Merge tag 'xtensa-20200805' of git://github.com/jcmvbkbc/linux-xtensa
Pull Xtensa updates from Max Filippov:
- add syscall audit support
- add seccomp filter support
- clean up make rules under arch/xtensa/boot
- fix state management for exclusive access opcodes
- fix build with PMU enabled
* tag 'xtensa-20200805' of git://github.com/jcmvbkbc/linux-xtensa:
xtensa: add missing exclusive access state management
xtensa: fix xtensa_pmu_setup prototype
xtensa: add boot subdirectories build artifacts to 'targets'
xtensa: add uImage and xipImage to targets
xtensa: move vmlinux.bin[.gz] to boot subdirectory
xtensa: initialize_mmu.h: fix a duplicated word
selftests/seccomp: add xtensa support
xtensa: add seccomp support
xtensa: expose syscall through user_pt_regs
xtensa: add audit support
diff --git a/Documentation/features/seccomp/seccomp-filter/arch-support.txt b/Documentation/features/seccomp/seccomp-filter/arch-support.txt
index f54ddfc..c688aba 100644
--- a/Documentation/features/seccomp/seccomp-filter/arch-support.txt
+++ b/Documentation/features/seccomp/seccomp-filter/arch-support.txt
@@ -29,5 +29,5 @@
| sparc: | TODO |
| um: | ok |
| x86: | ok |
- | xtensa: | TODO |
+ | xtensa: | ok |
-----------------------
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index b71ba91..e997e01 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -21,8 +21,10 @@
select GENERIC_PCI_IOMAP
select GENERIC_SCHED_CLOCK
select GENERIC_STRNCPY_FROM_USER if KASAN
+ select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
+ select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ARCH_TRACEHOOK
select HAVE_DEBUG_KMEMLEAK
select HAVE_DMA_CONTIGUOUS
@@ -215,6 +217,20 @@
Say N if you want to disable CPU hotplug.
+config SECCOMP
+ bool
+ prompt "Enable seccomp to safely compute untrusted bytecode"
+ help
+ This kernel feature is useful for number crunching applications
+ that may need to compute untrusted bytecode during their
+ execution. By using pipes or other transports made available to
+ the process as file descriptors supporting the read/write
+ syscalls, it's possible to isolate those applications in
+ their own address space using seccomp. Once seccomp is
+ enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
+ and the task is only allowed to execute a few safe syscalls
+ defined by each seccomp mode.
+
config FAST_SYSCALL_XTENSA
bool "Enable fast atomic syscalls"
default n
diff --git a/arch/xtensa/boot/Makefile b/arch/xtensa/boot/Makefile
index 1a14d38..f6bb352 100644
--- a/arch/xtensa/boot/Makefile
+++ b/arch/xtensa/boot/Makefile
@@ -17,6 +17,8 @@
export BIG_ENDIAN
subdir-y := lib
+targets += vmlinux.bin vmlinux.bin.gz
+targets += uImage xipImage
# Subdirs for the boot loader(s)
@@ -35,19 +37,19 @@
OBJCOPYFLAGS = --strip-all -R .comment -R .notes -O binary
