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, 295 insertions, 0 deletions

diff --git a/arch/powerpc/boot/cpm-serial.c b/arch/powerpc/boot/cpm-serial.c
new file mode 100644
index 000000000..dfb56829c
--- /dev/null
+++ b/arch/powerpc/boot/cpm-serial.c
@@ -0,0 +1,295 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CPM serial console support.
+ *
+ * Copyright 2007 Freescale Semiconductor, Inc.
+ * Author: Scott Wood <scottwood@freescale.com>
+ *
+ * It is assumed that the firmware (or the platform file) has already set
+ * up the port.
+ */
+
+#include "types.h"
+#include "io.h"
+#include "ops.h"
+#include "page.h"
+
+struct cpm_scc {
+	u32 gsmrl;
+	u32 gsmrh;
+	u16 psmr;
+	u8 res1[2];
+	u16 todr;
+	u16 dsr;
+	u16 scce;
+	u8 res2[2];
+	u16 sccm;
+	u8 res3;
+	u8 sccs;
+	u8 res4[8];
+};
+
+struct cpm_smc {
+	u8 res1[2];
+	u16 smcmr;
+	u8 res2[2];
+	u8 smce;
+	u8 res3[3];
+	u8 smcm;
+	u8 res4[5];
+};
+
+struct cpm_param {
+	u16 rbase;
+	u16 tbase;
+	u8 rfcr;
+	u8 tfcr;
+	u16 mrblr;
+	u32 rstate;
+	u8 res1[4];
+	u16 rbptr;
+	u8 res2[6];
+	u32 tstate;
+	u8 res3[4];
+	u16 tbptr;
+	u8 res4[6];
+	u16 maxidl;
+	u16 idlc;
+	u16 brkln;
+	u16 brkec;
+	u16 brkcr;
+	u16 rmask;
+	u8 res5[4];
+};
+
+struct cpm_bd {
+	u16 sc;   /* Status and Control */
+	u16 len;  /* Data length in buffer */
+	u8 *addr; /* Buffer address in host memory */
+};
+
+static void *cpcr;
+static struct cpm_param *param;
+static struct cpm_smc *smc;
+static struct cpm_scc *scc;
+static struct cpm_bd *tbdf, *rbdf;
+static u32 cpm_cmd;
+static void *cbd_addr;
+static u32 cbd_offset;
+
+static void (*do_cmd)(int op);
+static void (*enable_port)(void);
+static void (*disable_port)(void);
+
+#define CPM_CMD_STOP_TX     4
+#define CPM_CMD_RESTART_TX  6
+#define CPM_CMD_INIT_RX_TX  0
+
+static void cpm1_cmd(int op)
+{
+	while (in_be16(cpcr) & 1)
+		;
+
+	out_be16(cpcr, (op << 8) | cpm_cmd | 1);
+
+	while (in_be16(cpcr) & 1)
+		;
+}
+
+static void cpm2_cmd(int op)
+{
+	while (in_be32(cpcr) & 0x10000)
+		;
+
+	out_be32(cpcr, op | cpm_cmd | 0x10000);
+
+	while (in_be32(cpcr) & 0x10000)
+		;
+}
+
+static void smc_disable_port(void)
+{
+	do_cmd(CPM_CMD_STOP_TX);
+	out_be16(&smc->smcmr, in_be16(&smc->smcmr) & ~3);
+}
+
+static void scc_disable_port(void)
+{
+	do_cmd(CPM_CMD_STOP_TX);
+	out_be32(&scc->gsmrl, in_be32(&scc->gsmrl) & ~0x30);
+}
+
+static void smc_enable_port(void)
+{
+	out_be16(&smc->smcmr, in_be16(&smc->smcmr) | 3);
+	do_cmd(CPM_CMD_RESTART_TX);
+}
+
+static void scc_enable_port(void)
+{
+	out_be32(&scc->gsmrl, in_be32(&scc->gsmrl) | 0x30);
+	do_cmd(CPM_CMD_RESTART_TX);
+}
+
+static int cpm_serial_open(void)
+{
+	disable_port();
+
+	out_8(&param->rfcr, 0x10);
+	out_8(&param->tfcr, 0x10);
+	out_be16(&param->mrblr, 1);
+	out_be16(&param->maxidl, 0);
+	out_be16(&param->brkec, 0);
+	out_be16(&param->brkln, 0);
+	out_be16(&param->brkcr, 0);
+
+	rbdf = cbd_addr;
+	rbdf->addr = (u8 *)rbdf - 1;
+	rbdf->sc = 0xa000;
+	rbdf->len = 1;
