From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 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 --- arch/powerpc/boot/addnote.c | 248 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 248 insertions(+) create mode 100644 arch/powerpc/boot/addnote.c (limited to 'arch/powerpc/boot/addnote.c') diff --git a/arch/powerpc/boot/addnote.c b/arch/powerpc/boot/addnote.c new file mode 100644 index 000000000..787049274 --- /dev/null +++ b/arch/powerpc/boot/addnote.c @@ -0,0 +1,248 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Program to hack in a PT_NOTE program header entry in an ELF file. + * This is needed for OF on RS/6000s to load an image correctly. + * Note that OF needs a program header entry for the note, not an + * ELF section. + * + * Copyright 2000 Paul Mackerras. + * + * Adapted for 64 bit little endian images by Andrew Tauferner. + * + * Usage: addnote zImage + */ +#include +#include +#include +#include +#include + +/* CHRP note section */ +static const char arch[] = "PowerPC"; + +#define N_DESCR 6 +unsigned int descr[N_DESCR] = { + 0xffffffff, /* real-mode = true */ + 0x02000000, /* real-base, i.e. where we expect OF to be */ + 0xffffffff, /* real-size */ + 0xffffffff, /* virt-base */ + 0xffffffff, /* virt-size */ + 0x4000, /* load-base */ +}; + +/* RPA note section */ +static const char rpaname[] = "IBM,RPA-Client-Config"; + +/* + * Note: setting ignore_my_client_config *should* mean that OF ignores + * all the other fields, but there is a firmware bug which means that + * it looks at the splpar field at least. So these values need to be + * reasonable. + */ +#define N_RPA_DESCR 8 +unsigned int rpanote[N_RPA_DESCR] = { + 0, /* lparaffinity */ + 64, /* min_rmo_size */ + 0, /* min_rmo_percent */ + 40, /* max_pft_size */ + 1, /* splpar */ + -1, /* min_load */ + 0, /* new_mem_def */ + 1, /* ignore_my_client_config */ +}; + +#define ROUNDUP(len) (((len) + 3) & ~3) + +unsigned char buf[1024]; +#define ELFDATA2LSB 1 +#define ELFDATA2MSB 2 +static int e_data = ELFDATA2MSB; +#define ELFCLASS32 1 +#define ELFCLASS64 2 +static int e_class = ELFCLASS32; + +#define GET_16BE(off) ((buf[off] << 8) + (buf[(off)+1])) +#define GET_32BE(off) ((GET_16BE(off) << 16U) + GET_16BE((off)+2U)) +#define GET_64BE(off) ((((unsigned long long)GET_32BE(off)) << 32ULL) + \ + ((unsigned long long)GET_32BE((off)+4ULL))) +#define PUT_16BE(off, v)(buf[off] = ((v) >> 8) & 0xff, \ + buf[(off) + 1] = (v) & 0xff) +#define PUT_32BE(off, v)(PUT_16BE((off), (v) >> 16L), PUT_16BE((off) + 2, (v))) +#define PUT_64BE(off, v)((PUT_32BE((off), (unsigned long long)(v) >> 32L), \ + PUT_32BE((off) + 4, (unsigned long long)(v)))) + +#define GET_16LE(off) ((buf[off]) + (buf[(off)+1] << 8)) +#define GET_32LE(off) (GET_16LE(off) + (GET_16LE((off)+2U) << 16U)) +#define GET_64LE(off) ((unsigned long long)GET_32LE(off) + \ + (((unsigned long long)GET_32LE((off)+4ULL)) << 32ULL)) +#define PUT_16LE(off, v) (buf[off] = (v) & 0xff, \ + buf[(off) + 1] = ((v) >> 8) & 0xff) +#define PUT_32LE(off, v) (PUT_16LE((off), (v)), PUT_16LE((off) + 2, (v) >> 16L)) +#define PUT_64LE(off, v) (PUT_32LE((off), (unsigned long long)(v)), \ + PUT_32LE((off) + 4, (unsigned long long)(v) >> 32L)) + +#define GET_16(off) (e_data == ELFDATA2MSB ? GET_16BE(off) : GET_16LE(off)) +#define GET_32(off) (e_data == ELFDATA2MSB ? GET_32BE(off) : GET_32LE(off)) +#define GET_64(off) (e_data == ELFDATA2MSB ? GET_64BE(off) : GET_64LE(off)) +#define PUT_16(off, v) (e_data == ELFDATA2MSB ? PUT_16BE(off, v) : \ + PUT_16LE(off, v)) +#define PUT_32(off, v) (e_data == ELFDATA2MSB ? PUT_32BE(off, v) : \ + PUT_32LE(off, v)) +#define PUT_64(off, v) (e_data == ELFDATA2MSB ? PUT_64BE(off, v) : \ + PUT_64LE(off, v)) + +/* Structure of an ELF file */ +#define E_IDENT 0 /* ELF header */ +#define E_PHOFF (e_class == ELFCLASS32 ? 