user/sven/linux.git/scripts, branch v5.4.224

kbuild: remove the target in signal traps when interrupted

2022-10-26T11:22:46Z

[ Upstream commit a7f3257da8a86b96fb9bf1bba40ae0bbd7f1885a ] When receiving some signal, GNU Make automatically deletes the target if it has already been changed by the interrupted recipe. If the target is possibly incomplete due to interruption, it must be deleted so that it will be remade from scratch on the next run of make. Otherwise, the target would remain corrupted permanently because its timestamp had already been updated. Thanks to this behavior of Make, you can stop the build any time by pressing Ctrl-C, and just run 'make' to resume it. Kbuild also relies on this feature, but it is equivalently important for any build systems that make decisions based on timestamps (if you want to support Ctrl-C reliably). However, this does not always work as claimed; Make immediately dies with Ctrl-C if its stderr goes into a pipe. [Test Makefile] foo: echo hello > $@ sleep 3 echo world >> $@ [Test Result] $ make # hit Ctrl-C echo hello > foo sleep 3 ^Cmake: *** Deleting file 'foo' make: *** [Makefile:3: foo] Interrupt $ make 2>&1 | cat # hit Ctrl-C echo hello > foo sleep 3 ^C$ # 'foo' is often left-over The reason is because SIGINT is sent to the entire process group. In this example, SIGINT kills 'cat', and 'make' writes the message to the closed pipe, then dies with SIGPIPE before cleaning the target. A typical bad scenario (as reported by [1], [2]) is to save build log by using the 'tee' command: $ make 2>&1 | tee log This can be problematic for any build systems based on Make, so I hope it will be fixed in GNU Make. The maintainer of GNU Make stated this is a long-standing issue and difficult to fix [3]. It has not been fixed yet as of writing. So, we cannot rely on Make cleaning the target. We can do it by ourselves, in signal traps. As far as I understand, Make takes care of SIGHUP, SIGINT, SIGQUIT, and SITERM for the target removal. I added the traps for them, and also for SIGPIPE just in case cmd_* rule prints something to stdout or stderr (but I did not observe an actual case where SIGPIPE was triggered). [Note 1] The trap handler might be worth explaining. rm -f $@; trap - $(sig); kill -s $(sig) $$ This lets the shell kill itself by the signal it caught, so the parent process can tell the child has exited on the signal. Generally, this is a proper manner for handling signals, in case the calling program (like Bash) may monitor WIFSIGNALED() and WTERMSIG() for WCE although this may not be a big deal here because GNU Make handles SIGHUP, SIGINT, SIGQUIT in WUE and SIGTERM in IUE. IUE - Immediate Unconditional Exit WUE - Wait and Unconditional Exit WCE - Wait and Cooperative Exit For details, see "Proper handling of SIGINT/SIGQUIT" [4]. [Note 2] Reverting 392885ee82d3 ("kbuild: let fixdep directly write to .*.cmd files") would directly address [1], but it only saves if_changed_dep. As reported in [2], all commands that use redirection can potentially leave an empty (i.e. broken) target. [Note 3] Another (even safer) approach might be to always write to a temporary file, and rename it to $@ at the end of the recipe. > $(tmp-target) mv $(tmp-target) $@ It would require a lot of Makefile changes, and result in ugly code, so I did not take it. [Note 4] A little more thoughts about a pattern rule with multiple targets (or a grouped target). %.x %.y: %.z When interrupted, GNU Make deletes both %.x and %.y, while this solution only deletes $@. Probably, this is not a big deal. The next run of make will execute the rule again to create $@ along with the other files. [1]: https://lore.kernel.org/all/YLeot94yAaM4xbMY@gmail.com/ [2]: https://lore.kernel.org/all/20220510221333.2770571-1-robh@kernel.org/ [3]: https://lists.gnu.org/archive/html/help-make/2021-06/msg00001.html [4]: https://www.cons.org/cracauer/sigint.html Fixes: 392885ee82d3 ("kbuild: let fixdep directly write to .*.cmd files") Reported-by: Ingo Molnar Reported-by: Rob Herring Signed-off-by: Masahiro Yamada Tested-by: Ingo Molnar Reviewed-by: Nicolas Schier Signed-off-by: Sasha Levin

selinux: use "grep -E" instead of "egrep"

