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2021-03-02ftrace: Have recordmcount use w8 to read relp->r_info in arm64_is_fake_mcountChen Jun1-1/+1
On little endian system, Use aarch64_be(gcc v7.3) downloaded from linaro.org to build image with CONFIG_CPU_BIG_ENDIAN = y, CONFIG_FTRACE = y, CONFIG_DYNAMIC_FTRACE = y. gcc will create symbols of _mcount but recordmcount can not create mcount_loc for *.o. aarch64_be-linux-gnu-objdump -r fs/namei.o | grep mcount 00000000000000d0 R_AARCH64_CALL26 _mcount ... 0000000000007190 R_AARCH64_CALL26 _mcount The reason is than funciton arm64_is_fake_mcount can not work correctly. A symbol of _mcount in *.o compiled with big endian compiler likes: 00 00 00 2d 00 00 01 1b w(rp->r_info) will return 0x2d instead of 0x011b. Because w() takes uint32_t as parameter, which truncates rp->r_info. Use w8() instead w() to read relp->r_info Link: https://lkml.kernel.org/r/20210222135840.56250-1-chenjun102@huawei.com Fixes: ea0eada45632 ("recordmcount: only record relocation of type R_AARCH64_CALL26 on arm64.") Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Chen Jun <chenjun102@huawei.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-08-10recordmcount: Fix build failure on non arm64Christophe Leroy1-0/+2
Commit ea0eada45632 leads to the following build failure on powerpc: HOSTCC scripts/recordmcount scripts/recordmcount.c: In function 'arm64_is_fake_mcount': scripts/recordmcount.c:440: error: 'R_AARCH64_CALL26' undeclared (first use in this function) scripts/recordmcount.c:440: error: (Each undeclared identifier is reported only once scripts/recordmcount.c:440: error: for each function it appears in.) make[2]: *** [scripts/recordmcount] Error 1 Make sure R_AARCH64_CALL26 is always defined. Fixes: ea0eada45632 ("recordmcount: only record relocation of type R_AARCH64_CALL26 on arm64.") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Gregory Herrero <gregory.herrero@oracle.com> Cc: Gregory Herrero <gregory.herrero@oracle.com> Link: https://lore.kernel.org/r/5ca1be21fa6ebf73203b45fd9aadd2bafb5e6b15.1597049145.git.christophe.leroy@csgroup.eu Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-07-24recordmcount: only record relocation of type R_AARCH64_CALL26 on arm64.Gregory Herrero1-0/+6
Currently, if a section has a relocation to '_mcount' symbol, a new __mcount_loc entry will be added whatever the relocation type is. This is problematic when a relocation to '_mcount' is in the middle of a section and is not a call for ftrace use. Such relocation could be generated with below code for example: bool is_mcount(unsigned long addr) { return (target == (unsigned long) &_mcount); } With this snippet of code, ftrace will try to patch the mcount location generated by this code on module load and fail with: Call trace: ftrace_bug+0xa0/0x28c ftrace_process_locs+0x2f4/0x430 ftrace_module_init+0x30/0x38 load_module+0x14f0/0x1e78 __do_sys_finit_module+0x100/0x11c __arm64_sys_finit_module+0x28/0x34 el0_svc_common+0x88/0x194 el0_svc_handler+0x38/0x8c el0_svc+0x8/0xc ---[ end trace d828d06b36ad9d59 ]--- ftrace failed to modify [<ffffa2dbf3a3a41c>] 0xffffa2dbf3a3a41c actual: 66:a9:3c:90 Initializing ftrace call sites ftrace record flags: 2000000 (0) expected tramp: ffffa2dc6cf66724 So Limit the relocation type to R_AARCH64_CALL26 as in perl version of recordmcount. Fixes: af64d2aa872a ("ftrace: Add arm64 support to recordmcount") Signed-off-by: Gregory Herrero <gregory.herrero@oracle.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20200717143338.19302-1-gregory.herrero@oracle.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-01-19ARM: 8950/1: ftrace/recordmcount: filter relocation typesAlex Sverdlin1-0/+17
Scenario 1, ARMv7 ================= If code in arch/arm/kernel/ftrace.c would operate on mcount() pointer the following may be generated: 00000230 <prealloc_fixed_plts>: 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 ... [<c0314e3d>] (unwind_backtrace) from [<c03115e9>] (show_stack+0x11/0x14) [<c03115e9>] (show_stack) from [<c051a7f1>] (dump_stack+0x81/0xa8) [<c051a7f1>] (dump_stack) from [<c0321c5d>] (warn_slowpath_common+0x69/0x90) [<c0321c5d>] (warn_slowpath_common) from [<c0321cf3>] (warn_slowpath_null+0x17/0x1c) [<c0321cf3>] (warn_slowpath_null) from [<c038ee9d>] (ftrace_bug+0x1ad/0x230) [<c038ee9d>] (ftrace_bug) from [<c038f1f9>] (ftrace_process_locs+0x27d/0x444) [<c038f1f9>] (ftrace_process_locs) from [<c08915bd>] (ftrace_init+0x91/0xe8) [<c08915bd>] (ftrace_init) from [<c0885a67>] (start_kernel+0x34b/0x358) [<c0885a67>] (start_kernel) from [<00308095>] (0x308095) ---[ end trace cb88537fdc8fa200 ]--- ftrace failed to modify [<c031266c>] 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 [<c0010a24>] (unwind_backtrace) from [<c000ecb0>] (show_stack+0x20/0x2c) [<c000ecb0>] (show_stack) from [<c03c72e8>] (dump_stack+0x20/0x30) [<c03c72e8>] (dump_stack) from [<c0021c18>] (__warn+0xdc/0x104) [<c0021c18>] (__warn) from [<c0021d7c>] (warn_slowpath_null+0x4c/0x5c) [<c0021d7c>] (warn_slowpath_null) from [<c0095360>] (ftrace_bug+0x204/0x310) [<c0095360>] (ftrace_bug) from [<c04dabac>] (ftrace_init+0x3b4/0x4d4) [<c04dabac>] (ftrace_init) from [<c04cef4c>] (start_kernel+0x20c/0x410) [<c04cef4c>] (start_kernel) from [<00000000>] ( (null)) ---[ end trace 0506a2f5dae6b341 ]--- ftrace failed to modify [<c000c350>] 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 <alexander.sverdlin@nokia.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-08-31recordmcount: Clarify what cleanup() doesMatt Helsley1-70/+81
cleanup() mostly frees/unmaps the malloc'd/privately-mapped copy of the ELF file recordmcount is working on, which is set up in mmap_file(). It also deals with positioning within the pseduo prive-mapping of the file and appending to the ELF file. Split into two steps: mmap_cleanup() for the mapping itself file_append_cleanup() for allocations storing the appended ELF data. Also, move the global variable initializations out of the main, per-object-file loop and nearer to the alloc/init (mmap_file()) and two cleanup functions so we can more clearly see how they're related. Link: http://lkml.kernel.org/r/2a387ac86d133d22c68f57b9933c32bab1d09a2d.1564596289.git.mhelsley@vmware.com Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31recordmcount: Remove redundant cleanup() callsMatt Helsley1-13/+0
Redundant cleanup calls were introduced when transitioning from the old error/success handling via setjmp/longjmp -- the longjmp ensured the cleanup() call only happened once but replacing the success_file()/fail_file() calls with cleanup() meant that multiple cleanup() calls can happen as we return from function calls. In do_file(), looking just before and after the "goto out" jumps we can see that multiple cleanups() are being performed. We remove cleanup() calls from the nested functions because it makes the code easier to review -- the resources being cleaned up are generally allocated and initialized in the callers so freeing them there makes more sense. Other redundant cleanup() calls: mmap_file() is only called from do_file() and, if mmap_file() fails, then we goto out and do cleanup() there too. write_file() is only called from do_file() and do_file() calls cleanup() unconditionally after returning from write_file() therefore the cleanup() calls in write_file() are not necessary. find_secsym_ndx(), called from do_func()'s for-loop, when we are cleaning up here it's obvious that we break out of the loop and do another cleanup(). __has_rel_mcount() is called from two parts of do_func() and calls cleanup(). In theory we move them into do_func(), however these in turn prove redundant so another simplification step removes them as well. Link: http://lkml.kernel.org/r/de197e17fc5426623a847ea7cf3a1560a7402a4b.1564596289.git.mhelsley@vmware.com Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31recordmcount: Kernel style formattingMatt Helsley1-22/+25
Fix up the whitespace irregularity in the ELF switch blocks. Swapping the initial value of gpfx allows us to simplify all but one of the one-line switch cases even further. Link: http://lkml.kernel.org/r/647f21f43723d3e831cedd3238c893db03eea6f0.1564596289.git.mhelsley@vmware.com Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31recordmcount: Kernel style function signature formattingMatt Helsley1-14/+7
The uwrite() and ulseek() functions are formatted inconsistently with the rest of the file and the kernel overall. While we're making other changes here let's fix this. Link: http://lkml.kernel.org/r/4c67698f734be9867a2aba7035fe0ce59e1e4423.1564596289.git.mhelsley@vmware.com Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31recordmcount: Rewrite error/success handlingMatt Helsley1-77/+85
