[Qemu-devel] [PATCH v5 00/10] linux-user: strace improvements

[Qemu-devel] [PATCH v5 00/10] linux-user: strace improvements

[Philippe Mathieu-Daudé]

Hi Laurent,

Few patches I'v been writting while trying to figure out this issue:
http://lists.nongnu.org/archive/html/qemu-arm/2018-01/msg00514.html

As usual with linux-user files, this series will trigger some checkpatch
benign warnings.

Regards,

Phil.

Since v4:
- rebased on master (no change)

Since v3:
- addressed Laurent comments
- added print_sockfd()
- removed the print_sockaddr_ptr() patch, also the two
  getsockname()/recvfrom() patches for after 3.0.

Since v2:
- display invalid pointer in print_timeval() and print_timezone()
- do not display gettimeofday() arguments

Since v1:
- addressed Laurent comments
- added 'last' argument to print_sockaddr()
- reordered series, so patches already correct can get applied directly
- dropped "linux-user/syscall: simplify recvfrom()" for now

v1: http://lists.nongnu.org/archive/html/qemu-devel/2018-01/msg05855.html
v2: http://lists.nongnu.org/archive/html/qemu-devel/2018-06/msg08216.html
v3: http://lists.nongnu.org/archive/html/qemu-devel/2018-07/msg00411.html

$ git backport-diff
[----] : patches are identical
[####] : number of functional differences between upstream/downstream patch
[down] : patch is downstream-only
The flags [FC] indicate (F)unctional and (C)ontextual differences, respectively

001/12:[----] [--] 'linux-user/syscall: Verify recvfrom(addr) is user-writable'
002/12:[----] [--] 'linux-user/strace: Improve capget()/capset() output'
003/12:[0002] [FC] 'linux-user/strace: Display invalid pointer in print_timeval()'
004/12:[0002] [FC] 'linux-user/strace: Add print_timezone()'
005/12:[----] [--] 'linux-user/strace: Improve settimeofday()'
006/12:[down] 'linux-user/syscall: Introduce target_sockaddr_nl'
007/12:[0018] [FC] 'linux-user/strace: Dump AF_NETLINK sockaddr content'
008/12:[----] [--] 'linux-user/strace: Improve recvmsg() output'
009/12:[down] 'linux-user/strace: Add print_sockfd()'
010/12:[0004] [FC] 'linux-user/strace: Let print_sockaddr() have a 'last' argument'
011/12:[0004] [FC] 'linux-user/strace: Improve bind() output'
012/12:[0004] [FC] 'linux-user/strace: improve sendto() output'

Philippe Mathieu-Daudé (10):
  linux-user/syscall: Verify recvfrom(addr) is user-writable
  linux-user/strace: Display invalid pointer in print_timeval()
  linux-user/strace: Add print_timezone()
  linux-user/strace: Improve settimeofday()
  linux-user/syscall: Introduce target_sockaddr_nl
  linux-user/strace: Dump AF_NETLINK sockaddr content
  linux-user/strace: Add print_sockfd()
  linux-user/strace: Let print_sockaddr() have a 'last' argument
  linux-user/strace: Improve bind() output
  linux-user/strace: improve sendto() output

 linux-user/syscall_defs.h |   7 ++
 linux-user/strace.c       | 133 ++++++++++++++++++++++++++++++++++----
 linux-user/syscall.c      |  11 +++-
 linux-user/strace.list    |   6 +-
 4 files changed, 139 insertions(+), 18 deletions(-)

-- 
2.19.1

[Qemu-devel] [PATCH v5 01/10] linux-user/syscall: Verify recvfrom(addr) is user-writable

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-By: Guido Günther <agx@sigxcpu.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
---
 linux-user/syscall.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index ae3c0dfef7..ea503381aa 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -2968,6 +2968,11 @@ static abi_long do_recvfrom(int fd, abi_ulong msg, size_t len, int flags,
             ret = -TARGET_EINVAL;
             goto fail;
         }
+        if (!access_ok(VERIFY_WRITE, target_addr, addrlen)) {
+            ret = -TARGET_EFAULT;
+            goto fail;
+        }
+
         addr = alloca(addrlen);
         ret = get_errno(safe_recvfrom(fd, host_msg, len, flags,
                                       addr, &addrlen));
-- 
2.19.1

[Qemu-devel] [PATCH v5 01/10] linux-user/syscall: Verify recvfrom(addr) is user-writable

[Laurent Vivier]