2022-10-26T11:22:21Z

commit c969bb8dbaf2f3628927eae73e7c579a74cf1b6e upstream. The latest version of grep claims that egrep is now obsolete so the build now contains warnings that look like: egrep: warning: egrep is obsolescent; using grep -E fix this by using "grep -E" instead. Cc: Paul Moore Cc: Stephen Smalley Cc: Eric Paris Cc: selinux@vger.kernel.org Signed-off-by: Greg Kroah-Hartman [PM: tweak to remove vdso reference, cleanup subj line] Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

Makefile.extrawarn: Move -Wcast-function-type-strict to W=1

2022-10-07T07:16:57Z

commit 2120635108b35ecad9c59c8b44f6cbdf4f98214e upstream. We enable -Wcast-function-type globally in the kernel to warn about mismatching types in function pointer casts. Compilers currently warn only about ABI incompability with this flag, but Clang 16 will enable a stricter version of the check by default that checks for an exact type match. This will be very noisy in the kernel, so disable -Wcast-function-type-strict without W=1 until the new warnings have been addressed. Cc: stable@vger.kernel.org Link: https://reviews.llvm.org/D134831 Link: https://github.com/ClangBuiltLinux/linux/issues/1724 Suggested-by: Nathan Chancellor Signed-off-by: Sami Tolvanen Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220930203310.4010564-1-samitolvanen@google.com Signed-off-by: Greg Kroah-Hartman

mksysmap: Fix the mismatch of 'L0' symbols in System.map

2022-09-28T09:03:59Z

[ Upstream commit c17a2538704f926ee4d167ba625e09b1040d8439 ] When System.map was generated, the kernel used mksysmap to filter the kernel symbols, we need to filter "L0" symbols in LoongArch architecture. $ cat System.map | grep L0 9000000000221540 t L0 The L0 symbol exists in System.map, but not in .tmp_System.map. When "cmp -s System.map .tmp_System.map" will show "Inconsistent kallsyms data" error message in link-vmlinux.sh script. Signed-off-by: Youling Tang Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin

kbuild: Fix include path in scripts/Makefile.modpost

2022-09-05T08:27:45Z

commit 23a0cb8e3225122496bfa79172005c587c2d64bf upstream. When building an external module, if users don't need to separate the compilation output and source code, they run the following command: "make -C $(LINUX_SRC_DIR) M=$(PWD)". At this point, "$(KBUILD_EXTMOD)" and "$(src)" are the same. If they need to separate them, they run "make -C $(KERNEL_SRC_DIR) O=$(KERNEL_OUT_DIR) M=$(OUT_DIR) src=$(PWD)". Before running the command, they need to copy "Kbuild" or "Makefile" to "$(OUT_DIR)" to prevent compilation failure. So the kernel should change the included path to avoid the copy operation. Signed-off-by: Jing Leng [masahiro: I do not think "M=$(OUT_DIR) src=$(PWD)" is the official way, but this patch is a nice clean up anyway.] Signed-off-by: Masahiro Yamada [nsc: updated context for v4.19] Signed-off-by: Nicolas Schier Signed-off-by: Greg Kroah-Hartman

gcc-plugins: Undefine LATENT_ENTROPY_PLUGIN when plugin disabled for a file

2022-08-25T09:18:31Z

commit 012e8d2034f1bda8863435cd589636e618d6a659 upstream. Commit 36d4b36b6959 ("lib/nodemask: inline next_node_in() and node_random()") refactored some code by moving node_random() from lib/nodemask.c to include/linux/nodemask.h, thus requiring nodemask.h to include random.h, which conditionally defines add_latent_entropy() depending on whether the macro LATENT_ENTROPY_PLUGIN is defined. This broke the build on powerpc, where nodemask.h is indirectly included in arch/powerpc/kernel/prom_init.c, part of the early boot machinery that is excluded from the latent entropy plugin using DISABLE_LATENT_ENTROPY_PLUGIN. It turns out that while we add a gcc flag to disable the actual plugin, we don't undefine LATENT_ENTROPY_PLUGIN. This leads to the following: CC arch/powerpc/kernel/prom_init.o In file included from ./include/linux/nodemask.h:97, from ./include/linux/mmzone.h:17, from ./include/linux/gfp.h:7, from ./include/linux/xarray.h:15, from ./include/linux/radix-tree.h:21, from ./include/linux/idr.h:15, from ./include/linux/kernfs.h:12, from ./include/linux/sysfs.h:16, from ./include/linux/kobject.h:20, from ./include/linux/pci.h:35, from arch/powerpc/kernel/prom_init.c:24: ./include/linux/random.h: In function 'add_latent_entropy': ./include/linux/random.h:25:46: error: 'latent_entropy' undeclared (first use in this function); did you mean 'add_latent_entropy'? 25 | add_device_randomness((const void *)&latent_entropy, sizeof(latent_entropy)); | ^~~~~~~~~~~~~~ | add_latent_entropy ./include/linux/random.h:25:46: note: each undeclared identifier is reported only once for each function it appears in make[2]: *** [scripts/Makefile.build:249: arch/powerpc/kernel/prom_init.o] Fehler 1 make[1]: *** [scripts/Makefile.build:465: arch/powerpc/kernel] Fehler 2 make: *** [Makefile:1855: arch/powerpc] Error 2 Change the DISABLE_LATENT_ENTROPY_PLUGIN flags to undefine LATENT_ENTROPY_PLUGIN for files where the plugin is disabled. Cc: Yury Norov Fixes: 38addce8b600 ("gcc-plugins: Add latent_entropy plugin") Link: https://bugzilla.kernel.org/show_bug.cgi?id=216367 Link: https://lore.kernel.org/linuxppc-dev/alpine.DEB.2.22.394.2208152006320.289321@ramsan.of.borg/ Reported-by: Erhard Furtner Signed-off-by: Andrew Donnellan Reviewed-by: Yury Norov Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220816051720.44108-1-ajd@linux.ibm.com Signed-off-by: Greg Kroah-Hartman

