Le 14/07/2020 à 22:04, Filip Bozuta a écrit :
> Functions "print_ioctl()" and "print_syscall_ret_ioctl()" are used
> to print arguments of "ioctl()" with "-strace". These functions
> use "thunk_print()", which is defined in "thunk.c", to print the
> contents of ioctl's third arguments that are not basic types.
> However, this function doesn't handle ioctls of group ioctl_tty which
> are used for terminals and serial lines. These ioctls use a type
> "struct termios" which thunk type is defined in a non standard
> way using "STRUCT_SPECIAL()". This means that this type is not decoded
> regularly using "thunk_convert()" and uses special converting functions
> "target_to_host_termios()" and "host_to_target_termios()", which are defined
> in "syscall.c" to decode it's values. For simillar reasons, this type is
> also not printed regularly using "thunk_print()". That is the reason
> why a separate printing function "print_termios()" is defined in
> file "strace.c". This function decodes and prints flag values of the
> "termios" structure.
>
> Implementation notes:
>
> Function "print_termios()" was implemented in "strace.c" using
> an existing function "print_flags()" to print flag values of
> "struct termios" fields. These flag values were defined
> using an existing macro "FLAG_TARGET()" that generates aproppriate
> target flag values and string representations of these flags.
> This function was declared in "qemu.h" so that it can be accessed
> in "syscall.c". Type "StructEntry" defined in "exec/user/thunk.h"
> contains information that is used to decode structure values.
> Field "void print(void *arg)" was added in this structure as a
> special print function. Also, function "thunk_print()" was changed
> a little so that it uses this special print function in case
> it is defined. This printing function was instantiated with the
> defined "print_termios()" in "syscall.c" in "struct_termios_def".
>
> Signed-off-by: Filip Bozuta <filip.boz...@syrmia.com>
> ---
> include/exec/user/thunk.h | 1 +
> linux-user/qemu.h | 2 +
> linux-user/strace.c | 193 ++++++++++++++++++++++++++++++++++++++
> linux-user/syscall.c | 1 +
> thunk.c | 23 +++--
> 5 files changed, 211 insertions(+), 9 deletions(-)
>
> diff --git a/include/exec/user/thunk.h b/include/exec/user/thunk.h
> index 7992475c9f..a5bbb2c733 100644
> --- a/include/exec/user/thunk.h
> +++ b/include/exec/user/thunk.h
> @@ -55,6 +55,7 @@ typedef struct {
> int *field_offsets[2];
> /* special handling */
> void (*convert[2])(void *dst, const void *src);
> + void (*print)(void *arg);
> int size[2];
> int align[2];
> const char *name;
> diff --git a/linux-user/qemu.h b/linux-user/qemu.h
> index 5c964389c1..e51a0ededb 100644
> --- a/linux-user/qemu.h
> +++ b/linux-user/qemu.h
> @@ -706,6 +706,8 @@ static inline uint64_t target_offset64(uint64_t word0,
> uint64_t word1)
> }
> #endif /* TARGET_ABI_BITS != 32 */
>
> +extern void print_termios(void *arg);
> +
> /**
> * preexit_cleanup: housekeeping before the guest exits
> *
> diff --git a/linux-user/strace.c b/linux-user/strace.c
> index 5235b2260c..7b5408cf4a 100644
> --- a/linux-user/strace.c
> +++ b/linux-user/strace.c
> @@ -1193,6 +1193,138 @@ UNUSED static struct flags falloc_flags[] = {
> #endif
> };
>
> +UNUSED static struct flags termios_iflags[] = {
> + FLAG_TARGET(IGNBRK),
> + FLAG_TARGET(BRKINT),
> + FLAG_TARGET(IGNPAR),
> + FLAG_TARGET(PARMRK),
> + FLAG_TARGET(INPCK),
> + FLAG_TARGET(ISTRIP),
> + FLAG_TARGET(INLCR),
> + FLAG_TARGET(IGNCR),
> + FLAG_TARGET(ICRNL),
> + FLAG_TARGET(IUCLC),
> + FLAG_TARGET(IXON),
> + FLAG_TARGET(IXANY),
> + FLAG_TARGET(IXOFF),
> + FLAG_TARGET(IMAXBEL),
IUTF8 is missing
> + FLAG_END,
> +};
> +
> +UNUSED static struct flags termios_oflags[] = {
> + FLAG_TARGET(OPOST),
> + FLAG_TARGET(OLCUC),
> + FLAG_TARGET(ONLCR),
> + FLAG_TARGET(OCRNL),
> + FLAG_TARGET(ONOCR),
> + FLAG_TARGET(ONLRET),
> + FLAG_TARGET(OFILL),
> + FLAG_TARGET(OFDEL),
> + FLAG_END,
> +};
> +
the following entries are not flags: flags are bits, while we have
enumerated values in these cases.
