From fbe078d397b4d59232f05fde977d3b1e7d0c2028 Mon Sep 17 00:00:00 2001 From: Sami Tolvanen Date: Fri, 11 Dec 2020 10:46:23 -0800 Subject: kbuild: lto: add a default list of used symbols With CONFIG_LTO_CLANG, LLVM bitcode has not yet been compiled into a binary when the .mod files are generated, which means they don't yet contain references to certain symbols that will be present in the final binaries. This includes intrinsic functions, such as memcpy, memmove, and memset [1], and stack protector symbols [2]. This change adds a default symbol list to use with CONFIG_TRIM_UNUSED_KSYMS when Clang's LTO is used. [1] https://llvm.org/docs/LangRef.html#standard-c-c-library-intrinsics [2] https://llvm.org/docs/LangRef.html#llvm-stackprotector-intrinsic Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20201211184633.3213045-7-samitolvanen@google.com --- init/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index b77c60f8b963..5271138b8742 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -2297,6 +2297,7 @@ config TRIM_UNUSED_KSYMS config UNUSED_KSYMS_WHITELIST string "Whitelist of symbols to keep in ksymtab" depends on TRIM_UNUSED_KSYMS + default "scripts/lto-used-symbollist.txt" if LTO_CLANG help By default, all unused exported symbols will be un-exported from the build when TRIM_UNUSED_KSYMS is selected. -- cgit v1.2.3 From 432900f8164b77376df2c25113fb94f9d7fffd79 Mon Sep 17 00:00:00 2001 From: Yue Hu Date: Wed, 27 Jan 2021 13:44:51 +0800 Subject: init/Kconfig: Correct thermal pressure help text We're using arch_scale_thermal_pressure() to retrieve per CPU thermal pressure. Signed-off-by: Yue Hu Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Valentin Schneider Link: https://lkml.kernel.org/r/20210127054451.1240-1-zbestahu@gmail.com --- init/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index b77c60f8b963..058b99d12f99 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -525,7 +525,7 @@ config SCHED_THERMAL_PRESSURE i.e. put less load on throttled CPUs than on non/less throttled ones. This requires the architecture to implement - arch_set_thermal_pressure() and arch_get_thermal_pressure(). + arch_set_thermal_pressure() and arch_scale_thermal_pressure(). config BSD_PROCESS_ACCT bool "BSD Process Accounting" -- cgit v1.2.3 From f8408264c77a0cebb20244d1f4750501b36abe0e Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Thu, 14 Jan 2021 17:05:30 +0530 Subject: drivers: Remove CONFIG_OPROFILE support The "oprofile" user-space tools don't use the kernel OPROFILE support any more, and haven't in a long time. User-space has been converted to the perf interfaces. Remove kernel's old oprofile support. Suggested-by: Christoph Hellwig Suggested-by: Linus Torvalds Signed-off-by: Viresh Kumar Acked-by: Robert Richter Acked-by: Paul E. McKenney #RCU Acked-by: William Cohen Acked-by: Al Viro Acked-by: Thomas Gleixner --- init/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index b77c60f8b963..03eb36256405 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -2024,7 +2024,7 @@ config PROFILING bool "Profiling support" help Say Y here to enable the extended profiling support mechanisms used - by profilers such as OProfile. + by profilers. # # Place an empty function call at each tracepoint site. Can be -- cgit v1.2.3 From 7e0a9220467dbcfdc5bc62825724f3e52e50ab31 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Fri, 29 Jan 2021 10:13:53 -0500 Subject: fgraph: Initialize tracing_graph_pause at task creation On some archs, the idle task can call into cpu_suspend(). The cpu_suspend() will disable or pause function graph tracing, as there's some paths in bringing down the CPU that can have issues with its return address being modified. The task_struct structure has a "tracing_graph_pause" atomic counter, that when set to something other than zero, the function graph tracer will not modify the return address. The problem is that the tracing_graph_pause counter is initialized when the function graph tracer is enabled. This can corrupt the counter for the idle task if it is suspended in these architectures. CPU 1 CPU 2 ----- ----- do_idle() cpu_suspend() pause_graph_tracing() task_struct->tracing_graph_pause++ (0 -> 1) start_graph_tracing() for_each_online_cpu(cpu) { ftrace_graph_init_idle_task(cpu) task-struct->tracing_graph_pause = 0 (1 -> 0) unpause_graph_tracing() task_struct->tracing_graph_pause-- (0 -> -1) The above should have gone from 1 to zero, and enabled function graph tracing again. But instead, it is set to -1, which keeps it disabled. There's no reason that the field tracing_graph_pause on the task_struct can not be initialized at boot up. Cc: stable@vger.kernel.org Fixes: 380c4b1411ccd ("tracing/function-graph-tracer: append the tracing_graph_flag") Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=211339 Reported-by: pierre.gondois@arm.com Signed-off-by: Steven Rostedt (VMware) --- init/init_task.