-vmlinux.bin: vmlinux FORCE
+$(obj)/vmlinux.bin: vmlinux FORCE
$(call if_changed,objcopy)
-vmlinux.bin.gz: vmlinux.bin FORCE
+$(obj)/vmlinux.bin.gz: $(obj)/vmlinux.bin FORCE
$(call if_changed,gzip)
-boot-elf: vmlinux.bin
-boot-redboot: vmlinux.bin.gz
+boot-elf: $(obj)/vmlinux.bin
+boot-redboot: $(obj)/vmlinux.bin.gz
UIMAGE_LOADADDR = $(CONFIG_KERNEL_LOAD_ADDRESS)
UIMAGE_COMPRESSION = gzip
-$(obj)/uImage: vmlinux.bin.gz FORCE
+$(obj)/uImage: $(obj)/vmlinux.bin.gz FORCE
$(call if_changed,uimage)
$(Q)$(kecho) ' Kernel: $@ is ready'
diff --git a/arch/xtensa/boot/boot-elf/Makefile b/arch/xtensa/boot/boot-elf/Makefile
index 12ae1e9..0ebc982 100644
--- a/arch/xtensa/boot/boot-elf/Makefile
+++ b/arch/xtensa/boot/boot-elf/Makefile
@@ -15,12 +15,13 @@
export KBUILD_AFLAGS += -mtext-section-literals
boot-y := bootstrap.o
+targets += $(boot-y) boot.lds
OBJS := $(addprefix $(obj)/,$(boot-y))
-$(obj)/Image.o: vmlinux.bin $(OBJS)
+$(obj)/Image.o: $(obj)/../vmlinux.bin $(OBJS)
$(Q)$(OBJCOPY) $(OBJCOPY_ARGS) -R .comment \
- --add-section image=vmlinux.bin \
+ --add-section image=$< \
--set-section-flags image=contents,alloc,load,load,data \
$(OBJS) $@
diff --git a/arch/xtensa/boot/boot-redboot/Makefile b/arch/xtensa/boot/boot-redboot/Makefile
index 8632473..07cb24a 100644
--- a/arch/xtensa/boot/boot-redboot/Makefile
+++ b/arch/xtensa/boot/boot-redboot/Makefile
@@ -13,15 +13,16 @@
LD_ARGS = -T $(srctree)/$(obj)/boot.ld
boot-y := bootstrap.o
+targets += $(boot-y)
OBJS := $(addprefix $(obj)/,$(boot-y))
LIBS := arch/xtensa/boot/lib/lib.a arch/xtensa/lib/lib.a
LIBGCC := $(shell $(CC) $(KBUILD_CFLAGS) -print-libgcc-file-name)
-$(obj)/zImage.o: vmlinux.bin.gz $(OBJS)
+$(obj)/zImage.o: $(obj)/../vmlinux.bin.gz $(OBJS)
$(Q)$(OBJCOPY) $(OBJCOPY_ARGS) -R .comment \
- --add-section image=vmlinux.bin.gz \
+ --add-section image=$< \
--set-section-flags image=contents,alloc,load,load,data \
$(OBJS) $@
diff --git a/arch/xtensa/include/asm/Kbuild b/arch/xtensa/include/asm/Kbuild
index 9718e95..c59c42a 100644
--- a/arch/xtensa/include/asm/Kbuild
+++ b/arch/xtensa/include/asm/Kbuild
@@ -7,4 +7,5 @@
generic-y += param.h
generic-y += qrwlock.h
generic-y += qspinlock.h
+generic-y += seccomp.h
generic-y += user.h
diff --git a/arch/xtensa/include/asm/initialize_mmu.h b/arch/xtensa/include/asm/initialize_mmu.h
index 9ee0c1d..05cb13d 100644
--- a/arch/xtensa/include/asm/initialize_mmu.h
+++ b/arch/xtensa/include/asm/initialize_mmu.h
@@ -6,7 +6,7 @@
* For the new V3 MMU we remap the TLB from virtual == physical
* to the standard Linux mapping used in earlier MMU's.
*
- * The the MMU we also support a new configuration register that
+ * For the MMU we also support a new configuration register that
* specifies how the S32C1I instruction operates with the cache
* controller.
*
diff --git a/arch/xtensa/include/asm/thread_info.h b/arch/xtensa/include/asm/thread_info.h
index f092cc3..6acbbe0 100644
--- a/arch/xtensa/include/asm/thread_info.h
+++ b/arch/xtensa/include/asm/thread_info.h
@@ -55,6 +55,10 @@
mm_segment_t addr_limit; /* thread address space */
unsigned long cpenable;
+#if XCHAL_HAVE_EXCLUSIVE
+ /* result of the most recent exclusive store */
+ unsigned long atomctl8;
+#endif
/* Allocate storage for extra user states and coprocessor states. */
#if XTENSA_HAVE_COPROCESSORS
@@ -111,15 +115,20 @@
#define TIF_RESTORE_SIGMASK 6 /* restore signal mask in do_signal() */
#define TIF_NOTIFY_RESUME 7 /* callback before returning to user */
#define TIF_DB_DISABLED 8 /* debug trap disabled for syscall */
+#define TIF_SYSCALL_AUDIT 9 /* syscall auditing active */
+#define TIF_SECCOMP 10 /* secure computing */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
#define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)
#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
+#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
+#define _TIF_SECCOMP (1<<TIF_SECCOMP)
#define _TIF_WORK_MASK (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP | \
- _TIF_SYSCALL_TRACEPOINT)
+ _TIF_SYSCALL_TRACEPOINT | \
+ _TIF_SYSCALL_AUDIT | _TIF_SECCOMP)
#define THREAD_SIZE KERNEL_STACK_SIZE
#define THREAD_SIZE_ORDER (KERNEL_STACK_SHIFT - PAGE_SHIFT)
diff --git a/arch/xtensa/include/uapi/asm/ptrace.h b/arch/xtensa/include/uapi/asm/ptrace.h
index 2ec0f91..50db3e0 100644
--- a/arch/xtensa/include/uapi/asm/ptrace.h
+++ b/arch/xtensa/include/uapi/asm/ptrace.h
@@ -50,7 +50,8 @@
__u32 windowstart;
__u32 windowbase;
__u32 threadptr;
- __u32 reserved[7 + 48];
+ __u32 syscall;
+ __u32 reserved[6 + 48];
__u32 a[64];
};
diff --git a/arch/xtensa/kernel/asm-offsets.c b/arch/xtensa/kernel/asm-offsets.c
index 33a257b..dc5c83c 100644
--- a/arch/xtensa/kernel/asm-offsets.c
+++ b/arch/xtensa/kernel/asm-offsets.c
@@ -93,6 +93,9 @@
DEFINE(THREAD_RA, offsetof (struct task_struct, thread.ra));
DEFINE(THREAD_SP, offsetof (struct task_struct, thread.sp));
DEFINE(THREAD_CPENABLE, offsetof (struct thread_info, cpenable));
+#if XCHAL_HAVE_EXCLUSIVE
+ DEFINE(THREAD_ATOMCTL8, offsetof (struct thread_info, atomctl8));
+#endif
#if XTENSA_HAVE_COPROCESSORS
DEFINE(THREAD_XTREGS_CP0, offsetof(struct thread_info, xtregs_cp.cp0));
DEFINE(THREAD_XTREGS_CP1, offsetof(struct thread_info, xtregs_cp.cp1));
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 98515c2..703cf62 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -374,6 +374,11 @@
s32i a2, a1, PT_LCOUNT
#endif
+#if XCHAL_HAVE_EXCLUSIVE
+ /* Clear exclusive access monitor set by interrupted code */
+ clrex
+#endif
+
/* It is now save to restore the EXC_TABLE_FIXUP variable. */
rsr a2, exccause
@@ -2020,6 +2025,12 @@
s32i a3, a4, THREAD_CPENABLE
#endif
+#if XCHAL_HAVE_EXCLUSIVE
+ l32i a3, a5, THREAD_ATOMCTL8
+ getex a3
+ s32i a3, a4, THREAD_ATOMCTL8
+#endif
+
/* Flush register file. */
spill_registers_kernel
diff --git a/arch/xtensa/kernel/perf_event.c b/arch/xtensa/kernel/perf_event.c
index 99fcd63..a0d05c8 100644
--- a/arch/xtensa/kernel/perf_event.c
