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| author | Filip Bozuta <Filip.Bozuta@syrmia.com> | 2020-06-19 14:33:29 +0200 |
|---|---|---|
| committer | Laurent Vivier <laurent@vivier.eu> | 2020-06-29 13:08:48 +0200 |
| commit | af861deaed5aa979522ec72425913295dc050f10 (patch) | |
| tree | 62987e6b3fdf1e53f4bdc59d0a671e03107200f9 /linux-user/strace.c | |
| parent | 4fc3cdde40f977ee8deecf988eea7acfa373117a (diff) | |
| download | qemu-af861deaed5aa979522ec72425913295dc050f10.zip | |
linux-user: Add strace support for printing arguments of lseek()
This patch implements strace argument printing functionality for syscall:
*lseek - reposition read/write file offset
off_t lseek(int fd, off_t offset, int whence)
man page: https://www.man7.org/linux/man-pages/man2/lseek.2.html
Implementation notes:
The syscall's third argument "whence" has predefined values:
"SEEK_SET","SEEK_CUR","SEEK_END","SEEK_DATA","SEEK_HOLE"
and thus a separate printing function "print_lseek" was stated
in file "strace.list". This function is defined in "strace.c"
by using an existing function "print_raw_param()" to print
the first and second argument and a switch(case) statement
for the predefined values of the third argument.
Values "SEEK_DATA" and "SEEK_HOLE" are defined in kernel version 3.1.
That is the reason why case statements for these values are
enwrapped in #ifdef directive.
Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200619123331.17387-5-filip.bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Diffstat (limited to 'linux-user/strace.c')
| -rw-r--r-- | linux-user/strace.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/linux-user/strace.c b/linux-user/strace.c index 760020132b..a26736516b 100644 --- a/linux-user/strace.c +++ b/linux-user/strace.c @@ -1833,6 +1833,37 @@ print__llseek(const struct syscallname *name, } #endif +#ifdef TARGET_NR_lseek +static void +print_lseek(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_raw_param("%d", arg0, 0); + print_raw_param(TARGET_ABI_FMT_ld, arg1, 0); + switch (arg2) { + case SEEK_SET: + qemu_log("SEEK_SET"); break; + case SEEK_CUR: + qemu_log("SEEK_CUR"); break; + case SEEK_END: + qemu_log("SEEK_END"); break; +#ifdef SEEK_DATA + case SEEK_DATA: + qemu_log("SEEK_DATA"); break; +#endif +#ifdef SEEK_HOLE + case SEEK_HOLE: + qemu_log("SEEK_HOLE"); break; +#endif + default: + print_raw_param("%#x", arg2, 1); + } + print_syscall_epilogue(name); +} +#endif + #if defined(TARGET_NR_socket) static void print_socket(const struct syscallname *name, |