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'init') diff --git a/init/init_task.c b/init/init_task.c index 8a992d73e6fb..3711cdaafed2 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -198,7 +198,8 @@ struct task_struct init_task .lockdep_recursion = 0, #endif #ifdef CONFIG_FUNCTION_GRAPH_TRACER - .ret_stack = NULL, + .ret_stack = NULL, + .tracing_graph_pause = ATOMIC_INIT(0), #endif #if defined(CONFIG_TRACING) && defined(CONFIG_PREEMPTION) .trace_recursion = 0, -- cgit v1.2.3 From 55b6f763d8bcb5546997933105d66d3e6b080e6a Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 4 Feb 2021 18:32:28 -0800 Subject: init/gcov: allow CONFIG_CONSTRUCTORS on UML to fix module gcov On ARCH=um, loading a module doesn't result in its constructors getting called, which breaks module gcov since the debugfs files are never registered. On the other hand, in-kernel constructors have already been called by the dynamic linker, so we can't call them again. Get out of this conundrum by allowing CONFIG_CONSTRUCTORS to be selected, but avoiding the in-kernel constructor calls. Also remove the "if !UML" from GCOV selecting CONSTRUCTORS now, since we really do want CONSTRUCTORS, just not kernel binary ones. Link: https://lkml.kernel.org/r/20210120172041.c246a2cac2fb.I1358f584b76f1898373adfed77f4462c8705b736@changeid Signed-off-by: Johannes Berg Reviewed-by: Peter Oberparleiter Cc: Arnd Bergmann Cc: Jessica Yu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- init/Kconfig | 1 - init/main.c | 8 +++++++- 2 files changed, 7 insertions(+), 2 deletions(-) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index b77c60f8b963..29ad68325028 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -76,7 +76,6 @@ config CC_HAS_ASM_INLINE config CONSTRUCTORS bool - depends on !UML config IRQ_WORK bool diff --git a/init/main.c b/init/main.c index c68d784376ca..a626e78dbf06 100644 --- a/init/main.c +++ b/init/main.c @@ -1066,7 +1066,13 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void) /* Call all constructor functions linked into the kernel. */ static void __init do_ctors(void) { -#ifdef CONFIG_CONSTRUCTORS +/* + * For UML, the constructors have already been called by the + * normal setup code as it's just a normal ELF binary, so we + * cannot do it again - but we do need CONFIG_CONSTRUCTORS + * even on UML for modules. + */ +#if defined(CONFIG_CONSTRUCTORS) && !defined(CONFIG_UML) ctor_fn_t *fn = (ctor_fn_t *) __ctors_start; for (; fn < (ctor_fn_t *) __ctors_end; fn++) -- cgit v1.2.3 From 367948220fcefcad1bf0d3d595a06efe0694acae Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 2 Feb 2021 13:13:34 +0100 Subject: module: remove EXPORT_UNUSED_SYMBOL* EXPORT_UNUSED_SYMBOL* is not actually used anywhere. Remove the unused functionality as we generally just remove unused code anyway. Reviewed-by: Miroslav Benes Reviewed-by: Emil Velikov Signed-off-by: Christoph Hellwig Signed-off-by: Jessica Yu --- init/Kconfig | 17 ----------------- 1 file changed, 17 deletions(-) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index b77c60f8b963..11b803b45c19 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -2262,25 +2262,8 @@ config MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS If unsure, say N. -config UNUSED_SYMBOLS - bool "Enable unused/obsolete exported symbols" - default y if X86 - help - Unused but exported symbols make the kernel needlessly bigger. For - that reason most of these unused exports will soon be removed. This - option is provided temporarily to provide a transition period in case - some external kernel module needs one of these symbols anyway. If you - encounter such a case in your module, consider if you are actually - using the right API. (rationale: since nobody in the kernel is using - this in a module, there is a pretty good chance it's actually the - wrong interface to use). If you really need the symbol, please send a - mail to the linux kernel mailing list mentioning the symbol and why - you really need it, and what the merge plan to the mainline kernel for - your module is. - config TRIM_UNUSED_KSYMS bool "Trim unused exported kernel symbols" - depends on !UNUSED_SYMBOLS help The kernel and some modules make many symbols available for other modules to use via EXPORT_SYMBOL() and variants. Depending -- cgit v1.2.3 From 4590d98f5a4f466d17e5c81d7c9fc796da9a8cee Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Thu, 11 Feb 2021 15:40:02 +0200 Subject: sfi: Remove framework for deprecated firmware SFI-based platforms are gone. So does this framework. This removes mention of SFI through the drivers and other code as well. Signed-off-by: Andy Shevchenko Reviewed-by: Hans de Goede Acked-by: Linus Walleij Signed-off-by: Rafael J. Wysocki --- init/main.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'init') diff --git a/init/main.c b/init/main.c index a626e78dbf06..e9933cbf60d4 100644 --- a/init/main.c +++ b/init/main.c @@ -74,7 +74,6 @@ #include #include #include -#include #include #include #include @@ -1054,7 +1053,6 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void) acpi_subsystem_init(); arch_post_acpi_subsys_init(); - sfi_init_late(); kcsan_init(); /* Do the rest non-__init'ed, we're now alive */ -- cgit v1.2.3 From aec6c60a01d3a3170242d6a99372a388e1136dc6 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sat, 16 Jan 2021 08:35:42 +0900 Subject: kbuild: check the minimum compiler version in Kconfig Paul Gortmaker reported a regression in the GCC version check. [1] If you use GCC 4.8, the build breaks before showing the error message "error Sorry, your version of GCC is too old - please use 4.9 or newer." I do not want to apply his fix-up since it implies we would not be able to remove any cc-option test. Anyway, I admit checking the GCC version in is too late. Almost at