+
+	tbdf = rbdf + 1;
+	tbdf->addr = (u8 *)rbdf - 2;
+	tbdf->sc = 0x2000;
+	tbdf->len = 1;
+
+	sync();
+	out_be16(&param->rbase, cbd_offset);
+	out_be16(&param->tbase, cbd_offset + sizeof(struct cpm_bd));
+
+	do_cmd(CPM_CMD_INIT_RX_TX);
+
+	enable_port();
+	return 0;
+}
+
+static void cpm_serial_putc(unsigned char c)
+{
+	while (tbdf->sc & 0x8000)
+		barrier();
+
+	sync();
+
+	tbdf->addr[0] = c;
+	eieio();
+	tbdf->sc |= 0x8000;
+}
+
+static unsigned char cpm_serial_tstc(void)
+{
+	barrier();
+	return !(rbdf->sc & 0x8000);
+}
+
+static unsigned char cpm_serial_getc(void)
+{
+	unsigned char c;
+
+	while (!cpm_serial_tstc())
+		;
+
+	sync();
+	c = rbdf->addr[0];
+	eieio();
+	rbdf->sc |= 0x8000;
+
+	return c;
+}
+
+int cpm_console_init(void *devp, struct serial_console_data *scdp)
+{
+	void *vreg[2];
+	u32 reg[2];
+	int is_smc = 0, is_cpm2 = 0;
+	void *parent, *muram;
+	void *muram_addr;
+	unsigned long muram_offset, muram_size;
+
+	if (dt_is_compatible(devp, "fsl,cpm1-smc-uart")) {
+		is_smc = 1;
+	} else if (dt_is_compatible(devp, "fsl,cpm2-scc-uart")) {
+		is_cpm2 = 1;
+	} else if (dt_is_compatible(devp, "fsl,cpm2-smc-uart")) {
+		is_cpm2 = 1;
+		is_smc = 1;
+	}
+
+	if (is_smc) {
+		enable_port = smc_enable_port;
+		disable_port = smc_disable_port;
+	} else {
+		enable_port = scc_enable_port;
+		disable_port = scc_disable_port;
+	}
+
+	if (is_cpm2)
+		do_cmd = cpm2_cmd;
+	else
+		do_cmd = cpm1_cmd;
+
+	if (getprop(devp, "fsl,cpm-command", &cpm_cmd, 4) < 4)
+		return -1;
+
+	if (dt_get_virtual_reg(devp, vreg, 2) < 2)
+		return -1;
+
+	if (is_smc)
+		smc = vreg[0];
+	else
+		scc = vreg[0];
+
+	param = vreg[1];
+
+	parent = get_parent(devp);
+	if (!parent)
+		return -1;
+
+	if (dt_get_virtual_reg(parent, &cpcr, 1) < 1)
+		return -1;
+
+	muram = finddevice("/soc/cpm/muram/data");
+	if (!muram)
+		return -1;
+
+	/* For bootwrapper-compatible device trees, we assume that the first
+	 * entry has at least 128 bytes, and that #address-cells/#data-cells
+	 * is one for both parent and child.
+	 */
+
+	if (dt_get_virtual_reg(muram, &muram_addr, 1) < 1)
+		return -1;
+
+	if (getprop(muram, "reg", reg, 8) < 8)
+		return -1;
+
+	muram_offset = reg[0];
+	muram_size = reg[1];
+
+	/* Store the buffer descriptors at the end of the first muram chunk.
+	 * For SMC ports on CPM2-based platforms, relocate the parameter RAM
+	 * just before the buffer descriptors.
+	 */
+
+	cbd_offset = muram_offset + muram_size - 2 * sizeof(struct cpm_bd);
+
+	if (is_cpm2 && is_smc) {
+		u16 *smc_base = (u16 *)param;
+		u16 pram_offset;
+
+		pram_offset = cbd_offset - 64;
+		pram_offset = _ALIGN_DOWN(pram_offset, 64);
+
+		disable_port();
+		out_be16(smc_base, pram_offset);
+		param = muram_addr - muram_offset + pram_offset;
+	}
+
+	cbd_addr = muram_addr - muram_offset + cbd_offset;
+
+	scdp->open = cpm_serial_open;
+	scdp->putc = cpm_serial_putc;
+	scdp->getc = cpm_serial_getc;
+	scdp->tstc = cpm_serial_tstc;
+
+	return 0;
+}