only
+indicates that the source couldn't be determined when the call
+fails.
+
+With the advent of Gen9, iCRU replaces the CRU. The call back
+feature is no longer available in firmware. To be compatible and
+not attempt to call back into firmware on system not supporting CRU,
+the SMBIOS table is consulted to determine if it is safe to
+make the call back or not.
+
+This results in about half of the driver code being devoted
+to either making CRU calls or determing if it is safe to make
+CRU calls. As noted, the driver isn't really using the results of
+the CRU calls.
+
+Furthermore, as a consequence of the Spectre security issue, the
+BIOS/EFI calls are being wrapped into Spectre-disabling section.
+Removing the call back in hpwdt_pretimeout assists in this effort.
+
+As the CRU sourcing of the NMI isn't required for handling the
+NMI and there are security concerns with making the call back, remove
+the legacy (pre Gen9) NMI sourcing and the DMI code to determine if
+the system had the CRU interface.
+
+Signed-off-by: Jerry Hoemann <jerry.hoemann@hpe.com>
+Acked-by: Ingo Molnar <mingo@kernel.org>
+Reviewed-by: Guenter Roeck <linux@roeck-us.net>
+Signed-off-by: Guenter Roeck <linux@roeck-us.net>
+Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/watchdog/hpwdt.c | 501 -----------------------------------------------
+ 1 file changed, 9 insertions(+), 492 deletions(-)
+
+--- a/drivers/watchdog/hpwdt.c
++++ b/drivers/watchdog/hpwdt.c
+@@ -28,16 +28,7 @@
+ #include <linux/types.h>
+ #include <linux/uaccess.h>
+ #include <linux/watchdog.h>
+-#ifdef CONFIG_HPWDT_NMI_DECODING
+-#include <linux/dmi.h>
+-#include <linux/spinlock.h>
+-#include <linux/nmi.h>
+-#include <linux/kdebug.h>
+-#include <linux/notifier.h>
+-#include <asm/cacheflush.h>
+-#endif /* CONFIG_HPWDT_NMI_DECODING */
+ #include <asm/nmi.h>
+-#include <asm/frame.h>
+
+ #define HPWDT_VERSION "1.4.0"
+ #define SECS_TO_TICKS(secs) ((secs) * 1000 / 128)
+@@ -48,6 +39,9 @@
+ static unsigned int soft_margin = DEFAULT_MARGIN; /* in seconds */
+ static unsigned int reload; /* the computed soft_margin */
+ static bool nowayout = WATCHDOG_NOWAYOUT;
++#ifdef CONFIG_HPWDT_NMI_DECODING
++static unsigned int allow_kdump = 1;
++#endif
+ static char expect_release;
+ static unsigned long hpwdt_is_open;
+
+@@ -63,373 +57,6 @@ static const struct pci_device_id hpwdt_
+ };
+ MODULE_DEVICE_TABLE(pci, hpwdt_devices);
+
+-#ifdef CONFIG_HPWDT_NMI_DECODING
+-#define PCI_BIOS32_SD_VALUE 0x5F32335F /* "_32_" */
+-#define CRU_BIOS_SIGNATURE_VALUE 0x55524324
+-#define PCI_BIOS32_PARAGRAPH_LEN 16
+-#define PCI_ROM_BASE1 0x000F0000
+-#define ROM_SIZE 0x10000
+-
+-struct bios32_service_dir {
+- u32 signature;
+- u32 entry_point;
+- u8 revision;
+- u8 length;
+- u8 checksum;
+- u8 reserved[5];
+-};
+-
+-/* type 212 */
+-struct smbios_cru64_info {
+- u8 type;
+- u8 byte_length;
+- u16 handle;
+- u32 signature;
+- u64 physical_address;
+- u32 double_length;
+- u32 double_offset;
+-};
+-#define SMBIOS_CRU64_INFORMATION 212
+-
+-/* type 219 */
+-struct smbios_proliant_info {
+- u8 type;
+- u8 byte_length;
+- u16 handle;
+- u32 power_features;
+- u32 omega_features;
+- u32 reserved;
+- u32 misc_features;
+-};
+-#define SMBIOS_ICRU_INFORMATION 219
+-
+-
+-struct cmn_registers {
+- union {
+- struct {
+- u8 ral;
+- u8 rah;
+- u16 rea2;
+- };
+- u32 reax;
+- } u1;
+- union {
+- struct {
+- u8 rbl;
+- u8 rbh;
+- u8 reb2l;
+- u8 reb2h;
+- };
+- u32 rebx;
+- } u2;
+- union {
+- struct {
+- u8 rcl;
+- u8 rch;
+- u16 rec2;
+- };
+- u32 recx;
+- } u3;
+- union {
+- struct {
+- u8 rdl;