the same time, Linus also suggested to move the compiler version error to Kconfig time. [2] I unified the two similar scripts, gcc-version.sh and clang-version.sh into cc-version.sh. The old scripts invoked the compiler multiple times (3 times for gcc-version.sh, 4 times for clang-version.sh). I refactored the code so the new one invokes the compiler just once, and also tried my best to use shell-builtin commands where possible. The new script runs faster. $ time ./scripts/clang-version.sh clang 120000 real 0m0.029s user 0m0.012s sys 0m0.021s $ time ./scripts/cc-version.sh clang Clang 120000 real 0m0.009s user 0m0.006s sys 0m0.004s cc-version.sh also shows an error message if the compiler is too old: $ make defconfig CC=clang-9 *** Default configuration is based on 'x86_64_defconfig' *** *** Compiler is too old. *** Your Clang version: 9.0.1 *** Minimum Clang version: 10.0.1 *** scripts/Kconfig.include:46: Sorry, this compiler is not supported. make[1]: *** [scripts/kconfig/Makefile:81: defconfig] Error 1 make: *** [Makefile:602: defconfig] Error 2 The new script takes care of ICC because we have although I am not sure if building the kernel with ICC is well-supported. [1]: https://lore.kernel.org/r/20210110190807.134996-1-paul.gortmaker@windriver.com [2]: https://lore.kernel.org/r/CAHk-=wh-+TMHPTFo1qs-MYyK7tZh-OQovA=pP3=e06aCVp6_kA@mail.gmail.com Fixes: 87de84c9140e ("kbuild: remove cc-option test of -Werror=date-time") Reported-by: Paul Gortmaker Suggested-by: Linus Torvalds Reviewed-by: Nick Desaulniers Tested-by: Nick Desaulniers Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor Reviewed-by: Miguel Ojeda Tested-by: Miguel Ojeda Tested-by: Sedat Dilek Signed-off-by: Masahiro Yamada --- init/Kconfig | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index 29ad68325028..7bcfa24524c2 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -26,11 +26,11 @@ config CC_VERSION_TEXT and then every file will be rebuilt. config CC_IS_GCC - def_bool $(success,echo "$(CC_VERSION_TEXT)" | grep -q gcc) + def_bool $(success,test "$(cc-name)" = GCC) config GCC_VERSION int - default $(shell,$(srctree)/scripts/gcc-version.sh $(CC)) if CC_IS_GCC + default $(cc-version) if CC_IS_GCC default 0 config LD_VERSION @@ -38,14 +38,15 @@ config LD_VERSION default $(shell,$(LD) --version | $(srctree)/scripts/ld-version.sh) config CC_IS_CLANG - def_bool $(success,echo "$(CC_VERSION_TEXT)" | grep -q clang) + def_bool $(success,test "$(cc-name)" = Clang) config LD_IS_LLD def_bool $(success,$(LD) -v | head -n 1 | grep -q LLD) config CLANG_VERSION int - default $(shell,$(srctree)/scripts/clang-version.sh $(CC)) + default $(cc-version) if CC_IS_CLANG + default 0 config LLD_VERSION int -- cgit v1.2.3 From bfe3911a91047557eb0e620f95a370aee6a248c7 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 5 Feb 2021 22:00:12 +0000 Subject: kcmp: Support selection of SYS_kcmp without CHECKPOINT_RESTORE Userspace has discovered the functionality offered by SYS_kcmp and has started to depend upon it. In particular, Mesa uses SYS_kcmp for os_same_file_description() in order to identify when two fd (e.g. device or dmabuf) point to the same struct file. Since they depend on it for core functionality, lift SYS_kcmp out of the non-default CONFIG_CHECKPOINT_RESTORE into the selectable syscall category. Rasmus Villemoes also pointed out that systemd uses SYS_kcmp to deduplicate the per-service file descriptor store. Note that some distributions such as Ubuntu are already enabling CHECKPOINT_RESTORE in their configs and so, by extension, SYS_kcmp. References: https://gitlab.freedesktop.org/drm/intel/-/issues/3046 Signed-off-by: Chris Wilson Cc: Kees Cook Cc: Andy Lutomirski Cc: Will Drewry Cc: Andrew Morton Cc: Dave Airlie Cc: Daniel Vetter Cc: Lucas Stach Cc: Rasmus Villemoes Cc: Cyrill Gorcunov Cc: stable@vger.kernel.org Acked-by: Daniel Vetter # DRM depends on kcmp Acked-by: Rasmus Villemoes # systemd uses kcmp Reviewed-by: Cyrill Gorcunov Reviewed-by: Kees Cook Acked-by: Thomas Zimmermann Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20210205220012.1983-1-chris@chris-wilson.co.uk --- init/Kconfig | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index 29ad68325028..b7d3c6a12196 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1193,6 +1193,7 @@ endif # NAMESPACES config CHECKPOINT_RESTORE bool "Checkpoint/restore support" select PROC_CHILDREN + select KCMP default n help Enables additional kernel features in a sake of checkpoint/restore. @@ -1736,6 +1737,16 @@ config ARCH_HAS_MEMBARRIER_CALLBACKS config ARCH_HAS_MEMBARRIER_SYNC_CORE bool +config KCMP + bool "Enable kcmp() system call" if EXPERT + help + Enable the kernel resource comparison system call. It provides + user-space with the ability to compare two processes to see if they + share a common resource, such as a file descriptor or even virtual + memory space. + + If unsure, say N. + config RSEQ bool "Enable rseq() system call" if EXPERT default y -- cgit v1.2.3 From c72160fe05fb978ad859ba053c4462c2bb960b13 Mon Sep 17 00:00:00 2001 From: Kefeng Wang Date: Fri, 15 Jan 2021 13:46:04 +0800 Subject: initramfs: Provide a common initrd reserve function Some architectures(eg, ARM and riscv) have similar logic to check and reserve the memory of initrd, let's provide a common function reserve_initrd_mem() to reduce duplicated code. Signed-off-by: Kefeng Wang Signed-off-by: Palmer Dabbelt --- init/initramfs.