On 11/10/2018 00:36, Philippe Mathieu-Daudé wrote:
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> Tested-By: Guido Günther <agx@sigxcpu.org>
> Reviewed-by: Laurent Vivier <laurent@vivier.eu>
> ---
>  linux-user/syscall.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index ae3c0dfef7..ea503381aa 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -2968,6 +2968,11 @@ static abi_long do_recvfrom(int fd, abi_ulong msg, size_t len, int flags,
>              ret = -TARGET_EINVAL;
>              goto fail;
>          }
> +        if (!access_ok(VERIFY_WRITE, target_addr, addrlen)) {
> +            ret = -TARGET_EFAULT;
> +            goto fail;
> +        }
> +
>          addr = alloca(addrlen);
>          ret = get_errno(safe_recvfrom(fd, host_msg, len, flags,
>                                        addr, &addrlen));
> 

This one breaks the test recvfrom01 from the LTP testsuite
ltp-full-20180515 archive.

recvfrom01    3  TFAIL  :  recvfrom01.c:170: invalid socket buffer ;
returned -1 (expected 0), errno 14 (expected 88)

The testcase is with an invalid socket number (-1) and an invalid
addrlen pointer.

Thanks,
Laurent

[Qemu-devel] [PATCH v5 02/10] linux-user/strace: Display invalid pointer in print_timeval()

[Philippe Mathieu-Daudé]

Suggested-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 linux-user/strace.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/linux-user/strace.c b/linux-user/strace.c
index 33f4a506a2..c95557bf83 100644
--- a/linux-user/strace.c
+++ b/linux-user/strace.c
@@ -1173,8 +1173,10 @@ print_timeval(abi_ulong tv_addr, int last)
         struct target_timeval *tv;
 
         tv = lock_user(VERIFY_READ, tv_addr, sizeof(*tv), 1);
-        if (!tv)
+        if (!tv) {
+            print_pointer(tv_addr, last);
             return;
+        }
         gemu_log("{" TARGET_ABI_FMT_ld "," TARGET_ABI_FMT_ld "}%s",
             tswapal(tv->tv_sec), tswapal(tv->tv_usec), get_comma(last));
         unlock_user(tv, tv_addr, 0);
-- 
2.19.1

[Qemu-devel] [PATCH v5 03/10] linux-user/strace: Add print_timezone()

[Philippe Mathieu-Daudé]

Suggested-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 linux-user/strace.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/linux-user/strace.c b/linux-user/strace.c
index c95557bf83..10ae22263c 100644
--- a/linux-user/strace.c
+++ b/linux-user/strace.c
@@ -63,6 +63,7 @@ UNUSED static void print_string(abi_long, int);
 UNUSED static void print_buf(abi_long addr, abi_long len, int last);
 UNUSED static void print_raw_param(const char *, abi_long, int);
 UNUSED static void print_timeval(abi_ulong, int);
+UNUSED static void print_timezone(abi_ulong, int);
 UNUSED static void print_number(abi_long, int);
 UNUSED static void print_signal(abi_ulong, int);
 UNUSED static void print_sockaddr(abi_ulong addr, abi_long addrlen);
@@ -1184,6 +1185,26 @@ print_timeval(abi_ulong tv_addr, int last)
         gemu_log("NULL%s", get_comma(last));
 }
 
+static void
+print_timezone(abi_ulong tz_addr, int last)
+{
+    if (tz_addr) {
+        struct target_timezone *tz;
+
+        tz = lock_user(VERIFY_READ, tz_addr, sizeof(*tz), 1);
+        if (!tz) {
+            print_pointer(tz_addr, last);
+            return;
+        }
+        gemu_log("{" TARGET_ABI_FMT_ld "," TARGET_ABI_FMT_ld "}%s",
+                 tswapal(tz->tz_minuteswest), tswapal(tz->tz_dsttime),
+                 get_comma(last));
+        unlock_user(tz, tz_addr, 0);
+    } else {
+        gemu_log("NULL%s", get_comma(last));
+    }
+}
+
 #undef UNUSED
 
 #ifdef TARGET_NR_accept
-- 
2.19.1

[Qemu-devel] [PATCH v5 04/10] linux-user/strace: Improve settimeofday()

