Changes in Makefile

d3b08e5f - um: fix stub exe build with CONFIG_GCOV

Fri, 25 Oct 2024 08:27:01 +0000

um: fix stub exe build with CONFIG_GCOVCONFIG_GCOV is special and only in UML since it builds thekernel with a "userspace" option. This is fine, but the stubis even more special and not really a full userspace process,so it then fails to link as reported.Remove the GCOV options from the stub build.For good measure, also remove the GPROF options, even thoughthey don't seem to cause build failures now.To be able to do this, export the specific options (GCOV_OPTand GPROF_OPT) but rename them so there's less chance of anyconflicts.Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202410242238.SXhs2kQ4-lkp@intel.com/Fixes: 32e8eaf263d9 ("um: use execveat to create userspace MMs")Link: https://patch.msgid.link/20241025102700.9fbb9c34473f.I7f1537fe075638f8da64beb52ef6c9e5adc51bc3@changeidSigned-off-by: Johannes Berg List of files: /linux-6.15/arch/um/kernel/skas/Makefile

1e3071d6 - um: Disable auto variable initialization for stub_exe.c

Wed, 16 Oct 2024 21:12:38 +0000

um: Disable auto variable initialization for stub_exe.cWhen automatic variable initialization is enabled viaCONFIG_INIT_STACK_ALL_{PATTERN,ZERO}, clang will insert a call tomemset() to initialize an object created with __builtin_alloca(). Thisultimately breaks the build when linking stub_exe because it is astandalone executable that does not include or link against memset(). ld: arch/um/kernel/skas/stub_exe.o: in function `_start': arch/um/kernel/skas/stub_exe.c:83:(.ltext+0x15): undefined reference to `memset'Disable automatic variable initialization for stub_exe.c by passing thedefault value of 'uninitialized' to '-ftrivial-auto-var-init', whichavoids generating the call to memset(). This code is small and runsquickly as it is just designed to set up an environment, so stackvariable initialization is unnecessary overhead for little gain.Fixes: 32e8eaf263d9 ("um: use execveat to create userspace MMs")Signed-off-by: Nathan Chancellor Link: https://patch.msgid.link/20241016-uml-fix-stub_exe-clang-v1-2-3d6381dc5a78@kernel.orgSigned-off-by: Johannes Berg List of files: /linux-6.15/arch/um/kernel/skas/Makefile

89350def - um: Fix passing '-n' to linker for stub_exe

Wed, 16 Oct 2024 21:12:37 +0000

um: Fix passing '-n' to linker for stub_exeWhen building stub_exe with clang, there is an error because '-n' is nota recognized flag by the clang driver (which is being used to invoke thelinker): clang: error: unknown argument: '-n''-n' should be passed along to the linker, as it is the short flag for'--nmagic', so prefix it with '-Wl,'.Fixes: 32e8eaf263d9 ("um: use execveat to create userspace MMs")Signed-off-by: Nathan Chancellor Link: https://patch.msgid.link/20241016-uml-fix-stub_exe-clang-v1-1-3d6381dc5a78@kernel.orgSigned-off-by: Johannes Berg List of files: /linux-6.15/arch/um/kernel/skas/Makefile

32e8eaf2 - um: use execveat to create userspace MMs

Thu, 19 Sep 2024 12:45:03 +0000

um: use execveat to create userspace MMsUsing clone will not undo features that have been enabled by libc. Anexample of this already happening is rseq, which could cause the kernelto read/write memory of the userspace process. In the future thestandard library might also use mseal by default to protect itself,which would also thwart our attempts at unmapping everything.Solve all this by taking a step back and doing an execve into a tinystatic binary that sets up the minimal environment required for thestub without using any standard library. That way we have a cleanexecution environment that is fully under the control of UML.Note that this changes things a bit as the FDs are not anymore sharedwith the kernel. Instead, we explicitly share the FDs for the physicalmemory and all existing iomem regions. Doing this is fine, as iomemregions cannot be added at runtime.Signed-off-by: Benjamin Berg Link: https://patch.msgid.link/20240919124511.282088-3-benjamin@sipsolutions.net[use pipe() instead of pipe2(), remove unneeded close() calls]Signed-off-by: Johannes Berg List of files: /linux-6.15/arch/um/kernel/skas/Makefile

a5d2cfe7 - um: remove copy_context_skas0

Wed, 03 Jul 2024 13:45:31 +0000

um: remove copy_context_skas0The kernel flushes the memory ranges anyway for CoW and does not assumethat the userspace process has anything set up already. So, start with afresh process for the new mm context.Signed-off-by: Benjamin Berg Link: https://patch.msgid.link/20240703134536.1161108-8-benjamin@sipsolutions.netSigned-off-by: Johannes Berg List of files: /linux-6.15/arch/um/kernel/skas/Makefile