+- u8 rdh;
+- u16 red2;
+- };
+- u32 redx;
+- } u4;
+-
+- u32 resi;
+- u32 redi;
+- u16 rds;
+- u16 res;
+- u32 reflags;
+-} __attribute__((packed));
+-
+-static unsigned int hpwdt_nmi_decoding;
+-static unsigned int allow_kdump = 1;
+-static unsigned int is_icru;
+-static unsigned int is_uefi;
+-static DEFINE_SPINLOCK(rom_lock);
+-static void *cru_rom_addr;
+-static struct cmn_registers cmn_regs;
+-
+-extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
+- unsigned long *pRomEntry);
+-
+-#ifdef CONFIG_X86_32
+-/* --32 Bit Bios------------------------------------------------------------ */
+-
+-#define HPWDT_ARCH 32
+-
+-asm(".text \n\t"
+- ".align 4 \n\t"
+- ".globl asminline_call \n"
+- "asminline_call: \n\t"
+- "pushl %ebp \n\t"
+- "movl %esp, %ebp \n\t"
+- "pusha \n\t"
+- "pushf \n\t"
+- "push %es \n\t"
+- "push %ds \n\t"
+- "pop %es \n\t"
+- "movl 8(%ebp),%eax \n\t"
+- "movl 4(%eax),%ebx \n\t"
+- "movl 8(%eax),%ecx \n\t"
+- "movl 12(%eax),%edx \n\t"
+- "movl 16(%eax),%esi \n\t"
+- "movl 20(%eax),%edi \n\t"
+- "movl (%eax),%eax \n\t"
+- "push %cs \n\t"
+- "call *12(%ebp) \n\t"
+- "pushf \n\t"
+- "pushl %eax \n\t"
+- "movl 8(%ebp),%eax \n\t"
+- "movl %ebx,4(%eax) \n\t"
+- "movl %ecx,8(%eax) \n\t"
+- "movl %edx,12(%eax) \n\t"
+- "movl %esi,16(%eax) \n\t"
+- "movl %edi,20(%eax) \n\t"
+- "movw %ds,24(%eax) \n\t"
+- "movw %es,26(%eax) \n\t"
+- "popl %ebx \n\t"
+- "movl %ebx,(%eax) \n\t"
+- "popl %ebx \n\t"
+- "movl %ebx,28(%eax) \n\t"
+- "pop %es \n\t"
+- "popf \n\t"
+- "popa \n\t"
+- "leave \n\t"
+- "ret \n\t"
+- ".previous");
+-
+-
+-/*
+- * cru_detect
+- *
+- * Routine Description:
+- * This function uses the 32-bit BIOS Service Directory record to
+- * search for a $CRU record.
+- *
+- * Return Value:
+- * 0 : SUCCESS
+- * <0 : FAILURE
+- */
+-static int cru_detect(unsigned long map_entry,
+- unsigned long map_offset)
+-{
+- void *bios32_map;
+- unsigned long *bios32_entrypoint;
+- unsigned long cru_physical_address;
+- unsigned long cru_length;
+- unsigned long physical_bios_base = 0;
+- unsigned long physical_bios_offset = 0;
+- int retval = -ENODEV;
+-
+- bios32_map = ioremap(map_entry, (2 * PAGE_SIZE));
+-
+- if (bios32_map == NULL)
+- return -ENODEV;
+-
+- bios32_entrypoint = bios32_map + map_offset;
+-
+- cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
+-
+- set_memory_x((unsigned long)bios32_map, 2);
+- asminline_call(&cmn_regs, bios32_entrypoint);
+-
+- if (cmn_regs.u1.ral != 0) {
+- pr_warn("Call succeeded but with an error: 0x%x\n",
+- cmn_regs.u1.ral);
+- } else {
+- physical_bios_base = cmn_regs.u2.rebx;
+- physical_bios_offset = cmn_regs.u4.redx;
+- cru_length = cmn_regs.u3.recx;
+- cru_physical_address =
+- physical_bios_base + physical_bios_offset;
+-
+- /* If the values look OK, then map it in. */
+- if ((physical_bios_base + physical_bios_offset)) {
+- cru_rom_addr =
+- ioremap(cru_physical_address, cru_length);
+- if (cru_rom_addr) {
+- set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
+- (cru_length + PAGE_SIZE - 1) >> PAGE_SHIFT);
+- retval = 0;
+- }
+- }
+-
+- pr_debug("CRU Base Address: 0x%lx\n", physical_bios_base);
+- pr_debug("CRU Offset Address: 0x%lx\n", physical_bios_offset);
+- pr_debug("CRU Length: 0x%lx\n", cru_length);
+- pr_debug("CRU Mapped Address: %p\n", &cru_rom_addr);
+- }
+- iounmap(bios32_map);
+- return retval;
+-}
+-
+-/*
+- * bios_checksum
+- */
+-static int bios_checksum(const char __iomem *ptr, int len)
+-{
+- char sum = 0;
+- int i;
+-
+- /*
+- * calculate checksum of size bytes. This should add up
+- * to zero if we have a valid header.
