[PATCH 03/12] linux-user/strace: fix printing of file offsets

[deller@kernel.org]

From: Jean-Christian CÎRSTEA <jean.christian.cirstea@gmail.com>

Previously, 64-bit file offsets (loff_t) were printed using `print_raw_param()`
function, which led to silent truncation of the upper part. This commit fixes
this issue by adding two helper functions:

1. print_file_offset32(): prints 32-bit file offsets (off_t)
2. print_file_offset64(): prints 64-bit file offsets (loff_t)

Changelog v2:

1. Make `print_file_offset32()` static.
2. Use `last` parameter in `print_file_offset32()`.
3. Rename `low` and `high` parameters of `print_file_offset64()` to `word0`,
`word1` respectively
4. Convert `last` to bool for `print_file_offset[32,64]()`
5. Use `PRId64` instead of `PRIu64` for `print_file_offset64()`
6. Fix `print__llseek()`

Signed-off-by: Jean-Christian CÎRSTEA <jean.christian.cirstea@gmail.com>
Reviewed-by: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>
---
 linux-user/strace.c | 43 +++++++++++++++++++++++++++++++------------
 1 file changed, 31 insertions(+), 12 deletions(-)

diff --git a/linux-user/strace.c b/linux-user/strace.c
index ca67cfd09d..d253b522bf 100644
--- a/linux-user/strace.c
+++ b/linux-user/strace.c
@@ -85,6 +85,10 @@ UNUSED static void print_enums(const struct enums *, abi_long, int);
 UNUSED static void print_at_dirfd(abi_long, int);
 UNUSED static void print_file_mode(abi_long, int);
 UNUSED static void print_open_flags(abi_long, int);
+UNUSED static void print_file_offset32(abi_long offset, bool last);
+UNUSED static void print_file_offset64(abi_long word0,
+                                       abi_long word1,
+                                       bool last);
 UNUSED static void print_syscall_prologue(const struct syscallname *);
 UNUSED static void print_syscall_epilogue(const struct syscallname *);
 UNUSED static void print_string(abi_long, int);
@@ -1664,6 +1668,20 @@ print_open_flags(abi_long flags, int last)
     print_flags(open_flags, flags, last);
 }
 
+/* Prints 32-bit file offset (off_t) */
+static void
+print_file_offset32(abi_long offset, bool last)
+{
+    print_raw_param(TARGET_ABI_FMT_ld, offset, last);
+}
+
+/* Prints 64-bit file offset (loff_t) */
+static void
+print_file_offset64(abi_long word0, abi_long word1, bool last)
+{
+    print_raw_param64("%" PRId64, target_offset64(word0, word1), last);
+}
+
 static void
 print_syscall_prologue(const struct syscallname *sc)
 {
@@ -2256,11 +2274,13 @@ print_fallocate(CPUArchState *cpu_env, const struct syscallname *name,
     print_raw_param("%d", arg0, 0);
     print_flags(falloc_flags, arg1, 0);
 #if TARGET_ABI_BITS == 32
-    print_raw_param("%" PRIu64, target_offset64(arg2, arg3), 0);
-    print_raw_param("%" PRIu64, target_offset64(arg4, arg5), 1);
+    /* On 32-bit targets, two registers are used for `loff_t` */
+    print_file_offset64(arg2, arg3, false);
+    print_file_offset64(arg4, arg5, true);
 #else
-    print_raw_param(TARGET_ABI_FMT_ld, arg2, 0);
-    print_raw_param(TARGET_ABI_FMT_ld, arg3, 1);
+    /* On 64-bit targets, one register is used for `loff_t` */
+    print_file_offset64(arg2, 0, false);
+    print_file_offset64(arg3, 0, true);
 #endif
     print_syscall_epilogue(name);
 }
@@ -2666,8 +2686,7 @@ print__llseek(CPUArchState *cpu_env, const struct syscallname *name,
     const char *whence = "UNKNOWN";
     print_syscall_prologue(name);
     print_raw_param("%d", arg0, 0);
-    print_raw_param("%ld", arg1, 0);
-    print_raw_param("%ld", arg2, 0);
+    print_file_offset64(arg1, arg2, false);
     print_pointer(arg3, 0);
     switch(arg4) {
     case SEEK_SET: whence = "SEEK_SET"; break;
@@ -2688,7 +2707,7 @@ print_lseek(CPUArchState *cpu_env, const struct syscallname *name,
 {
     print_syscall_prologue(name);
     print_raw_param("%d", arg0, 0);
-    print_raw_param(TARGET_ABI_FMT_ld, arg1, 0);
+    print_file_offset32(arg1, false);
     switch (arg2) {
     case SEEK_SET:
         qemu_log("SEEK_SET"); break;
@@ -2719,7 +2738,7 @@ print_truncate(CPUArchState *cpu_env, const struct syscallname *name,
 {
     print_syscall_prologue(name);
     print_string(arg0, 0);
-    print_raw_param(TARGET_ABI_FMT_ld, arg1, 1);
+    print_file_offset32(arg1, true);
     print_syscall_epilogue(name);
 }
 #endif
@@ -2736,7 +2755,7 @@ print_truncate64(CPUArchState *cpu_env, const struct syscallname *name,
         arg1 = arg2;
         arg2 = arg3;
     }
-    print_raw_param("%" PRIu64, target_offset64(arg1, arg2), 1);
+    print_file_offset64(arg1, arg2, true);
     print_syscall_epilogue(name);
 }
 #endif
@@ -2753,7 +2772,7 @@ print_ftruncate64(CPUArchState *cpu_env, const struct syscallname *name,
         arg1 = arg2;
         arg2 = arg3;
     }
-    print_raw_param("%" PRIu64, target_offset64(arg1, arg2), 1);
+    print_file_offset64(arg1, arg2, true);
     print_syscall_epilogue(name);
 }
 #endif
@@ -3308,7 +3327,7 @@ print_stat(CPUArchState *cpu_env, const struct syscallname *name,
     print_syscall_epilogue(name);
 }
 #define print_lstat     print_stat
-#define print_stat64	print_stat
+#define print_stat64    print_stat
 #define print_lstat64   print_stat
 #endif
 
@@ -4302,7 +4321,7 @@ print_pread64(CPUArchState *cpu_env, const struct syscallname *name,
     print_raw_param("%d", arg0, 0);
     print_pointer(arg1, 0);
     print_raw_param("%d", arg2, 0);
-    print_raw_param("%" PRIu64, target_offset64(arg3, arg4), 1);
+    print_file_offset64(arg3, arg4, true);
     print_syscall_epilogue(name);
 }
 #endif
-- 
2.53.0