user/sven/linux.git/scripts/recordmcount.c, branch v4.14.236

scripts/recordmcount.{c,pl}: support -ffunction-sections .text.* section names

2021-03-17T15:34:28Z

commit 9c8e2f6d3d361439cc6744a094f1c15681b55269 upstream. When building with -ffunction-sections, the compiler will place each function into its own ELF section, prefixed with ".text". For example, a simple test module with functions test_module_do_work() and test_module_wq_func(): % objdump --section-headers test_module.o | awk '/\.text/{print $2}' .text .text.test_module_do_work .text.test_module_wq_func .init.text .exit.text Adjust the recordmcount scripts to look for ".text" as a section name prefix. This will ensure that those functions will be included in the __mcount_loc relocations: % objdump --reloc --section __mcount_loc test_module.o OFFSET TYPE VALUE 0000000000000000 R_X86_64_64 .text.test_module_do_work 0000000000000008 R_X86_64_64 .text.test_module_wq_func 0000000000000010 R_X86_64_64 .init.text Link: http://lkml.kernel.org/r/1542745158-25392-2-git-send-email-joe.lawrence@redhat.com Signed-off-by: Joe Lawrence Signed-off-by: Steven Rostedt (VMware) Cc: Manoj Gupta Signed-off-by: Greg Kroah-Hartman

ARM: 8950/1: ftrace/recordmcount: filter relocation types

2020-01-29T14:02:37Z

commit 927d780ee371d7e121cea4fc7812f6ef2cea461c upstream. Scenario 1, ARMv7 ================= If code in arch/arm/kernel/ftrace.c would operate on mcount() pointer the following may be generated: 00000230 : 230: b5f8 push {r3, r4, r5, r6, r7, lr} 232: b500 push {lr} 234: f7ff fffe bl 0 <__gnu_mcount_nc> 234: R_ARM_THM_CALL __gnu_mcount_nc 238: f240 0600 movw r6, #0 238: R_ARM_THM_MOVW_ABS_NC __gnu_mcount_nc 23c: f8d0 1180 ldr.w r1, [r0, #384] ; 0x180 FTRACE currently is not able to deal with it: WARNING: CPU: 0 PID: 0 at .../kernel/trace/ftrace.c:1979 ftrace_bug+0x1ad/0x230() ... CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.116-... #1 ... [] (unwind_backtrace) from [] (show_stack+0x11/0x14) [] (show_stack) from [] (dump_stack+0x81/0xa8) [] (dump_stack) from [] (warn_slowpath_common+0x69/0x90) [] (warn_slowpath_common) from [] (warn_slowpath_null+0x17/0x1c) [] (warn_slowpath_null) from [] (ftrace_bug+0x1ad/0x230) [] (ftrace_bug) from [] (ftrace_process_locs+0x27d/0x444) [] (ftrace_process_locs) from [] (ftrace_init+0x91/0xe8) [] (ftrace_init) from [] (start_kernel+0x34b/0x358) [] (start_kernel) from [<00308095>] (0x308095) ---[ end trace cb88537fdc8fa200 ]--- ftrace failed to modify [] prealloc_fixed_plts+0x8/0x60 actual: 44:f2:e1:36 ftrace record flags: 0 (0) expected tramp: c03143e9 Scenario 2, ARMv4T ================== ftrace: allocating 14435 entries in 43 pages ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:2029 ftrace_bug+0x204/0x310 CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.5 #1 Hardware name: Cirrus Logic EDB9302 Evaluation Board [] (unwind_backtrace) from [] (show_stack+0x20/0x2c) [] (show_stack) from [] (dump_stack+0x20/0x30) [] (dump_stack) from [] (__warn+0xdc/0x104) [] (__warn) from [] (warn_slowpath_null+0x4c/0x5c) [] (warn_slowpath_null) from [] (ftrace_bug+0x204/0x310) [] (ftrace_bug) from [] (ftrace_init+0x3b4/0x4d4) [] (ftrace_init) from [] (start_kernel+0x20c/0x410) [] (start_kernel) from [<00000000>] ( (null)) ---[ end trace 0506a2f5dae6b341 ]--- ftrace failed to modify [] perf_trace_sys_exit+0x5c/0xe8 actual: 1e:ff:2f:e1 Initializing ftrace call sites ftrace record flags: 0 (0) expected tramp: c000fb24 The analysis for this problem has been already performed previously, refer to the link below. Fix the above problems by allowing only selected reloc types in __mcount_loc. The list itself comes from the legacy recordmcount.pl script. Link: https://lore.kernel.org/lkml/56961010.6000806@pengutronix.de/ Cc: stable@vger.kernel.org Fixes: ed60453fa8f8 ("ARM: 6511/1: ftrace: add ARM support for C version of recordmcount") Signed-off-by: Alexander Sverdlin Acked-by: Steven Rostedt (VMware) Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman

ftrace: Allow for function tracing to record init functions on boot up

2017-03-25T00:51:49Z

Adding a hook into free_reserve_area() that informs ftrace that boot up init text is being free, lets ftrace safely remove those init functions from its records, which keeps ftrace from trying to modify text that no longer exists. Note, this still does not allow for tracing .init text of modules, as modules require different work for freeing its init code. Link: http://lkml.kernel.org/r/1488502497.7212.24.camel@linux.intel.com Cc: linux-mm@kvack.org Cc: Vlastimil Babka Cc: Mel Gorman Cc: Peter Zijlstra Requested-by: Todd Brandt Signed-off-by: Steven Rostedt (VMware)