+- */
+- for (i = 0; i < len; i++)
+- sum += ptr[i];
+-
+- return ((sum == 0) && (len > 0));
+-}
+-
+-/*
+- * bios32_present
+- *
+- * Routine Description:
+- * This function finds the 32-bit BIOS Service Directory
+- *
+- * Return Value:
+- * 0 : SUCCESS
+- * <0 : FAILURE
+- */
+-static int bios32_present(const char __iomem *p)
+-{
+- struct bios32_service_dir *bios_32_ptr;
+- int length;
+- unsigned long map_entry, map_offset;
+-
+- bios_32_ptr = (struct bios32_service_dir *) p;
+-
+- /*
+- * Search for signature by checking equal to the swizzled value
+- * instead of calling another routine to perform a strcmp.
+- */
+- if (bios_32_ptr->signature == PCI_BIOS32_SD_VALUE) {
+- length = bios_32_ptr->length * PCI_BIOS32_PARAGRAPH_LEN;
+- if (bios_checksum(p, length)) {
+- /*
+- * According to the spec, we're looking for the
+- * first 4KB-aligned address below the entrypoint
+- * listed in the header. The Service Directory code
+- * is guaranteed to occupy no more than 2 4KB pages.
+- */
+- map_entry = bios_32_ptr->entry_point & ~(PAGE_SIZE - 1);
+- map_offset = bios_32_ptr->entry_point - map_entry;
+-
+- return cru_detect(map_entry, map_offset);
+- }
+- }
+- return -ENODEV;
+-}
+-
+-static int detect_cru_service(void)
+-{
+- char __iomem *p, *q;
+- int rc = -1;
+-
+- /*
+- * Search from 0x0f0000 through 0x0fffff, inclusive.
+- */
+- p = ioremap(PCI_ROM_BASE1, ROM_SIZE);
+- if (p == NULL)
+- return -ENOMEM;
+-
+- for (q = p; q < p + ROM_SIZE; q += 16) {
+- rc = bios32_present(q);
+- if (!rc)
+- break;
+- }
+- iounmap(p);
+- return rc;
+-}
+-/* ------------------------------------------------------------------------- */
+-#endif /* CONFIG_X86_32 */
+-#ifdef CONFIG_X86_64
+-/* --64 Bit Bios------------------------------------------------------------ */
+-
+-#define HPWDT_ARCH 64
+-
+-asm(".text \n\t"
+- ".align 4 \n\t"
+- ".globl asminline_call \n\t"
+- ".type asminline_call, @function \n\t"
+- "asminline_call: \n\t"
+- FRAME_BEGIN
+- "pushq %rax \n\t"
+- "pushq %rbx \n\t"
+- "pushq %rdx \n\t"
+- "pushq %r12 \n\t"
+- "pushq %r9 \n\t"
+- "movq %rsi, %r12 \n\t"
+- "movq %rdi, %r9 \n\t"
+- "movl 4(%r9),%ebx \n\t"
+- "movl 8(%r9),%ecx \n\t"
+- "movl 12(%r9),%edx \n\t"
+- "movl 16(%r9),%esi \n\t"
+- "movl 20(%r9),%edi \n\t"
+- "movl (%r9),%eax \n\t"
+- "call *%r12 \n\t"
+- "pushfq \n\t"
+- "popq %r12 \n\t"
+- "movl %eax, (%r9) \n\t"
+- "movl %ebx, 4(%r9) \n\t"
+- "movl %ecx, 8(%r9) \n\t"
+- "movl %edx, 12(%r9) \n\t"
+- "movl %esi, 16(%r9) \n\t"
+- "movl %edi, 20(%r9) \n\t"
+- "movq %r12, %rax \n\t"
+- "movl %eax, 28(%r9) \n\t"
+- "popq %r9 \n\t"
+- "popq %r12 \n\t"
+- "popq %rdx \n\t"
+- "popq %rbx \n\t"
+- "popq %rax \n\t"
+- FRAME_END
+- "ret \n\t"
+- ".previous");
+-
+-/*
+- * dmi_find_cru
+- *
