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authorLinus Torvalds <torvalds@linux-foundation.org>2014-10-14 03:47:00 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2014-10-14 03:47:00 +0200
commit1ee07ef6b5db7235b133ee257a3adf507697e6b3 (patch)
tree9c7a00cf98462c2a70610da9d09770c835ef8fcd /arch/s390/kernel/traps.c
parent77654908ff1a58cee4886298968b5262884aff0b (diff)
parent0cccdda8d1512af4d3f6913044e8c8e58e15ef37 (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky: "This patch set contains the main portion of the changes for 3.18 in regard to the s390 architecture. It is a bit bigger than usual, mainly because of a new driver and the vector extension patches. The interesting bits are: - Quite a bit of work on the tracing front. Uprobes is enabled and the ftrace code is reworked to get some of the lost performance back if CONFIG_FTRACE is enabled. - To improve boot time with CONFIG_DEBIG_PAGEALLOC, support for the IPTE range facility is added. - The rwlock code is re-factored to improve writer fairness and to be able to use the interlocked-access instructions. - The kernel part for the support of the vector extension is added. - The device driver to access the CD/DVD on the HMC is added, this will hopefully come in handy to improve the installation process. - Add support for control-unit initiated reconfiguration. - The crypto device driver is enhanced to enable the additional AP domains and to allow the new crypto hardware to be used. - Bug fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (39 commits) s390/ftrace: simplify enabling/disabling of ftrace_graph_caller s390/ftrace: remove 31 bit ftrace support s390/kdump: add support for vector extension s390/disassembler: add vector instructions s390: add support for vector extension s390/zcrypt: Toleration of new crypto hardware s390/idle: consolidate idle functions and definitions s390/nohz: use a per-cpu flag for arch_needs_cpu s390/vtime: do not reset idle data on CPU hotplug s390/dasd: add support for control unit initiated reconfiguration s390/dasd: fix infinite loop during format s390/mm: make use of ipte range facility s390/setup: correct 4-level kernel page table detection s390/topology: call set_sched_topology early s390/uprobes: architecture backend for uprobes s390/uprobes: common library for kprobes and uprobes s390/rwlock: use the interlocked-access facility 1 instructions s390/rwlock: improve writer fairness s390/rwlock: remove interrupt-enabling rwlock variant. s390/mm: remove change bit override support ...
Diffstat (limited to 'arch/s390/kernel/traps.c')
-rw-r--r--arch/s390/kernel/traps.c115
1 files changed, 104 insertions, 11 deletions
diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
index c5762324d9e..9ff5ecba26a 100644
--- a/arch/s390/kernel/traps.c
+++ b/arch/s390/kernel/traps.c
@@ -18,6 +18,8 @@
#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/mm.h>
+#include <linux/slab.h>
+#include <asm/switch_to.h>
#include "entry.h"
int show_unhandled_signals = 1;
@@ -58,15 +60,10 @@ int is_valid_bugaddr(unsigned long addr)
return 1;
}
-static void __kprobes do_trap(struct pt_regs *regs,
- int si_signo, int si_code, char *str)
+void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str)
{
siginfo_t info;
- if (notify_die(DIE_TRAP, str, regs, 0,
- regs->int_code, si_signo) == NOTIFY_STOP)
- return;
-
if (user_mode(regs)) {
info.si_signo = si_signo;
info.si_errno = 0;
@@ -90,6 +87,15 @@ static void __kprobes do_trap(struct pt_regs *regs,
}
}
+static void __kprobes do_trap(struct pt_regs *regs, int si_signo, int si_code,
+ char *str)
+{
+ if (notify_die(DIE_TRAP, str, regs, 0,
+ regs->int_code, si_signo) == NOTIFY_STOP)
+ return;
+ do_report_trap(regs, si_signo, si_code, str);
+}
+
void __kprobes do_per_trap(struct pt_regs *regs)
{
siginfo_t info;
@@ -178,6 +184,7 @@ void __kprobes illegal_op(struct pt_regs *regs)
siginfo_t info;
__u8 opcode[6];
__u16 __user *location;
+ int is_uprobe_insn = 0;
int signal = 0;
location = get_trap_ip(regs);
@@ -194,6 +201,10 @@ void __kprobes illegal_op(struct pt_regs *regs)
force_sig_info(SIGTRAP, &info, current);
} else
signal = SIGILL;
+#ifdef CONFIG_UPROBES
+ } else if (*((__u16 *) opcode) == UPROBE_SWBP_INSN) {
+ is_uprobe_insn = 1;
+#endif
#ifdef CONFIG_MATHEMU
} else if (opcode[0] == 0xb3) {
if (get_user(*((__u16 *) (opcode+2)), location+1))
@@ -219,11 +230,13 @@ void __kprobes illegal_op(struct pt_regs *regs)
#endif
} else
signal = SIGILL;
- } else {
- /*
- * If we get an illegal op in kernel mode, send it through the
- * kprobes notifier. If kprobes doesn't pick it up, SIGILL
- */
+ }
+ /*
+ * We got either an illegal op in kernel mode, or user space trapped
+ * on a uprobes illegal instruction. See if kprobes or uprobes picks
+ * it up. If not, SIGILL.