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) (limited to 'init') diff --git a/init/initramfs.c b/init/initramfs.c index 55b74d7e5260..f75c89e9d602 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -535,6 +535,51 @@ extern unsigned long __initramfs_size; #include #include +void __init reserve_initrd_mem(void) +{ + phys_addr_t start; + unsigned long size; + + /* Ignore the virtul address computed during device tree parsing */ + initrd_start = initrd_end = 0; + + if (!phys_initrd_size) + return; + /* + * Round the memory region to page boundaries as per free_initrd_mem() + * This allows us to detect whether the pages overlapping the initrd + * are in use, but more importantly, reserves the entire set of pages + * as we don't want these pages allocated for other purposes. + */ + start = round_down(phys_initrd_start, PAGE_SIZE); + size = phys_initrd_size + (phys_initrd_start - start); + size = round_up(size, PAGE_SIZE); + + if (!memblock_is_region_memory(start, size)) { + pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region", + (u64)start, size); + goto disable; + } + + if (memblock_is_region_reserved(start, size)) { + pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n", + (u64)start, size); + goto disable; + } + + memblock_reserve(start, size); + /* Now convert initrd to virtual addresses */ + initrd_start = (unsigned long)__va(phys_initrd_start); + initrd_end = initrd_start + phys_initrd_size; + initrd_below_start_ok = 1; + + return; +disable: + pr_cont(" - disabling initrd\n"); + initrd_start = 0; + initrd_end = 0; +} + void __weak __init free_initrd_mem(unsigned long start, unsigned long end) { #ifdef CONFIG_ARCH_KEEP_MEMBLOCK -- cgit v1.2.3 From 02aff85922043cf175ebbe5fc3430acfeaeb8393 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Tue, 16 Feb 2021 12:10:04 +0900 Subject: kbuild: check the minimum linker version in Kconfig Unify the two scripts/ld-version.sh and scripts/lld-version.sh, and check the minimum linker version like scripts/cc-version.sh did. I tested this script for some corner cases reported in the past: - GNU ld version 2.25-15.fc23 as reported by commit 8083013fc320 ("ld-version: Fix it on Fedora") - GNU ld (GNU Binutils) 2.20.1.20100303 as reported by commit 0d61ed17dd30 ("ld-version: Drop the 4th and 5th version components") This script show an error message if the linker is too old: $ make LD=ld.lld-9 SYNC include/config/auto.conf *** *** Linker is too old. *** Your LLD version: 9.0.1 *** Minimum LLD version: 10.0.1 *** scripts/Kconfig.include:50: Sorry, this linker is not supported. make[2]: *** [scripts/kconfig/Makefile:71: syncconfig] Error 1 make[1]: *** [Makefile:600: syncconfig] Error 2 make: *** [Makefile:708: include/config/auto.conf] Error 2 I also moved the check for gold to this script, so gold is still rejected: $ make LD=gold SYNC include/config/auto.conf gold linker is not supported as it is not capable of linking the kernel proper. scripts/Kconfig.include:50: Sorry, this linker is not supported. make[2]: *** [scripts/kconfig/Makefile:71: syncconfig] Error 1 make[1]: *** [Makefile:600: syncconfig] Error 2 make: *** [Makefile:708: include/config/auto.conf] Error 2 Thanks to David Laight for suggesting shell script improvements. Signed-off-by: Masahiro Yamada Acked-by: Nick Desaulniers Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor --- init/Kconfig | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index 7bcfa24524c2..42b69ee29dca 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -33,24 +33,29 @@ config GCC_VERSION default $(cc-version) if CC_IS_GCC default 0 -config LD_VERSION - int - default $(shell,$(LD) --version | $(srctree)/scripts/ld-version.sh) - config CC_IS_CLANG def_bool $(success,test "$(cc-name)" = Clang) -config LD_IS_LLD - def_bool $(success,$(LD) -v | head -n 1 | grep -q LLD) - config CLANG_VERSION int default $(cc-version) if CC_IS_CLANG default 0 +config LD_IS_BFD + def_bool $(success,test "$(ld-name)" = BFD) + +config LD_VERSION + int + default $(ld-version) if LD_IS_BFD + default 0 + +config LD_IS_LLD + def_bool $(success,test "$(ld-name)" = LLD) + config LLD_VERSION int - default $(shell,$(srctree)/scripts/lld-version.sh $(LD)) + default $(ld-version) if LD_IS_LLD + default 0 config CC_CAN_LINK bool -- cgit v1.2.3 From 5cf0fd591f2e7833405bdc7ce2176c3502e8a11e Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 23 Feb 2021 12:21:58 -0800 Subject: Kbuild: disable TRIM_UNUSED_KSYMS option The removal of EXPORT_UNUSED_SYMBOL() in commit 367948220fce looks like (and was sold as) a no-op, but it actually had a rather serious and subtle side effect: the UNUSED_SYMBOLS option not only enabled the removed (unused) functionality, it also _disabled_ the TRIM_UNUSED_KSYMS functionality. And it turns out that TRIM_UNUSED_KSYMS is a huge time waste, and takes up a third of the kernel build time for me. For no actual upside, since no distro is likely to ever be able to enable it (because they all support external kernel modules). Rather than re-enable EXPORT_UNUSED_SYMBOL, this just disables the TRIM_UNUSED_KSYMS option by marking it broken. I'm tempted to just remove the support entirely, but maybe somebody has a use-case and can fix the behavior of it. I could have just disabled it for COMPILE_TEST, but