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

2 files changed, 437 insertions, 0 deletions

diff --git a/arch/alpha/boot/tools/mkbb.c b/arch/alpha/boot/tools/mkbb.c
new file mode 100644
index 000000000..fc47f33f8
--- /dev/null
+++ b/arch/alpha/boot/tools/mkbb.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0
+/* This utility makes a bootblock suitable for the SRM console/miniloader */
+
+/* Usage:
+ *	mkbb <device> <lxboot>
+ *
+ * Where <device> is the name of the device to install the bootblock on,
+ * and <lxboot> is the name of a bootblock to merge in.  This bootblock
+ * contains the offset and size of the bootloader.  It must be exactly
+ * 512 bytes long.
+ */
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+/* Minimal definition of disklabel, so we don't have to include
+ * asm/disklabel.h (confuses make)
+ */
+#ifndef MAXPARTITIONS
+#define MAXPARTITIONS   8                       /* max. # of partitions */
+#endif
+
+#ifndef u8
+#define u8 unsigned char
+#endif
+
+#ifndef u16
+#define u16 unsigned short
+#endif
+
+#ifndef u32
+#define u32 unsigned int
+#endif
+
+struct disklabel {
+    u32	d_magic;				/* must be DISKLABELMAGIC */
+    u16	d_type, d_subtype;
+    u8	d_typename[16];
+    u8	d_packname[16];
+    u32	d_secsize;
+    u32	d_nsectors;
+    u32	d_ntracks;
+    u32	d_ncylinders;
+    u32	d_secpercyl;
+    u32	d_secprtunit;
+    u16	d_sparespertrack;
+    u16	d_sparespercyl;
+    u32	d_acylinders;
+    u16	d_rpm, d_interleave, d_trackskew, d_cylskew;
+    u32	d_headswitch, d_trkseek, d_flags;
+    u32	d_drivedata[5];
+    u32	d_spare[5];
+    u32	d_magic2;				/* must be DISKLABELMAGIC */
+    u16	d_checksum;
+    u16	d_npartitions;
+    u32	d_bbsize, d_sbsize;
+    struct d_partition {
+	u32	p_size;
+	u32	p_offset;
+	u32	p_fsize;
+	u8	p_fstype;
+	u8	p_frag;
+	u16	p_cpg;
+    } d_partitions[MAXPARTITIONS];
+};
+
+
+typedef union __bootblock {
+    struct {
+        char			__pad1[64];
+        struct disklabel	__label;
+    } __u1;
+    struct {
+	unsigned long		__pad2[63];
+	unsigned long		__checksum;
+    } __u2;
+    char		bootblock_bytes[512];
+    unsigned long	bootblock_quadwords[64];
+} bootblock;
+
+#define	bootblock_label		__u1.__label
+#define bootblock_checksum	__u2.__checksum
+
+int main(int argc, char ** argv)
+{
+    bootblock		bootblock_from_disk;
+    bootblock		bootloader_image;
+    int			dev, fd;
+    int			i;
+    int			nread;
+
+    /* Make sure of the arg count */
+    if(argc != 3) {
+	fprintf(stderr, "Usage: %s device lxboot\n", argv[0]);
+	exit(0);
+    }
+
+    /* First, open the device and make sure it's accessible */
+    dev = open(argv[1], O_RDWR);
+    if(dev < 0) {
+	perror(argv[1]);
+	exit(0);
+    }
+
+    /* Now open the lxboot and make sure it's reasonable */
+    fd = open(argv[2], O_RDONLY);
+    if(fd < 0) {
+	perror(argv[2]);
+	close(dev);
+	exit(0);
+    }
+
+    /* Read in the lxboot */
+    nread = read(fd, &bootloader_image, sizeof(bootblock));
+    if(nread != sizeof(bootblock)) {
+	perror("lxboot read");
+	fprintf(stderr, "expected %zd, got %d\n", sizeof(bootblock), nread);
+	exit(0);
+    }
+
+    /* Read in the bootblock from disk. */
+    nread = read(dev, &bootblock_from_disk, sizeof(bootblock));
+    if(nread != sizeof(bootblock)) {
+	perror("bootblock read");
+	fprintf(stderr, "expected %zd, got %d\n", sizeof(bootblock), nread);
+	exit(0);
+    }
+
+    /* Swap the bootblock's disklabel into the bootloader */
+    bootloader_image.bootblock_label = bootblock_from_disk.bootblock_label;
+
+    /* Calculate the bootblock checksum */
+    bootloader_image.bootblock_checksum = 0;
+    for(i = 0; i < 63; i++) {
+	bootloader_image.bootblock_checksum += 
+			bootloader_image.bootblock_quadwords[i];
+    }
+
+    /* Write the whole thing out! */
+    lseek(dev, 0L, SEEK_SET);
+    if(write(dev, &bootloader_image, sizeof(bootblock)) != sizeof(bootblock)) {
+	perror("bootblock write");
+	exit(0);
+    }
+
+    close(fd);
+    close(dev);
+    exit(0);
+}
+
+
diff --git a/arch/alpha/boot/tools/objstrip.c b/arch/alpha/boot/tools/objstrip.c
new file mode 100644
index 000000000..7cf92d172
--- /dev/null
+++ b/arch/alpha/boot/tools/objstrip.c
@@ -0,0 +1,284 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * arch/alpha/boot/tools/objstrip.c
+ *
+ * Strip the object file headers/trailers from an executable (ELF or ECOFF).