+ */
+ if (is_uprobe_insn || !user_mode(regs)) {
if (notify_die(DIE_BPT, "bpt", regs, 0,
3, SIGTRAP) != NOTIFY_STOP)
signal = SIGILL;
@@ -292,6 +305,74 @@ DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
"specification exception");
#endif
+#ifdef CONFIG_64BIT
+int alloc_vector_registers(struct task_struct *tsk)
+{
+ __vector128 *vxrs;
+ int i;
+
+ /* Allocate vector register save area. */
+ vxrs = kzalloc(sizeof(__vector128) * __NUM_VXRS,
+ GFP_KERNEL|__GFP_REPEAT);
+ if (!vxrs)
+ return -ENOMEM;
+ preempt_disable();
+ if (tsk == current)
+ save_fp_regs(tsk->thread.fp_regs.fprs);
+ /* Copy the 16 floating point registers */
+ for (i = 0; i < 16; i++)
+ *(freg_t *) &vxrs[i] = tsk->thread.fp_regs.fprs[i];
+ tsk->thread.vxrs = vxrs;
+ if (tsk == current) {
+ __ctl_set_bit(0, 17);
+ restore_vx_regs(vxrs);
+ }
+ preempt_enable();
+ return 0;
+}
+
+void vector_exception(struct pt_regs *regs)
+{
+ int si_code, vic;
+
+ if (!MACHINE_HAS_VX) {
+ do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
+ return;
+ }
+
+ /* get vector interrupt code from fpc */
+ asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
+ vic = (current->thread.fp_regs.fpc & 0xf00) >> 8;
+ switch (vic) {
+ case 1: /* invalid vector operation */
+ si_code = FPE_FLTINV;
+ break;
+ case 2: /* division by zero */
+ si_code = FPE_FLTDIV;
+ break;
+ case 3: /* overflow */
+ si_code = FPE_FLTOVF;
+ break;
+ case 4: /* underflow */
+ si_code = FPE_FLTUND;
+ break;
+ case 5: /* inexact */
+ si_code = FPE_FLTRES;
+ break;
+ default: /* unknown cause */
+ si_code = 0;
+ }
+ do_trap(regs, SIGFPE, si_code, "vector exception");
+}
+
+static int __init disable_vector_extension(char *str)
+{
+ S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
+ return 1;
+}
+__setup("novx", disable_vector_extension);
+#endif
+
void data_exception(struct pt_regs *regs)
{
__u16 __user *location;
@@ -357,6 +438,18 @@ void data_exception(struct pt_regs *regs)
}
}
#endif
+#ifdef CONFIG_64BIT
+ /* Check for vector register enablement */
+ if (MACHINE_HAS_VX && !current->thread.vxrs &&
+ (current->thread.fp_regs.fpc & FPC_DXC_MASK) == 0xfe00) {
+ alloc_vector_registers(current);
+ /* Vector data exception is suppressing, rewind psw. */
+ regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16);
+ clear_pt_regs_flag(regs, PIF_PER_TRAP);
+ return;
+ }
+#endif
+
if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
signal = SIGFPE;
else