From: "H. Peter Anvin (Intel)" hpa@zytor.com
It turns out that Alpha is the only architecture that never implemented BOTHER and IBSHIFT, which is otherwise ages old. This is one thing that has held up glibc support for this feature (all other architectures have supported these for about a decade, at least before the current 3.2 glibc cutoff.)
Furthermore, in the process of dealing with this, I discovered that the current code in tty_baudrate.c can read past the end of the baud_table[] on Alpha and PowerPC. The second patch in this series fixes that, but it also cleans up the code substantially by auto-generating the table and, since all architectures now have them, removing all conditionals for BOTHER and IBSHIFT existing.
Tagging for stable because these are concrete problems. I have a much bigger update in process, nearly done, which will clean up a lot of duplicated code and make the uapi headers usable for libc, but that is not critical on the same level.
Tested on x86, compile-tested on Alpha.
Signed-off-by: H. Peter Anvin (Intel) hpa@zytor.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Jiri Slaby jslaby@suse.com Cc: Al Viro viro@zeniv.linux.org.uk Cc: Richard Henderson rth@twiddle.net Cc: Ivan Kokshaysky ink@jurassic.park.msu.ru Cc: Matt Turner mattst88@gmail.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Kate Stewart kstewart@linuxfoundation.org Cc: Philippe Ombredanne pombredanne@nexb.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Eugene Syromiatnikov esyr@redhat.com Cc: linux-alpha@vger.kernel.org Cc: linux-serial@vger.kernel.org Cc: Johan Hovold johan@kernel.org Cc: Alan Cox alan@lxorguk.ukuu.org.uk Cc: Benjamin Herrenschmidt benh@kernel.crashing.org Cc: Paul Mackerras paulus@samba.org Cc: Michael Ellerman mpe@ellerman.id.au Cc: stable@vger.kernel.org --- arch/alpha/include/asm/termios.h | 8 +- arch/alpha/include/uapi/asm/ioctls.h | 5 + arch/alpha/include/uapi/asm/termbits.h | 17 +++ drivers/tty/.gitignore | 1 + drivers/tty/Makefile | 16 +++ drivers/tty/bmacros.c | 2 + drivers/tty/tty_baudrate.c | 190 +++++++++++++-------------------- 7 files changed, 122 insertions(+), 117 deletions(-)
From: "H. Peter Anvin (Intel)" hpa@zytor.com
Alpha has had c_ispeed and c_ospeed, but still set speeds in c_cflags using arbitrary flags. Because BOTHER is not defined, the general Linux code doesn't allow setting arbitrary baud rates, and because CBAUDEX == 0, we can have an array overrun of the baud_rate[] table in drivers/tty/tty_baudrate.c if (c_cflags & CBAUD) == 037.
Resolve both problems by #defining BOTHER to 037 on Alpha.
However, userspace still needs to know if setting BOTHER is actually safe given legacy kernels (does anyone actually care about that on Alpha anymore?), so enable the TCGETS2/TCSETS*2 ioctls on Alpha, even though they use the same structure. Define struct termios2 just for compatibility; it is the exact same structure as struct termios. In a future patchset, this will be cleaned up so the uapi headers are usable from libc.