28 : 32) +#define E_PHENTSIZE (e_class == ELFCLASS32 ? 42 : 54) +#define E_PHNUM (e_class == ELFCLASS32 ? 44 : 56) +#define E_HSIZE (e_class == ELFCLASS32 ? 52 : 64) + +#define EI_MAGIC 0 /* offsets in E_IDENT area */ +#define EI_CLASS 4 +#define EI_DATA 5 + +#define PH_TYPE 0 /* ELF program header */ +#define PH_OFFSET (e_class == ELFCLASS32 ? 4 : 8) +#define PH_FILESZ (e_class == ELFCLASS32 ? 16 : 32) +#define PH_HSIZE (e_class == ELFCLASS32 ? 32 : 56) + +#define PT_NOTE 4 /* Program header type = note */ + + +unsigned char elf_magic[4] = { 0x7f, 'E', 'L', 'F' }; + +int +main(int ac, char **av) +{ + int fd, n, i; + unsigned long ph, ps, np; + long nnote, nnote2, ns; + + if (ac != 2) { + fprintf(stderr, "Usage: %s elf-file\n", av[0]); + exit(1); + } + fd = open(av[1], O_RDWR); + if (fd < 0) { + perror(av[1]); + exit(1); + } + + nnote = 12 + ROUNDUP(strlen(arch) + 1) + sizeof(descr); + nnote2 = 12 + ROUNDUP(strlen(rpaname) + 1) + sizeof(rpanote); + + n = read(fd, buf, sizeof(buf)); + if (n < 0) { + perror("read"); + exit(1); + } + + if (memcmp(&buf[E_IDENT+EI_MAGIC], elf_magic, 4) != 0) + goto notelf; + e_class = buf[E_IDENT+EI_CLASS]; + if (e_class != ELFCLASS32 && e_class != ELFCLASS64) + goto notelf; + e_data = buf[E_IDENT+EI_DATA]; + if (e_data != ELFDATA2MSB && e_data != ELFDATA2LSB) + goto notelf; + if (n < E_HSIZE) + goto notelf; + + ph = (e_class == ELFCLASS32 ? GET_32(E_PHOFF) : GET_64(E_PHOFF)); + ps = GET_16(E_PHENTSIZE); + np = GET_16(E_PHNUM); + if (ph < E_HSIZE || ps < PH_HSIZE || np < 1) + goto notelf; + if (ph + (np + 2) * ps + nnote + nnote2 > n) + goto nospace; + + for (i = 0; i < np; ++i) { + if (GET_32(ph + PH_TYPE) == PT_NOTE) { + fprintf(stderr, "%s already has a note entry\n", + av[1]); + exit(0); + } + ph += ps; + } + + /* XXX check that the area we want to use is all zeroes */ + for (i = 0; i < 2 * ps + nnote + nnote2; ++i) + if (buf[ph + i] != 0) + goto nospace; + + /* fill in the program header entry */ + ns = ph + 2 * ps; + PUT_32(ph + PH_TYPE, PT_NOTE); + if (e_class == ELFCLASS32) + PUT_32(ph + PH_OFFSET, ns); + else + PUT_64(ph + PH_OFFSET, ns); + + if (e_class == ELFCLASS32) + PUT_32(ph + PH_FILESZ, nnote); + else + PUT_64(ph + PH_FILESZ, nnote); + + /* fill in the note area we point to */ + /* XXX we should probably make this a proper section */ + PUT_32(ns, strlen(arch) + 1); + PUT_32(ns + 4, N_DESCR * 4); + PUT_32(ns + 8, 0x1275); + strcpy((char *) &buf[ns + 12], arch); + ns += 12 + strlen(arch) + 1; + for (i = 0; i < N_DESCR; ++i, ns += 4) + PUT_32BE(ns, descr[i]); + + /* fill in the second program header entry and the RPA note area */ + ph += ps; + PUT_32(ph + PH_TYPE, PT_NOTE); + if (e_class == ELFCLASS32) + PUT_32(ph + PH_OFFSET, ns); + else + PUT_64(ph + PH_OFFSET, ns); + + if (e_class == ELFCLASS32) + PUT_32(ph + PH_FILESZ, nnote); + else + PUT_64(ph + PH_FILESZ, nnote2); + + /* fill in the note area we point to */ + PUT_32(ns, strlen(rpaname) + 1); + PUT_32(ns + 4, sizeof(rpanote)); + PUT_32(ns + 8, 0x12759999); + strcpy((char *) &buf[ns + 12], rpaname); + ns += 12 + ROUNDUP(strlen(rpaname) + 1); + for (i = 0; i < N_RPA_DESCR; ++i, ns += 4) + PUT_32BE(ns, rpanote[i]); + + /* Update the number of program headers */ + PUT_16(E_PHNUM, np + 2); + + /* write back */ + i = lseek(fd, (long) 0, SEEK_SET); + if (i < 0) { + perror("lseek"); + exit(1); + } + i = write(fd, buf, n); + if (i < 0) { + perror("write"); + exit(1); + } + if (i < n) { + fprintf(stderr, "%s: write truncated\n", av[1]); + exit(1); + } + + exit(0); + + notelf: + fprintf(stderr, "%s does not appear to be an ELF file\n", av[1]); + exit(1); + + nospace: + fprintf(stderr, "sorry, I can't find space in %s to put the note\n", + av[1]); + exit(1); +} -- cgit v1.3.1