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authorLinus Torvalds <torvalds@linux-foundation.org>2019-08-18 09:45:42 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-08-18 09:45:42 -0700
commitc332f3a70e7a094e4a60d68a2c4c6f051ed7f04d (patch)
tree898fdc281a401a44dc83df22dac27e4d64d298a2 /arch
parent645c03aaca2bc02f5d5cc70804ca00b248b729dc (diff)
parenta90118c445cc7f07781de26a9684d4ec58bfcfd1 (diff)
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner: "A set of fixes for x86: - Fix the inconsistent error handling in the umwait init code - Rework the boot param zeroing so gcc9 stops complaining about out of bound memset. The resulting source code is actually more sane to read than the smart solution we had - Maintainers update so Tony gets involved when Intel models are added - Some more fallthrough fixes" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Save fields explicitly, zero out everything else MAINTAINERS, x86/CPU: Tony Luck will maintain asm/intel-family.h x86/fpu/math-emu: Address fallthrough warnings x86/apic/32: Fix yet another implicit fallthrough warning x86/umwait: Fix error handling in umwait_init()
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/bootparam_utils.h63
-rw-r--r--arch/x86/kernel/apic/probe_32.c3
-rw-r--r--arch/x86/kernel/cpu/umwait.c39
-rw-r--r--arch/x86/math-emu/errors.c5
-rw-r--r--arch/x86/math-emu/fpu_trig.c2
5 files changed, 92 insertions, 20 deletions
diff --git a/arch/x86/include/asm/bootparam_utils.h b/arch/x86/include/asm/bootparam_utils.h
index 101eb944f13c..f5e90a849bca 100644
--- a/arch/x86/include/asm/bootparam_utils.h
+++ b/arch/x86/include/asm/bootparam_utils.h
@@ -18,6 +18,20 @@
* Note: efi_info is commonly left uninitialized, but that field has a
* private magic, so it is better to leave it unchanged.
*/
+
+#define sizeof_mbr(type, member) ({ sizeof(((type *)0)->member); })
+
+#define BOOT_PARAM_PRESERVE(struct_member) \
+ { \
+ .start = offsetof(struct boot_params, struct_member), \
+ .len = sizeof_mbr(struct boot_params, struct_member), \
+ }
+
+struct boot_params_to_save {
+ unsigned int start;
+ unsigned int len;
+};
+
static void sanitize_boot_params(struct boot_params *boot_params)
{
/*
@@ -35,21 +49,40 @@ static void sanitize_boot_params(struct boot_params *boot_params)
* problems again.
*/
if (boot_params->sentinel) {
- /* fields in boot_params are left uninitialized, clear them */
- boot_params->acpi_rsdp_addr = 0;
- memset(&boot_params->ext_ramdisk_image, 0,
- (char *)&boot_params->efi_info -
- (char *)&boot_params->ext_ramdisk_image);
- memset(&boot_params->kbd_status, 0,
- (char *)&boot_params->hdr -
- (char *)&boot_params->kbd_status);
- memset(&boot_params->_pad7[0], 0,
- (char *)&boot_params->edd_mbr_sig_buffer[0] -
- (char *)&boot_params->_pad7[0]);
- memset(&boot_params->_pad8[0], 0,
- (char *)&boot_params->eddbuf[0] -
- (char *)&boot_params->_pad8[0]);
- memset(&boot_params->_pad9[0], 0, sizeof(boot_params->_pad9));
+ static struct boot_params scratch;
+ char *bp_base = (char *)boot_params;
+ char *save_base = (char *)&scratch;
+ int i;
+
+ const struct boot_params_to_save to_save[] = {
+ BOOT_PARAM_PRESERVE(screen_info),
+ BOOT_PARAM_PRESERVE(apm_bios_info),
+ BOOT_PARAM_PRESERVE(tboot_addr),
+ BOOT_PARAM_PRESERVE(ist_info),
+ BOOT_PARAM_PRESERVE(acpi_rsdp_addr),
+ BOOT_PARAM_PRESERVE(hd0_info),
+ BOOT_PARAM_PRESERVE(hd1_info),
+ BOOT_PARAM_PRESERVE(sys_desc_table),
+ BOOT_PARAM_PRESERVE(olpc_ofw_header),
+ BOOT_PARAM_PRESERVE(efi_info),
+ BOOT_PARAM_PRESERVE(alt_mem_k),
+ BOOT_PARAM_PRESERVE(scratch),
+ BOOT_PARAM_PRESERVE(e820_entries),
+ BOOT_PARAM_PRESERVE(eddbuf_entries),
+ BOOT_PARAM_PRESERVE(edd_mbr_sig_buf_entries),
+ BOOT_PARAM_PRESERVE(edd_mbr_sig_buffer),
+ BOOT_PARAM_PRESERVE(e820_table),
+ BOOT_PARAM_PRESERVE(eddbuf),
+ };
+
+ memset(&scratch, 0, sizeof(scratch));
+
+ for (i = 0; i < ARRAY_SIZE(to_save); i++) {
+ memcpy(save_base + to_save[i].start,
+ bp_base + to_save[i].start, to_save[i].len);
+ }
+
+ memcpy(boot_params, save_base, sizeof(*boot_params));
}
}
diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c
index 1492799b8f43..ee2d91e382f1 100644
--- a/arch/x86/kernel/apic/probe_32.c
+++ b/arch/x86/kernel/apic/probe_32.c
@@ -184,7 +184,8 @@ void __init default_setup_apic_routing(void)
def_to_bigsmp = 0;
break;
}
- /* If P4 and above fall through */
+ /* P4 and above */
+ /* fall through */
case X86_VENDOR_HYGON:
case X86_VENDOR_AMD:
def_to_bigsmp = 1;
diff --git a/arch/x86/kernel/cpu/umwait.c b/arch/x86/kernel/cpu/umwait.c
index 6a204e7336c1..32b4dc9030aa 100644
--- a/arch/x86/kernel/cpu/umwait.c
+++ b/arch/x86/kernel/cpu/umwait.c
@@ -18,6 +18,12 @@
static u32 umwait_control_cached = UMWAIT_CTRL_VAL(100000, UMWAIT_C02_ENABLE);
/*
+ * Cache the original IA32_UMWAIT_CONTROL MSR value which is configured by
+ * hardware or BIOS before kernel boot.
