linux-user/strace: fix printing of file offsets
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>
Jean-Christian CÎRSTEA committed
Dec 26, 2025 at 19:35 UTC
cec27d2fa9cfd8c0018e19a62db590682569aa81
1 file changed
+31
-12
linux-user/strace.c
+31
-12
@@ -85,6 +85,10 @@ UNUSED static void print_enums(const struct enums *, abi_long, int);
85
UNUSED static void print_at_dirfd(abi_long, int);
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UNUSED static void print_file_mode(abi_long, int);
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UNUSED static void print_open_flags(abi_long, int);
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+UNUSED static void print_file_offset32(abi_long offset, bool last);
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+UNUSED static void print_file_offset64(abi_long word0,
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+ abi_long word1,
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+ bool last);
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UNUSED static void print_syscall_prologue(const struct syscallname *);
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UNUSED static void print_syscall_epilogue(const struct syscallname *);
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UNUSED static void print_string(abi_long, int);
@@ -1664,6 +1668,20 @@ print_open_flags(abi_long flags, int last)
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print_flags(open_flags, flags, last);
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}
1670
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+/* Prints 32-bit file offset (off_t) */
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+static void
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+print_file_offset32(abi_long offset, bool last)
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+{
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+ print_raw_param(TARGET_ABI_FMT_ld, offset, last);
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+}
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+
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+/* Prints 64-bit file offset (loff_t) */
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+static void
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+print_file_offset64(abi_long word0, abi_long word1, bool last)
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+{
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+ print_raw_param64("%" PRId64, target_offset64(word0, word1), last);
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+}
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+
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static void
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print_syscall_prologue(const struct syscallname *sc)
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{
@@ -2256,11 +2274,13 @@ print_fallocate(CPUArchState *cpu_env, const struct syscallname *name,
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print_raw_param("%d", arg0, 0);
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print_flags(falloc_flags, arg1, 0);
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#if TARGET_ABI_BITS == 32
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- print_raw_param("%" PRIu64, target_offset64(arg2, arg3), 0);
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- print_raw_param("%" PRIu64, target_offset64(arg4, arg5), 1);
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+ /* On 32-bit targets, two registers are used for `loff_t` */
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+ print_file_offset64(arg2, arg3, false);
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+ print_file_offset64(arg4, arg5, true);
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#else
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- print_raw_param(TARGET_ABI_FMT_ld, arg2, 0);
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- print_raw_param(TARGET_ABI_FMT_ld, arg3, 1);
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+ /* On 64-bit targets, one register is used for `loff_t` */
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+ print_file_offset64(arg2, 0, false);
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+ print_file_offset64(arg3, 0, true);
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#endif
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print_syscall_epilogue(name);
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}
@@ -2666,8 +2686,7 @@ print__llseek(CPUArchState *cpu_env, const struct syscallname *name,
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const char *whence = "UNKNOWN";
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print_syscall_prologue(name);
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print_raw_param("%d", arg0, 0);
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- print_raw_param("%ld", arg1, 0);
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- print_raw_param("%ld", arg2, 0);
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+ print_file_offset64(arg1, arg2, false);
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print_pointer(arg3, 0);
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switch(arg4) {
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case SEEK_SET: whence = "SEEK_SET"; break;
@@ -2688,7 +2707,7 @@ print_lseek(CPUArchState *cpu_env, const struct syscallname *name,
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{
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print_syscall_prologue(name);
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print_raw_param("%d", arg0, 0);
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- print_raw_param(TARGET_ABI_FMT_ld, arg1, 0);
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+ print_file_offset32(arg1, false);
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switch (arg2) {
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case SEEK_SET:
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qemu_log("SEEK_SET"); break;
@@ -2719,7 +2738,7 @@ print_truncate(CPUArchState *cpu_env, const struct syscallname *name,
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{
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print_syscall_prologue(name);
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print_string(arg0, 0);
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- print_raw_param(TARGET_ABI_FMT_ld, arg1, 1);
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+ print_file_offset32(arg1, true);
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print_syscall_epilogue(name);
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}
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#endif
@@ -2736,7 +2755,7 @@ print_truncate64(CPUArchState *cpu_env, const struct syscallname *name,
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arg1 = arg2;
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arg2 = arg3;
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}
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- print_raw_param("%" PRIu64, target_offset64(arg1, arg2), 1);
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+ print_file_offset64(arg1, arg2, true);
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print_syscall_epilogue(name);
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}
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#endif
@@ -2753,7 +2772,7 @@ print_ftruncate64(CPUArchState *cpu_env, const struct syscallname *name,
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arg1 = arg2;
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arg2 = arg3;
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}
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- print_raw_param("%" PRIu64, target_offset64(arg1, arg2), 1);
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+ print_file_offset64(arg1, arg2, true);
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print_syscall_epilogue(name);
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}
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#endif
@@ -3308,7 +3327,7 @@ print_stat(CPUArchState *cpu_env, const struct syscallname *name,
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print_syscall_epilogue(name);
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}
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#define print_lstat print_stat
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-#define print_stat64 print_stat
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+#define print_stat64 print_stat
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#define print_lstat64 print_stat
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#endif
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@@ -4302,7 +4321,7 @@ print_pread64(CPUArchState *cpu_env, const struct syscallname *name,
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print_raw_param("%d", arg0, 0);
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print_pointer(arg1, 0);
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print_raw_param("%d", arg2, 0);
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- print_raw_param("%" PRIu64, target_offset64(arg3, arg4), 1);
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+ print_file_offset64(arg3, arg4, true);
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print_syscall_epilogue(name);
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}
4327
#endif