NL0, NL1 = 0,1
> +UNUSED static struct flags termios_oflags_NLDLY[] = {
> + FLAG_TARGET(NL0),
> + FLAG_TARGET(NL1),
> + FLAG_END,
> +};
CR0, CR1, CR2, CR3 = 0, 1, 2, 3
> +UNUSED static struct flags termios_oflags_CRDLY[] = {
> + FLAG_TARGET(CR0),
> + FLAG_TARGET(CR1),
> + FLAG_TARGET(CR2),
> + FLAG_TARGET(CR3),
> + FLAG_END,
> +};
>
TAB0 is 0 so it cannot be detected
> +UNUSED static struct flags termios_oflags_TABDLY[] = {
> + FLAG_TARGET(TAB0),
> + FLAG_TARGET(TAB1),
> + FLAG_TARGET(TAB2),
> + FLAG_TARGET(TAB3),
> + FLAG_END,
> +};
VT0 is 0
> +UNUSED static struct flags termios_oflags_VTDLY[] = {
> + FLAG_TARGET(VT0),
> + FLAG_TARGET(VT1),
> + FLAG_END,
> +};
FF0 is 0
> +UNUSED static struct flags termios_oflags_FFDLY[] = {
> + FLAG_TARGET(FF0),
> + FLAG_TARGET(FF1),
> + FLAG_END,
> +};
BS0 is 0
> +UNUSED static struct flags termios_oflags_BSDLY[] = {
> + FLAG_TARGET(BS0),
> + FLAG_TARGET(BS1),
> + FLAG_END,
> +};
ditto: these are not bits but enumerated values (B0 is 0).
> +UNUSED static struct flags termios_cflags_CBAUD[] = {
> + FLAG_TARGET(B0),
> + FLAG_TARGET(B50),
> + FLAG_TARGET(B75),
> + FLAG_TARGET(B110),
> + FLAG_TARGET(B134),
> + FLAG_TARGET(B150),
> + FLAG_TARGET(B200),
> + FLAG_TARGET(B300),
> + FLAG_TARGET(B600),
> + FLAG_TARGET(B1200),
> + FLAG_TARGET(B1800),
> + FLAG_TARGET(B2400),
> + FLAG_TARGET(B4800),
> + FLAG_TARGET(B9600),
> + FLAG_TARGET(B19200),
> + FLAG_TARGET(B38400),
> + FLAG_TARGET(B57600),
> + FLAG_TARGET(B115200),
> + FLAG_TARGET(B230400),
> + FLAG_TARGET(B460800),
> + FLAG_END,
> +};
CS5 is 0
> +UNUSED static struct flags termios_cflags_CSIZE[] = {
> + FLAG_TARGET(CS5),
> + FLAG_TARGET(CS6),
> + FLAG_TARGET(CS7),
> + FLAG_TARGET(CS8),
> + FLAG_END,
> +};
These ones are ok:
> +UNUSED static struct flags termios_cflags[] = {
> + FLAG_TARGET(CSTOPB),
> + FLAG_TARGET(CREAD),
> + FLAG_TARGET(PARENB),
> + FLAG_TARGET(PARODD),
> + FLAG_TARGET(HUPCL),
> + FLAG_TARGET(CLOCAL),
> + FLAG_TARGET(CRTSCTS),
> + FLAG_END,
> +};
These ones too:
> +UNUSED static struct flags termios_lflags[] = {
> + FLAG_TARGET(ISIG),
> + FLAG_TARGET(ICANON),
> + FLAG_TARGET(XCASE),
> + FLAG_TARGET(ECHO),
> + FLAG_TARGET(ECHOE),
> + FLAG_TARGET(ECHOK),
> + FLAG_TARGET(ECHONL),
> + FLAG_TARGET(NOFLSH),
> + FLAG_TARGET(TOSTOP),
> + FLAG_TARGET(ECHOCTL),
> + FLAG_TARGET(ECHOPRT),
> + FLAG_TARGET(ECHOKE),
> + FLAG_TARGET(FLUSHO),
> + FLAG_TARGET(PENDIN),
> + FLAG_TARGET(IEXTEN),
missing EXTPROC
> + FLAG_END,
> +};
> +
> /*
> * print_xxx utility functions. These are used to print syscall
> * parameters in certain format. All of these have parameter
> @@ -1420,6 +1552,67 @@ print_timezone(abi_ulong tz_addr, int last)
> }
> }
>
> +void
> +print_termios(void *arg)
> +{
> + const struct target_termios *target = arg;
> +
> + abi_long iflags = tswap32(target->c_iflag);
> + abi_long oflags = tswap32(target->c_oflag);
> + abi_long cflags = tswap32(target->c_cflag);
> + abi_long lflags = tswap32(target->c_lflag);
You should use target_tcflag_t here, rather than abi_long.