scripts/faddr2line: Fix vmlinux detection on arm64

2022-08-25T09:18:08Z

[ Upstream commit b6a5068854cfe372da7dee3224dcf023ed5b00cb ] Since commit dcea997beed6 ("faddr2line: Fix overlapping text section failures, the sequel"), faddr2line is completely broken on arm64. For some reason, on arm64, the vmlinux ELF object file type is ET_DYN rather than ET_EXEC. Check for both when determining whether the object is vmlinux. Modules and vmlinux.o have type ET_REL on all arches. Fixes: dcea997beed6 ("faddr2line: Fix overlapping text section failures, the sequel") Reported-by: John Garry Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Tested-by: John Garry Link: https://lore.kernel.org/r/dad1999737471b06d6188ce4cdb11329aa41682c.1658426357.git.jpoimboe@kernel.org Signed-off-by: Sasha Levin

modpost: fix section mismatch check for exported init/exit sections

2022-06-29T06:58:49Z

commit 28438794aba47a27e922857d27b31b74e8559143 upstream. Since commit f02e8a6596b7 ("module: Sort exported symbols"), EXPORT_SYMBOL* is placed in the individual section ___ksymtab(_gpl)+ (3 leading underscores instead of 2). Since then, modpost cannot detect the bad combination of EXPORT_SYMBOL and __init/__exit. Fix the .fromsec field. Fixes: f02e8a6596b7 ("module: Sort exported symbols") Signed-off-by: Masahiro Yamada Reviewed-by: Nick Desaulniers Signed-off-by: Greg Kroah-Hartman

faddr2line: Fix overlapping text section failures, the sequel

2022-06-22T12:11:22Z

[ Upstream commit dcea997beed694cbd8705100ca1a6eb0d886de69 ] If a function lives in a section other than .text, but .text also exists in the object, faddr2line may wrongly assume .text. This can result in comically wrong output. For example: $ scripts/faddr2line vmlinux.o enter_from_user_mode+0x1c enter_from_user_mode+0x1c/0x30: find_next_bit at /home/jpoimboe/git/linux/./include/linux/find.h:40 (inlined by) perf_clear_dirty_counters at /home/jpoimboe/git/linux/arch/x86/events/core.c:2504 Fix it by passing the section name to addr2line, unless the object file is vmlinux, in which case the symbol table uses absolute addresses. Fixes: 1d1a0e7c5100 ("scripts/faddr2line: Fix overlapping text section failures") Reported-by: Peter Zijlstra Signed-off-by: Josh Poimboeuf Link: https://lore.kernel.org/r/7d25bc1408bd3a750ac26e60d2f2815a5f4a8363.1654130536.git.jpoimboe@kernel.org Signed-off-by: Sasha Levin

scripts/gdb: change kernel config dumping method

2022-06-14T16:12:02Z

[ Upstream commit 1f7a6cf6b07c74a17343c2559cd5f5018a245961 ] MAGIC_START("IKCFG_ST") and MAGIC_END("IKCFG_ED") are moved out from the kernel_config_data variable. Thus, we parse kernel_config_data directly instead of considering offset of MAGIC_START and MAGIC_END. Fixes: 13610aa908dc ("kernel/configs: use .incbin directive to embed config_data.gz") Signed-off-by: Kuan-Ying Lee Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin