linux/kernel/kallsyms.c, branch v5.0

kallsyms: reduce size a little on 64-bit

2018-09-10T13:54:33Z

Both kallsyms_num_syms and kallsyms_markers[] don't really need to use unsigned long as their (base) types; unsigned int fully suffices. Signed-off-by: Jan Beulich Signed-off-by: Masahiro Yamada

kallsyms, x86: Export addresses of PTI entry trampolines

2018-08-14T22:12:29Z

Currently, the addresses of PTI entry trampolines are not exported to user space. Kernel profiling tools need these addresses to identify the kernel code, so add a symbol and address for each CPU's PTI entry trampoline. Signed-off-by: Alexander Shishkin Acked-by: Andi Kleen Acked-by: Peter Zijlstra (Intel) Cc: Andy Lutomirski Cc: Dave Hansen Cc: H. Peter Anvin Cc: Jiri Olsa Cc: Joerg Roedel Cc: Thomas Gleixner Cc: x86@kernel.org Link: http://lkml.kernel.org/r/1528289651-4113-3-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

kallsyms: Simplify update_iter_mod()

2018-08-14T22:10:23Z

The logic in update_iter_mod() is overcomplicated and gets worse every time another get_ksymbol_* function is added. In preparation for adding another get_ksymbol_* function, simplify logic in update_iter_mod(). Signed-off-by: Adrian Hunter Tested-by: (ftrace changes only) Steven Rostedt (VMware) Acked-by: Andi Kleen Acked-by: Peter Zijlstra (Intel) Cc: Alexander Shishkin Cc: Andy Lutomirski Cc: Dave Hansen Cc: H. Peter Anvin Cc: Jiri Olsa Cc: Joerg Roedel Cc: Thomas Gleixner Cc: x86@kernel.org Link: http://lkml.kernel.org/r/1528289651-4113-2-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk

2018-02-01T21:36:15Z

Pull printk updates from Petr Mladek: - Add a console_msg_format command line option: The value "default" keeps the old "[time stamp] text\n" format. The value "syslog" allows to see the syslog-like "[timestamp] text" format. This feature was requested by people doing regression tests, for example, 0day robot. They want to have both filtered and full logs at hands. - Reduce the risk of softlockup: Pass the console owner in a busy loop. This is a new approach to the old problem. It was first proposed by Steven Rostedt on Kernel Summit 2017. It marks a context in which the console_lock owner calls console drivers and could not sleep. On the other side, printk() callers could detect this state and use a busy wait instead of a simple console_trylock(). Finally, the console_lock owner checks if there is a busy waiter at the end of the special context and eventually passes the console_lock to the waiter. The hand-off works surprisingly well and helps in many situations. Well, there is still a possibility of the softlockup, for example, when the flood of messages stops and the last owner still has too much to flush. There is increasing number of people having problems with printk-related softlockups. We might eventually need to get better solution. Anyway, this looks like a good start and promising direction. - Do not allow to schedule in console_unlock() called from printk(): This reverts an older controversial commit. The reschedule helped to avoid softlockups. But it also slowed down the console output. This patch is obsoleted by the new console waiter logic described above. In fact, the reschedule made the hand-off less effective. - Deprecate "%pf" and "%pF" format specifier: It was needed on ia64, ppc64 and parisc64 to dereference function descriptors and show the real function address. It is done transparently by "%ps" and "pS" format specifier now. Sergey Senozhatsky found that all the function descriptors were in a special elf section and could be easily detected. - Remove printk_symbol() API: It has been obsoleted by "%pS" format specifier, and this change helped to remove few continuous lines and a less intuitive old API. - Remove redundant memsets: Sergey removed unnecessary memset when processing printk.devkmsg command line option. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (27 commits) printk: drop redundant devkmsg_log_str memsets printk: Never set console_may_schedule in console_trylock() printk: Hide console waiter logic into helpers printk: Add console owner and waiter logic to load balance console writes kallsyms: remove print_symbol() function checkpatch: add pF/pf deprecation warning symbol lookup: introduce dereference_symbol_descriptor() parisc64: Add .opd based function descriptor dereference powerpc64: Add .opd based function descriptor dereference ia64: Add .opd based function descriptor dereference sections: split dereference_function_descriptor() openrisc: Fix conflicting types for _exext and _stext lib: do not use print_symbol() irq debug: do not use print_symbol() sysfs: do not use print_symbol() drivers: do not use print_symbol() x86: do not use print_symbol() unicore32: do not use print_symbol() sh: do not use print_symbol() mn10300: do not use print_symbol() ...

Merge branch 'for-4.16-print-symbol' into for-4.16

2018-01-22T09:40:50Z

kallsyms: remove print_symbol() function

2018-01-16T15:59:55Z

No more print_symbol()/__print_symbol() users left, remove these symbols. It was a very old API that encouraged people use continuous lines. It had been obsoleted by %pS format specifier in a normal printk() call. Link: http://lkml.kernel.org/r/20180105102538.GC471@jagdpanzerIV Cc: Andrew Morton Cc: Russell King Cc: Catalin Marinas Cc: Mark Salter Cc: Tony Luck Cc: David Howells Cc: Yoshinori Sato Cc: Guan Xuetao Cc: Borislav Petkov Cc: Greg Kroah-Hartman Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Vineet Gupta Cc: Fengguang Wu Cc: Steven Rostedt Cc: LKML Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: linux-ia64@vger.kernel.org Cc: linux-am33-list@redhat.com Cc: linux-sh@vger.kernel.org Cc: linux-edac@vger.kernel.org Cc: x86@kernel.org Cc: linux-snps-arc@lists.infradead.org Cc: Sergey Senozhatsky Signed-off-by: Sergey Senozhatsky Suggested-by: Joe Perches [pmladek@suse.com: updated commit message] Signed-off-by: Petr Mladek

symbol lookup: introduce dereference_symbol_descriptor()

2018-01-09T09:45:38Z

dereference_symbol_descriptor() invokes appropriate ARCH specific function descriptor dereference callbacks: - dereference_kernel_function_descriptor() if the pointer is a kernel symbol; - dereference_module_function_descriptor() if the pointer is a module symbol. This is the last step needed to make '%pS/%ps' smart enough to handle function descriptor dereference on affected ARCHs and to retire '%pF/%pf'. To refresh it: Some architectures (ia64, ppc64, parisc64) use an indirect pointer for C function pointers - the function pointer points to a function descriptor and we need to dereference it to get the actual function pointer. Function descriptors live in .opd elf section and all affected ARCHs (ia64, ppc64, parisc64) handle it properly for kernel and modules. So we, technically, can decide if the dereference is needed by simply looking at the pointer: if it belongs to .opd section then we need to dereference it. The kernel and modules have their own .opd sections, obviously, that's why we need to split dereference_function_descriptor() and use separate kernel and module dereference arch callbacks. Link: http://lkml.kernel.org/r/20171206043649.GB15885@jagdpanzerIV Cc: Fenghua Yu Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: James Bottomley Cc: Andrew Morton Cc: Jessica Yu Cc: Steven Rostedt Cc: linux-ia64@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Sergey Senozhatsky Tested-by: Tony Luck #ia64 Tested-by: Santosh Sivaraj #powerpc Tested-by: Helge Deller #parisc64 Signed-off-by: Petr Mladek

kallsyms: take advantage of the new '%px' format

2017-11-29T18:30:13Z

The conditional kallsym hex printing used a special fixed-width '%lx' output (KALLSYM_FMT) in preparation for the hashing of %p, but that series ended up adding a %px specifier to help with the conversions. Use it, and avoid the "print pointer as an unsigned long" code. Signed-off-by: Linus Torvalds

Merge tag 'trace-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2017-11-17T22:58:01Z

Pull tracing updates from - allow module init functions to be traced - clean up some unused or not used by config events (saves space) - clean up of trace histogram code - add support for preempt and interrupt enabled/disable events - other various clean ups * tag 'trace-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (30 commits) tracing, thermal: Hide cpu cooling trace events when not in use tracing, thermal: Hide devfreq trace events when not in use ftrace: Kill FTRACE_OPS_FL_PER_CPU perf/ftrace: Small cleanup perf/ftrace: Fix function trace events perf/ftrace: Revert ("perf/ftrace: Fix double traces of perf on ftrace:function") tracing, dma-buf: Remove unused trace event dma_fence_annotate_wait_on tracing, memcg, vmscan: Hide trace events when not in use tracing/xen: Hide events that are not used when X86_PAE is not defined tracing: mark trace_test_buffer as __maybe_unused printk: Remove superfluous memory barriers from printk_safe ftrace: Clear hashes of stale ips of init memory tracing: Add support for preempt and irq enable/disable events tracing: Prepare to add preempt and irq trace events ftrace/kallsyms: Have /proc/kallsyms show saved mod init functions ftrace: Add freeing algorithm to free ftrace_mod_maps ftrace: Save module init functions kallsyms symbols for tracing ftrace: Allow module init functions to be traced ftrace: Add a ftrace_free_mem() function for modules to use tracing: Reimplement log2 ...

/proc/module: use the same logic as /proc/kallsyms for address exposure

2017-11-13T03:01:23Z

The (alleged) users of the module addresses are the same: kernel profiling. So just expose the same helper and format macros, and unify the logic. Signed-off-by: Linus Torvalds