Recordmcount uses setjmp/longjmp to manage control flow as it reads and then writes the ELF file. This unusual control flow is hard to follow and check in addition to being unlike kernel coding style. So we rewrite these paths to use regular return values to indicate error/success. When an error or previously-completed object file is found we return an error code following kernel coding conventions -- negative error values and 0 for success when we're not returning a pointer. We return NULL for those that fail and return non-NULL pointers otherwise. One oddity is already_has_rel_mcount -- there we use pointer comparison rather than string comparison to differentiate between previously-processed object files and returning the name of a text section. Link: http://lkml.kernel.org/r/8ba8633d4afe444931f363c8d924bf9565b89a86.1564596289.git.mhelsley@vmware.com Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31recordmcount: Remove unused fd from uwrite() and ulseek()Matt Helsley1-8/+8
uwrite() works within the pseudo-mapping and extends it as necessary without needing the file descriptor (fd) parameter passed to it. Similarly, ulseek() doesn't need its fd parameter. These parameters were only added because the functions bear a conceptual resemblance to write() and lseek(). Worse, they obscure the fact that at the time uwrite() and ulseek() are called fd_map is not a valid file descriptor. Remove the unused file descriptor parameters that make it look like fd_map is still valid. Link: http://lkml.kernel.org/r/2a136e820ee208469d375265c7b8eb28570749a0.1563992889.git.mhelsley@vmware.com Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31recordmcount: Remove uread()Matt Helsley1-13/+5
uread() is only used to initialize the ELF file's pseudo private-memory mapping while uwrite() and ulseek() work within the pseudo-mapping and extend it as necessary. Thus it is not a complementary function to uwrite() and ulseek(). It also makes no sense to do cleanups inside uread() when its only caller, mmap_file(), is doing the relevant allocations and associated initializations. Therefore it's clearer to use a plain read() call to initialize the data in mmap_file() and remove uread(). Link: http://lkml.kernel.org/r/31a87c22b19150cec1c8dc800c8b0873a2741703.1563992889.git.mhelsley@vmware.com Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-08-31recordmcount: Remove redundant strcmpMatt Helsley1-2/+1
The strcmp is unnecessary since .text is already accepted as a prefix in the strncmp(). Link: http://lkml.kernel.org/r/358e590b49adbe4185e161a8b364e323f3d52857.1563992889.git.mhelsley@vmware.com Signed-off-by: Matt Helsley <mhelsley@vmware.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 378Thomas Gleixner1-1/+1
Based on 1 normalized pattern(s): licensed under the gnu general public license version 2 gplv2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 5 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531081036.993848054@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-08scripts/recordmcount.{c,pl}: support -ffunction-sections .text.* section namesJoe Lawrence1-1/+1
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 <joe.lawrence@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-05-29scripts: Fixed printf format mismatchnixiaoming1-1/+1
scripts/kallsyms.c: function write_src: "printf", the #1 format specifier "d" need arg type "int", but the according arg "table_cnt" has type "unsigned int" scripts/recordmcount.c: function do_file: "fprintf", the #1 format specifier "d" need arg type "int", but the according arg "(*w2)(ehdr->e_machine)" has type "unsigned int" scripts/recordmcount.h: function find_secsym_ndx: "fprintf", the #1 format specifier "d" need arg type "int", but the according arg "txtndx" has type "unsigned int" Signed-off-by: nixiaoming <nixiaoming@huawei.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-02-23Drop a bunch of metag referencesJames Hogan1-20/+0
Now that arch/metag/ has been removed, drop a bunch of metag references in various codes across the whole tree: - VM_GROWSUP and __VM_ARCH_SPECIFIC_1. - MT_METAG_* ELF note types. - METAG Kconfig dependencies (FRAME_POINTER) and ranges (MAX_STACK_SIZE_MB). - metag cases in tools (checkstack.pl, recordmcount.c, perf). Signed-off-by: James Hogan <jhogan@kernel.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: linux-mm@kvack.org Cc: linux-metag@vger.kernel.org
2017-03-24ftrace: Allow for function tracing to record init functions on boot upSteven Rostedt (VMware)1-0/+1
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 <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Requested-by: Todd Brandt <todd.e.brandt@linux.intel.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2016-11-14recordmcount: arm: Implement make_nopStephen Boyd1-0/+65
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 <rmk+kernel@armlinux.org.uk> Acked-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-10-07nmi_backtrace: generate one-line reports for idle cpusChris Metcalf1-0/+1
