Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 329 insertions, 0 deletions

diff --git a/arch/m68k/atari/debug.c b/arch/m68k/atari/debug.c
new file mode 100644
index 000000000..03cb5e08d
--- /dev/null
+++ b/arch/m68k/atari/debug.c
@@ -0,0 +1,329 @@
+/*
+ * linux/arch/m68k/atari/debug.c
+ *
+ * Atari debugging and serial console stuff
+ *
+ * Assembled of parts of former atari/config.c 97-12-18 by Roman Hodek
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/types.h>
+#include <linux/tty.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+
+#include <asm/atarihw.h>
+#include <asm/atariints.h>
+
+/* Can be set somewhere, if a SCC master reset has already be done and should
+ * not be repeated; used by kgdb */
+int atari_SCC_reset_done;
+EXPORT_SYMBOL(atari_SCC_reset_done);
+
+static struct console atari_console_driver = {
+	.name	= "debug",
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+};
+
+
+static inline void ata_mfp_out(char c)
+{
+	while (!(st_mfp.trn_stat & 0x80))	/* wait for tx buf empty */
+		barrier();
+	st_mfp.usart_dta = c;
+}
+
+static void atari_mfp_console_write(struct console *co, const char *str,
+				    unsigned int count)
+{
+	while (count--) {
+		if (*str == '\n')
+			ata_mfp_out('\r');
+		ata_mfp_out(*str++);
+	}
+}
+
+static inline void ata_scc_out(char c)
+{
+	do {
+		MFPDELAY();
+	} while (!(atari_scc.cha_b_ctrl & 0x04)); /* wait for tx buf empty */
+	MFPDELAY();
+	atari_scc.cha_b_data = c;
+}
+
+static void atari_scc_console_write(struct console *co, const char *str,
+				    unsigned int count)
+{
+	while (count--) {
+		if (*str == '\n')
+			ata_scc_out('\r');
+		ata_scc_out(*str++);
+	}
+}
+
+static inline void ata_midi_out(char c)
+{
+	while (!(acia.mid_ctrl & ACIA_TDRE))	/* wait for tx buf empty */
+		barrier();
+	acia.mid_data = c;
+}
+
+static void atari_midi_console_write(struct console *co, const char *str,
+				     unsigned int count)
+{
+	while (count--) {
+		if (*str == '\n')
+			ata_midi_out('\r');
+		ata_midi_out(*str++);
+	}
+}
+
+static int ata_par_out(char c)
+{
+	unsigned char tmp;
+	/* This a some-seconds timeout in case no printer is connected */
+	unsigned long i = loops_per_jiffy > 1 ? loops_per_jiffy : 10000000/HZ;
+
+	while ((st_mfp.par_dt_reg & 1) && --i) /* wait for BUSY == L */
+		;
+	if (!i)
+		return 0;
+
+	sound_ym.rd_data_reg_sel = 15;	/* select port B */
+	sound_ym.wd_data = c;		/* put char onto port */
+	sound_ym.rd_data_reg_sel = 14;	/* select port A */
+	tmp = sound_ym.rd_data_reg_sel;
+	sound_ym.wd_data = tmp & ~0x20;	/* set strobe L */
+	MFPDELAY();			/* wait a bit */
+	sound_ym.wd_data = tmp | 0x20;	/* set strobe H */
+	return 1;
+}
+
+static void atari_par_console_write(struct console *co, const char *str,
+				    unsigned int count)
+{
+	static int printer_present = 1;
+
+	if (!printer_present)
+		return;
+
+	while (count--) {
+		if (*str == '\n') {
+			if (!ata_par_out('\r')) {
+				printer_present = 0;
+				return;
+			}
+		}
+		if (!ata_par_out(*str++)) {
+			printer_present = 0;
+			return;
+		}
+	}
+}
+
+#if 0
+int atari_mfp_console_wait_key(struct console *co)
+{
+	while (!(st_mfp.rcv_stat & 0x80))	/* wait for rx buf filled */
+		barrier();
+	return st_mfp.usart_dta;
+}
+
+int atari_scc_console_wait_key(struct console *co)
+{
+	do {
+		MFPDELAY();
+	} while (!(atari_scc.cha_b_ctrl & 0x01)); /* wait for rx buf filled */
+	MFPDELAY();
+	return atari_scc.cha_b_data;
+}
+
+int atari_midi_console_wait_key(struct console *co)
+{
+	while (!(acia.mid_ctrl & ACIA_RDRF)) /* wait for rx buf filled */
+		barrier();
+	return acia.mid_data;
+}
+#endif
+
+/*
+ * The following two functions do a quick'n'dirty initialization of the MFP or
+ * SCC serial ports. They're used by the debugging interface, kgdb, and the
+ * serial console code.
