From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- arch/powerpc/boot/mktree.c | 151 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 151 insertions(+) create mode 100644 arch/powerpc/boot/mktree.c (limited to 'arch/powerpc/boot/mktree.c') diff --git a/arch/powerpc/boot/mktree.c b/arch/powerpc/boot/mktree.c new file mode 100644 index 000000000..dc603f3c1 --- /dev/null +++ b/arch/powerpc/boot/mktree.c @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Makes a tree bootable image for IBM Evaluation boards. + * Basically, just take a zImage, skip the ELF header, and stuff + * a 32 byte header on the front. + * + * We use htonl, which is a network macro, to make sure we're doing + * The Right Thing on an LE machine. It's non-obvious, but it should + * work on anything BSD'ish. + */ + +#include +#include +#include +#include +#include +#include +#include +#ifdef __sun__ +#include +#else +#include +#endif + +/* This gets tacked on the front of the image. There are also a few + * bytes allocated after the _start label used by the boot rom (see + * head.S for details). + */ +typedef struct boot_block { + uint32_t bb_magic; /* 0x0052504F */ + uint32_t bb_dest; /* Target address of the image */ + uint32_t bb_num_512blocks; /* Size, rounded-up, in 512 byte blks */ + uint32_t bb_debug_flag; /* Run debugger or image after load */ + uint32_t bb_entry_point; /* The image address to start */ + uint32_t bb_checksum; /* 32 bit checksum including header */ + uint32_t reserved[2]; +} boot_block_t; + +#define IMGBLK 512 +unsigned int tmpbuf[IMGBLK / sizeof(unsigned int)]; + +int main(int argc, char *argv[]) +{ + int in_fd, out_fd; + int nblks, i; + unsigned int cksum, *cp; + struct stat st; + boot_block_t bt; + + if (argc < 5) { + fprintf(stderr, "usage: %s \n",argv[0]); + exit(1); + } + + if (stat(argv[1], &st) < 0) { + perror("stat"); + exit(2); + } + + nblks = (st.st_size + IMGBLK) / IMGBLK; + + bt.bb_magic = htonl(0x0052504F); + + /* If we have the optional entry point parameter, use it */ + bt.bb_dest = htonl(strtoul(argv[3], NULL, 0)); + bt.bb_entry_point = htonl(strtoul(argv[4], NULL, 0)); + + /* We know these from the linker command. + * ...and then move it up into memory a little more so the + * relocation can happen. + */ + bt.bb_num_512blocks = htonl(nblks); + bt.bb_debug_flag = 0; + + bt.bb_checksum = 0; + + /* To be neat and tidy :-). + */ + bt.reserved[0] = 0; + bt.reserved[1] = 0; + + if ((in_fd = open(argv[1], O_RDONLY)) < 0) { + perror("zImage open"); + exit(3); + } + + if ((out_fd = open(argv[2], (O_RDWR | O_CREAT | O_TRUNC), 0666)) < 0) { + perror("bootfile open"); + exit(3); + } + + cksum = 0; + cp = (void *)&bt; + for (i = 0; i < sizeof(bt) / sizeof(unsigned int); i++) + cksum += *cp++; + + /* Assume zImage is an ELF file, and skip the 64K header. + */ + if (read(in_fd, tmpbuf, sizeof(tmpbuf)) != sizeof(tmpbuf)) { + fprintf(stderr, "%s is too small to be an ELF image\n", + argv[1]); + exit(4); + } + + if (tmpbuf[0] != htonl(0x7f454c46)) { + fprintf(stderr, "%s is not an ELF image\n", argv[1]); + exit(4); + } + + if (lseek(in_fd, (64 * 1024), SEEK_SET) < 0) { + fprintf(stderr, "%s failed to seek in ELF image\n", argv[1]); + exit(4); + } + + nblks -= (64 * 1024) / IMGBLK; + + /* And away we go...... + */ + if (write(out_fd, &bt, sizeof(bt)) != sizeof(bt)) { + perror("boot-image write"); + exit(5); + } + + while (nblks-- > 0) { + if (read(in_fd, tmpbuf, sizeof(tmpbuf)) < 0) { + perror("zImage read"); + exit(5); + } + cp = tmpbuf; + for (i = 0; i < sizeof(tmpbuf) / sizeof(unsigned int); i++) + cksum += *cp++; + if (write(out_fd, tmpbuf, sizeof(tmpbuf)) != sizeof(tmpbuf)) { + perror("boot-image write"); + exit(5); + } + } + + /* rewrite the header with the computed checksum. + */ + bt.bb_checksum = htonl(cksum); + if (lseek(out_fd, 0, SEEK_SET) < 0) { + perror("rewrite seek"); + exit(1); + } + if (write(out_fd, &bt, sizeof(bt)) != sizeof(bt)) { + perror("boot-image rewrite"); + exit(1); + } + + exit(0); +} -- cgit v1.3.1