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-By: Guido Günther <agx@sigxcpu.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
---
 linux-user/strace.c    | 13 +++++++++++++
 linux-user/strace.list |  2 +-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/linux-user/strace.c b/linux-user/strace.c
index 10ae22263c..ca2cd75993 100644
--- a/linux-user/strace.c
+++ b/linux-user/strace.c
@@ -1502,6 +1502,19 @@ print_futimesat(const struct syscallname *name,
 }
 #endif
 
+#ifdef TARGET_NR_settimeofday
+static void
+print_settimeofday(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_timeval(arg0, 0);
+    print_timezone(arg1, 1);
+    print_syscall_epilogue(name);
+}
+#endif
+
 #ifdef TARGET_NR_link
 static void
 print_link(const struct syscallname *name,
diff --git a/linux-user/strace.list b/linux-user/strace.list
index ff8bb19f5f..31093c3371 100644
--- a/linux-user/strace.list
+++ b/linux-user/strace.list
@@ -1345,7 +1345,7 @@
 { TARGET_NR_set_tid_address, "set_tid_address" , NULL, NULL, NULL },
 #endif
 #ifdef TARGET_NR_settimeofday
-{ TARGET_NR_settimeofday, "settimeofday" , NULL, NULL, NULL },
+{ TARGET_NR_settimeofday, "settimeofday" , NULL, print_settimeofday, NULL },
 #endif
 #ifdef TARGET_NR_setuid
 { TARGET_NR_setuid, "setuid" , NULL, NULL, NULL },
-- 
2.19.1

[Qemu-devel] [PATCH v5 05/10] linux-user/syscall: Introduce target_sockaddr_nl

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-By: Guido Günther <agx@sigxcpu.org>
---
 linux-user/syscall_defs.h | 7 +++++++
 linux-user/syscall.c      | 6 ++++--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
index 18d434d6dc..8ddeec1bae 100644
--- a/linux-user/syscall_defs.h
+++ b/linux-user/syscall_defs.h
@@ -152,6 +152,13 @@ struct target_sockaddr_un {
     uint8_t sun_path[108];
 };
 
+struct target_sockaddr_nl {
+    uint16_t nl_family;     /* AF_NETLINK */
+    uint16_t __pad;
+    uint32_t nl_pid;
+    uint32_t nl_groups;
+};
+
 struct target_in_addr {
     uint32_t s_addr; /* big endian */
 };
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index ea503381aa..e9cadfd748 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -1447,8 +1447,10 @@ static inline abi_long host_to_target_sockaddr(abi_ulong target_addr,
         sizeof(target_saddr->sa_family)) {
         target_saddr->sa_family = tswap16(addr->sa_family);
     }
-    if (addr->sa_family == AF_NETLINK && len >= sizeof(struct sockaddr_nl)) {
-        struct sockaddr_nl *target_nl = (struct sockaddr_nl *)target_saddr;
+    if (addr->sa_family == AF_NETLINK &&
+        len >= sizeof(struct target_sockaddr_nl)) {
+        struct target_sockaddr_nl *target_nl =
+               (struct target_sockaddr_nl *)target_saddr;
         target_nl->nl_pid = tswap32(target_nl->nl_pid);
         target_nl->nl_groups = tswap32(target_nl->nl_groups);
     } else if (addr->sa_family == AF_PACKET) {
-- 
2.19.1

[Qemu-devel] [PATCH v5 06/10] linux-user/strace: Dump AF_NETLINK sockaddr content

[Philippe Mathieu-Daudé]

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-By: Guido Günther <agx@sigxcpu.org>
---
 linux-user/strace.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/linux-user/strace.c b/linux-user/strace.c
index ca2cd75993..425c06d169 100644
--- a/linux-user/strace.c
+++ b/linux-user/strace.c
@@ -8,6 +8,7 @@
 #include <arpa/inet.h>
 #include <netinet/tcp.h>
 #include <linux/if_packet.h>
+#include <linux/netlink.h>
 #include <sched.h>
 #include "qemu.h"
 
@@ -398,6 +399,12 @@ print_sockaddr(abi_ulong addr, abi_long addrlen)
             gemu_log("}");
             break;
         }
+        case AF_NETLINK: {
+            struct target_sockaddr_nl *nl = (struct target_sockaddr_nl *)sa;
+            gemu_log("{nl_family=AF_NETLINK,nl_pid=%u,nl_groups=%u}",
+                     nl->nl_pid, nl->nl_groups);
+            break;
+        }
         default:
             gemu_log("{sa_family=%d, sa_data={", sa->sa_family);
             for (i = 0; i < 13; i++) {
@@ -424,6 +431,9 @@ print_socket_domain(int domain)
     case PF_INET:
         gemu_log("PF_INET");
         break;
+    case PF_NETLINK:
+        gemu_log("PF_NETLINK");
+        break;
     case PF_PACKET:
         gemu_log("PF_PACKET");
         break;
@@ -473,6 +483,33 @@ print_socket_protocol(int domain, int type, int protocol)
         return;
     }
 
+    if (domain == PF_NETLINK) {
+        switch (protocol) {
+        case NETLINK_ROUTE:
+            gemu_log("NETLINK_ROUTE");
+            break;
+        case NETLINK_AUDIT:
+            gemu_log("NETLINK_AUDIT");
+            break;
+        case NETLINK_NETFILTER:
+            gemu_log("NETLINK_NETFILTER");
+            break;
+        case NETLINK_KOBJECT_UEVENT:
+            gemu_log("NETLINK_KOBJECT_UEVENT");
+            break;
+        case NETLINK_RDMA:
+            gemu_log("NETLINK_RDMA");
+            break;
+        case NETLINK_CRYPTO:
+            gemu_log("NETLINK_CRYPTO");
+            break;
+        default:
+            gemu_log("%d", protocol);
+            break;
+        }
+        return;
+    }
+
     switch (protocol) {
     case IPPROTO_IP:
         gemu_log("IPPROTO_IP");
-- 
2.19.1

[Qemu-devel] [PATCH v5 07/10] linux-user/strace: Add print_sockfd()

[Philippe Mathieu-Daudé]

Extract common print_sockfd() from various socket related syscalls.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 linux-user/strace.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/linux-user/strace.c b/linux-user/strace.c
index 425c06d169..5435d01569 100644
--- a/linux-user/strace.c
+++ b/linux-user/strace.c
@@ -1651,6 +1651,11 @@ static void do_print_socket(const char *name, abi_long arg1)
     gemu_log(")");
 }
 
+static void print_sockfd(abi_long sockfd, int last)
+{
+    print_raw_param(TARGET_ABI_FMT_ld, sockfd, last);
+}
+
 static void do_print_sockaddr(const char *name, abi_long arg1)
 {
     abi_ulong sockfd, addr, addrlen;
@@ -1660,7 +1665,7 @@ static void do_print_sockaddr(const char *name, abi_long arg1)
     get_user_ualx(addrlen, arg1, 2);
 
     gemu_log("%s(", name);
-    print_raw_param(TARGET_ABI_FMT_ld, sockfd, 0);
+    print_sockfd(sockfd, 0);
     print_sockaddr(addr, addrlen);
     gemu_log(")");
 }
@@ -1673,7 +1678,7 @@ static void do_print_listen(const char *name, abi_long arg1)
     get_user_ualx(backlog, arg1, 1);
 
     gemu_log("%s(", name);
-    print_raw_param(TARGET_ABI_FMT_ld, sockfd, 0);
+    print_sockfd(sockfd, 0);
     print_raw_param(TARGET_ABI_FMT_ld, backlog, 1);
     gemu_log(")");
 }
@@ -1708,7 +1713,7 @@ static void do_print_sendrecv(const char *name, abi_long arg1)
     get_user_ualx(flags, arg1, 3);
 
     gemu_log("%s(", name);
-    print_raw_param(TARGET_ABI_FMT_ld, sockfd, 0);
+    print_sockfd(sockfd, 0);
     print_buf(msg, len, 0);
     print_raw_param(TARGET_ABI_FMT_ld, len, 0);
     print_flags(msg_flags, flags, 1);
@@ -1727,7 +1732,7 @@ static void do_print_msgaddr(const char *name, abi_long arg1)
     get_user_ualx(addrlen, arg1, 5);
 
     gemu_log("%s(", name);
-    print_raw_param(TARGET_ABI_FMT_ld, sockfd, 0);
+    print_sockfd(sockfd, 0);
     print_buf(msg, len, 0);
     print_raw_param(TARGET_ABI_FMT_ld, len, 0);
     print_flags(msg_flags, flags, 0);
@@ -1743,7 +1748,7 @@ static void do_print_shutdown(const char *name, abi_long arg1)
     get_user_ualx(how, arg1, 1);
 
     gemu_log("shutdown(");
-    print_raw_param(TARGET_ABI_FMT_ld, sockfd, 0);
+    print_sockfd(sockfd, 0);
     switch (how) {
     case SHUT_RD:
         gemu_log("SHUT_RD");
@@ -1770,7 +1775,7 @@ static void do_print_msg(const char *name, abi_long arg1)
     get_user_ualx(flags, arg1, 2);
 
