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authorKees Cook <kees+treewide@kernel.org>2026-09-02 15:31:14 -0700
committerKees Cook <kees@kernel.org>2026-09-04 21:37:00 -0700
commit3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch)
treec65086f9bdcd48c6360fb7cb4598bca084da1f32 /drivers/tty/tty_baudrate.c
downloadlinux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz
linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip
treewide: refresh kmalloc_obj() conversionsgrafted
This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook <kees+treewide@kernel.org>
Diffstat (limited to 'drivers/tty/tty_baudrate.c')
-rw-r--r--drivers/tty/tty_baudrate.c215
1 files changed, 215 insertions, 0 deletions
diff --git a/drivers/tty/tty_baudrate.c b/drivers/tty/tty_baudrate.c
new file mode 100644
index 000000000..f9b49939c
--- /dev/null
+++ b/drivers/tty/tty_baudrate.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/termios.h>
+#include <linux/tty.h>
+#include <linux/export.h>
+#include "tty.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.
+ */
+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, 500000, 576000,
+ 1000000, 1152000, 1500000, 2000000
+#else
+ 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
+ 2500000, 3000000, 3500000, 4000000
+#endif
+};
+
+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,
+#ifdef __sparc__
+ B76800, B153600, B307200, B614400, B921600, B500000, B576000,
+ B1000000, B1152000, B1500000, B2000000
+#else
+ B500000, B576000, B921600, B1000000, B1152000, B1500000, B2000000,
+ B2500000, B3000000, B3500000, B4000000
+#endif
+};
+
+static int n_baud_table = ARRAY_SIZE(baud_table);
+
+/**
+ * tty_termios_baud_rate
+ * @termios: termios structure
+ *
+ * Convert termios baud rate data into a speed. This should be called
+ * with the termios lock held if this termios is a terminal termios
+ * structure. Device drivers can call this function but should use
+ * ->c_[io]speed directly as they are updated.
+ *
+ * Locking: none
+ */
+
+speed_t tty_termios_baud_rate(const struct ktermios *termios)
+{
+ unsigned int cbaud;
+
+ cbaud = termios->c_cflag & CBAUD;
+
+ /* Magic token for arbitrary speed via c_ispeed/c_ospeed */
+ if (cbaud == BOTHER)
+ return termios->c_ospeed;
+
+ if (cbaud & CBAUDEX) {
+ cbaud &= ~CBAUDEX;
+ cbaud += 15;
+ }
+ return cbaud >= n_baud_table ? 0 : baud_table[cbaud];
+}
+EXPORT_SYMBOL(tty_termios_baud_rate);
+
+/**
+ * tty_termios_input_baud_rate
+ * @termios: termios structure
+ *
+ * Convert termios baud rate data into a speed. This should be called
+ * with the termios lock held if this termios is a terminal termios
+ * structure. Device drivers can call this function but should use
+ * ->c_[io]speed directly as they are updated.
+ *
+ * Locking: none
+ */
+
+speed_t tty_termios_input_baud_rate(const struct ktermios *termios)
+{
+ unsigned int cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD;
+
+ if (cbaud == B0)
+ return tty_termios_baud_rate(termios);
+
+ /* Magic token for arbitrary speed via c_ispeed */
+ if (cbaud == BOTHER)
+ return termios->c_ispeed;
+
+ if (cbaud & CBAUDEX) {
+ cbaud &= ~CBAUDEX;
+ cbaud += 15;
+ }
+ return cbaud >= n_baud_table ? 0 : baud_table[cbaud];
+}
+EXPORT_SYMBOL(tty_termios_input_baud_rate);
+
+/**
+ * tty_termios_encode_baud_rate
+ * @termios: ktermios structure holding user requested state
+ * @ibaud: input speed
+ * @obaud: output speed
+ *
+ * Encode the speeds set into the passed termios structure. This is
+ * used as a library helper for drivers so that they can report back
+ * the actual speed selected when it differs from the speed requested
+ *
+ * For maximal back compatibility with legacy SYS5/POSIX *nix behaviour
+ * we need to carefully set the bits when the user does not get the
+ * desired speed. We allow small margins and preserve as much of possible
+ * of the input intent to keep compatibility.
+ *
+ * Locking: Caller should hold termios lock. This is already held
+ * when calling this function from the driver termios handler.
+ *
+ * The ifdefs deal with platforms whose owners have yet to update them
+ * and will all go away once this is done.
+ */
+
+void tty_termios_encode_baud_rate(struct ktermios *termios,
+ speed_t ibaud, speed_t obaud)
+{
+ int i = 0;
+ int ifound = -1, ofound = -1;
+ int iclose = ibaud/50, oclose = obaud/50;
+ int ibinput = 0;
+
+ if (obaud == 0) /* CD dropped */
+ ibaud = 0; /* Clear ibaud to be sure */
+
+ termios->c_ispeed = ibaud;
+ termios->c_ospeed = obaud;
+
+ if (((termios->c_cflag >> IBSHIFT) & CBAUD) != B0)
+ ibinput = 1; /* An input speed was specified */
+
+ /* 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) {
+ oclose = 0;
+ if (!ibinput)
+ iclose = 0;
+ }
+ if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER)
+ iclose = 0;
+
+ termios->c_cflag &= ~CBAUD;
+ termios->c_cflag &= ~(CBAUD << IBSHIFT);
+
+ /*
+ * Our goal is to find a close match to the standard baud rate
+ * returned. Walk the baud rate table and if we get a very close
+ * match then report back the speed as a POSIX Bxxxx value by
+ * preference
+ */
+
+ do {
+ if (obaud - oclose <= baud_table[i] &&
+ obaud + oclose >= baud_table[i]) {
+ termios->c_cflag |= baud_bits[i];
+ ofound = i;
+ }
+ 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;
+ } else {
+ ifound = i;
+ termios->c_cflag |= (baud_bits[i] << IBSHIFT);
+ }
+ }
+ } while (++i < n_baud_table);
+
+ /* If we found no match then use 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);
+}
+EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate);
+
+/**
+ * tty_encode_baud_rate - set baud rate of the tty
+ * @tty: terminal device
+ * @ibaud: input baud rate
+ * @obaud: output baud rate
+ *
+ * Update the current termios data for the tty with the new speed
+ * settings. The caller must hold the termios_rwsem for the tty in
+ * question.
+ */
+
+void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud)
+{
+ tty_termios_encode_baud_rate(&tty->termios, ibaud, obaud);
+}
+EXPORT_SYMBOL_GPL(tty_encode_baud_rate);