+ */
+static void __init atari_init_mfp_port(int cflag)
+{
+	/*
+	 * timer values for 1200...115200 bps; > 38400 select 110, 134, or 150
+	 * bps, resp., and work only correct if there's a RSVE or RSSPEED
+	 */
+	static int baud_table[9] = { 16, 11, 8, 4, 2, 1, 175, 143, 128 };
+	int baud = cflag & CBAUD;
+	int parity = (cflag & PARENB) ? ((cflag & PARODD) ? 0x04 : 0x06) : 0;
+	int csize = ((cflag & CSIZE) == CS7) ? 0x20 : 0x00;
+
+	if (cflag & CBAUDEX)
+		baud += B38400;
+	if (baud < B1200 || baud > B38400+2)
+		baud = B9600;		/* use default 9600bps for non-implemented rates */
+	baud -= B1200;			/* baud_table[] starts at 1200bps */
+
+	st_mfp.trn_stat &= ~0x01;	/* disable TX */
+	st_mfp.usart_ctr = parity | csize | 0x88; /* 1:16 clk mode, 1 stop bit */
+	st_mfp.tim_ct_cd &= 0x70;	/* stop timer D */
+	st_mfp.tim_dt_d = baud_table[baud];
+	st_mfp.tim_ct_cd |= 0x01;	/* start timer D, 1:4 */
+	st_mfp.trn_stat |= 0x01;	/* enable TX */
+}
+
+#define SCC_WRITE(reg, val)				\
+	do {						\
+		atari_scc.cha_b_ctrl = (reg);		\
+		MFPDELAY();				\
+		atari_scc.cha_b_ctrl = (val);		\
+		MFPDELAY();				\
+	} while (0)
+
+/* loops_per_jiffy isn't initialized yet, so we can't use udelay(). This does a
+ * delay of ~ 60us. */
+#define LONG_DELAY()					\
+	do {						\
+		int i;					\
+		for (i = 100; i > 0; --i)		\
+			MFPDELAY();			\
+	} while (0)
+
+static void __init atari_init_scc_port(int cflag)
+{
+	static int clksrc_table[9] =
+		/* reg 11: 0x50 = BRG, 0x00 = RTxC, 0x28 = TRxC */
+		{ 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x50, 0x00, 0x00 };
+	static int brgsrc_table[9] =
+		/* reg 14: 0 = RTxC, 2 = PCLK */
+		{ 2, 2, 2, 2, 2, 2, 0, 2, 2 };
+	static int clkmode_table[9] =
+		/* reg 4: 0x40 = x16, 0x80 = x32, 0xc0 = x64 */
+		{ 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0xc0, 0x80 };
+	static int div_table[9] =
+		/* reg12 (BRG low) */
+		{ 208, 138, 103, 50, 24, 11, 1, 0, 0 };
+
+	int baud = cflag & CBAUD;
+	int clksrc, clkmode, div, reg3, reg5;
+
+	if (cflag & CBAUDEX)
+		baud += B38400;
+	if (baud < B1200 || baud > B38400+2)
+		baud = B9600;		/* use default 9600bps for non-implemented rates */
+	baud -= B1200;			/* tables starts at 1200bps */
+
+	clksrc  = clksrc_table[baud];
+	clkmode = clkmode_table[baud];
+	div     = div_table[baud];
+	if (ATARIHW_PRESENT(TT_MFP) && baud >= 6) {
+		/* special treatment for TT, where rates >= 38400 are done via TRxC */
+		clksrc = 0x28;		/* TRxC */
+		clkmode = baud == 6 ? 0xc0 :
+			  baud == 7 ? 0x80 : /* really 76800bps */
+				      0x40;  /* really 153600bps */
+		div = 0;
+	}
+
+	reg3 = (cflag & CSIZE) == CS8 ? 0xc0 : 0x40;
+	reg5 = (cflag & CSIZE) == CS8 ? 0x60 : 0x20 | 0x82 /* assert DTR/RTS */;
+
+	(void)atari_scc.cha_b_ctrl;	/* reset reg pointer */
+	SCC_WRITE(9, 0xc0);		/* reset */
+	LONG_DELAY();			/* extra delay after WR9 access */