To be able to do that we need some cleanup before:
- define target_tcflag_t, target_cc_t, target_speed_t in a new file
linux-user/generic/termbits.h
- update all the existing target_termios to use them
> +
> + qemu_log("{");
> +
> + qemu_log("c_iflag = ");
> + print_flags(termios_iflags, iflags, 0);
> +
> + qemu_log("c_oflag = ");
> + abi_long oflags_clean = oflags & ~(TARGET_NLDLY) & ~(TARGET_CRDLY) &
> + ~(TARGET_TABDLY) & ~(TARGET_BSDLY) &
> + ~(TARGET_VTDLY) & ~(TARGET_FFDLY);
I think would simpler to write:
oflags & ~(TARGET_NLDLY | TARGET_CRDLY | TARGET_TABDLY | TARGET_BSDLY |
TARGET_VTDLY | TARGET_FFDLY)
> + print_flags(termios_oflags, oflags_clean, 0);
> + if (oflags & TARGET_NLDLY) {
NL0 is 0 so you never display it.
> + print_flags(termios_oflags_NLDLY, oflags & TARGET_NLDLY, 0);
> + }
> + if (oflags & TARGET_CRDLY) {
CR0 is 0, same comment for the following ones.
> + print_flags(termios_oflags_CRDLY, oflags & TARGET_CRDLY, 0);
> + }
> + if (oflags & TARGET_TABDLY) {
> + print_flags(termios_oflags_TABDLY, oflags & TARGET_TABDLY, 0);
> + }
> + if (oflags & TARGET_BSDLY) {
> + print_flags(termios_oflags_BSDLY, oflags & TARGET_BSDLY, 0);
> + }
> + if (oflags & TARGET_VTDLY) {
> + print_flags(termios_oflags_VTDLY, oflags & TARGET_VTDLY, 0);
> + }
> + if (oflags & TARGET_FFDLY) {
> + print_flags(termios_oflags_FFDLY, oflags & TARGET_FFDLY, 0);
> + }
> +
> + qemu_log("c_cflag = ");
> + if (cflags & TARGET_CBAUD) {
> + print_flags(termios_cflags_CBAUD, cflags & TARGET_CBAUD, 0);
> + }
> + if (cflags & TARGET_CSIZE) {
> + print_flags(termios_cflags_CSIZE, cflags & TARGET_CSIZE, 0);
> + }
> + abi_long cflags_clean = cflags & ~(TARGET_CBAUD) & ~(TARGET_CSIZE);
> + print_flags(termios_cflags, cflags_clean, 0);
> +
> + qemu_log("c_lflag = ");
> + print_flags(termios_lflags, lflags, 0);
> +
> + qemu_log("c_cc = ");
> + qemu_log("\"%s\",", target->c_cc);
> +
> + qemu_log("c_line = ");
> + print_raw_param("\'%c\'", target->c_line, 1);
> +
> + qemu_log("}");
> +}
> +
> #undef UNUSED
>
> #ifdef TARGET_NR_accept
Thanks,
Laurent
