Le 25/12/2025 à 19:36, Jean-Christian CÎRSTEA a écrit :
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)
*NOTE*: checkpatch.pl gives the following errors:
```
ERROR: externs should be avoided in .c files
#30: FILE: linux-user/strace.c:88:
+UNUSED void print_file_offset32(abi_long offset, int);
I think there is an actual error here: the static is missing.
ERROR: storage class should be at the beginning of the declaration
#31: FILE: linux-user/strace.c:89:
+UNUSED static void print_file_offset64(abi_long low, abi_long high, int);
```
The errors are may be removed if `UNUSED` and `static` are switched. Should this
patch fix this and swap all `UNUSED`s and `static`s?
The missing `static` on print_file_offset32 is a real error . The other checkpatch warning about
`UNUSED static` matches existing style here, so I’d leave that alone.
Signed-off-by: Jean-Christian CÎRSTEA <[email protected]>
---
linux-user/strace.c | 38 ++++++++++++++++++++++++++++----------
1 file changed, 28 insertions(+), 10 deletions(-)
diff --git a/linux-user/strace.c b/linux-user/strace.c
index 758c5d32b6..f790cab4da 100644
--- a/linux-user/strace.c
+++ b/linux-user/strace.c
@@ -85,6 +85,8 @@ 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 void print_file_offset32(abi_long offset, int);
Missing static
+UNUSED static void print_file_offset64(abi_long low, abi_long high, int);
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 +1666,20 @@ 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, int last)
+{
+ print_raw_param(TARGET_ABI_FMT_ld, offset, 0);
You should pass "last" instead of 0.
+}
+
+/* Prints 64-bit file offset (loff_t) */
+static void
+print_file_offset64(abi_long low, abi_long high, int last)
You shouldn't call them "low", "high", because it depends on the endianness of
the architecture.
Use word0, word1 as it is in target_offset64() definition.
+{
+ print_raw_param64("%" PRIu64, target_offset64(low, high), last);
You should use PRId64 as loff_t is supposed to be signed (PRIu64 is an existing
bug)
+}
+
static void
print_syscall_prologue(const struct syscallname *sc)
{
@@ -2187,11 +2203,13 @@ 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, 0);
+ print_file_offset64(arg4, arg5, 1);
#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, 0);
+ print_file_offset64(arg3, 0, 1);
#endif
print_syscall_epilogue(name);
}
@@ -2619,7 +2637,7 @@ 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, 0);
switch (arg2) {
case SEEK_SET:
qemu_log("SEEK_SET"); break;
I think print__llseek() should be updated/fixed too.
@@ -2650,7 +2668,7 @@ 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, 1);
print_syscall_epilogue(name);
}
#endif
@@ -2667,7 +2685,7 @@ 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, 1);
print_syscall_epilogue(name);
}
#endif
@@ -2684,7 +2702,7 @@ 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, 1);
print_syscall_epilogue(name);
}
#endif
@@ -3239,7 +3257,7 @@ 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
@@ -4228,7 +4246,7 @@ 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, 1);
print_syscall_epilogue(name);
}
#endif
Thanks,
Laurent