     gemu_log("%s(", name);
-    print_raw_param(TARGET_ABI_FMT_ld, sockfd, 0);
+    print_sockfd(sockfd, 0);
     print_pointer(msg, 0);
     print_flags(msg_flags, flags, 1);
     gemu_log(")");
@@ -1787,7 +1792,7 @@ static void do_print_sockopt(const char *name, abi_long arg1)
     get_user_ualx(optlen, arg1, 4);
 
     gemu_log("%s(", name);
-    print_raw_param(TARGET_ABI_FMT_ld, sockfd, 0);
+    print_sockfd(sockfd, 0);
     switch (level) {
     case SOL_TCP:
         gemu_log("SOL_TCP,");
-- 
2.19.1

[Qemu-devel] [PATCH v5 08/10] linux-user/strace: Let print_sockaddr() have a 'last' argument

[Philippe Mathieu-Daudé]

If the format is not the syscall last argument, a comma is append.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
---
 linux-user/strace.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/linux-user/strace.c b/linux-user/strace.c
index 5435d01569..14ec5f9f23 100644
--- a/linux-user/strace.c
+++ b/linux-user/strace.c
@@ -67,7 +67,7 @@ UNUSED static void print_timeval(abi_ulong, int);
 UNUSED static void print_timezone(abi_ulong, int);
 UNUSED static void print_number(abi_long, int);
 UNUSED static void print_signal(abi_ulong, int);
-UNUSED static void print_sockaddr(abi_ulong addr, abi_long addrlen);
+UNUSED static void print_sockaddr(abi_ulong addr, abi_long addrlen, int);
 UNUSED static void print_socket_domain(int domain);
 UNUSED static void print_socket_type(int type);
 UNUSED static void print_socket_protocol(int domain, int type, int protocol);
@@ -336,7 +336,7 @@ static void print_siginfo(const target_siginfo_t *tinfo)
 }
 
 static void
-print_sockaddr(abi_ulong addr, abi_long addrlen)
+print_sockaddr(abi_ulong addr, abi_long addrlen, int last)
 {
     struct target_sockaddr *sa;
     int i;
@@ -418,7 +418,7 @@ print_sockaddr(abi_ulong addr, abi_long addrlen)
     } else {
         print_raw_param("0x"TARGET_ABI_FMT_lx, addr, 0);
     }
-    gemu_log(", "TARGET_ABI_FMT_ld, addrlen);
+    gemu_log(", "TARGET_ABI_FMT_ld"%s", addrlen, get_comma(last));
 }
 
 static void
@@ -1666,7 +1666,7 @@ static void do_print_sockaddr(const char *name, abi_long arg1)
 
     gemu_log("%s(", name);
     print_sockfd(sockfd, 0);
-    print_sockaddr(addr, addrlen);
+    print_sockaddr(addr, addrlen, 0);
     gemu_log(")");
 }
 
@@ -1736,7 +1736,7 @@ static void do_print_msgaddr(const char *name, abi_long arg1)
     print_buf(msg, len, 0);
     print_raw_param(TARGET_ABI_FMT_ld, len, 0);
     print_flags(msg_flags, flags, 0);
-    print_sockaddr(addr, addrlen);
+    print_sockaddr(addr, addrlen, 0);
     gemu_log(")");
 }
 
-- 
2.19.1

Re: [Qemu-devel] [PATCH v5 09/10] linux-user/strace: Improve bind() output

[Laurent Vivier]

On 11/10/2018 00:36, Philippe Mathieu-Daudé wrote:
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> Tested-By: Guido Günther <agx@sigxcpu.org>
> ---
>  linux-user/strace.c    | 13 +++++++++++++
>  linux-user/strace.list |  2 +-
>  2 files changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/linux-user/strace.c b/linux-user/strace.c
> index 14ec5f9f23..9f7480c449 100644
> --- a/linux-user/strace.c
> +++ b/linux-user/strace.c
> @@ -1966,6 +1966,19 @@ print_socketcall(const struct syscallname *name,
>  }
>  #endif
>  
> +#if defined(TARGET_NR_bind)
> +static void
> +print_bind(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_sockfd(arg0, 0);

print_sockfd() is only defined if TARGET_NR_socketcall is defined, so in
this case it can be undefined.

Thanks,
Laurent