+- * Routine Description:
+- * This function checks whether or not a SMBIOS/DMI record is
+- * the 64bit CRU info or not
+- */
+-static void dmi_find_cru(const struct dmi_header *dm, void *dummy)
+-{
+- struct smbios_cru64_info *smbios_cru64_ptr;
+- unsigned long cru_physical_address;
+-
+- if (dm->type == SMBIOS_CRU64_INFORMATION) {
+- smbios_cru64_ptr = (struct smbios_cru64_info *) dm;
+- if (smbios_cru64_ptr->signature == CRU_BIOS_SIGNATURE_VALUE) {
+- cru_physical_address =
+- smbios_cru64_ptr->physical_address +
+- smbios_cru64_ptr->double_offset;
+- cru_rom_addr = ioremap(cru_physical_address,
+- smbios_cru64_ptr->double_length);
+- set_memory_x((unsigned long)cru_rom_addr & PAGE_MASK,
+- smbios_cru64_ptr->double_length >> PAGE_SHIFT);
+- }
+- }
+-}
+-
+-static int detect_cru_service(void)
+-{
+- cru_rom_addr = NULL;
+-
+- dmi_walk(dmi_find_cru, NULL);
+-
+- /* if cru_rom_addr has been set then we found a CRU service */
+- return ((cru_rom_addr != NULL) ? 0 : -ENODEV);
+-}
+-/* ------------------------------------------------------------------------- */
+-#endif /* CONFIG_X86_64 */
+-#endif /* CONFIG_HPWDT_NMI_DECODING */
+
+ /*
+ * Watchdog operations
+@@ -486,30 +113,12 @@ static int hpwdt_my_nmi(void)
+ */
+ static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
+ {
+- unsigned long rom_pl;
+- static int die_nmi_called;
+-
+- if (!hpwdt_nmi_decoding)
+- return NMI_DONE;
+-
+ if ((ulReason == NMI_UNKNOWN) && !hpwdt_my_nmi())
+ return NMI_DONE;
+
+- spin_lock_irqsave(&rom_lock, rom_pl);
+- if (!die_nmi_called && !is_icru && !is_uefi)
+- asminline_call(&cmn_regs, cru_rom_addr);
+- die_nmi_called = 1;
+- spin_unlock_irqrestore(&rom_lock, rom_pl);
+-
+ if (allow_kdump)
+ hpwdt_stop();
+
+- if (!is_icru && !is_uefi) {
+- if (cmn_regs.u1.ral == 0) {
+- nmi_panic(regs, "An NMI occurred, but unable to determine source.\n");
+- return NMI_HANDLED;
+- }
+- }
+ nmi_panic(regs, "An NMI occurred. Depending on your system the reason "
+ "for the NMI is logged in any one of the following "
+ "resources:\n"
+@@ -675,84 +284,11 @@ static struct miscdevice hpwdt_miscdev =
+ * Init & Exit
+ */
+
+-#ifdef CONFIG_HPWDT_NMI_DECODING
+-#ifdef CONFIG_X86_LOCAL_APIC
+-static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
+-{
+- /*
+- * If nmi_watchdog is turned off then we can turn on
+- * our nmi decoding capability.
+- */
+- hpwdt_nmi_decoding = 1;
+-}
+-#else
+-static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
+-{
+- dev_warn(&dev->dev, "NMI decoding is disabled. "
+- "Your kernel does not support a NMI Watchdog.\n");
+-}
+-#endif /* CONFIG_X86_LOCAL_APIC */
+-
+-/*
+- * dmi_find_icru
+- *
+- * Routine Description:
+- * This function checks whether or not we are on an iCRU-based server.
