linux-user: Add strace support for printing arguments of syscalls use…

…d to lock and unlock memory

This patch implements strace argument printing functionality for following syscalls:

    * mlock, munlock, mlockall, munlockall - lock and unlock memory

       int mlock(const void *addr, size_t len)
       int munlock(const void *addr, size_t len)
       int mlockall(int flags)
       int munlockall(void)
       man page: https://man7.org/linux/man-pages/man2/mlock.2.html

Implementation notes:

    Syscall mlockall() takes an argument that is composed of predefined values
    which represent flags that determine the type of locking operation that is
    to be performed. For that reason, a printing function "print_mlockall" was
    stated in file "strace.list". This printing function uses an already existing
    function "print_flags()" to print the "flags" argument.  These flags are stated
    inside an array "mlockall_flags" that contains values of type "struct flags".
    These values are instantiated using an existing macro "FLAG_TARGET()" that
    crates aproppriate target flag values based on those defined in files
    '/target_syscall.h'. These target flag values were changed from
    "TARGET_MLOCKALL_MCL*" to "TARGET_MCL_*" so that they can be aproppriately set
    and recognised in "strace.c" with "FLAG_TARGET()". Value for "MCL_ONFAULT"
    was added in this patch. This value was also added in "syscall.c" in function
    "target_to_host_mlockall_arg()". Because this flag value was added in kernel
    version 4.4, it is enwrapped in an #ifdef directive (both in "syscall.c" and
    in "strace.c") as to support older kernel versions.
    The other syscalls have only primitive argument types, so the
    rest of the implementation was handled by stating an appropriate
    printing format in file "strace.list". Syscall mlock2() is not implemented in
    "syscall.c" and thus it's argument printing is not implemented in this patch.

Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200811164553.27713-4-Filip.Bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

linux-user/aarch64/target_syscall.h

@@ -16,8 +16,9 @@ struct target_pt_regs {
 #define UNAME_MINIMUM_RELEASE "3.8.0"
 #define TARGET_CLONE_BACKWARDS
 #define TARGET_MINSIGSTKSZ       2048
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
 
 #define TARGET_PR_SVE_SET_VL  50
 #define TARGET_PR_SVE_GET_VL  51

linux-user/alpha/target_syscall.h

@@ -258,7 +258,8 @@ struct target_pt_regs {
 #define TARGET_UAC_NOFIX		2
 #define TARGET_UAC_SIGBUS		4
 #define TARGET_MINSIGSTKSZ              4096
-#define TARGET_MLOCKALL_MCL_CURRENT     0x2000
-#define TARGET_MLOCKALL_MCL_FUTURE      0x4000
+#define TARGET_MCL_CURRENT     0x2000
+#define TARGET_MCL_FUTURE      0x4000
+#define TARGET_MCL_ONFAULT     0x8000
 
 #endif /* ALPHA_TARGET_SYSCALL_H */

linux-user/arm/target_syscall.h

@@ -28,8 +28,10 @@ struct target_pt_regs {
 #define TARGET_CLONE_BACKWARDS
 
 #define TARGET_MINSIGSTKSZ 2048
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
+
 #define TARGET_WANT_OLD_SYS_SELECT
 
 #define TARGET_FORCE_SHMLBA

linux-user/cris/target_syscall.h

@@ -40,7 +40,8 @@ struct target_pt_regs {
 
 #define TARGET_CLONE_BACKWARDS2
 #define TARGET_MINSIGSTKSZ 2048
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
 
 #endif

linux-user/hppa/target_syscall.h

@@ -23,8 +23,9 @@ struct target_pt_regs {
 #define UNAME_MINIMUM_RELEASE "2.6.32"
 #define TARGET_CLONE_BACKWARDS
 #define TARGET_MINSIGSTKSZ       2048
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
 
 #undef  TARGET_ENOMSG
 #define TARGET_ENOMSG          35

linux-user/i386/target_syscall.h

@@ -151,8 +151,9 @@ struct target_vm86plus_struct {
 
 #define TARGET_CLONE_BACKWARDS
 #define TARGET_MINSIGSTKSZ 2048
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
 #define TARGET_WANT_OLD_SYS_SELECT
 
 #endif /* I386_TARGET_SYSCALL_H */

linux-user/m68k/target_syscall.h

@@ -21,9 +21,9 @@ struct target_pt_regs {
 #define UNAME_MINIMUM_RELEASE "2.6.32"
 
 #define TARGET_MINSIGSTKSZ 2048
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
-
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
 #define TARGET_WANT_OLD_SYS_SELECT
 
