[GIT PULL] x86 fixes

Ingo Molnar
2015-08-22T12:21:30Z

Linus,

Please pull the latest x86-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-for-linus

# HEAD: 827409b2f5b58573ae3774fe6bd2d6daeb335878 x86/fpu/math-emu: Fix crash in fork()

Various low level fixes: fix more fallout from the FPU rework and the asm entry
code rework, plus an MSI rework fix, and an idle-tracing fix.

Thanks,

Ingo

------------------>
Andy Lutomirski (1):
Revert "sched/x86_64: Don't save flags on context switch"

Ingo Molnar (2):
x86/fpu/math-emu: Fix math-emu boot crash
x86/fpu/math-emu: Fix crash in fork()

Jiang Liu (1):
x86/irq: Build correct vector mapping for multiple MSI interrupts

Jisheng Zhang (1):
x86/idle: Restore trace_cpu_idle to mwait_idle() calls

arch/x86/include/asm/switch_to.h | 12 ++++--------
arch/x86/kernel/apic/vector.c | 2 +-
arch/x86/kernel/fpu/core.c | 2 +-
arch/x86/kernel/fpu/init.c | 7 ++++++-
arch/x86/kernel/process.c | 2 ++
5 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h
index 751bf4b7bf11..d7f3b3b78ac3 100644
--- a/arch/x86/include/asm/switch_to.h
+++ b/arch/x86/include/asm/switch_to.h
@@ -79,12 +79,12 @@ do { \
#else /* CONFIG_X86_32 */

/* frame pointer must be last for get_wchan */
-#define SAVE_CONTEXT "pushq %%rbp ; movq %%rsi,%%rbp\n\t"
-#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp\t"
+#define SAVE_CONTEXT "pushf ; pushq %%rbp ; movq %%rsi,%%rbp\n\t"
+#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp ; popf\t"

#define __EXTRA_CLOBBER \
, "rcx", "rbx", "rdx", "r8", "r9", "r10", "r11", \
- "r12", "r13", "r14", "r15", "flags"
+ "r12", "r13", "r14", "r15"

#ifdef CONFIG_CC_STACKPROTECTOR
#define __switch_canary \
@@ -100,11 +100,7 @@ do { \
#define __switch_canary_iparam
#endif /* CC_STACKPROTECTOR */

-/*
- * There is no need to save or restore flags, because flags are always
- * clean in kernel mode, with the possible exception of IOPL. Kernel IOPL
- * has no effect.
- */
+/* Save restore flags to clear handle leaking NT */
#define switch_to(prev, next, last) \
asm volatile(SAVE_CONTEXT \
"movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */ \
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index f813261d9740..2683f36e4e0a 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -322,7 +322,7 @@ static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq,
irq_data->chip = &lapic_controller;
irq_data->chip_data = data;
irq_data->hwirq = virq + i;
- err = assign_irq_vector_policy(virq, irq_data->node, data,
+ err = assign_irq_vector_policy(virq + i, irq_data->node, data,
info);
if (err)
goto error;
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 79de954626fd..d25097c3fc1d 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -270,7 +270,7 @@ int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu)
dst_fpu->fpregs_active = 0;
dst_fpu->last_cpu = -1;

- if (src_fpu->fpstate_active)
+ if (src_fpu->fpstate_active && cpu_has_fpu)
fpu_copy(dst_fpu, src_fpu);

return 0;
diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c
index 1e173f6285c7..d14e9ac3235a 100644
--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -40,7 +40,12 @@ static void fpu__init_cpu_generic(void)
write_cr0(cr0);

/* Flush out any pending x87 state: */
- asm volatile ("fninit");
+#ifdef CONFIG_MATH_EMULATION
+ if (!cpu_has_fpu)
+ fpstate_init_soft(&current->thread.fpu.state.soft);
+ else
+#endif
+ asm volatile ("fninit");
}

/*
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 397688beed4b..c27cad726765 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -408,6 +408,7 @@ static int prefer_mwait_c1_over_halt(const struct cpuinfo_x86 *c)
static void mwait_idle(void)
{
if (!current_set_polling_and_test()) {
+ trace_cpu_idle_rcuidle(1, smp_processor_id());
if (this_cpu_has(X86_BUG_CLFLUSH_MONITOR)) {
smp_mb(); /* quirk */
clflush((void *)&current_thread_info()->flags);
@@ -419,6 +420,7 @@ static void mwait_idle(void)
__sti_mwait(0, 0);
else
local_irq_enable();
+ trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
} else {
local_irq_enable();
}