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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-09-08 01:01:14 -0300
commite5fd91f1ef340da553f7a79da9540c3db711c937 (patch)
treeb11842027dc6641da63f4bcc524f8678263304a3 /arch/x86/kernel/traps.c
parent2a9b0348e685a63d97486f6749622b61e9e3292f (diff)
Linux-libre 4.2-gnu
Diffstat (limited to 'arch/x86/kernel/traps.c')
-rw-r--r--arch/x86/kernel/traps.c155
1 files changed, 28 insertions, 127 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 324ab5247..f5791927a 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -54,12 +54,13 @@
#include <asm/ftrace.h>
#include <asm/traps.h>
#include <asm/desc.h>
-#include <asm/i387.h>
-#include <asm/fpu-internal.h>
+#include <asm/fpu/internal.h>
#include <asm/mce.h>
#include <asm/fixmap.h>
#include <asm/mach_traps.h>
#include <asm/alternative.h>
+#include <asm/fpu/xstate.h>
+#include <asm/trace/mpx.h>
#include <asm/mpx.h>
#ifdef CONFIG_X86_64
@@ -72,8 +73,7 @@ gate_desc debug_idt_table[NR_VECTORS] __page_aligned_bss;
#else
#include <asm/processor-flags.h>
#include <asm/setup.h>
-
-asmlinkage int system_call(void);
+#include <asm/proto.h>
#endif
/* Must be page-aligned because the real IDT is used in a fixmap. */
@@ -371,10 +371,8 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
dotraplinkage void do_bounds(struct pt_regs *regs, long error_code)
{
- struct task_struct *tsk = current;
- struct xsave_struct *xsave_buf;
enum ctx_state prev_state;
- struct bndcsr *bndcsr;
+ const struct bndcsr *bndcsr;
siginfo_t *info;
prev_state = exception_enter();
@@ -393,15 +391,15 @@ dotraplinkage void do_bounds(struct pt_regs *regs, long error_code)
/*
* We need to look at BNDSTATUS to resolve this exception.
- * It is not directly accessible, though, so we need to
- * do an xsave and then pull it out of the xsave buffer.
+ * A NULL here might mean that it is in its 'init state',
+ * which is all zeros which indicates MPX was not
+ * responsible for the exception.
*/
- fpu_save_init(&tsk->thread.fpu);
- xsave_buf = &(tsk->thread.fpu.state->xsave);
- bndcsr = get_xsave_addr(xsave_buf, XSTATE_BNDCSR);
+ bndcsr = get_xsave_field_ptr(XSTATE_BNDCSR);
if (!bndcsr)
goto exit_trap;
+ trace_bounds_exception_mpx(bndcsr);
/*
* The error code field of the BNDSTATUS register communicates status
* information of a bound range exception #BR or operation involving
@@ -409,11 +407,11 @@ dotraplinkage void do_bounds(struct pt_regs *regs, long error_code)
*/
switch (bndcsr->bndstatus & MPX_BNDSTA_ERROR_CODE) {
case 2: /* Bound directory has invalid entry. */
- if (mpx_handle_bd_fault(xsave_buf))
+ if (mpx_handle_bd_fault())
goto exit_trap;
break; /* Success, it was handled */
case 1: /* Bound violation. */
- info = mpx_generate_siginfo(regs, xsave_buf);
+ info = mpx_generate_siginfo(regs);
if (IS_ERR(info)) {
/*
* We failed to decode the MPX instruction. Act as if
@@ -709,8 +707,8 @@ NOKPROBE_SYMBOL(do_debug);
static void math_error(struct pt_regs *regs, int error_code, int trapnr)
{
struct task_struct *task = current;
+ struct fpu *fpu = &task->thread.fpu;
siginfo_t info;
- unsigned short err;
char *str = (trapnr == X86_TRAP_MF) ? "fpu exception" :
"simd exception";
@@ -718,8 +716,7 @@ static void math_error(struct pt_regs *regs, int error_code, int trapnr)
return;
conditional_sti(regs);
- if (!user_mode(regs))
- {
+ if (!user_mode(regs)) {
if (!fixup_exception(regs)) {
task->thread.error_code = error_code;
task->thread.trap_nr = trapnr;
@@ -731,62 +728,20 @@ static void math_error(struct pt_regs *regs, int error_code, int trapnr)
/*
* Save the info for the exception handler and clear the error.
