From 7e61560628d17ea6b1d8ee370f6d42694cff8758 Mon Sep 17 00:00:00 2001 From: Ulises Mendez Martinez Date: Fri, 4 Sep 2026 15:07:09 +0000 Subject: objtool: Validate disassembler headers in libopcodes probe commit 3f2de814c059 ("objtool: Fix libopcodes linking with static libraries") tested for libopcodes availability by linking a test snippet with a forward declaration of disassemble_init_for_target(). However, testing symbol linkage with an extern declaration only verifies the presence of the library (.so/.a) and bypasses checking for development headers (binutils-dev). On systems where libopcodes is present without development headers installed, the probe succeeds, enabling BUILD_DISAS. Subsequent compilation of objtool then fails: fatal error: 'bfd.h' file not found 113 | #include Additionally, the probe invokes $(HOSTCC) without $(HOSTCFLAGS), ignoring any sysroot or include flags specified for the host compiler. Fix this by including and directly in the test snippet, passing $(HOSTCFLAGS) so host compiler options are respected, and defining PACKAGE="objtool" to satisfy the configuration check in . Fixes: 3f2de814c059 ("objtool: Fix libopcodes linking with static libraries") Fixes: 436326bc525d ("objtool: fix build failure due to missing libopcodes check") Reported-by: Alice Ryhl Assisted-by: Antigravity:Gemini-Next Signed-off-by: Ulises Mendez Martinez Link: https://patch.msgid.link/20260904150710.2997558-1-umendez@google.com Signed-off-by: Josh Poimboeuf --- fs/proc/kmsg.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 fs/proc/kmsg.c (limited to 'fs/proc/kmsg.c') diff --git a/fs/proc/kmsg.c b/fs/proc/kmsg.c new file mode 100644 index 000000000..2fc92a13f --- /dev/null +++ b/fs/proc/kmsg.c @@ -0,0 +1,63 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/proc/kmsg.c + * + * Copyright (C) 1992 by Linus Torvalds + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +static int kmsg_open(struct inode * inode, struct file * file) +{ + return do_syslog(SYSLOG_ACTION_OPEN, NULL, 0, SYSLOG_FROM_PROC); +} + +static int kmsg_release(struct inode * inode, struct file * file) +{ + (void) do_syslog(SYSLOG_ACTION_CLOSE, NULL, 0, SYSLOG_FROM_PROC); + return 0; +} + +static ssize_t kmsg_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + if ((file->f_flags & O_NONBLOCK) && + !do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_PROC)) + return -EAGAIN; + return do_syslog(SYSLOG_ACTION_READ, buf, count, SYSLOG_FROM_PROC); +} + +static __poll_t kmsg_poll(struct file *file, poll_table *wait) +{ + poll_wait(file, &log_wait, wait); + if (do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_PROC)) + return EPOLLIN | EPOLLRDNORM; + return 0; +} + + +static const struct proc_ops kmsg_proc_ops = { + .proc_flags = PROC_ENTRY_PERMANENT, + .proc_read = kmsg_read, + .proc_poll = kmsg_poll, + .proc_open = kmsg_open, + .proc_release = kmsg_release, + .proc_lseek = generic_file_llseek, +}; + +static int __init proc_kmsg_init(void) +{ + proc_create("kmsg", S_IRUSR, NULL, &kmsg_proc_ops); + return 0; +} +fs_initcall(proc_kmsg_init); -- cgit v1.3.1