 #endif /* M68K_TARGET_SYSCALL_H */

linux-user/microblaze/target_syscall.h

@@ -50,8 +50,9 @@ struct target_pt_regs {
 
 #define TARGET_CLONE_BACKWARDS
 #define TARGET_MINSIGSTKSZ      2048
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
 
 #define TARGET_WANT_NI_OLD_SELECT
 

linux-user/mips/target_syscall.h

@@ -234,8 +234,9 @@ struct target_pt_regs {
 
 #define TARGET_CLONE_BACKWARDS
 #define TARGET_MINSIGSTKSZ 2048
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
 
 #define TARGET_FORCE_SHMLBA
 

linux-user/mips64/target_syscall.h

@@ -231,8 +231,9 @@ struct target_pt_regs {
 
 #define TARGET_CLONE_BACKWARDS
 #define TARGET_MINSIGSTKSZ      2048
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
 
 #define TARGET_FORCE_SHMLBA
 

linux-user/nios2/target_syscall.h

@@ -31,7 +31,8 @@ struct target_pt_regs {
 };
 
 #define TARGET_MINSIGSTKSZ 2048
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
 
 #endif /* NIOS2_TARGET_SYSCALL_H */

linux-user/openrisc/target_syscall.h

@@ -16,8 +16,9 @@ struct target_pt_regs {
 #define UNAME_MINIMUM_RELEASE "2.6.32"
 
 #define TARGET_MINSIGSTKSZ 2048
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
 
 #define MMAP_SHIFT TARGET_PAGE_BITS
 

linux-user/ppc/target_syscall.h

@@ -72,8 +72,9 @@ struct target_revectored_struct {
 #define TARGET_CLONE_BACKWARDS
 
 #define TARGET_MINSIGSTKSZ 2048
-#define TARGET_MLOCKALL_MCL_CURRENT 0x2000
-#define TARGET_MLOCKALL_MCL_FUTURE  0x4000
+#define TARGET_MCL_CURRENT 0x2000
+#define TARGET_MCL_FUTURE  0x4000
+#define TARGET_MCL_ONFAULT 0x8000
 #define TARGET_WANT_NI_OLD_SELECT
 
 #endif /* PPC_TARGET_SYSCALL_H */

linux-user/riscv/target_syscall.h

@@ -51,8 +51,9 @@ struct target_pt_regs {
 #define UNAME_MINIMUM_RELEASE "4.15.0"
 
 #define TARGET_MINSIGSTKSZ 2048
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
 
 /* clone(flags, newsp, ptidptr, tls, ctidptr) for RISC-V */
 /* This comes from linux/kernel/fork.c, CONFIG_CLONE_BACKWARDS */

linux-user/s390x/target_syscall.h

@@ -28,7 +28,8 @@ struct target_pt_regs {
 
 #define TARGET_CLONE_BACKWARDS2
 #define TARGET_MINSIGSTKSZ        2048
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
 
 #endif /* S390X_TARGET_SYSCALL_H */

linux-user/sh4/target_syscall.h

@@ -16,8 +16,9 @@ struct target_pt_regs {
 #define UNAME_MINIMUM_RELEASE "2.6.32"
 
 #define TARGET_MINSIGSTKSZ 2048
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
 
 #define TARGET_FORCE_SHMLBA
 

linux-user/sparc/target_syscall.h

@@ -21,8 +21,9 @@ struct target_pt_regs {
  */
 #define TARGET_CLONE_BACKWARDS
 #define TARGET_MINSIGSTKSZ      4096
-#define TARGET_MLOCKALL_MCL_CURRENT 0x2000
-#define TARGET_MLOCKALL_MCL_FUTURE  0x4000
+#define TARGET_MCL_CURRENT 0x2000
+#define TARGET_MCL_FUTURE  0x4000
+#define TARGET_MCL_ONFAULT 0x8000
 
 /* For SPARC SHMLBA is determined at runtime in the kernel, and
  * libc has to runtime-detect it using the hwcaps (see glibc

linux-user/sparc64/target_syscall.h

@@ -22,8 +22,9 @@ struct target_pt_regs {
  */
 #define TARGET_CLONE_BACKWARDS
 #define TARGET_MINSIGSTKSZ      4096
-#define TARGET_MLOCKALL_MCL_CURRENT 0x2000
-#define TARGET_MLOCKALL_MCL_FUTURE  0x4000
+#define TARGET_MCL_CURRENT 0x2000
+#define TARGET_MCL_FUTURE  0x4000
+#define TARGET_MCL_ONFAULT 0x8000
 
 #define TARGET_FORCE_SHMLBA
 

linux-user/strace.c

@@ -1198,6 +1198,15 @@ UNUSED static struct flags falloc_flags[] = {
 #endif
 };
 