+ *
+ * Copyright (C) 1996 David Mosberger-Tang.
+ */
+/*
+ * Converts an ECOFF or ELF object file into a bootable file.  The
+ * object file must be a OMAGIC file (i.e., data and bss follow immediately
+ * behind the text).  See DEC "Assembly Language Programmer's Guide"
+ * documentation for details.  The SRM boot process is documented in
+ * the Alpha AXP Architecture Reference Manual, Second Edition by
+ * Richard L. Sites and Richard T. Witek.
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <sys/fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <linux/a.out.h>
+#include <linux/coff.h>
+#include <linux/param.h>
+#ifdef __ELF__
+# include <linux/elf.h>
+# define elfhdr elf64_hdr
+# define elf_phdr elf64_phdr
+# define elf_check_arch(x) ((x)->e_machine == EM_ALPHA)
+#endif
+
+/* bootfile size must be multiple of BLOCK_SIZE: */
+#define BLOCK_SIZE	512
+
+const char * prog_name;
+
+
+static void
+usage (void)
+{
+    fprintf(stderr,
+	    "usage: %s [-v] -p file primary\n"
+	    "       %s [-vb] file [secondary]\n", prog_name, prog_name);
+    exit(1);
+}
+
+
+int
+main (int argc, char *argv[])
+{
+    size_t nwritten, tocopy, n, mem_size, fil_size, pad = 0;
+    int fd, ofd, i, j, verbose = 0, primary = 0;
+    char buf[8192], *inname;
+    struct exec * aout;		/* includes file & aout header */
+    long offset;
+#ifdef __ELF__
+    struct elfhdr *elf;
+    struct elf_phdr *elf_phdr;	/* program header */
+    unsigned long long e_entry;
+#endif
+
+    prog_name = argv[0];
+
+    for (i = 1; i < argc && argv[i][0] == '-'; ++i) {
+	for (j = 1; argv[i][j]; ++j) {
+	    switch (argv[i][j]) {
+	      case 'v':
+		  verbose = ~verbose;
+		  break;
+
+	      case 'b':
+		  pad = BLOCK_SIZE;
+		  break;
+
+	      case 'p':
+		  primary = 1;		/* make primary bootblock */
+		  break;
+	    }
+	}
+    }
+
+    if (i >= argc) {
+	usage();
+    }
+    inname = argv[i++];
+
+    fd = open(inname, O_RDONLY);
+    if (fd == -1) {
+	perror("open");
+	exit(1);
+    }
+
+    ofd = 1;
+    if (i < argc) {
+	ofd = open(argv[i++], O_WRONLY | O_CREAT | O_TRUNC, 0666);
+	if (ofd == -1) {
+	    perror("open");
+	    exit(1);
+	}
+    }
+
+    if (primary) {
+	/* generate bootblock for primary loader */
+	
+	unsigned long bb[64], sum = 0;
+	struct stat st;
+	off_t size;
+	int i;
+
+	if (ofd == 1) {
+	    usage();
+	}
+
+	if (fstat(fd, &st) == -1) {
+	    perror("fstat");
+	    exit(1);
+	}
+
+	size = (st.st_size + BLOCK_SIZE - 1) & ~(BLOCK_SIZE - 1);
+	memset(bb, 0, sizeof(bb));
+	strcpy((char *) bb, "Linux SRM bootblock");
+	bb[60] = size / BLOCK_SIZE;	/* count */
+	bb[61] = 1;			/* starting sector # */
+	bb[62] = 0;			/* flags---must be 0 */
+	for (i = 0; i < 63; ++i) {
+	    sum += bb[i];
+	}
+	bb[63] = sum;
+	if (write(ofd, bb, sizeof(bb)) != sizeof(bb)) {
+	    perror("boot-block write");
+	    exit(1);
+	}
+	printf("%lu\n", size);
+	return 0;
+    }
+
+    /* read and inspect exec header: */
+
+    if (read(fd, buf, sizeof(buf)) < 0) {
+	perror("read");
+	exit(1);
+    }
+
+#ifdef __ELF__
+    elf = (struct elfhdr *) buf;
+
+    if (memcmp(&elf->e_ident[EI_MAG0], ELFMAG, SELFMAG) == 0) {