Signed-off-by: H. Peter Anvin (Intel) hpa@zytor.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Jiri Slaby jslaby@suse.com Cc: Al Viro viro@zeniv.linux.org.uk Cc: Richard Henderson rth@twiddle.net Cc: Ivan Kokshaysky ink@jurassic.park.msu.ru Cc: Matt Turner mattst88@gmail.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Kate Stewart kstewart@linuxfoundation.org Cc: Philippe Ombredanne pombredanne@nexb.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Eugene Syromiatnikov esyr@redhat.com Cc: linux-alpha@vger.kernel.org Cc: linux-serial@vger.kernel.org Cc: Johan Hovold johan@kernel.org Cc: Alan Cox alan@lxorguk.ukuu.org.uk Cc: stable@vger.kernel.org --- arch/alpha/include/asm/termios.h | 8 +++++++- arch/alpha/include/uapi/asm/ioctls.h | 5 +++++ arch/alpha/include/uapi/asm/termbits.h | 17 +++++++++++++++++ 3 files changed, 29 insertions(+), 1 deletion(-)
diff --git a/arch/alpha/include/asm/termios.h b/arch/alpha/include/asm/termios.h index 6a8c53dec57e..b7c77bb1bfd2 100644 --- a/arch/alpha/include/asm/termios.h +++ b/arch/alpha/include/asm/termios.h @@ -73,9 +73,15 @@ })
#define user_termios_to_kernel_termios(k, u) \ - copy_from_user(k, u, sizeof(struct termios)) + copy_from_user(k, u, sizeof(struct termios2))
#define kernel_termios_to_user_termios(u, k) \ + copy_to_user(u, k, sizeof(struct termios2)) + +#define user_termios_to_kernel_termios_1(k, u) \ + copy_from_user(k, u, sizeof(struct termios)) + +#define kernel_termios_to_user_termios_1(u, k) \ copy_to_user(u, k, sizeof(struct termios))
#endif /* _ALPHA_TERMIOS_H */ diff --git a/arch/alpha/include/uapi/asm/ioctls.h b/arch/alpha/include/uapi/asm/ioctls.h index 3729d92d3fa8..dc8c20ac7191 100644 --- a/arch/alpha/include/uapi/asm/ioctls.h +++ b/arch/alpha/include/uapi/asm/ioctls.h @@ -32,6 +32,11 @@ #define TCXONC _IO('t', 30) #define TCFLSH _IO('t', 31)
+#define TCGETS2 _IOR('T', 42, struct termios2) +#define TCSETS2 _IOW('T', 43, struct termios2) +#define TCSETSW2 _IOW('T', 44, struct termios2) +#define TCSETSF2 _IOW('T', 45, struct termios2) + #define TIOCSWINSZ _IOW('t', 103, struct winsize) #define TIOCGWINSZ _IOR('t', 104, struct winsize) #define TIOCSTART _IO('t', 110) /* start output, like ^Q */ diff --git a/arch/alpha/include/uapi/asm/termbits.h b/arch/alpha/include/uapi/asm/termbits.h index de6c8360fbe3..4575ba34a0ea 100644 --- a/arch/alpha/include/uapi/asm/termbits.h +++ b/arch/alpha/include/uapi/asm/termbits.h @@ -26,6 +26,19 @@ struct termios { speed_t c_ospeed; /* output speed */ };
+/* Alpha has identical termios and termios2 */ + +struct termios2 { + tcflag_t c_iflag; /* input mode flags */ + tcflag_t c_oflag; /* output mode flags */ + tcflag_t c_cflag; /* control mode flags */ + tcflag_t c_lflag; /* local mode flags */ + cc_t c_cc[NCCS]; /* control characters */ + cc_t c_line; /* line discipline (== c_cc[19]) */ + speed_t c_ispeed; /* input speed */ + speed_t c_ospeed; /* output speed */ +}; + /* Alpha has matching termios and ktermios */
struct ktermios { @@ -152,6 +165,7 @@ struct ktermios { #define B3000000 00034 #define B3500000 00035 #define B4000000 00036 +#define BOTHER 00037
#define CSIZE 00001400 #define CS5 00000000 @@ -169,6 +183,9 @@ struct ktermios { #define CMSPAR 010000000000 /* mark or space (stick) parity */ #define CRTSCTS 020000000000 /* flow control */
+#define CIBAUD 07600000 +#define IBSHIFT 16 + /* c_lflag bits */ #define ISIG 0x00000080 #define ICANON 0x00000100
From: "H. Peter Anvin (Intel)" hpa@zytor.com
Now when all architectures define BOTHER and IBSHIFT, we can unconditionally rely on these constants. Furthermore, the code can be significantly simplified in a number of places.
Finally, rather than having two tables and needing to be able to keep them in sync at all times, have one auto-generated table. This also lets us avoid the fact that architectures that have CBAUDEX == 0 have BOTHER in a different location that those that don't.
Finally, this patch avoids overrunning the baud_table[] for architectures with CBAUDEX == 0 (Alpha and PowerPC).
Signed-off-by: H. Peter Anvin (Intel) hpa@zytor.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Jiri Slaby jslaby@suse.com Cc: Al Viro viro@zeniv.linux.org.uk Cc: Richard Henderson rth@twiddle.net Cc: Ivan Kokshaysky ink@jurassic.park.msu.ru Cc: Matt Turner mattst88@gmail.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Kate Stewart kstewart@linuxfoundation.org Cc: Philippe Ombredanne pombredanne@nexb.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Eugene Syromiatnikov esyr@redhat.com Cc: linux-alpha@vger.kernel.org Cc: linux-serial@vger.kernel.org Cc: Johan Hovold johan@kernel.org Cc: Alan Cox alan@lxorguk.ukuu.org.uk Cc: Benjamin Herrenschmidt benh@kernel.crashing.org Cc: Paul Mackerras paulus@samba.org Cc: Michael Ellerman mpe@ellerman.id.au Cc: stable@vger.kernel.org --- drivers/tty/.gitignore | 1 + drivers/tty/Makefile | 16 ++++ drivers/tty/bmacros.c | 2 + drivers/tty/tty_baudrate.c | 190 +++++++++++++++---------------------- 4 files changed, 93 insertions(+), 116 deletions(-) create mode 100644 drivers/tty/.gitignore create mode 100644 drivers/tty/bmacros.c
diff --git a/drivers/tty/.gitignore b/drivers/tty/.gitignore new file mode 100644 index 000000000000..d436c18a912c --- /dev/null +++ b/drivers/tty/.gitignore @@ -0,0 +1 @@ +bmacros.h diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile index c72cafdf32b4..489b222ab1ce 100644 --- a/drivers/tty/Makefile +++ b/drivers/tty/Makefile @@ -35,3 +35,19 @@ obj-$(CONFIG_MIPS_EJTAG_FDC_TTY) += mips_ejtag_fdc.o obj-$(CONFIG_VCC) += vcc.o
obj-y += ipwireless/ + +# +# Rules for generating the baud rate table +# +CFLAGS_bmacros.o += -Wp,-dM + +$(obj)/tty_baudrate.o: $(obj)/bmacros.h + +quiet_cmd_bmacros = BMACROS $@ + cmd_bmacros = ( \ + sed -nr -e 's/^.define B([0-9]+) .*$$/BTBL(B\1,\1)/p' $< \ + | sort -n -k1.7 > $@ ) || (rm -f $@ ; echo false) + +targets += bmacros.h +$(obj)/bmacros.h: $(obj)/bmacros.i FORCE + $(call if_changed,bmacros) diff --git a/drivers/tty/bmacros.c b/drivers/tty/bmacros.c new file mode 100644 index 000000000000..0af865ff00de --- /dev/null +++ b/drivers/tty/bmacros.c @@ -0,0 +1,2 @@ +/* This file is used to extract the B... macros from header files */ +#include <linux/termios.h> diff --git a/drivers/tty/tty_baudrate.c b/drivers/tty/tty_baudrate.c index 7576ceace571..5a41eda7912a 100644 --- a/drivers/tty/tty_baudrate.c +++ b/drivers/tty/tty_baudrate.c @@ -9,43 +9,56 @@ #include <linux/tty.h> #include <linux/export.h>
- /* - * Routine which returns the baud rate of the tty - * - * Note that the baud_table needs to be kept in sync with the - * include/asm/termbits.h file. + * Routine which returns the baud rate of the tty. The B... constants + * are extracted from the appropriate header files via + * bmacros.c -> bmacros.h. */ -static const speed_t baud_table[] = { - 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, - 9600, 19200, 38400, 57600, 115200, 230400, 460800, -#ifdef __sparc__ - 76800, 153600, 307200, 614400, 921600 -#else - 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000, - 2500000, 3000000, 3500000, 4000000 + +/* CBAUD mask with CBAUDEX removed */ +#define CBAUDNX (CBAUD & ~CBAUDEX) + +/* Lowest bit in CBAUDEX, if any. CBAUDEX is assumed contiguous. */ +#define CBAUDEL (CBAUDEX & ~(CBAUDEX << 1)) +#if CBAUDEL & (CBAUDEL-1) +# error "CBAUDEX is not contiguous" #endif -};