it really smells like the TRIM_UNUSED_KSYMS option is badly done and not really useful, so this takes the more direct approach - let's see if anybody ever actually notices or complains. Cc: Miroslav Benes Cc: Emil Velikov Cc: Christoph Hellwig Cc: Jessica Yu Fixes: 367948220fce ("module: remove EXPORT_UNUSED_SYMBOL*") Signed-off-by: Linus Torvalds --- init/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index 8a2c0e41f1bb..ba8bd5256980 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -2274,6 +2274,7 @@ config MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS config TRIM_UNUSED_KSYMS bool "Trim unused exported kernel symbols" + depends on BROKEN help The kernel and some modules make many symbols available for other modules to use via EXPORT_SYMBOL() and variants. Depending -- cgit v1.2.3 From a555bdd0c58ce368fb1324f0e93d17f7c4babece Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 24 Feb 2021 08:57:06 -0800 Subject: Kbuild: enable TRIM_UNUSED_KSYMS again, with some guarding In commit 5cf0fd591f2e ("Kbuild: disable TRIM_UNUSED_KSYMS option") I disabled this option because it's hugely expensive at build time, and I questioned how much use it gets. Several people piped up and convinced me it's actually useful, so instead of disabling it entirely, it now depends on EXPERT and gets disabled by COMPILE_TEST builds so that 'allmodconfig' style things don't enable it. I still hope somebody will take a look at the build time issue, because as Arnd also noted: "However, the combination of thinlto and trim indeed has a steep cost in compile time, taking almost twice as long as a normal defconfig (gc-sections makes it slightly faster)" Cc: Masahiro Yamada Cc: Arnd Bergmann Cc: Jessica Yu Cc: Cristoph Hellwig , Cc: Miroslav Benes Cc: Emil Velikov Signed-off-by: Linus Torvalds --- init/Kconfig | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index ba8bd5256980..c2a18f56e944 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -2273,8 +2273,8 @@ config MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS If unsure, say N. config TRIM_UNUSED_KSYMS - bool "Trim unused exported kernel symbols" - depends on BROKEN + bool "Trim unused exported kernel symbols" if EXPERT + depends on !COMPILE_TEST help The kernel and some modules make many symbols available for other modules to use via EXPORT_SYMBOL() and variants. Depending -- cgit v1.2.3 From fe2cce15d6821aea1766708a1cf031071cec815f Mon Sep 17 00:00:00 2001 From: Vlastimil Babka Date: Wed, 24 Feb 2021 12:01:22 -0800 Subject: mm, slub: remove slub_memcg_sysfs boot param and CONFIG_SLUB_MEMCG_SYSFS_ON The boot param and config determine the value of memcg_sysfs_enabled, which is unused since commit 10befea91b61 ("mm: memcg/slab: use a single set of kmem_caches for all allocations") as there are no per-memcg kmem caches anymore. Link: https://lkml.kernel.org/r/20210127124745.7928-1-vbabka@suse.cz Signed-off-by: Vlastimil Babka Reviewed-by: David Hildenbrand Acked-by: Roman Gushchin Acked-by: David Rientjes Reviewed-by: Miaohe Lin Cc: Christoph Lameter Cc: Pekka Enberg Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- init/Kconfig | 14 -------------- 1 file changed, 14 deletions(-) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index ba8bd5256980..8f3a6c4fc0b4 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1861,20 +1861,6 @@ config SLUB_DEBUG SLUB sysfs support. /sys/slab will not exist and there will be no support for cache validation etc. -config SLUB_MEMCG_SYSFS_ON - default n - bool "Enable memcg SLUB sysfs support by default" if EXPERT - depends on SLUB && SYSFS && MEMCG - help - SLUB creates a directory under /sys/kernel/slab for each - allocation cache to host info and debug files. If memory - cgroup is enabled, each cache can have per memory cgroup - caches. SLUB can create the same sysfs directories for these - caches under /sys/kernel/slab/CACHE/cgroup but it can lead - to a very high number of debug files being created. This is - controlled by slub_memcg_sysfs boot parameter and this - config option determines the parameter's default value. - config COMPAT_BRK bool "Disable heap randomization" default y -- cgit v1.2.3 From 0ce20dd840897b12ae70869c69f1ba34d6d16965 Mon Sep 17 00:00:00 2001 From: Alexander Potapenko Date: Thu, 25 Feb 2021 17:18:53 -0800 Subject: mm: add Kernel Electric-Fence infrastructure Patch series "KFENCE: A low-overhead sampling-based memory safety error detector", v7. This adds the Kernel Electric-Fence (KFENCE) infrastructure. KFENCE is a low-overhead sampling-based memory safety error detector of heap use-after-free, invalid-free, and out-of-bounds access errors. This series enables KFENCE for the x86 and arm64 architectures, and adds KFENCE hooks to the SLAB and SLUB allocators. KFENCE is designed to be enabled in production kernels, and has near zero performance overhead. Compared to KASAN, KFENCE trades performance for precision. The main motivation behind KFENCE's design, is that with enough total uptime KFENCE will detect bugs in code paths not typically exercised by non-production test workloads. One way to quickly achieve a large enough total uptime is when the tool is deployed across a large fleet of machines. KFENCE objects each reside on a dedicated page, at either the left or right page boundaries. The pages to the left and right of the object