From 904326ecac022ebaeb39cdfb206fd3b6551cdfca Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Thu, 16 Oct 2014 16:54:21 -0400 Subject: tty,serial: Unify UPF_* and ASYNC_* flag definitions The userspace-defined ASYNC_* flags in include/uapi/linux/tty_flags.h are the authoritative bit definitions for the serial_struct flags, and thus for any derivative values or fields. Although the serial core provides the TIOCSSERIAL and TIOCGSERIAL ioctls to set and retrieve these flags from userspace, it defines these bits independently, as UPF_* macros. Define the UPF_* macros which are userspace-modifiable directly from the ASYNC_* symbolic constants. Add compile-time test to ensure the bits changeable by TIOCSSERIAL match the defined range in the uapi header. Add ASYNCB_MAGIC_MULTIPLIER to the uapi header since this bit is programmable by userspace. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- include/uapi/linux/tty_flags.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'include/uapi/linux/tty_flags.h') diff --git a/include/uapi/linux/tty_flags.h b/include/uapi/linux/tty_flags.h index eefcb483a2c0..7b516f7ee7e6 100644 --- a/include/uapi/linux/tty_flags.h +++ b/include/uapi/linux/tty_flags.h @@ -6,6 +6,8 @@ * shared by the tty_port flags structures. * * Define ASYNCB_* for convenient use with {test,set,clear}_bit. + * + * Bits [0..ASYNCB_LAST_USER] are userspace defined/visible/changeable */ #define ASYNCB_HUP_NOTIFY 0 /* Notify getty on hangups and closes * on the callout port */ @@ -26,7 +28,8 @@ #define ASYNCB_BUGGY_UART 14 /* This is a buggy UART, skip some safety * checks. Note: can be dangerous! */ #define ASYNCB_AUTOPROBE 15 /* Port was autoprobed by PCI or PNP code */ -#define ASYNCB_LAST_USER 15 +#define ASYNCB_MAGIC_MULTIPLIER 16 /* Use special CLK or divisor */ +#define ASYNCB_LAST_USER 16 /* Internal flags used only by kernel */ #define ASYNCB_INITIALIZED 31 /* Serial port was initialized */ @@ -57,6 +60,7 @@ #define ASYNC_LOW_LATENCY (1U << ASYNCB_LOW_LATENCY) #define ASYNC_BUGGY_UART (1U << ASYNCB_BUGGY_UART) #define ASYNC_AUTOPROBE (1U << ASYNCB_AUTOPROBE) +#define ASYNC_MAGIC_MULTIPLIER (1U << ASYNCB_MAGIC_MULTIPLIER) #define ASYNC_FLAGS ((1U << (ASYNCB_LAST_USER + 1)) - 1) #define ASYNC_USR_MASK (ASYNC_SPD_MASK|ASYNC_CALLOUT_NOHUP| \ -- cgit From 352f86187e1d3e9e27d3be237103dc83a48f882c Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Thu, 16 Oct 2014 16:54:22 -0400 Subject: tty: Document defunct ASYNC_* bits in uapi header Note the serial_struct flags for which the kernel ignores and performs no action. The flags cannot be removed since they form part of the userspace interface via the TIOCSSERIAL/TIOCGSERIAL ioctls. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- include/uapi/linux/tty_flags.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'include/uapi/linux/tty_flags.h') diff --git a/include/uapi/linux/tty_flags.h b/include/uapi/linux/tty_flags.h index 7b516f7ee7e6..4e021e31c219 100644 --- a/include/uapi/linux/tty_flags.h +++ b/include/uapi/linux/tty_flags.h @@ -8,6 +8,7 @@ * Define ASYNCB_* for convenient use with {test,set,clear}_bit. * * Bits [0..ASYNCB_LAST_USER] are userspace defined/visible/changeable + * [x] in the bit comments indicates the flag is defunct and no longer used. */ #define ASYNCB_HUP_NOTIFY 0 /* Notify getty on hangups and closes * on the callout port */ @@ -19,15 +20,15 @@ #define ASYNCB_SKIP_TEST 6 /* Skip UART test during autoconfiguration */ #define ASYNCB_AUTO_IRQ 7 /* Do automatic IRQ during * autoconfiguration */ -#define ASYNCB_SESSION_LOCKOUT 8 /* Lock out cua opens based on session */ -#define ASYNCB_PGRP_LOCKOUT 9 /* Lock out cua opens based on pgrp */ -#define ASYNCB_CALLOUT_NOHUP 10 /* Don't do hangups for cua device */ +#define ASYNCB_SESSION_LOCKOUT 8 /* [x] Lock out cua opens based on session */ +#define ASYNCB_PGRP_LOCKOUT 9 /* [x] Lock out cua opens based on pgrp */ +#define ASYNCB_CALLOUT_NOHUP 10 /* [x] Don't do hangups for cua device */ #define ASYNCB_HARDPPS_CD 11 /* Call hardpps when CD goes high */ #define ASYNCB_SPD_SHI 12 /* Use 230400 instead of 38400 bps */ #define ASYNCB_LOW_LATENCY 13 /* Request low latency behaviour */ #define ASYNCB_BUGGY_UART 14 /* This is a buggy UART, skip some safety * checks. Note: can be dangerous! */ -#define ASYNCB_AUTOPROBE 15 /* Port was autoprobed by PCI or PNP code */ +#define ASYNCB_AUTOPROBE 15 /* [x] Port was autoprobed by PCI/PNP code */ #define ASYNCB_MAGIC_MULTIPLIER 16 /* Use special CLK or divisor */ #define ASYNCB_LAST_USER 16 -- cgit From 5ac9c05d789044d30735402f387355a394ec8e18 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Wed, 5 Nov 2014 12:26:30 -0500 Subject: tty: Document defunct ASYNC_SPLIT_TERMIOS flag in uapi header The last vestige of ASYNC_SPLIT_TERMIOS was removed by commit 'cris: Remove obsolete ASYNC_SPLIT_TERMIOS behavior'. Mark the flag as defunct in the uapi header. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- include/uapi/linux/tty_flags.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/uapi/linux/tty_flags.h') diff --git a/include/uapi/linux/tty_flags.h b/include/uapi/linux/tty_flags.h index 4e021e31c219..d2bc4ff94f43 100644 --- a/include/uapi/linux/tty_flags.h +++ b/include/uapi/linux/tty_flags.h @@ -14,7 +14,7 @@ * on the callout port */ #define ASYNCB_FOURPORT 1 /* Set OU1, OUT2 per AST Fourport settings */ #define ASYNCB_SAK 2 /* Secure Attention Key (Orange book) */ -#define ASYNCB_SPLIT_TERMIOS 3 /* Separate termios for dialin/callout */ +#define ASYNCB_SPLIT_TERMIOS 3 /* [x] Separate termios for dialin/callout */ #define ASYNCB_SPD_HI 4 /* Use 56000 instead of 38400 bps */ #define ASYNCB_SPD_VHI 5 /* Use 115200 instead of 38400 bps */ #define ASYNCB_SKIP_TEST 6 /* Skip UART test during autoconfiguration */ -- cgit From 8a8ae62f8296760a2a1eee7009a1444c327603e0 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Thu, 6 Nov 2014 16:56:33 +0100 Subject: tty: warn on deprecated serial flags When somebody calls TIOCSSERIAL ioctl with serial flags to set one of * ASYNC_SESSION_LOCKOUT * ASYNC_PGRP_LOCKOUT * ASYNC_CALLOUT_NOHUP * ASYNC_AUTOPROBE nothing happens. We actually ignore the flags for over a decade at least (I checked 2.6.0). So start yelling at users who use those flags, that they shouldn't. Signed-off-by: Jiri Slaby Cc: Peter Hurley Cc: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_io.c | 21 +++++++++++++++++++++ include/uapi/linux/tty_flags.h | 2 ++ 2 files changed, 23 insertions(+) (limited to 'include/uapi/linux/tty_flags.h') diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 01d45fd7d359..705885891b87 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2760,6 +2760,24 @@ static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) return 0; } +static void tty_warn_deprecated_flags(struct serial_struct __user *ss) +{ + static DEFINE_RATELIMIT_STATE(depr_flags, + DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); + char comm[TASK_COMM_LEN]; + int flags; + + if (get_user(flags, &ss->flags)) + return; + + flags &= ASYNC_DEPRECATED; + + if (flags && __ratelimit(&depr_flags)) + pr_warning("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", + __func__, get_task_comm(comm, current), flags); +} + /* * if pty, return the slave side (real_tty) * otherwise, return self @@ -2903,6 +2921,9 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) break; } break; + case TIOCSSERIAL: + tty_warn_deprecated_flags(p); + break; } if (tty->ops->ioctl) { retval = tty->ops->ioctl(tty, cmd, arg); diff --git a/include/uapi/linux/tty_flags.h b/include/uapi/linux/tty_flags.h index d2bc4ff94f43..fae4864737fa 100644 --- a/include/uapi/linux/tty_flags.h +++ b/include/uapi/linux/tty_flags.h @@ -64,6 +64,8 @@ #define ASYNC_MAGIC_MULTIPLIER (1U << ASYNCB_MAGIC_MULTIPLIER) #define ASYNC_FLAGS ((1U << (ASYNCB_LAST_USER + 1)) - 1) +#define ASYNC_DEPRECATED (ASYNC_SESSION_LOCKOUT | ASYNC_PGRP_LOCKOUT | \ + ASYNC_CALLOUT_NOHUP | ASYNC_AUTOPROBE) #define ASYNC_USR_MASK (ASYNC_SPD_MASK|ASYNC_CALLOUT_NOHUP| \ ASYNC_LOW_LATENCY) #define ASYNC_SPD_CUST (ASYNC_SPD_HI|ASYNC_SPD_VHI) -- cgit