-#ifndef __sparc__ -static const tcflag_t baud_bits[] = { - B0, B50, B75, B110, B134, B150, B200, B300, B600, - B1200, B1800, B2400, B4800, B9600, B19200, B38400, - B57600, B115200, B230400, B460800, B500000, B576000, - B921600, B1000000, B1152000, B1500000, B2000000, B2500000, - B3000000, B3500000, B4000000 -}; -#else -static const tcflag_t baud_bits[] = { - B0, B50, B75, B110, B134, B150, B200, B300, B600, - B1200, B1800, B2400, B4800, B9600, B19200, B38400, - B57600, B115200, B230400, B460800, B76800, B153600, - B307200, B614400, B921600 +/* Convert from B... constant to table position */ +#define BPOS(x) (((x) & CBAUDNX) + \ + (CBAUDEX ? ((x) & CBAUDEX)/CBAUDEL*(CBAUDNX+1) : 0)) + +/* Convert from table position to B... constant */ +#define BVAL(x) (((x) & CBAUDNX) + (((x)/(CBAUDNX+1)*CBAUDEX) & CBAUDEX)) + +/* Entry into the baud_table */ +#define BTBL(b,v) [BPOS(b)] = (v), + +static const speed_t baud_table[] = { +#include "bmacros.h" }; -#endif
static int n_baud_table = ARRAY_SIZE(baud_table);
+/* Helper function; will be called with cbaud already masked */ +static speed_t _tty_termios_baud_rate(unsigned int cbaud, speed_t bother_speed) +{ + /* Magic token for arbitrary speed via c_ispeed/c_ospeed */ + if (cbaud == BOTHER) + return bother_speed; + + cbaud = BPOS(cbaud); + + /* If CBAUDEX != 0, and we overrun the table, try dropping CBAUDEX */ + if (cbaud & ~CBAUDNX) { + if (BPOS(cbaud) >= n_baud_table) { + /* Try without CBAUDEX */ + cbaud &= ~CBAUDNX; + } + } + return (cbaud >= n_baud_table) ? 0 : baud_table[cbaud]; +} + /** * tty_termios_baud_rate * @termios: termios structure @@ -60,24 +73,8 @@ static int n_baud_table = ARRAY_SIZE(baud_table);
speed_t tty_termios_baud_rate(struct ktermios *termios) { - unsigned int cbaud; - - cbaud = termios->c_cflag & CBAUD; - -#ifdef BOTHER - /* Magic token for arbitrary speed via c_ispeed/c_ospeed */ - if (cbaud == BOTHER) - return termios->c_ospeed; -#endif - if (cbaud & CBAUDEX) { - cbaud &= ~CBAUDEX; - - if (cbaud < 1 || cbaud + 15 > n_baud_table) - termios->c_cflag &= ~CBAUDEX; - else - cbaud += 15; - } - return baud_table[cbaud]; + return _tty_termios_baud_rate(termios->c_cflag & CBAUD, + termios->c_ospeed); } EXPORT_SYMBOL(tty_termios_baud_rate);
@@ -95,28 +92,15 @@ EXPORT_SYMBOL(tty_termios_baud_rate);
speed_t tty_termios_input_baud_rate(struct ktermios *termios) { -#ifdef IBSHIFT - unsigned int cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD; - - if (cbaud == B0) - return tty_termios_baud_rate(termios); -#ifdef BOTHER - /* Magic token for arbitrary speed via c_ispeed*/ - if (cbaud == BOTHER) - return termios->c_ispeed; -#endif - if (cbaud & CBAUDEX) { - cbaud &= ~CBAUDEX; + unsigned int cbaud; + speed_t bother_speed = termios->c_ispeed;