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 <cmetcalf@mellanox.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Daniel Thompson <daniel.thompson@linaro.org> [arm] Tested-by: Petr Mladek <pmladek@suse.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-28scripts/recordmcount.c: account for .softirqentry.textDmitry Vyukov1-0/+1
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 <dvyukov@google.com> Acked-by: Steve Rostedt <rostedt@goodmis.org> Cc: <stable@vger.kernel.org> [4.6+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02ftrace/recordmcount: Work around for addition of metag magic but not relocationsLaura Abbott1-1/+8
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 <james.hogan@imgtec.com> Fixes: 00512bdd4573 ("metag: ftrace support") Reported-by: Ross Burton <ross.burton@intel.com> Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-01-04ftrace/scripts: Fix incorrect use of sprintf in recordmcountColin Ian King1-1/+1
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 <huawei.libin@huawei.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: stable@vger.kernel.org # 2.6.37+ Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-16ftrace/scripts: Have recordmcount copy the object fileSteven Rostedt (Red Hat)1-35/+110
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 <rostedt@goodmis.org>
2015-12-16scripts: recordmcount: break hardlinksRussell King1-0/+14
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 <rmk+kernel@arm.linux.org.uk> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-03recordmcount: arm64: Replace the ignored mcount call into nopLi Bin1-1/+23
By now, the recordmcount only records the function that in following sections: .text/.ref.text/.sched.text/.spinlock.text/.irqentry.text/ .kprobes.text/.text.unlikely For the function that not in these sections, the call mcount will be in place and not be replaced when kernel boot up. And it will bring performance overhead, such as do_mem_abort (in .exception.text section). This patch make the call mcount to nop for this case in recordmcount. Link: http://lkml.kernel.org/r/1446019445-14421-1-git-send-email-huawei.libin@huawei.com Link: http://lkml.kernel.org/r/1446193864-24593-4-git-send-email-huawei.libin@huawei.com Cc: <lkp@intel.com> Cc: <catalin.marinas@arm.com> Cc: <takahiro.akashi@linaro.org> Cc: <stable@vger.kernel.org> # 3.18+ Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Li Bin <huawei.libin@huawei.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-11-02recordmcount: x86: Assign a meaningful value to rel_type_nopLi Bin1-0/+2
Although, the default value of rel_type_nop is zero, and the value of R_386_NONE/R_X86_64_NONE is zero too, but it should be assigned a meaningful value explicitly, otherwise it looks confused. Assign R_386_NONE to rel_type_nop for 386, assign R_X86_64_NONE to rel_type_nop for x86_64. Link: http://lkml.kernel.org/r/1446020606-16352-1-git-send-email-huawei.libin@huawei.com Signed-off-by: Li Bin <huawei.libin@huawei.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-10-27s390/ftrace,kprobes: allow to patch first instructionHeiko Carstens1-1/+1
If the function tracer is enabled, allow to set kprobes on the first instruction of a function (which is the function trace caller): If no kprobe is set handling of enabling and disabling function tracing of a function simply patches the first instruction. Either it is a nop (right now it's an unconditional branch, which skips the mcount block), or it's a branch to the ftrace_caller() function. If a kprobe is being placed on a function tracer calling instruction we encode if we actually have a nop or branch in the remaining bytes after the breakpoint instruction (illegal opcode). This is possible, since the size of the instruction used for the nop and branch is six bytes, while the size of the breakpoint is only two bytes. Therefore the first two bytes contain the illegal opcode and the last four bytes contain either "0" for nop or "1" for branch. The kprobes code will then execute/simulate the correct instruction. Instruction patching for kprobes and function tracer is always done with stop_machine(). Therefore we don't have any races where an instruction is patched concurrently on a different cpu. Besides that also the program check handler which executes the function trace caller instruction won't be executed concurrently to any stop_machine() execution. This allows to keep full fault based kprobes handling which generates correct pt_regs contents automatically. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-10-09s390/ftrace: remove 31 bit ftrace supportHeiko Carstens1-4/+0