76ed9158 - um: Rework syscall handling

Wed, 03 Jul 2024 13:45:28 +0000

um: Rework syscall handlingRework syscall handling to be platform independent. Also create a cleansplit between queueing of syscalls and flushing them out, removing theneed to keep state in the code that triggers the syscalls.The code adds syscall_data_len to the global mm_id structure. This willbe used later to allow surrounding code to track whether syscalls stillneed to run and if errors occurred.Signed-off-by: Benjamin Berg Link: https://patch.msgid.link/20240703134536.1161108-5-benjamin@sipsolutions.netSigned-off-by: Johannes Berg List of files: /linux-6.15/arch/um/kernel/skas/Makefile

67d7c302 - kbuild: remove --include-dir MAKEFLAG from top Makefile

Sat, 28 Jan 2023 09:24:23 +0000

kbuild: remove --include-dir MAKEFLAG from top MakefileI added $(srctree)/ to some included Makefiles in the following commits: - 3204a7fb98a3 ("kbuild: prefix $(srctree)/ to some included Makefiles") - d82856395505 ("kbuild: do not require sub-make for separate output tree builds")They were a preparation for removing --include-dir flag.I have never thought --include-dir useful. Rather, it _is_ harmful.For example, run the following commands: $ make -s ARCH=x86 mrproper defconfig $ make ARCH=arm O=foo dtbs make[1]: Entering directory '/tmp/linux/foo' HOSTCC scripts/basic/fixdep Error: kernelrelease not valid - run 'make prepare' to update it UPD include/config/kernel.release make[1]: Leaving directory '/tmp/linux/foo'The first command configures the source tree for x86. The next commandtries to build ARM device trees in the separate foo/ directory - thismust stop because the directory foo/ has not been configured yet.However, due to --include-dir=$(abs_srctree), the top Makefile includesthe wrong include/config/auto.conf from the source tree and continuesbuilding. Kbuild traverses the directory tree, but of course it doesnot work correctly. The Error message is also pointless - 'make prepare'does not help at all for fixing the issue.This commit fixes more arch Makefile, and finally removes --include-dirfrom the top Makefile.There are more breakages under drivers/, but I do not volunteer to fixthem all. I just moved --include-dir to drivers/Makefile.With this commit, the second command will stop with a sensible message. $ make -s ARCH=x86 mrproper defconfig $ make ARCH=arm O=foo dtbs make[1]: Entering directory '/tmp/linux/foo' SYNC include/config/auto.conf.cmd *** *** The source tree is not clean, please run 'make ARCH=arm mrproper' *** in /tmp/linux *** make[2]: *** [../Makefile:646: outputmakefile] Error 1 /tmp/linux/Makefile:770: include/config/auto.conf.cmd: No such file or directory make[1]: *** [/tmp/linux/Makefile:793: include/config/auto.conf.cmd] Error 2 make[1]: Leaving directory '/tmp/linux/foo' make: *** [Makefile:226: __sub-make] Error 2Signed-off-by: Masahiro Yamada List of files: /linux-6.15/arch/um/kernel/skas/Makefile

0d1fb0a4 - um: Add SPDX headers to files in arch/um/kernel/

Sun, 25 Aug 2019 09:49:17 +0000

um: Add SPDX headers to files in arch/um/kernel/Convert files to use SPDX header. All files are licensed under theGPLv2.Signed-off-by: Alex Dewar Signed-off-by: Richard Weinberger List of files: /linux-6.15/arch/um/kernel/skas/Makefile

c4683cd5 - um: Fix kcov crash during startup

Tue, 04 Jun 2019 11:20:50 +0000

um: Fix kcov crash during startupKcov fails to start when compiled with kcov. Disable KCOV onarch/uml/kernel/skas. $ gdb -q -ex r ./vmlinux Program received signal SIGSEGV, Segmentation fault. check_kcov_mode (t=<>, needed_mode=<>) at kernel/kcov.c:70 70 mode = READ_ONCE(t->kcov_mode);Signed-off-by: Marek Majkowski Signed-off-by: Richard Weinberger List of files: /linux-6.15/arch/um/kernel/skas/Makefile

ba180fd4 - uml: style fixes pass 3

Tue, 16 Oct 2007 08:27:00 +0000

uml: style fixes pass 3Formatting changes in the files which have been changed in the courseof folding foo_skas functions into their callers. These include: copyright updates header file trimming style fixes adding severity to printksThese changes should be entirely non-functional.Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux-6.15/arch/um/kernel/skas/Makefile