+UNUSED static struct flags mlockall_flags[] = {
+    FLAG_TARGET(MCL_CURRENT),
+    FLAG_TARGET(MCL_FUTURE),
+#ifdef MCL_ONFAULT
+    FLAG_TARGET(MCL_ONFAULT),
+#endif
+    FLAG_END,
+};
+
 /*
  * print_xxx utility functions.  These are used to print syscall
  * parameters in certain format.  All of these have parameter
@@ -2009,6 +2018,18 @@ print_ftruncate64(void *cpu_env, const struct syscallname *name,
 }
 #endif
 
+#ifdef TARGET_NR_mlockall
+static void
+print_mlockall(void *cpu_env, const struct syscallname *name,
+               abi_long arg0, abi_long arg1, abi_long arg2,
+               abi_long arg3, abi_long arg4, abi_long arg5)
+{
+    print_syscall_prologue(name);
+    print_flags(mlockall_flags, arg0, 1);
+    print_syscall_epilogue(name);
+}
+#endif
+
 #if defined(TARGET_NR_socket)
 static void
 print_socket(void *cpu_env, const struct syscallname *name,

linux-user/strace.list

@@ -568,13 +568,13 @@
 { TARGET_NR_mknodat, "mknodat" , NULL, print_mknodat, NULL },
 #endif
 #ifdef TARGET_NR_mlock
-{ TARGET_NR_mlock, "mlock" , NULL, NULL, NULL },
+{ TARGET_NR_mlock, "mlock" , "%s(%p," TARGET_FMT_lu ")", NULL, NULL },
 #endif
 #ifdef TARGET_NR_mlock2
 { TARGET_NR_mlock2, "mlock2" , NULL, NULL, NULL },
 #endif
 #ifdef TARGET_NR_mlockall
-{ TARGET_NR_mlockall, "mlockall" , NULL, NULL, NULL },
+{ TARGET_NR_mlockall, "mlockall" , NULL, print_mlockall, NULL },
 #endif
 #ifdef TARGET_NR_mmap
 { TARGET_NR_mmap, "mmap" , NULL, print_mmap, print_syscall_ret_addr },
@@ -637,10 +637,10 @@
 { TARGET_NR_multiplexer, "multiplexer" , NULL, NULL, NULL },
 #endif
 #ifdef TARGET_NR_munlock
-{ TARGET_NR_munlock, "munlock" , NULL, NULL, NULL },
+{ TARGET_NR_munlock, "munlock" , "%s(%p," TARGET_FMT_lu ")", NULL, NULL },
 #endif
 #ifdef TARGET_NR_munlockall
-{ TARGET_NR_munlockall, "munlockall" , NULL, NULL, NULL },
+{ TARGET_NR_munlockall, "munlockall" , "%s()", NULL, NULL },
 #endif
 #ifdef TARGET_NR_munmap
 { TARGET_NR_munmap, "munmap" , NULL, print_munmap, NULL },

linux-user/syscall.c

@@ -6975,12 +6975,18 @@ static inline int target_to_host_mlockall_arg(int arg)
 {
     int result = 0;
 
-    if (arg & TARGET_MLOCKALL_MCL_CURRENT) {
+    if (arg & TARGET_MCL_CURRENT) {
         result |= MCL_CURRENT;
     }
-    if (arg & TARGET_MLOCKALL_MCL_FUTURE) {
+    if (arg & TARGET_MCL_FUTURE) {
         result |= MCL_FUTURE;
     }
+#ifdef MCL_ONFAULT
+    if (arg & TARGET_MCL_ONFAULT) {
+        result |= MCL_ONFAULT;
+    }
+#endif
+
     return result;
 }
 #endif

linux-user/tilegx/target_syscall.h

@@ -34,8 +34,9 @@ struct target_pt_regs {
     tilegx_reg_t pad[2];
 };
 
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
 
 /* For faultnum */
 #define TARGET_INT_SWINT_1            14

linux-user/x86_64/target_syscall.h

@@ -101,7 +101,8 @@ struct target_msqid64_ds {
 #define TARGET_ARCH_GET_FS 0x1003
 #define TARGET_ARCH_GET_GS 0x1004
 #define TARGET_MINSIGSTKSZ 2048
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
 
 #endif /* X86_64_TARGET_SYSCALL_H */

linux-user/xtensa/target_syscall.h

@@ -43,7 +43,8 @@ struct target_pt_regs {
     xtensa_reg_t areg[16];
 };
 
-#define TARGET_MLOCKALL_MCL_CURRENT 1
-#define TARGET_MLOCKALL_MCL_FUTURE  2
+#define TARGET_MCL_CURRENT 1
+#define TARGET_MCL_FUTURE  2
+#define TARGET_MCL_ONFAULT 4
 
 #endif