+++ b/arch/xtensa/kernel/perf_event.c
@@ -399,7 +399,7 @@
.read = xtensa_pmu_read,
};
-static int xtensa_pmu_setup(int cpu)
+static int xtensa_pmu_setup(unsigned int cpu)
{
unsigned i;
diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c
index b4c07bd..ce4a32b 100644
--- a/arch/xtensa/kernel/ptrace.c
+++ b/arch/xtensa/kernel/ptrace.c
@@ -12,6 +12,7 @@
* Marc Gauthier<marc@tensilica.com> <marc@alumni.uwaterloo.ca>
*/
+#include <linux/audit.h>
#include <linux/errno.h>
#include <linux/hw_breakpoint.h>
#include <linux/kernel.h>
@@ -21,6 +22,7 @@
#include <linux/regset.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
+#include <linux/seccomp.h>
#include <linux/security.h>
#include <linux/signal.h>
#include <linux/smp.h>
@@ -51,6 +53,7 @@
.threadptr = regs->threadptr,
.windowbase = regs->windowbase,
.windowstart = regs->windowstart,
+ .syscall = regs->syscall,
};
memcpy(newregs.a,
@@ -90,6 +93,9 @@
regs->sar = newregs.sar;
regs->threadptr = newregs.threadptr;
+ if (newregs.syscall)
+ regs->syscall = newregs.syscall;
+
if (newregs.windowbase != regs->windowbase ||
newregs.windowstart != regs->windowstart) {
u32 rotws, wmask;
@@ -554,7 +560,8 @@
return 0;
}
- if (regs->syscall == NO_SYSCALL) {
+ if (regs->syscall == NO_SYSCALL ||
+ secure_computing() == -1) {
do_syscall_trace_leave(regs);
return 0;
}
@@ -562,6 +569,9 @@
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
trace_sys_enter(regs, syscall_get_nr(current, regs));
+ audit_syscall_entry(regs->syscall, regs->areg[6],
+ regs->areg[3], regs->areg[4],
+ regs->areg[5]);
return 1;
}
@@ -569,6 +579,8 @@
{
int step;
+ audit_syscall_exit(regs);
+
if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
trace_sys_exit(regs, regs_return_value(regs));
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index 5267b9f..06bd590 100644
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -129,6 +129,8 @@
# define __NR_seccomp 358
# elif defined(__s390__)
# define __NR_seccomp 348
+# elif defined(__xtensa__)
+# define __NR_seccomp 337
# else
# warning "seccomp syscall number unknown for this architecture"
# define __NR_seccomp 0xffff
@@ -1699,6 +1701,14 @@
# define SYSCALL_SYSCALL_NUM regs[4]
# define SYSCALL_RET regs[2]
# define SYSCALL_NUM_RET_SHARE_REG
+#elif defined(__xtensa__)
+# define ARCH_REGS struct user_pt_regs
+# define SYSCALL_NUM syscall
+/*
+ * On xtensa syscall return value is in the register
+ * a2 of the current window which is not fixed.
+ */
+#define SYSCALL_RET(reg) a[(reg).windowbase * 4 + 2]
#else
# error "Do not know how to find your architecture's registers and syscalls"
#endif
@@ -1770,7 +1780,8 @@
EXPECT_EQ(0, ret) {}
#if defined(__x86_64__) || defined(__i386__) || defined(__powerpc__) || \
- defined(__s390__) || defined(__hppa__) || defined(__riscv)
+ defined(__s390__) || defined(__hppa__) || defined(__riscv) || \
+ defined(__xtensa__)
{
regs.SYSCALL_NUM = syscall;
}
@@ -1813,6 +1824,9 @@
if (syscall == -1)
#ifdef SYSCALL_NUM_RET_SHARE_REG
TH_LOG("Can't modify syscall return on this architecture");
+
+#elif defined(__xtensa__)
+ regs.SYSCALL_RET(regs) = result;
#else
regs.SYSCALL_RET = result;
#endif