recordmcount: arm: Implement make_nop

2016-11-14T21:43:00Z

In similar spirit to x86 and arm64 support, add a make_nop_arm() to replace calls to mcount with a nop in sections that aren't traced. Link: http://lkml.kernel.org/r/20161018234200.5804-1-sboyd@codeaurora.org Acked-by: Russell King Acked-by: Rabin Vincent Signed-off-by: Stephen Boyd Signed-off-by: Steven Rostedt

nmi_backtrace: generate one-line reports for idle cpus

2016-10-08T01:46:30Z

When doing an nmi backtrace of many cores, most of which are idle, the output is a little overwhelming and very uninformative. Suppress messages for cpus that are idling when they are interrupted and just emit one line, "NMI backtrace for N skipped: idling at pc 0xNNN". We do this by grouping all the cpuidle code together into a new .cpuidle.text section, and then checking the address of the interrupted PC to see if it lies within that section. This commit suitably tags x86 and tile idle routines, and only adds in the minimal framework for other architectures. Link: http://lkml.kernel.org/r/1472487169-14923-5-git-send-email-cmetcalf@mellanox.com Signed-off-by: Chris Metcalf Acked-by: Peter Zijlstra (Intel) Tested-by: Peter Zijlstra (Intel) Tested-by: Daniel Thompson [arm] Tested-by: Petr Mladek Cc: Aaron Tomlin Cc: Peter Zijlstra (Intel) Cc: "Rafael J. Wysocki" Cc: Russell King Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

scripts/recordmcount.c: account for .softirqentry.text

2016-09-28T23:19:02Z

be7635e7287e ("arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections") added .softirqentry.text section, but it was not added to recordmcount. So functions in the section are untracable. Add the section to scripts/recordmcount.c and scripts/recordmcount.pl. Fixes: be7635e7287e ("arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections") Link: http://lkml.kernel.org/r/1474902626-73468-1-git-send-email-dvyukov@google.com Signed-off-by: Dmitry Vyukov Acked-by: Steve Rostedt Cc: [4.6+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ftrace/recordmcount: Work around for addition of metag magic but not relocations

2016-08-02T16:57:24Z

glibc recently did a sync up (94e73c95d9b5 "elf.h: Sync with the gabi webpage") that added a #define for EM_METAG but did not add relocations This triggers build errors: scripts/recordmcount.c: In function 'do_file': scripts/recordmcount.c:466:28: error: 'R_METAG_ADDR32' undeclared (first use in this function) case EM_METAG: reltype = R_METAG_ADDR32; ^~~~~~~~~~~~~~ scripts/recordmcount.c:466:28: note: each undeclared identifier is reported only once for each function it appears in scripts/recordmcount.c:468:20: error: 'R_METAG_NONE' undeclared (first use in this function) rel_type_nop = R_METAG_NONE; ^~~~~~~~~~~~ Work around this change with some more #ifdefery for the relocations. Fedora Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1354034 Link: http://lkml.kernel.org/r/1468005530-14757-1-git-send-email-labbott@redhat.com Cc: stable@vger.kernel.org # v3.9+ Cc: James Hogan Fixes: 00512bdd4573 ("metag: ftrace support") Reported-by: Ross Burton Signed-off-by: Laura Abbott Signed-off-by: Steven Rostedt

ftrace/scripts: Fix incorrect use of sprintf in recordmcount

2016-01-04T16:13:16Z

Fix build warning: scripts/recordmcount.c:589:4: warning: format not a string literal and no format arguments [-Wformat-security] sprintf("%s: failed\n", file); Fixes: a50bd43935586 ("ftrace/scripts: Have recordmcount copy the object file") Link: http://lkml.kernel.org/r/1451516801-16951-1-git-send-email-colin.king@canonical.com Cc: Li Bin Cc: Russell King Cc: Will Deacon Cc: stable@vger.kernel.org # 2.6.37+ Signed-off-by: Colin Ian King Signed-off-by: Steven Rostedt

ftrace/scripts: Have recordmcount copy the object file

2015-12-16T20:46:07Z

Russell King found that he had weird side effects when compiling the kernel with hard linked ccache. The reason was that recordmcount modified the kernel in place via mmap, and when a file gets modified twice by recordmcount, it will complain about it. To fix this issue, Russell wrote a patch that checked if the file was hard linked more than once and would unlink it if it was. Linus Torvalds was not happy with the fact that recordmcount does this in place modification. Instead of doing the unlink only if the file has two or more hard links, it does the unlink all the time. In otherwords, it always does a copy if it changed something. That is, it does the write out if a change was made. Cc: stable@vger.kernel.org # 2.6.37+ Signed-off-by: Steven Rostedt

scripts: recordmcount: break hardlinks

2015-12-16T14:28:23Z

recordmcount edits the file in-place, which can cause problems when using ccache in hardlink mode. Arrange for recordmcount to break a hardlinked object. Link: http://lkml.kernel.org/r/E1a7MVT-0000et-62@rmk-PC.arm.linux.org.uk Cc: stable@vger.kernel.org # 2.6.37+ Signed-off-by: Russell King Signed-off-by: Steven Rostedt