+ */
+static u32 orig_umwait_control_cached __ro_after_init;
+
+/*
* Serialize access to umwait_control_cached and IA32_UMWAIT_CONTROL MSR in
* the sysfs write functions.
*/
@@ -53,6 +59,23 @@ static int umwait_cpu_online(unsigned int cpu)
}
/*
+ * The CPU hotplug callback sets the control MSR to the original control
+ * value.
+ */
+static int umwait_cpu_offline(unsigned int cpu)
+{
+ /*
+ * This code is protected by the CPU hotplug already and
+ * orig_umwait_control_cached is never changed after it caches
+ * the original control MSR value in umwait_init(). So there
+ * is no race condition here.
+ */
+ wrmsr(MSR_IA32_UMWAIT_CONTROL, orig_umwait_control_cached, 0);
+
+ return 0;
+}
+
+/*
* On resume, restore IA32_UMWAIT_CONTROL MSR on the boot processor which
* is the only active CPU at this time. The MSR is set up on the APs via the
* CPU hotplug callback.
@@ -185,8 +208,22 @@ static int __init umwait_init(void)
if (!boot_cpu_has(X86_FEATURE_WAITPKG))
return -ENODEV;
+ /*
+ * Cache the original control MSR value before the control MSR is
+ * changed. This is the only place where orig_umwait_control_cached
+ * is modified.
+ */
+ rdmsrl(MSR_IA32_UMWAIT_CONTROL, orig_umwait_control_cached);
+
ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "umwait:online",
- umwait_cpu_online, NULL);
+ umwait_cpu_online, umwait_cpu_offline);
+ if (ret < 0) {
+ /*
+ * On failure, the control MSR on all CPUs has the
+ * original control value.
+ */
+ return ret;
+ }
register_syscore_ops(&umwait_syscore_ops);
diff --git a/arch/x86/math-emu/errors.c b/arch/x86/math-emu/errors.c
index 6b468517ab71..73dc66d887f3 100644
--- a/arch/x86/math-emu/errors.c
+++ b/arch/x86/math-emu/errors.c
@@ -178,13 +178,15 @@ void FPU_printall(void)
for (i = 0; i < 8; i++) {
FPU_REG *r = &st(i);
u_char tagi = FPU_gettagi(i);
+
switch (tagi) {
case TAG_Empty:
continue;
- break;
case TAG_Zero:
case TAG_Special:
+ /* Update tagi for the printk below */
tagi = FPU_Special(r);
+ /* fall through */
case TAG_Valid:
printk("st(%d) %c .%04lx %04lx %04lx %04lx e%+-6d ", i,
getsign(r) ? '-' : '+',
@@ -198,7 +200,6 @@ void FPU_printall(void)
printk("Whoops! Error in errors.c: tag%d is %d ", i,
tagi);
continue;
- break;
}
printk("%s\n", tag_desc[(int)(unsigned)tagi]);
}
diff --git a/arch/x86/math-emu/fpu_trig.c b/arch/x86/math-emu/fpu_trig.c
index 783c509f957a..127ea54122d7 100644
--- a/arch/x86/math-emu/fpu_trig.c
+++ b/arch/x86/math-emu/fpu_trig.c
@@ -1352,7 +1352,7 @@ static void fyl2xp1(FPU_REG *st0_ptr, u_char st0_tag)
case TW_Denormal:
if (denormal_operand() < 0)
return;
-
+ /* fall through */
case TAG_Zero:
case TAG_Valid:
setsign(st0_ptr, getsign(st0_ptr) ^ getsign(st1_ptr));