page are "guard pages", whose attributes are changed to a protected state, and cause page faults on any attempted access to them. Such page faults are then intercepted by KFENCE, which handles the fault gracefully by reporting a memory access error. Guarded allocations are set up based on a sample interval (can be set via kfence.sample_interval). After expiration of the sample interval, the next allocation through the main allocator (SLAB or SLUB) returns a guarded allocation from the KFENCE object pool. At this point, the timer is reset, and the next allocation is set up after the expiration of the interval. To enable/disable a KFENCE allocation through the main allocator's fast-path without overhead, KFENCE relies on static branches via the static keys infrastructure. The static branch is toggled to redirect the allocation to KFENCE. The KFENCE memory pool is of fixed size, and if the pool is exhausted no further KFENCE allocations occur. The default config is conservative with only 255 objects, resulting in a pool size of 2 MiB (with 4 KiB pages). We have verified by running synthetic benchmarks (sysbench I/O, hackbench) and production server-workload benchmarks that a kernel with KFENCE (using sample intervals 100-500ms) is performance-neutral compared to a non-KFENCE baseline kernel. KFENCE is inspired by GWP-ASan [1], a userspace tool with similar properties. The name "KFENCE" is a homage to the Electric Fence Malloc Debugger [2]. For more details, see Documentation/dev-tools/kfence.rst added in the series -- also viewable here: https://raw.githubusercontent.com/google/kasan/kfence/Documentation/dev-tools/kfence.rst [1] http://llvm.org/docs/GwpAsan.html [2] https://linux.die.net/man/3/efence This patch (of 9): This adds the Kernel Electric-Fence (KFENCE) infrastructure. KFENCE is a low-overhead sampling-based memory safety error detector of heap use-after-free, invalid-free, and out-of-bounds access errors. KFENCE is designed to be enabled in production kernels, and has near zero performance overhead. Compared to KASAN, KFENCE trades performance for precision. The main motivation behind KFENCE's design, is that with enough total uptime KFENCE will detect bugs in code paths not typically exercised by non-production test workloads. One way to quickly achieve a large enough total uptime is when the tool is deployed across a large fleet of machines. KFENCE objects each reside on a dedicated page, at either the left or right page boundaries. The pages to the left and right of the object page are "guard pages", whose attributes are changed to a protected state, and cause page faults on any attempted access to them. Such page faults are then intercepted by KFENCE, which handles the fault gracefully by reporting a memory access error. To detect out-of-bounds writes to memory within the object's page itself, KFENCE also uses pattern-based redzones. The following figure illustrates the page layout: ---+-----------+-----------+-----------+-----------+-----------+--- | xxxxxxxxx | O : | xxxxxxxxx | : O | xxxxxxxxx | | xxxxxxxxx | B : | xxxxxxxxx | : B | xxxxxxxxx | | x GUARD x | J : RED- | x GUARD x | RED- : J | x GUARD x | | xxxxxxxxx | E : ZONE | xxxxxxxxx | ZONE : E | xxxxxxxxx | | xxxxxxxxx | C : | xxxxxxxxx | : C | xxxxxxxxx | | xxxxxxxxx | T : | xxxxxxxxx | : T | xxxxxxxxx | ---+-----------+-----------+-----------+-----------+-----------+--- Guarded allocations are set up based on a sample interval (can be set via kfence.sample_interval). After expiration of the sample interval, a guarded allocation from the KFENCE object pool is returned to the main allocator (SLAB or SLUB). At this point, the timer is reset, and the next allocation is set up after the expiration of the interval. To enable/disable a KFENCE allocation through the main allocator's fast-path without overhead, KFENCE relies on static branches via the static keys infrastructure. The static branch is toggled to redirect the allocation to KFENCE. To date, we have verified by running synthetic benchmarks (sysbench I/O, hackbench) that a kernel compiled with KFENCE is performance-neutral compared to the non-KFENCE baseline. For more details, see Documentation/dev-tools/kfence.rst (added later in the series). [elver@google.com: fix parameter description for kfence_object_start()] Link: https://lkml.kernel.org/r/20201106092149.GA2851373@elver.google.com [elver@google.com: avoid stalling work queue task without allocations] Link: https://lkml.kernel.org/r/CADYN=9J0DQhizAGB0-jz4HOBBh+05kMBXb4c0cXMS7Qi5NAJiw@mail.gmail.com Link: https://lkml.kernel.org/r/20201110135320.3309507-1-elver@google.com [elver@google.com: fix potential deadlock due to wake_up()] Link: https://lkml.kernel.org/r/000000000000c0645805b7f982e4@google.com Link: https://lkml.kernel.org/r/20210104130749.1768991-1-elver@google.com [elver@google.com: add option to use KFENCE without static keys] Link: https://lkml.kernel.org/r/20210111091544.3287013-1-elver@google.com [elver@google.com: add missing copyright and description headers] Link: https://lkml.kernel.org/r/20210118092159.145934-1-elver@google.com Link: https://lkml.kernel.org/r/20201103175841.3495947-2-elver@google.com Signed-off-by: Marco Elver Signed-off-by: Alexander Potapenko Reviewed-by: Dmitry Vyukov Reviewed-by: SeongJae Park Co-developed-by: Marco Elver Reviewed-by: Jann Horn Cc: "H. Peter Anvin" Cc: Paul E. McKenney Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Catalin Marinas Cc: Christopher Lameter Cc: Dave Hansen Cc: David Rientjes Cc: Eric Dumazet Cc: Greg Kroah-Hartman Cc: Hillf Danton Cc: Ingo Molnar Cc: Jonathan Corbet Cc: Joonsoo Kim Cc: Joern Engel Cc: Kees Cook Cc: Mark Rutland Cc: Pekka Enberg Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Vlastimil Babka Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- init/main.