31 bit and 64 bit diverge more and more and it is rather painful to keep both parts running. To make things simpler just remove the 31 bit support which nobody uses anyway. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-06-12Merge branch 'misc' of ↵Linus Torvalds1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild Pull kbuild misc updates from Michal Marek: "This is the non-critical part of kbuild for v3.16-rc1: - make deb-pkg can do s390x and arm64 - new patterns in scripts/tags.sh - scripts/tags.sh skips userspace tools' sources (which sometimes have copies of kernel structures) and symlinks - improvements to the objdiff tool - two new coccinelle patches - other minor fixes" * 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: scripts: objdiff: support directories for the augument of record command scripts: objdiff: fix a comment scripts: objdiff: change the extension of disassembly from .o to .dis scripts: objdiff: improve path flexibility for record command scripts: objdiff: remove unnecessary code scripts: objdiff: direct error messages to stderr scripts: objdiff: get the path to .tmp_objdiff more simply deb-pkg: Add automatic support for s390x architecture coccicheck: Add unneeded return variable test kbuild: Fix a typo in documentation kbuild: trivial - use tabs for code indent where possible kbuild: trivial - remove trailing empty lines coccinelle: Check for missing NULL terminators in of_device_id tables scripts/tags.sh: ignore symlink'ed source files scripts/tags.sh: add regular expression replacement pattern for memcg builddeb: add arm64 in the supported architectures builddeb: use $OBJCOPY variable instead of objcopy scripts/tags.sh: ignore code of user space tools scripts/tags.sh: add pattern for DEFINE_HASHTABLE .gitignore: ignore Module.symvers in all directories
2014-06-10kbuild: trivial - remove trailing empty linesMasahiro Yamada1-2/+0
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2014-05-29ftrace: Add arm64 support to recordmcountAKASHI Takahiro1-0/+7
Recordmcount utility under scripts is run, after compiling each object, to find out all the locations of calling _mcount() and put them into specific seciton named __mcount_loc. Then linker collects all such information into a table in the kernel image (between __start_mcount_loc and __stop_mcount_loc) for later use by ftrace. This patch adds arm64 specific definitions to identify such locations. There are two types of implementation, C and Perl. On arm64, only C version is used to build the kernel now that CONFIG_HAVE_C_RECORDMCOUNT is on. But Perl version is also maintained. This patch also contains a workaround just in case where a header file, elf.h, on host machine doesn't have definitions of EM_AARCH64 nor R_AARCH64_ABS64. Without them, compiling C version of recordmcount will fail. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2013-03-02metag: ftrace supportJames Hogan1-0/+13
Add ftrace support for metag. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace/s390: mcount offset calculationMartin Schwidefsky1-2/+6
Do the mcount offset adjustment in the recordmcount.pl/recordmcount.[ch] at compile time and not in ftrace_call_adjust at run time. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace/x86: mcount offset calculationMartin Schwidefsky1-0/+2
Do the mcount offset adjustment in the recordmcount.pl/recordmcount.[ch] at compile time and not in ftrace_call_adjust at run time. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace/recordmcount: Add warning logic to warn on mcount not recordedSteven Rostedt1-8/+24
There's some sections that should not have mcount recorded and should not have modifications to the that code. But currently they waste some time by calling mcount anyway (which simply returns). As the real answer should be to either whitelist the section or have gcc ignore it fully. This change adds a option to recordmcount to warn when it finds a section that is ignored by ftrace but still contains mcount callers. This is not on by default as developers may not know if the section should be completely ignored or added to the whitelist. Cc: John Reiser <jreiser@bitwagon.com> Link: http://lkml.kernel.org/r/20110421023738.476989377@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace/recordmcount: Make ignored mcount calls into nops at compile timeSteven Rostedt1-2/+38