*/
- unlazy_fpu(task);
- task->thread.trap_nr = trapnr;
+ fpu__save(fpu);
+
+ task->thread.trap_nr = trapnr;
task->thread.error_code = error_code;
- info.si_signo = SIGFPE;
- info.si_errno = 0;
- info.si_addr = (void __user *)uprobe_get_trap_addr(regs);
- if (trapnr == X86_TRAP_MF) {
- unsigned short cwd, swd;
- /*
- * (~cwd & swd) will mask out exceptions that are not set to unmasked
- * status. 0x3f is the exception bits in these regs, 0x200 is the
- * C1 reg you need in case of a stack fault, 0x040 is the stack
- * fault bit. We should only be taking one exception at a time,
- * so if this combination doesn't produce any single exception,
- * then we have a bad program that isn't synchronizing its FPU usage
- * and it will suffer the consequences since we won't be able to
- * fully reproduce the context of the exception
- */
- cwd = get_fpu_cwd(task);
- swd = get_fpu_swd(task);
+ info.si_signo = SIGFPE;
+ info.si_errno = 0;
+ info.si_addr = (void __user *)uprobe_get_trap_addr(regs);
- err = swd & ~cwd;
- } else {
- /*
- * The SIMD FPU exceptions are handled a little differently, as there
- * is only a single status/control register. Thus, to determine which
- * unmasked exception was caught we must mask the exception mask bits
- * at 0x1f80, and then use these to mask the exception bits at 0x3f.
- */
- unsigned short mxcsr = get_fpu_mxcsr(task);
- err = ~(mxcsr >> 7) & mxcsr;
- }
+ info.si_code = fpu__exception_code(fpu, trapnr);
- if (err & 0x001) { /* Invalid op */
- /*
- * swd & 0x240 == 0x040: Stack Underflow
- * swd & 0x240 == 0x240: Stack Overflow
- * User must clear the SF bit (0x40) if set
- */
- info.si_code = FPE_FLTINV;
- } else if (err & 0x004) { /* Divide by Zero */
- info.si_code = FPE_FLTDIV;
- } else if (err & 0x008) { /* Overflow */
- info.si_code = FPE_FLTOVF;
- } else if (err & 0x012) { /* Denormal, Underflow */
- info.si_code = FPE_FLTUND;
- } else if (err & 0x020) { /* Precision */
- info.si_code = FPE_FLTRES;
- } else {
- /*
- * If we're using IRQ 13, or supposedly even some trap
- * X86_TRAP_MF implementations, it's possible
- * we get a spurious trap, which is not an error.
- */
+ /* Retry when we get spurious exceptions: */
+ if (!info.si_code)
return;
- }
+
force_sig_info(SIGFPE, &info, task);
}
@@ -813,62 +768,8 @@ dotraplinkage void
do_spurious_interrupt_bug(struct pt_regs *regs, long error_code)
{
conditional_sti(regs);
-#if 0
- /* No need to warn about this any longer. */
- pr_info("Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
-#endif
-}
-
-asmlinkage __visible void __attribute__((weak)) smp_thermal_interrupt(void)
-{
}
-asmlinkage __visible void __attribute__((weak)) smp_threshold_interrupt(void)
-{
-}
-
-/*
- * 'math_state_restore()' saves the current math information in the
- * old math state array, and gets the new ones from the current task
- *
- * Careful.. There are problems with IBM-designed IRQ13 behaviour.
- * Don't touch unless you *really* know how it works.
- *
- * Must be called with kernel preemption disabled (eg with local
- * local interrupts as in the case of do_device_not_available).
- */
-void math_state_restore(void)
-{
- struct task_struct *tsk = current;
-
- if (!tsk_used_math(tsk)) {
- local_irq_enable();
- /*
- * does a slab alloc which can sleep
- */
- if (init_fpu(tsk)) {
- /*
- * ran out of memory!
- */
- do_group_exit(SIGKILL);
- return;
- }
- local_irq_disable();
- }
-
- /* Avoid __kernel_fpu_begin() right after __thread_fpu_begin() */
- kernel_fpu_disable();
- __thread_fpu_begin(tsk);
- if (unlikely(restore_fpu_checking(tsk))) {
- fpu_reset_state(tsk);
- force_sig_info(SIGSEGV, SEND_SIG_PRIV, tsk);
- } else {
- tsk->thread.fpu_counter++;
- }
- kernel_fpu_enable();
-}
-EXPORT_SYMBOL_GPL(math_state_restore);
-
dotraplinkage void
do_device_not_available(struct pt_regs *regs, long error_code)
{
@@ -889,7 +790,7 @@ do_device_not_available(struct pt_regs *regs, long error_code)
return;
}
#endif
- math_state_restore(); /* interrupts still off */
+ fpu__restore(&current->thread.fpu); /* interrupts still off */
#ifdef CONFIG_X86_32
conditional_sti(regs);
#endif
@@ -992,13 +893,13 @@ void __init trap_init(void)
set_bit(i, used_vectors);
#ifdef CONFIG_IA32_EMULATION
- set_system_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
+ set_system_intr_gate(IA32_SYSCALL_VECTOR, entry_INT80_compat);
set_bit(IA32_SYSCALL_VECTOR, used_vectors);
#endif
#ifdef CONFIG_X86_32
- set_system_trap_gate(SYSCALL_VECTOR, &system_call);
- set_bit(SYSCALL_VECTOR, used_vectors);
+ set_system_trap_gate(IA32_SYSCALL_VECTOR, entry_INT80_32);
+ set_bit(IA32_SYSCALL_VECTOR, used_vectors);
#endif
/*