+	if (elf->e_type != ET_EXEC) {
+	    fprintf(stderr, "%s: %s is not an ELF executable\n",
+		    prog_name, inname);
+	    exit(1);
+	}
+	if (!elf_check_arch(elf)) {
+	    fprintf(stderr, "%s: is not for this processor (e_machine=%d)\n",
+		    prog_name, elf->e_machine);
+	    exit(1);
+	}
+	if (elf->e_phnum != 1) {
+	    fprintf(stderr,
+		    "%s: %d program headers (forgot to link with -N?)\n",
+		    prog_name, elf->e_phnum);
+	}
+
+	e_entry = elf->e_entry;
+
+	lseek(fd, elf->e_phoff, SEEK_SET);
+	if (read(fd, buf, sizeof(*elf_phdr)) != sizeof(*elf_phdr)) {
+	    perror("read");
+	    exit(1);
+	}
+
+	elf_phdr = (struct elf_phdr *) buf;
+	offset	 = elf_phdr->p_offset;
+	mem_size = elf_phdr->p_memsz;
+	fil_size = elf_phdr->p_filesz;
+
+	/* work around ELF bug: */
+	if (elf_phdr->p_vaddr < e_entry) {
+	    unsigned long delta = e_entry - elf_phdr->p_vaddr;
+	    offset   += delta;
+	    mem_size -= delta;
+	    fil_size -= delta;
+	    elf_phdr->p_vaddr += delta;
+	}
+
+	if (verbose) {
+	    fprintf(stderr, "%s: extracting %#016lx-%#016lx (at %lx)\n",
+		    prog_name, (long) elf_phdr->p_vaddr,
+		    elf_phdr->p_vaddr + fil_size, offset);
+	}
+    } else
+#endif
+    {
+	aout = (struct exec *) buf;
+
+	if (!(aout->fh.f_flags & COFF_F_EXEC)) {
+	    fprintf(stderr, "%s: %s is not in executable format\n",
+		    prog_name, inname);
+	    exit(1);
+	}
+
+	if (aout->fh.f_opthdr != sizeof(aout->ah)) {
+	    fprintf(stderr, "%s: %s has unexpected optional header size\n",
+		    prog_name, inname);
+	    exit(1);
+	}
+
+	if (N_MAGIC(*aout) != OMAGIC) {
+	    fprintf(stderr, "%s: %s is not an OMAGIC file\n",
+		    prog_name, inname);
+	    exit(1);
+	}
+	offset = N_TXTOFF(*aout);
+	fil_size = aout->ah.tsize + aout->ah.dsize;
+	mem_size = fil_size + aout->ah.bsize;
+
+	if (verbose) {
+	    fprintf(stderr, "%s: extracting %#016lx-%#016lx (at %lx)\n",
+		    prog_name, aout->ah.text_start,
+		    aout->ah.text_start + fil_size, offset);
+	}
+    }
+
+    if (lseek(fd, offset, SEEK_SET) != offset) {
+	perror("lseek");
+	exit(1);
+    }
+
+    if (verbose) {
+	fprintf(stderr, "%s: copying %lu byte from %s\n",
+		prog_name, (unsigned long) fil_size, inname);
+    }
+
+    tocopy = fil_size;
+    while (tocopy > 0) {
+	n = tocopy;
+	if (n > sizeof(buf)) {
+	    n = sizeof(buf);
+	}
+	tocopy -= n;
+	if ((size_t) read(fd, buf, n) != n) {
+	    perror("read");
+	    exit(1);
+	}
+	do {
+	    nwritten = write(ofd, buf, n);
+	    if ((ssize_t) nwritten == -1) {
+		perror("write");
+		exit(1);
+	    }
+	    n -= nwritten;
+	} while (n > 0);
+    }
+
+    if (pad) {
+	mem_size = ((mem_size + pad - 1) / pad) * pad;
+    }
+
+    tocopy = mem_size - fil_size;
+    if (tocopy > 0) {
+	fprintf(stderr,
+		"%s: zero-filling bss and aligning to %lu with %lu bytes\n",
+		prog_name, pad, (unsigned long) tocopy);
+
+	memset(buf, 0x00, sizeof(buf));
+	do {
+	    n = tocopy;
+	    if (n > sizeof(buf)) {
+		n = sizeof(buf);
+	    }
+	    nwritten = write(ofd, buf, n);
+	    if ((ssize_t) nwritten == -1) {
+		perror("write");
+		exit(1);
+	    }
+	    tocopy -= nwritten;
+	} while (tocopy > 0);
+    }
+    return 0;
+}