Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

Pull x86 fixes from Ingo Molnar:
 "Misc fixes: a SYSRET single-stepping fix, a dmi-scan robustization
  fix, a reboot quirk and a kgdb fixlet"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  kgdb/x86: Fix reporting of 'si' in kgdb on x86_64
  x86/asm/entry/64: Disable opportunistic SYSRET if regs->flags has TF set
  x86/reboot: Add ASRock Q1900DC-ITX mainboard reboot quirk
  MAINTAINERS: Change the x86 microcode loader maintainer
  firmware: dmi_scan: Prevent dmi_num integer overflow

diff --git a/MAINTAINERS b/MAINTAINERS
index ac976acd9841031c816ed5885bc19df0d3793677..efbcb50e496954934295b3147e1de9dbdd05ff9e 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -637,8 +637,7 @@ F:      drivers/gpu/drm/radeon/radeon_kfd.h
 F:      include/uapi/linux/kfd_ioctl.h
 
 AMD MICROCODE UPDATE SUPPORT
-M:     Andreas Herrmann <herrmann.der.user@googlemail.com>
-L:     amd64-microcode@amd64.org
+M:     Borislav Petkov <bp@alien8.de>
 S:     Maintained
 F:     arch/x86/kernel/cpu/microcode/amd*
 
@@ -5095,7 +5094,7 @@ S:        Supported
 F:     drivers/platform/x86/intel_menlow.c
 
 INTEL IA32 MICROCODE UPDATE SUPPORT
-M:     Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
+M:     Borislav Petkov <bp@alien8.de>
 S:     Maintained
 F:     arch/x86/kernel/cpu/microcode/core*
 F:     arch/x86/kernel/cpu/microcode/intel*

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 2babb393915e76dbeb8a1b757305b819fddd324b..f0095a76c18211813d711bfa52b82c916190f42d 100644 (file)
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -799,7 +799,21 @@ retint_swapgs:             /* return to user-space */
        cmpq %r11,(EFLAGS-ARGOFFSET)(%rsp)      /* R11 == RFLAGS */
        jne opportunistic_sysret_failed
 
-       testq $X86_EFLAGS_RF,%r11               /* sysret can't restore RF */
+       /*
+        * SYSRET can't restore RF.  SYSRET can restore TF, but unlike IRET,
+        * restoring TF results in a trap from userspace immediately after
+        * SYSRET.  This would cause an infinite loop whenever #DB happens
+        * with register state that satisfies the opportunistic SYSRET
+        * conditions.  For example, single-stepping this user code:
+        *
+        *           movq $stuck_here,%rcx
+        *           pushfq
+        *           popq %r11
+        *   stuck_here:
+        *
+        * would never get past 'stuck_here'.
+        */
+       testq $(X86_EFLAGS_RF|X86_EFLAGS_TF), %r11
        jnz opportunistic_sysret_failed
 
        /* nothing to check for RSP */

diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index 7ec1d5f8d28339bce0b74191a1d458c6c8e5d5df..25ecd56cefa8f22496153cf29b763c266bd8d91e 100644 (file)
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -72,7 +72,7 @@ struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
        { "bx", 8, offsetof(struct pt_regs, bx) },
        { "cx", 8, offsetof(struct pt_regs, cx) },
        { "dx", 8, offsetof(struct pt_regs, dx) },
-       { "si", 8, offsetof(struct pt_regs, dx) },
+       { "si", 8, offsetof(struct pt_regs, si) },
        { "di", 8, offsetof(struct pt_regs, di) },
        { "bp", 8, offsetof(struct pt_regs, bp) },
        { "sp", 8, offsetof(struct pt_regs, sp) },

diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index bae6c609888e7fdff25784d5bd96fd8dcd5ea88a..86db4bcd7ce52bcb74a5bf42efcd8e7152488cf1 100644 (file)
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -183,6 +183,16 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
                },
        },
 
+       /* ASRock */
+       {       /* Handle problems with rebooting on ASRock Q1900DC-ITX */
+               .callback = set_pci_reboot,
+               .ident = "ASRock Q1900DC-ITX",
+               .matches = {
+                       DMI_MATCH(DMI_BOARD_VENDOR, "ASRock"),
+                       DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"),
+               },
+       },
+
        /* ASUS */
        {       /* Handle problems with rebooting on ASUS P4S800 */
                .callback = set_bios_reboot,

diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 69fac068669fde566f41013cefbdf48db023466c..2eebd28b4c40af2789c32e0008f2b60006fc03ac 100644 (file)
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -86,10 +86,13 @@ static void dmi_table(u8 *buf, u32 len, int num,
        int i = 0;
 
        /*
-        *      Stop when we see all the items the table claimed to have
-        *      OR we run off the end of the table (also happens)
+        * Stop when we have seen all the items the table claimed to have
+        * (SMBIOS < 3.0 only) OR we reach an end-of-table marker OR we run
+        * off the end of the table (should never happen but sometimes does
+        * on bogus implementations.)
         */
-       while ((i < num) && (data - buf + sizeof(struct dmi_header)) <= len) {
+       while ((!num || i < num) &&
+              (data - buf + sizeof(struct dmi_header)) <= len) {
                const struct dmi_header *dm = (const struct dmi_header *)data;
 
                /*
@@ -529,21 +532,10 @@ static int __init dmi_smbios3_present(const u8 *buf)
        if (memcmp(buf, "_SM3_", 5) == 0 &&
            buf[6] < 32 && dmi_checksum(buf, buf[6])) {
                dmi_ver = get_unaligned_be16(buf + 7);
+               dmi_num = 0;                    /* No longer specified */
                dmi_len = get_unaligned_le32(buf + 12);
                dmi_base = get_unaligned_le64(buf + 16);
 
-               /*
-                * The 64-bit SMBIOS 3.0 entry point no longer has a field
-                * containing the number of structures present in the table.
-                * Instead, it defines the table size as a maximum size, and
-                * relies on the end-of-table structure type (#127) to be used
-                * to signal the end of the table.
-                * So let's define dmi_num as an upper bound as well: each
-                * structure has a 4 byte header, so dmi_len / 4 is an upper
-                * bound for the number of structures in the table.
-                */
-               dmi_num = dmi_len / 4;
-
                if (dmi_walk_early(dmi_decode) == 0) {
                        pr_info("SMBIOS %d.%d present.\n",
                                dmi_ver >> 8, dmi_ver & 0xFF);