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'init') diff --git a/init/main.c b/init/main.c index e9933cbf60d4..261051070e3c 100644 --- a/init/main.c +++ b/init/main.c @@ -40,6 +40,7 @@ #include #include #include +#include #include #include #include @@ -824,6 +825,7 @@ static void __init mm_init(void) */ page_ext_init_flatmem(); init_mem_debugging_and_hardening(); + kfence_alloc_pool(); report_meminit(); mem_init(); /* page_owner must be initialized after buddy is ready */ @@ -955,6 +957,7 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void) hrtimers_init(); softirq_init(); timekeeping_init(); + kfence_init(); /* * For best initial stack canary entropy, prepare it after: -- cgit v1.2.3 From e1fdc403349c64fa58f4c163f4bf9b860b4db808 Mon Sep 17 00:00:00 2001 From: Vijayanand Jitta Date: Thu, 25 Feb 2021 17:21:27 -0800 Subject: lib: stackdepot: add support to disable stack depot Add a kernel parameter stack_depot_disable to disable stack depot. So that stack hash table doesn't consume any memory when stack depot is disabled. The use case is CONFIG_PAGE_OWNER without page_owner=on. Without this patch, stackdepot will consume the memory for the hashtable. By default, it's 8M which is never trivial. With this option, in CONFIG_PAGE_OWNER configured system, page_owner=off, stack_depot_disable in kernel command line, we could save the wasted memory for the hashtable. [akpm@linux-foundation.org: fix CONFIG_STACKDEPOT=n build] Link: https://lkml.kernel.org/r/1611749198-24316-2-git-send-email-vjitta@codeaurora.org Signed-off-by: Vinayak Menon Signed-off-by: Vijayanand Jitta Cc: Alexander Potapenko Cc: Minchan Kim Cc: Yogesh Lal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- init/main.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'init') diff --git a/init/main.c b/init/main.c index 261051070e3c..3648c9f94882 100644 --- a/init/main.c +++ b/init/main.c @@ -97,6 +97,7 @@ #include #include #include +#include #include #include @@ -827,6 +828,7 @@ static void __init mm_init(void) init_mem_debugging_and_hardening(); kfence_alloc_pool(); report_meminit(); + stack_depot_init(); mem_init(); /* page_owner must be initialized after buddy is ready */ page_ext_init_flatmem_late(); -- cgit v1.2.3 From 073a9ecb3a73401662430bb955aedeac1de643d1 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 25 Feb 2021 17:22:11 -0800 Subject: init/version.c: remove Version_ symbol This code hunk creates a Version_ symbol if CONFIG_KALLSYMS is disabled. For example, building the kernel v5.10 for allnoconfig creates the following symbol: $ nm vmlinux | grep Version_ c116b028 B Version_330240 There is no in-tree user of this symbol. Commit 197dcffc8ba0 ("init/version.c: define version_string only if CONFIG_KALLSYMS is not defined") mentions that Version_* is only used with ksymoops. However, a commit in the pre-git era [1] had added the statement, "ksymoops is useless on 2.6. Please use the Oops in its original format". That statement existed until commit 4eb9241127a0 ("Documentation: admin-guide: update bug-hunting.rst") finally removed the stale ksymoops information. This symbol is no longer needed. [1] https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=ad68b2f085f5c79e4759ca2d13947b3c885ee831 Link: https://lkml.kernel.org/r/20210120033452.2895170-1-masahiroy@kernel.org Signed-off-by: Masahiro Yamada Cc: Mauro Carvalho Chehab Cc: Randy Dunlap Cc: Daniel Guilak Cc: Lee Revell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- init/version.c | 8 -------- 1 file changed, 8 deletions(-) (limited to 'init') diff --git a/init/version.c b/init/version.c index 80d2b7566b39..92afc782b043 100644 --- a/init/version.c +++ b/init/version.c @@ -16,14 +16,6 @@ #include #include -#ifndef CONFIG_KALLSYMS -#define version(a) Version_ ## a -#define version_string(a) version(a) - -extern int version_string(LINUX_VERSION_CODE); -int version_string(LINUX_VERSION_CODE); -#endif - struct uts_namespace init_uts_ns = { .ns.count = REFCOUNT_INIT(2), .name = { -- cgit v1.2.3 From f9c8bc4604c95a7c55293f244f67753f6e96096f Mon Sep 17 00:00:00 2001 From: Bhaskar Chowdhury Date: Thu, 25 Feb 2021 17:22:18 -0800 Subject: init/Kconfig: fix a typo in CC_VERSION_TEXT help text s/compier/compiler/ Link: https://lkml.kernel.org/r/20210224223325.29099-1-unixbhaskar@gmail.com Signed-off-by: Bhaskar Chowdhury Acked-by: Randy Dunlap Reviewed-by: Nathan Chancellor Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- init/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index 719871f8727c..efdc35abccb6 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -19,7 +19,7 @@ config CC_VERSION_TEXT CC_VERSION_TEXT so it is recorded in include/config/auto.conf.cmd. When the compiler is updated, Kconfig will be invoked. - - Ensure full rebuild when the compier is updated + - Ensure full rebuild when the compiler is updated