- if (cbaud < 1 || cbaud + 15 > n_baud_table) - termios->c_cflag &= ~(CBAUDEX << IBSHIFT); - else - cbaud += 15; + cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD; + if (cbaud == B0) { + cbaud = termios->c_cflag & CBAUD; + bother_speed = termios->c_ospeed; } - return baud_table[cbaud]; -#else /* IBSHIFT */ - return tty_termios_baud_rate(termios); -#endif /* IBSHIFT */ + return _tty_termios_baud_rate(cbaud, bother_speed); } EXPORT_SYMBOL(tty_termios_input_baud_rate);
@@ -145,38 +129,27 @@ EXPORT_SYMBOL(tty_termios_input_baud_rate); void tty_termios_encode_baud_rate(struct ktermios *termios, speed_t ibaud, speed_t obaud) { - int i = 0; - int ifound = -1, ofound = -1; + int i; + unsigned int ifound, ofound; int iclose = ibaud/50, oclose = obaud/50; - int ibinput = 0; + bool ibinput = false;
- if (obaud == 0) /* CD dropped */ + if (obaud == 0) /* CD dropped */ ibaud = 0; /* Clear ibaud to be sure */
termios->c_ispeed = ibaud; termios->c_ospeed = obaud;
-#ifdef IBSHIFT - if ((termios->c_cflag >> IBSHIFT) & CBAUD) - ibinput = 1; /* An input speed was specified */ -#endif -#ifdef BOTHER + ibinput = ((termios->c_cflag >> IBSHIFT) & CBAUD) != B0; + /* If the user asked for a precise weird speed give a precise weird answer. If they asked for a Bfoo speed they may have problems digesting non-exact replies so fuzz a bit */
- if ((termios->c_cflag & CBAUD) == BOTHER) { + if ((termios->c_cflag & CBAUD) == BOTHER) oclose = 0; - if (!ibinput) - iclose = 0; - } if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER) iclose = 0; -#endif - termios->c_cflag &= ~CBAUD; -#ifdef IBSHIFT - termios->c_cflag &= ~(CBAUD << IBSHIFT); -#endif
/* * Our goal is to find a close match to the standard baud rate @@ -184,43 +157,28 @@ void tty_termios_encode_baud_rate(struct ktermios *termios, * match then report back the speed as a POSIX Bxxxx value by * preference */ - - do { + ofound = ifound = BOTHER; + for (i = 0; i < n_baud_table; i++) { if (obaud - oclose <= baud_table[i] && obaud + oclose >= baud_table[i]) { - termios->c_cflag |= baud_bits[i]; - ofound = i; + ofound = BVAL(i); + break; } - if (ibaud - iclose <= baud_table[i] && - ibaud + iclose >= baud_table[i]) { - /* For the case input == output don't set IBAUD bits - if the user didn't do so */ - if (ofound == i && !ibinput) - ifound = i; -#ifdef IBSHIFT - else { - ifound = i; - termios->c_cflag |= (baud_bits[i] << IBSHIFT); + } + if (!ibinput) { + ifound = 0; + } else { + for (i = 0; i < n_baud_table; i++) { + if (ibaud - iclose <= baud_table[i] && + ibaud + iclose >= baud_table[i]) { + ifound = BVAL(i); + break; } -#endif } - } while (++i < n_baud_table); + }
- /* - * If we found no match then use BOTHER if provided or warn - * the user their platform maintainer needs to wake up if not. - */ -#ifdef BOTHER - if (ofound == -1) - termios->c_cflag |= BOTHER; - /* Set exact input bits only if the input and output differ or the - user already did */ - if (ifound == -1 && (ibaud != obaud || ibinput)) - termios->c_cflag |= (BOTHER << IBSHIFT); -#else - if (ifound == -1 || ofound == -1) - pr_warn_once("tty: Unable to return correct speed data as your architecture needs updating.\n"); -#endif + termios->c_cflag &= ~(CBAUD | (CBAUD << IBSHIFT)); + termios->c_cflag |= ofound | (ifound << IBSHIFT); } EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate);
linux-stable-mirror@lists.linaro.org
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H. Peter Anvin