+	SCC_WRITE(4, (cflag & PARENB) ? ((cflag & PARODD) ? 0x01 : 0x03)
+				      : 0 | 0x04 /* 1 stopbit */ | clkmode);
+	SCC_WRITE(3, reg3);
+	SCC_WRITE(5, reg5);
+	SCC_WRITE(9, 0);		/* no interrupts */
+	LONG_DELAY();			/* extra delay after WR9 access */
+	SCC_WRITE(10, 0);		/* NRZ mode */
+	SCC_WRITE(11, clksrc);		/* main clock source */
+	SCC_WRITE(12, div);		/* BRG value */
+	SCC_WRITE(13, 0);		/* BRG high byte */
+	SCC_WRITE(14, brgsrc_table[baud]);
+	SCC_WRITE(14, brgsrc_table[baud] | (div ? 1 : 0));
+	SCC_WRITE(3, reg3 | 1);
+	SCC_WRITE(5, reg5 | 8);
+
+	atari_SCC_reset_done = 1;
+}
+
+static void __init atari_init_midi_port(int cflag)
+{
+	int baud = cflag & CBAUD;
+	int csize = ((cflag & CSIZE) == CS8) ? 0x10 : 0x00;
+	/* warning 7N1 isn't possible! (instead 7O2 is used...) */
+	int parity = (cflag & PARENB) ? ((cflag & PARODD) ? 0x0c : 0x08) : 0x04;
+	int div;
+
+	/* 4800 selects 7812.5, 115200 selects 500000, all other (incl. 9600 as
+	 * default) the standard MIDI speed 31250. */
+	if (cflag & CBAUDEX)
+		baud += B38400;
+	if (baud == B4800)
+		div = ACIA_DIV64;	/* really 7812.5 bps */
+	else if (baud == B38400+2 /* 115200 */)
+		div = ACIA_DIV1;	/* really 500 kbps (does that work??) */
+	else
+		div = ACIA_DIV16;	/* 31250 bps, standard for MIDI */
+
+	/* RTS low, ints disabled */
+	acia.mid_ctrl = div | csize | parity |
+		    ((atari_switches & ATARI_SWITCH_MIDI) ?
+		     ACIA_RHTID : ACIA_RLTID);
+}
+
+static int __init atari_debug_setup(char *arg)
+{
+	bool registered;
+
+	if (!MACH_IS_ATARI)
+		return 0;
+
+	if (!strcmp(arg, "ser"))
+		/* defaults to ser2 for a Falcon and ser1 otherwise */
+		arg = MACH_IS_FALCON ? "ser2" : "ser1";
+
+	registered = !!atari_console_driver.write;
+	if (!strcmp(arg, "ser1")) {
+		/* ST-MFP Modem1 serial port */
+		atari_init_mfp_port(B9600|CS8);
+		atari_console_driver.write = atari_mfp_console_write;
+	} else if (!strcmp(arg, "ser2")) {
+		/* SCC Modem2 serial port */
+		atari_init_scc_port(B9600|CS8);
+		atari_console_driver.write = atari_scc_console_write;
+	} else if (!strcmp(arg, "midi")) {
+		/* MIDI port */
+		atari_init_midi_port(B9600|CS8);
+		atari_console_driver.write = atari_midi_console_write;
+	} else if (!strcmp(arg, "par")) {
+		/* parallel printer */
+		atari_turnoff_irq(IRQ_MFP_BUSY); /* avoid ints */
+		sound_ym.rd_data_reg_sel = 7;	/* select mixer control */
+		sound_ym.wd_data = 0xff;	/* sound off, ports are output */
+		sound_ym.rd_data_reg_sel = 15;	/* select port B */
+		sound_ym.wd_data = 0;		/* no char */
+		sound_ym.rd_data_reg_sel = 14;	/* select port A */
+		sound_ym.wd_data = sound_ym.rd_data_reg_sel | 0x20; /* strobe H */
+		atari_console_driver.write = atari_par_console_write;
+	}
+	if (atari_console_driver.write && !registered)
+		register_console(&atari_console_driver);
+
+	return 0;
+}
+
+early_param("debug", atari_debug_setup);