There are sections that are ignored by ftrace for the function tracing because the text is in a section that can be removed without notice. The mcount calls in these sections are ignored and ftrace never sees them. The downside of this is that the functions in these sections still call mcount. Although the mcount function is defined in assembly simply as a return, this added overhead is unnecessary. The solution is to convert these callers into nops at compile time. A better solution is to add 'notrace' to the section markers, but as new sections come up all the time, it would be nice that they are delt with when they are created. Later patches will deal with finding these sections and doing the proper solution. Thanks to H. Peter Anvin for giving me the right nops to use for x86. Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: John Reiser <jreiser@bitwagon.com> Link: http://lkml.kernel.org/r/20110421023738.237101176@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace: Add .kprobe.text section to whitelist for recordmcount.cSteven Rostedt1-0/+1
The .kprobe.text section is safe to modify mcount to nop and tracing. Add it to the whitelist in recordmcount.c and recordmcount.pl. Cc: John Reiser <jreiser@bitwagon.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Link: http://lkml.kernel.org/r/20110421023737.743350547@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace/trivial: Clean up record mcount to use Linux switch styleSteven Rostedt1-21/+22
The Linux style for switch statements is: switch (var) { case x: [...] break; } Not: switch (var) { case x: { [...] } break; Cc: John Reiser <jreiser@bitwagon.com> Link: http://lkml.kernel.org/r/20110421023737.523968644@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-05-16ftrace/trivial: Clean up recordmcount.c to use Linux style comparisonsSteven Rostedt1-24/+24
The Linux ftrace subsystem style for comparing is: var == 1 var > 0 and not: 1 == var 0 < var It is considered that Linux developers are smart enough not to do the if (var = 1) mistake. Cc: John Reiser <jreiser@bitwagon.com> Link: http://lkml.kernel.org/r/20110421023737.290712238@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-03-10ftrace: Add .ref.text as one of the safe areas to traceSteven Rostedt1-1/+2
The section .ref.text will not go away unexpectedly and is safe to trace. Add it to the safe list of sections to allow tracing. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-04ARM: 6511/1: ftrace: add ARM support for C version of recordmcountRabin Vincent1-1/+4
Depending on the compiler version, ARM GCC calls the mcount function either __gnu_mcount_nc or mcount. Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-04ARM: 6509/1: ftrace: ignore any ftrace.o in C version of recordmcountRabin Vincent1-1/+1
arch/arm/kernel/ftrace.c references mcount like kernel/tracing/ftrace.c, so change the exclusion filter to match any ftrace.o. Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-10-29ftrace/MIPS: Add module support for C version of recordmcountWu Zhangjin1-1/+4
Since MIPS modules' address space differs from the core kernel space, to access the _mcount in the core kernel, the kernel functions in modules must use long call (-mlong-calls): load the _mcount address into one register and jump to the address stored by the register: c: 3c030000 lui v1,0x0 <--------> b label c: R_MIPS_HI16 _mcount c: R_MIPS_NONE *ABS* c: R_MIPS_NONE *ABS* 10: 64630000 daddiu v1,v1,0 10: R_MIPS_LO16 _mcount 10: R_MIPS_NONE *ABS* 10: R_MIPS_NONE *ABS* 14: 03e0082d move at,ra 18: 0060f809 jalr v1 label: In the old Perl version of recordmcount, we only need to record the position of the 1st R_MIPS_HI16 type of _mcount, and later, in ftrace_make_nop(), replace the instruction in this position by a "b label" and in ftrace_make_call(), replace it back. But, the default C version of recordmcount records all of the _mcount symbols, so, we must filter the 2nd _mcount like the Perl version of recordmcount does. The C version of recordmcount copes with the symbols before they are linked, So It doesn't know the type of the symbols and therefore can not filter the symbols as the Perl version of recordmcount does. But as we can see above, the 2nd _mcount symbols of the long call alawys follows the 1st _mcount symbol of the same long call, which means the offset from the 1st to the 2nd is fixed, it is 0x10-0xc = 4 here, 4 is the length of the 1st load instruciton, for MIPS has fixed length of instructions, this offset is always 4. And as we know, the _mcount is inserted into the entry of every kernel function, the offset between the other _mcount's is expected to be always bigger than 4. So, to filter the 2ns _mcount symbol of the long call, we can simply check the offset