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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Minios-devel] [UNIKRAFT PATCH 3/4] plat: switch thread-local storage area on context switch
On x86, the standard way is writing to an MSR to switch the fs register,
which is used as the pointer to the TLS area. However, this is a
privileged instruction, so for the linuxu platform, use a system call
provided by Linux that does exactly that instead.
Signed-off-by: Florian Schmidt <florian.schmidt@xxxxxxxxx>
---
arch/x86/x86_64/include/uk/asm/thread.h | 5 +++
include/uk/plat/thread.h | 8 ++--
lib/uksched/thread.c | 5 ++-
plat/common/include/sw_ctx.h | 1 +
plat/common/include/thread_switch.h | 43 +++++++++++++++++++
plat/common/include/x86/thread_switch.h | 41 ++++++++++++++++++
plat/common/sw_ctx.c | 10 ++++-
plat/linuxu/include/linuxu/syscall-x86_64.h | 1 +
plat/linuxu/include/linuxu/syscall.h | 7 ++++
plat/linuxu/include/thread_switch.h | 46 +++++++++++++++++++++
10 files changed, 160 insertions(+), 7 deletions(-)
create mode 100644 plat/common/include/thread_switch.h
create mode 100644 plat/common/include/x86/thread_switch.h
create mode 100644 plat/linuxu/include/thread_switch.h
diff --git a/arch/x86/x86_64/include/uk/asm/thread.h
b/arch/x86/x86_64/include/uk/asm/thread.h
index 6e95848d..f07eb521 100644
--- a/arch/x86/x86_64/include/uk/asm/thread.h
+++ b/arch/x86/x86_64/include/uk/asm/thread.h
@@ -62,3 +62,8 @@ static inline void tls_copy(void *tls_area)
memset(tls_area+tls_data_len, 0, tls_bss_len);
*((uintptr_t *)(tls_area+tls_len)) = (uintptr_t)(tls_area+tls_len);
}
+
+static inline void *tls_pointer(void *tls_area)
+{
+ return tls_area + (_tls_end - _tls_start);
+}
diff --git a/include/uk/plat/thread.h b/include/uk/plat/thread.h
index 69fc5e28..4b349ea7 100644
--- a/include/uk/plat/thread.h
+++ b/include/uk/plat/thread.h
@@ -51,7 +51,8 @@ enum ukplat_ctx_type {
struct uk_alloc;
typedef void *(*ukplat_ctx_create_func_t)
- (struct uk_alloc *allocator, unsigned long sp);
+ (struct uk_alloc *allocator, unsigned long sp,
+ unsigned long tlsp);
typedef void (*ukplat_ctx_start_func_t)
(void *ctx);
typedef void (*ukplat_ctx_switch_func_t)
@@ -72,12 +73,13 @@ int ukplat_ctx_callbacks_init(struct ukplat_ctx_callbacks
*ctx_cbs,
static inline
void *ukplat_thread_ctx_create(struct ukplat_ctx_callbacks *cbs,
- struct uk_alloc *allocator, unsigned long sp)
+ struct uk_alloc *allocator, unsigned long sp,
+ unsigned long tlsp)
{
UK_ASSERT(cbs != NULL);
UK_ASSERT(allocator != NULL);
- return cbs->create_cb(allocator, sp);
+ return cbs->create_cb(allocator, sp, tlsp);
}
void ukplat_thread_ctx_destroy(struct uk_alloc *allocator, void *ctx);
diff --git a/lib/uksched/thread.c b/lib/uksched/thread.c
index a97fad9e..45f79206 100644
--- a/lib/uksched/thread.c
+++ b/lib/uksched/thread.c
@@ -39,7 +39,7 @@
#include <uk/wait.h>
#include <uk/print.h>
#include <uk/assert.h>
-
+#include <uk/arch/thread.h>
/* Pushes the specified value onto the stack of the specified thread */
static void stack_push(unsigned long *sp, unsigned long value)
@@ -103,7 +103,8 @@ int uk_thread_init(struct uk_thread *thread,
init_sp(&sp, stack, function, arg);
/* Call platform specific setup. */
- thread->ctx = ukplat_thread_ctx_create(cbs, allocator, sp);
+ thread->ctx = ukplat_thread_ctx_create(cbs, allocator, sp,
+ (uintptr_t)tls_pointer(tls));
if (thread->ctx == NULL)
return -1;
diff --git a/plat/common/include/sw_ctx.h b/plat/common/include/sw_ctx.h
index d52fe65b..366c6a8f 100644
--- a/plat/common/include/sw_ctx.h
+++ b/plat/common/include/sw_ctx.h
@@ -41,6 +41,7 @@
struct sw_ctx {
unsigned long sp; /* Stack pointer */
unsigned long ip; /* Instruction pointer */
+ unsigned long tlsp; /* thread-local storage pointer */
uintptr_t extregs; /* Pointer to an area to which extended
* registers are saved on context switch.
*/
diff --git a/plat/common/include/thread_switch.h
b/plat/common/include/thread_switch.h
new file mode 100644
index 00000000..b04c38c5
--- /dev/null
+++ b/plat/common/include/thread_switch.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Authors: Florian Schmidt <florian.schmidt@xxxxxxxxx>
+ *
+ * Copyright (c) 2019, NEC Europe Ltd., NEC Corporation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
+ */
+#ifndef __PLAT_CMN_THREAD_SWITCH_H__
+#define __PLAT_CMN_THREAD_SWITCH_H__
+
+#if defined(__X86_64__)
+#include <x86/thread_switch.h>
+#else
+#error "Add thread_switch.h for current architecture."
+#endif
+
+#endif /* __PLAT_CMN_THREAD_SWITCH_H__ */
diff --git a/plat/common/include/x86/thread_switch.h
b/plat/common/include/x86/thread_switch.h
new file mode 100644
index 00000000..f8252916
--- /dev/null
+++ b/plat/common/include/x86/thread_switch.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Authors: Florian Schmidt <florian.schmidt@xxxxxxxxx>
+ *
+ * Copyright (c) 2019, NEC Europe Ltd., NEC Corporation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
+ */
+#ifndef __PLAT_CMN_X86_THREAD_SWITCH_H__
+#define __PLAT_CMN_X86_THREAD_SWITCH_H__
+
+#define MSR_FS_BASE 0xc0000100
+
+#define set_tls_pointer(ptr) wrmsrl(MSR_FS_BASE, ptr)
+
+#endif /* __PLAT_CMN_X86_THREAD_SWITCH_H__ */
diff --git a/plat/common/sw_ctx.c b/plat/common/sw_ctx.c
index 06795244..088d1233 100644
--- a/plat/common/sw_ctx.c
+++ b/plat/common/sw_ctx.c
@@ -39,9 +39,11 @@
#include <uk/alloc.h>
#include <sw_ctx.h>
#include <uk/assert.h>
+#include <thread_switch.h>
#include <x86/cpu.h>
-static void *sw_ctx_create(struct uk_alloc *allocator, unsigned long sp);
+static void *sw_ctx_create(struct uk_alloc *allocator, unsigned long sp,
+ unsigned long tlsp);
static void sw_ctx_start(void *ctx) __noreturn;
static void sw_ctx_switch(void *prevctx, void *nextctx);
@@ -51,7 +53,8 @@ static void sw_ctx_switch(void *prevctx, void *nextctx);
*/
extern void asm_thread_starter(void);
-static void *sw_ctx_create(struct uk_alloc *allocator, unsigned long sp)
+static void *sw_ctx_create(struct uk_alloc *allocator, unsigned long sp,
+ unsigned long tlsp)
{
struct sw_ctx *ctx;
size_t sz;
@@ -68,6 +71,7 @@ static void *sw_ctx_create(struct uk_alloc *allocator,
unsigned long sp)
}
ctx->sp = sp;
+ ctx->tlsp = tlsp;
ctx->ip = (unsigned long) asm_thread_starter;
ctx->extregs = ALIGN_UP(((uintptr_t)ctx + sizeof(struct sw_ctx)),
x86_cpu_features.extregs_align);
@@ -86,6 +90,7 @@ static void sw_ctx_start(void *ctx)
UK_ASSERT(sw_ctx != NULL);
+ set_tls_pointer(sw_ctx->tlsp);
/* Switch stacks and run the thread */
asm_ctx_start(sw_ctx->sp, sw_ctx->ip);
@@ -101,6 +106,7 @@ static void sw_ctx_switch(void *prevctx, void *nextctx)
save_extregs(p);
restore_extregs(n);
+ set_tls_pointer(n->tlsp);
asm_sw_ctx_switch(prevctx, nextctx);
}
diff --git a/plat/linuxu/include/linuxu/syscall-x86_64.h
b/plat/linuxu/include/linuxu/syscall-x86_64.h
index 26820dcd..553f0ba4 100644
--- a/plat/linuxu/include/linuxu/syscall-x86_64.h
+++ b/plat/linuxu/include/linuxu/syscall-x86_64.h
@@ -48,6 +48,7 @@
#define __SC_RT_SIGPROCMASK 14
#define __SC_IOCTL 16
#define __SC_EXIT 60
+#define __SC_ARCH_PRCTL 158
#define __SC_TIMER_CREATE 222
#define __SC_TIMER_SETTIME 223
#define __SC_TIMER_GETTIME 224
diff --git a/plat/linuxu/include/linuxu/syscall.h
b/plat/linuxu/include/linuxu/syscall.h
index d378d265..d5b66698 100644
--- a/plat/linuxu/include/linuxu/syscall.h
+++ b/plat/linuxu/include/linuxu/syscall.h
@@ -123,6 +123,13 @@ static inline int sys_sigprocmask(int how,
sizeof(k_sigset_t));
}
+static inline int sys_arch_prctl(int code, unsigned long addr)
+{
+ return (int) syscall2(__SC_ARCH_PRCTL,
+ (long) code,
+ (long) addr);
+}
+
static inline int sys_pselect6(int nfds,
k_fd_set *readfds, k_fd_set *writefds, k_fd_set *exceptfds,
const struct k_timespec *timeout, const void *sigmask)
diff --git a/plat/linuxu/include/thread_switch.h
b/plat/linuxu/include/thread_switch.h
new file mode 100644
index 00000000..3a0f962f
--- /dev/null
+++ b/plat/linuxu/include/thread_switch.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Authors: Florian Schmidt <florian.schmidt@xxxxxxxxx>
+ *
+ * Copyright (c) 2019, NEC Europe Ltd., NEC Corporation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
+ */
+#ifndef __PLAT_THREAD_SWITCH_H__
+#define __PLAT_THREAD_SWITCH_H__
+
+#include <linuxu/syscall.h>
+
+#define ARCH_SET_FS 0x1002
+
+static inline void set_tls_pointer(unsigned long arg)
+{
+ sys_arch_prctl(ARCH_SET_FS, arg);
+}
+
+#endif /* __PLAT_THREAD_SWITCH_H__ */
--
2.21.0
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