include/linux/kconfig.h contains this option in the comment line so fixdep adds include/config/cc/version/text.h into the auto-generated dependency. When the compiler is updated, syncconfig will touch it -- cgit v1.2.3 From d54ce6158e354f5358a547b96299ecd7f3725393 Mon Sep 17 00:00:00 2001 From: Sumit Garg Date: Thu, 25 Feb 2021 17:22:38 -0800 Subject: kgdb: fix to kill breakpoints on initmem after boot Currently breakpoints in kernel .init.text section are not handled correctly while allowing to remove them even after corresponding pages have been freed. Fix it via killing .init.text section breakpoints just prior to initmem pages being freed. Doug: "HW breakpoints aren't handled by this patch but it's probably not such a big deal". Link: https://lkml.kernel.org/r/20210224081652.587785-1-sumit.garg@linaro.org Signed-off-by: Sumit Garg Suggested-by: Doug Anderson Acked-by: Doug Anderson Acked-by: Daniel Thompson Tested-by: Daniel Thompson Cc: Masami Hiramatsu Cc: Steven Rostedt (VMware) Cc: Jason Wessel Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- init/main.c | 1 + 1 file changed, 1 insertion(+) (limited to 'init') diff --git a/init/main.c b/init/main.c index 3648c9f94882..53b278845b88 100644 --- a/init/main.c +++ b/init/main.c @@ -1426,6 +1426,7 @@ static int __ref kernel_init(void *unused) async_synchronize_full(); kprobe_free_init_mem(); ftrace_free_init_mem(); + kgdb_free_init_mem(); free_initmem(); mark_readonly(); -- cgit v1.2.3 From dd23e8098f33a55b22b869bc7fc0a795ccbb9f87 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Thu, 25 Feb 2021 17:22:46 -0800 Subject: initramfs: panic with memory information On systems with large amounts of reserved memory we may fail to successfully complete unpack_to_rootfs() and be left with: Kernel panic - not syncing: write error this is not too helpful to understand what happened, so let's wrap the panic() calls with a surrounding show_mem() such that we have a chance of understanding the memory conditions leading to these allocation failures. [akpm@linux-foundation.org: replace macro with C function] Link: https://lkml.kernel.org/r/20210114231517.1854379-1-f.fainelli@gmail.com Signed-off-by: Florian Fainelli Cc: Barret Rhoden Cc: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- init/initramfs.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'init') diff --git a/init/initramfs.c b/init/initramfs.c index 55b74d7e5260..5fa84711127a 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include @@ -45,6 +46,16 @@ static void __init error(char *x) message = x; } +static void panic_show_mem(const char *fmt, ...) +{ + va_list args; + + show_mem(0, NULL); + va_start(args, fmt); + panic(fmt, args); + va_end(args); +} + /* link hash */ #define N_ALIGN(len) ((((len) + 1) & ~3) + 2) @@ -80,7 +91,7 @@ static char __init *find_link(int major, int minor, int ino, } q = kmalloc(sizeof(struct hash), GFP_KERNEL); if (!q) - panic("can't allocate link hash entry"); + panic_show_mem("can't allocate link hash entry"); q->major = major; q->minor = minor; q->ino = ino; @@ -125,7 +136,7 @@ static void __init dir_add(const char *name, time64_t mtime) { struct dir_entry *de = kmalloc(sizeof(struct dir_entry), GFP_KERNEL); if (!de) - panic("can't allocate dir_entry buffer"); + panic_show_mem("can't allocate dir_entry buffer"); INIT_LIST_HEAD(&de->list); de->name = kstrdup(name, GFP_KERNEL); de->mtime = mtime; @@ -460,7 +471,7 @@ static char * __init unpack_to_rootfs(char *buf, unsigned long len) name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL); if (!header_buf || !symlink_buf || !name_buf) - panic("can't allocate buffers"); + panic_show_mem("can't allocate buffers"); state = Start; this_header = 0; @@ -607,7 +618,7 @@ static int __init populate_rootfs(void) /* Load the built in initramfs */ char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size); if (err) - panic("%s", err); /* Failed to decompress INTERNAL initramfs */ + panic_show_mem("%s", err); /* Failed to decompress INTERNAL initramfs */ if (!initrd_start || IS_ENABLED(CONFIG_INITRAMFS_FORCE)) goto done; -- cgit v1.2.3 From a6aaeb841198016083663ae56c568de4e065d090 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 26 Feb 2021 15:25:48 +0900 Subject: kbuild: fix UNUSED_KSYMS_WHITELIST for Clang LTO Commit fbe078d397b4 ("kbuild: lto: add a default list of used symbols") does not work as expected if the .config file has already specified CONFIG_UNUSED_KSYMS_WHITELIST="my/own/white/list" before enabling CONFIG_LTO_CLANG. So, the user-supplied whitelist and LTO-specific white list must be independent of each other. I refactored the shell script so CONFIG_MODVERSIONS and CONFIG_CLANG_LTO handle whitelists in the same way. Fixes: fbe078d397b4 ("kbuild: lto: add a default list of used symbols") Signed-off-by: Masahiro Yamada Tested-by: Sedat Dilek --- init/Kconfig | 1 - 1 file changed, 1 deletion(-) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index efdc35abccb6..22946fe5ded9 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -2283,7 +2283,6 @@ config TRIM_UNUSED_KSYMS config UNUSED_KSYMS_WHITELIST string "Whitelist of symbols to keep in ksymtab" depends on TRIM_UNUSED_KSYMS - default "scripts/lto-used-symbollist.txt" if LTO_CLANG help By default, all unused exported symbols will be un-exported from the build when TRIM_UNUSED_KSYMS is selected. -- cgit v1.2.3