between two _mcount symbols, If it is 4, then, filter the 2nd _mcount symbol. To avoid touching too much code, an 'empty' function fn_is_fake_mcount() is added for all of the archs, and the specific archs can override it via chaning the function pointer: is_fake_mcount in do_file() with the e_machine. e.g. This patch adds MIPS_is_fake_mcount() to override the default fn_is_fake_mcount() pointed by is_fake_mcount. This fn_is_fake_mcount() checks if the _mcount symbol is fake, e.g. the 2nd _mcount symbol of the long call is fake, for there are 2 _mcount symbols mapped to one real mcount call, so, one of them is fake and must be filtered. This fn_is_fake_mcount() is called in sift_rel_mcount() after finding the _mcount symbols and before adding the _mcount symbol into mrelp, so, it can prevent the fake mcount symbol going into the last __mcount_loc table. Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com> LKML-Reference: <b866f0138224340a132d31861fa3f9300dee30ac.1288176026.git.wuzhangjin@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-10-29ftrace/MIPS: Add MIPS64 support for C version of recordmcountJohn Reiser1-0/+41
MIPS64 has 'weird' Elf64_Rel.r_info[1,2], which must be used instead of the generic Elf64_Rel.r_info, otherwise, the C version of recordmcount will not work for "segmentation fault". Usage of "union mips_r_info" and the functions MIPS64_r_sym() and MIPS64_r_info() written by Maciej W. Rozycki <macro@linux-mips.org> ---- [1] http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf [2] arch/mips/include/asm/module.h Tested-by: Wu Zhangjin <wuzhangjin@gmail.com> Signed-off-by: John Reiser <jreiser@BitWagon.com> Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> LKML-Reference: <AANLkTinwXjLAYACUfhLYaocHD_vBbiErLN3NjwN8JqSy@mail.gmail.com> LKML-Reference: <910dc2d5ae1ed042df4f96815fe4a433078d1c2a.1288176026.git.wuzhangjin@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-10-15ftrace: Do not process kernel/trace/ftrace.o with C recordmcount programSteven Rostedt1-2/+20
The file kernel/trace/ftrace.c references the mcount() call to convert the mcount() callers to nops. But because it references mcount(), the mcount() address is placed in the relocation table. The C version of recordmcount reads the relocation table of all object files, and it will add all references to mcount to the __mcount_loc table that is used to find the places that call mcount() and change the call to a nop. When recordmcount finds the mcount reference in kernel/trace/ftrace.o, it saves that location even though the code is not a call, but references mcount as data. On boot up, when all calls are converted to nops, the code has a safety check to determine what op code it is actually replacing before it replaces it. If that op code at the address does not match, then a warning is printed and the function tracer is disabled. The reference to mcount in ftrace.c, causes this warning to trigger, since the reference is not a call to mcount(). The ftrace.c file is not compiled with the -pg flag, so no calls to mcount() should be expected. This patch simply makes recordmcount.c skip the kernel/trace/ftrace.c file. This was the same solution used by the perl version of recordmcount. Reported-by: Ingo Molnar <mingo@elte.hu> Cc: John Reiser <jreiser@bitwagon.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-14ftrace: Remove duplicate code for 64 and 32 bit in recordmcount.cSteven Rostedt1-544/+4
The elf reader for recordmcount.c had duplicate functions for both 32 bit and 64 bit elf handling. This was due to the need of using the 32 and 64 bit elf structures. This patch consolidates the two by using macros to define the 32 and 64 bit names in a recordmcount.h file, and then by just defining a RECORD_MCOUNT_64 macro and including recordmcount.h twice we create the funtions for both the 32 bit version as well as the 64 bit version using one code source. Cc: John Reiser <jreiser@bitwagon.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-14ftrace: Add C version of recordmcount compile time codeJohn Reiser1-0/+885
Currently, the mcount callers are found with a perl script that does an objdump on every file in the kernel. This is a C version of that same code which should increase the performance time of compiling the kernel with dynamic ftrace enabled. Signed-off-by: John Reiser <jreiser@bitwagon.com> [ Updated the code to include .text.unlikely section as well as changing the format to follow Linux coding style. ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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