[CRIU] [PATCHv2 21/22] x86/parasite: call get_thread_area on 32-bit addr
Dmitry Safonov
dsafonov at virtuozzo.com
Wed Dec 7 09:56:36 PST 2016
It's 32-bit syscall and the high-part of address is dropped,
so call it only on 32-bit addr.
Signed-off-by: Dmitry Safonov <dsafonov at virtuozzo.com>
---
criu/arch/x86/include/asm/compat.h | 44 ++++++++++++++++++++++++++++++++++++
criu/arch/x86/include/asm/parasite.h | 23 +++++++++++++++++--
criu/arch/x86/include/asm/restorer.h | 13 +++--------
criu/arch/x86/sigaction_compat.c | 20 +---------------
4 files changed, 69 insertions(+), 31 deletions(-)
create mode 100644 criu/arch/x86/include/asm/compat.h
diff --git a/criu/arch/x86/include/asm/compat.h b/criu/arch/x86/include/asm/compat.h
new file mode 100644
index 000000000000..cc1718775633
--- /dev/null
+++ b/criu/arch/x86/include/asm/compat.h
@@ -0,0 +1,44 @@
+#ifndef __CR_ASM_COMPAT_H__
+#define __CR_ASM_COMPAT_H__
+
+#ifdef CR_NOGLIBC
+# include <compel/plugins/std/syscall.h>
+# include <compel/plugins/std/syscall-codes.h>
+#else
+# define sys_mmap mmap
+# define sys_munmap munmap
+#endif
+
+#include <sys/mman.h>
+
+#ifdef CONFIG_COMPAT
+static inline void *alloc_compat_syscall_stack(void)
+{
+ void *mem = (void*)sys_mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE,
+ MAP_32BIT | MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+
+ if (mem == MAP_FAILED)
+ return 0;
+ return mem;
+}
+
+static inline void free_compat_syscall_stack(void *mem)
+{
+ long int ret = sys_munmap(mem, PAGE_SIZE);
+
+ if (ret)
+ pr_err("munmap of compat addr %p failed with %ld", mem, ret);
+}
+
+extern unsigned long call32_from_64(void *stack, void *func);
+#else /* CONFIG_COMPAT */
+static inline void *alloc_compat_syscall_stack(void) { return NULL; }
+static inline void free_compat_syscall_stack(void *stack32) { }
+#endif /* !CONFIG_COMPAT */
+
+#ifndef CR_NOGLIBC
+# undef sys_mmap
+# undef sys_munmap
+#endif
+
+#endif
diff --git a/criu/arch/x86/include/asm/parasite.h b/criu/arch/x86/include/asm/parasite.h
index 6dbef294661b..8c96d04dbdd5 100644
--- a/criu/arch/x86/include/asm/parasite.h
+++ b/criu/arch/x86/include/asm/parasite.h
@@ -3,12 +3,13 @@
#include "asm-generic/string.h"
#include <compel/plugins/std/syscall-codes.h>
+#include "asm/compat.h"
#ifdef CONFIG_X86_32
# define __parasite_entry __attribute__((regparm(3)))
#endif
-static void arch_get_user_desc(user_desc_t *desc)
+static int arch_get_user_desc(user_desc_t *desc)
{
int ret;
/*
@@ -46,21 +47,39 @@ static void arch_get_user_desc(user_desc_t *desc)
if (ret && ret != -EINTR)
pr_err("Failed to dump TLS descriptor #%d: %d\n",
desc->entry_number, ret);
+ return ret;
}
static void arch_get_tls(tls_t *ptls)
{
+ void *syscall_mem;
int i;
+ syscall_mem = alloc_compat_syscall_stack();
+ if (!syscall_mem) {
+ pr_err("Failed to allocate memory <4Gb for compat syscall\n");
+
+ for (i = 0; i < GDT_ENTRY_TLS_NUM; i++) {
+ user_desc_t *d = &ptls->desc[i];
+
+ d->seg_not_present = 1;
+ d->entry_number = GDT_ENTRY_TLS_MIN + i;
+ }
+ return;
+ }
+
for (i = 0; i < GDT_ENTRY_TLS_NUM; i++)
{
- user_desc_t *d = &ptls->desc[i];
+ user_desc_t *d = syscall_mem;
builtin_memset(d, 0, sizeof(user_desc_t));
d->seg_not_present = 1;
d->entry_number = GDT_ENTRY_TLS_MIN + i;
arch_get_user_desc(d);
+ builtin_memcpy(&ptls->desc[i], d, sizeof(user_desc_t));
}
+
+ free_compat_syscall_stack(syscall_mem);
}
#endif
diff --git a/criu/arch/x86/include/asm/restorer.h b/criu/arch/x86/include/asm/restorer.h
index c552fbdc0570..4a50e2342db0 100644
--- a/criu/arch/x86/include/asm/restorer.h
+++ b/criu/arch/x86/include/asm/restorer.h
@@ -5,25 +5,18 @@
#include <compel/asm/fpu.h>
#include "images/core.pb-c.h"
#include <compel/plugins/std/syscall-codes.h>
-
#include <compel/asm/sigframe.h>
+#include "asm/compat.h"
#ifdef CONFIG_COMPAT
-extern void *alloc_compat_syscall_stack(void);
-extern void free_compat_syscall_stack(void *mem);
-extern unsigned long call32_from_64(void *stack, void *func);
extern void restore_tls(tls_t *ptls);
-
extern int arch_compat_rt_sigaction(void *stack32, int sig,
rt_sigaction_t_compat *act);
-#else
-static inline void *alloc_compat_syscall_stack(void) { return NULL; }
-static inline void free_compat_syscall_stack(void *stack32) { }
+#else /* CONFIG_COMPAT */
static inline void restore_tls(tls_t *ptls) { }
static inline int
arch_compat_rt_sigaction(void *stack, int sig, void *act) { return -1; }
-#endif
-
+#endif /* !CONFIG_COMPAT */
#ifdef CONFIG_X86_64
#define RUN_CLONE_RESTORE_FN(ret, clone_flags, new_sp, parent_tid, \
diff --git a/criu/arch/x86/sigaction_compat.c b/criu/arch/x86/sigaction_compat.c
index 076c014ef353..0e9e23bddbd3 100644
--- a/criu/arch/x86/sigaction_compat.c
+++ b/criu/arch/x86/sigaction_compat.c
@@ -1,14 +1,11 @@
#include "asm/restorer.h"
#include <compel/asm/fpu.h>
#include "asm/string.h"
-
-#include <sys/mman.h>
+#include "asm/compat.h"
#ifdef CR_NOGLIBC
# include <compel/plugins/std/syscall.h>
#else
-# define sys_mmap mmap
-# define sys_munmap munmap
# ifndef __NR32_rt_sigaction
# define __NR32_rt_sigaction 174
# endif
@@ -16,21 +13,6 @@
#include "log.h"
#include "cpu.h"
-void *alloc_compat_syscall_stack(void)
-{
- void *mem = (void*)sys_mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE,
- MAP_32BIT | MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
-
- if (mem == MAP_FAILED)
- return 0;
- return mem;
-}
-
-void free_compat_syscall_stack(void *mem)
-{
- sys_munmap(mem, PAGE_SIZE);
-}
-
asm ( " .pushsection .text \n"
" .global restore_rt_sigaction \n"
" .code32 \n"
--
2.10.2
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