+- * This check is independent of architecture and needs to be made for
+- * any ProLiant system.
+- */
+-static void dmi_find_icru(const struct dmi_header *dm, void *dummy)
+-{
+- struct smbios_proliant_info *smbios_proliant_ptr;
+-
+- if (dm->type == SMBIOS_ICRU_INFORMATION) {
+- smbios_proliant_ptr = (struct smbios_proliant_info *) dm;
+- if (smbios_proliant_ptr->misc_features & 0x01)
+- is_icru = 1;
+- if (smbios_proliant_ptr->misc_features & 0x1400)
+- is_uefi = 1;
+- }
+-}
+
+ static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
+ {
++#ifdef CONFIG_HPWDT_NMI_DECODING
+ int retval;
+-
+- /*
+- * On typical CRU-based systems we need to map that service in
+- * the BIOS. For 32 bit Operating Systems we need to go through
+- * the 32 Bit BIOS Service Directory. For 64 bit Operating
+- * Systems we get that service through SMBIOS.
+- *
+- * On systems that support the new iCRU service all we need to
+- * do is call dmi_walk to get the supported flag value and skip
+- * the old cru detect code.
+- */
+- dmi_walk(dmi_find_icru, NULL);
+- if (!is_icru && !is_uefi) {
+-
+- /*
+- * We need to map the ROM to get the CRU service.
+- * For 32 bit Operating Systems we need to go through the 32 Bit
+- * BIOS Service Directory
+- * For 64 bit Operating Systems we get that service through SMBIOS.
+- */
+- retval = detect_cru_service();
+- if (retval < 0) {
+- dev_warn(&dev->dev,
+- "Unable to detect the %d Bit CRU Service.\n",
+- HPWDT_ARCH);
+- return retval;
+- }
+-
+- /*
+- * We know this is the only CRU call we need to make so lets keep as
+- * few instructions as possible once the NMI comes in.
+- */
+- cmn_regs.u1.rah = 0x0D;
+- cmn_regs.u1.ral = 0x02;
+- }
+-
+ /*
+ * Only one function can register for NMI_UNKNOWN
+ */
+@@ -780,45 +316,26 @@ error:
+ dev_warn(&dev->dev,
+ "Unable to register a die notifier (err=%d).\n",
+ retval);
+- if (cru_rom_addr)
+- iounmap(cru_rom_addr);
+ return retval;
++#endif /* CONFIG_HPWDT_NMI_DECODING */
++ return 0;
+ }
+
+ static void hpwdt_exit_nmi_decoding(void)
+ {
++#ifdef CONFIG_HPWDT_NMI_DECODING
+ unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
+ unregister_nmi_handler(NMI_SERR, "hpwdt");
+ unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
+- if (cru_rom_addr)
+- iounmap(cru_rom_addr);
+-}
+-#else /* !CONFIG_HPWDT_NMI_DECODING */
+-static void hpwdt_check_nmi_decoding(struct pci_dev *dev)
+-{
+-}
+-
+-static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
+-{
+- return 0;
++#endif
+ }
+
+-static void hpwdt_exit_nmi_decoding(void)
+-{
+-}
+-#endif /* CONFIG_HPWDT_NMI_DECODING */
+-
+ static int hpwdt_init_one(struct pci_dev *dev,
+ const struct pci_device_id *ent)
+ {
+ int retval;
+
+ /*
+- * Check if we can do NMI decoding or not
+- */
+- hpwdt_check_nmi_decoding(dev);
+-
+- /*
+ * First let's find out if we are on an iLO2+ server. We will
+ * not run on a legacy ASM box.
+ * So we only support the G5 ProLiant servers and higher.
+@@ -922,6 +439,6 @@ MODULE_PARM_DESC(nowayout, "Watchdog can
+ #ifdef CONFIG_HPWDT_NMI_DECODING
+ module_param(allow_kdump, int, 0);
+ MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
+-#endif /* !CONFIG_HPWDT_NMI_DECODING */
++#endif /* CONFIG_HPWDT_NMI_DECODING */
+
+ module_pci_driver(hpwdt_driver);
projects / thirdparty / kernel / stable-queue.git / commitdiff