77bf4400 - uml: remove code made redundant by CHOOSE_MODE removal

Tue, 16 Oct 2007 08:26:58 +0000

uml: remove code made redundant by CHOOSE_MODE removalThis patch makes a number of simplifications enabled by the removal ofCHOOSE_MODE. There were lots of functions that looked like int foo(args){ foo_skas(args); }The bodies of foo_skas are now folded into foo, and their declarations (andsometimes entire header files) are deleted.In addition, the union uml_pt_regs, which was a union between the tt and skasregister formats, is now a struct, with the tt-mode arm of the union beingremoved.It turns out that usr2_handler was unused, so it is gone.Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux-6.15/arch/um/kernel/skas/Makefile

995473ae - [PATCH] uml: file renaming

Wed, 27 Sep 2006 08:50:40 +0000

[PATCH] uml: file renamingMove some foo_kern.c files to foo.c now that the old foo.c files are outof the way.Also cleaned up some whitespace and an emacs formatting comment.Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux-6.15/arch/um/kernel/skas/Makefile

7b12b913 - [PATCH] uml: cleanup unprofile expression and build infrastructure

Mon, 01 May 2006 19:16:05 +0000

[PATCH] uml: cleanup unprofile expression and build infrastructure*) Rather than duplicate in various buggy ways the application of CFLAGS_NO_HARDENING and UNPROFILE (which apply to the same files), centralize it in Makefile.rules. UNPROFILE_OBJS mustn't be listed in USER_OBJS but are compiled as such.I've also verified that unprofile didn't work in the current form, because weset _c_flags directly (using CFLAGS and not USER_CFLAGS, which is wrong),which is normally used by c_flags, but we also override c_flags for allUSER_OBJS, and there we don't call unprofile.Instead it only worked for unmap.o, the only one which wasn't a USER_OBJ.We need to set c_flags (which is not a public Kbuild API) to clear a lot ofcompilation flags like -nostdinc which Kbuild forces on everything.*) Rather than $(CFLAGS_$(notdir $@)), which expands to CFLAGS_anObj.s when building "anObj.s", use $(CFLAGS_$(*F).o) which always accesses CFLAGS_anObj.o, like done by Kbuild.*) Make c_flags apply to all targets having the same basename, rather than listing .s, .i, .lst and .o, with the use (which I tested) of $(USER_OBJS:.o=.%): c_flags = ...and of - $(obj)/unmap.c: _c_flags = ... + $(obj)/unmap.%: _c_flags = ...Signed-off-by: Paolo 'Blaisorblade' Giarrusso Acked-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux-6.15/arch/um/kernel/skas/Makefile

275e6e1e - [PATCH] uml: fix compilation and execution with hardened GCC

Mon, 01 May 2006 19:16:04 +0000

[PATCH] uml: fix compilation and execution with hardened GCCTo make some half-assembly stubs compile, disable various "hardened" GCCfeatures:*) we can't make it build PIC code as we need %ebx to do syscalls and GCC wants it free for PIC*) we can't leave stack protection as the stub is moved (not relocated!) in memory so the RIP-relative access to the canary tries reading from an unmapped address and causes a segfault, since we move the stub of various megabytes (the exact amount will be decided at runtime) away from the link-time address.Signed-off-by: Paolo 'Blaisorblade' Giarrusso Acked-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux-6.15/arch/um/kernel/skas/Makefile

abaf6977 - [PATCH] uml: move libc-dependent skas process handling

Thu, 19 Jan 2006 01:42:46 +0000

[PATCH] uml: move libc-dependent skas process handlingThe serial UML OS-abstraction layer patch (um/kernel/skas dir).This moves all systemcalls from skas/process.c file under os-Linux dir andjoin skas/process.c and skas/process_kern.c files.Signed-off-by: Gennady Sharapov Signed-off-by: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux-6.15/arch/um/kernel/skas/Makefile

f45d9fc9 - [PATCH] uml: move libc-dependent skas memory mapping code

Thu, 19 Jan 2006 01:42:45 +0000

[PATCH] uml: move libc-dependent skas memory mapping codeThe serial UML OS-abstraction layer patch (um/kernel/skas dir).This moves all systemcalls from skas/mem_user.c file under os-Linux dir andjoin skas/mem_user.c and skas/mem.c files.Signed-off-by: Gennady Sharapov Signed-off-by: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux-6.15/arch/um/kernel/skas/Makefile

ea2ba7dc - [PATCH] uml: move libc-dependent code from trap_user.c

Sun, 08 Jan 2006 09:01:31 +0000

[PATCH] uml: move libc-dependent code from trap_user.cThe serial UML OS-abstraction layer patch (um/kernel dir).This moves all systemcalls from trap_user.c file under os-Linux dirSigned-off-by: Gennady Sharapov Signed-off-by: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux-6.15/arch/um/kernel/skas/Makefile

ecba97d4 - [PATCH] uml makefiles sanitized

Wed, 28 Sep 2005 21:27:23 +0000

[PATCH] uml makefiles sanitizedUML makefiles sanitized: - number of generated headers reduced to 2 (from user-offsets.c and kernel-offsets.c resp.). The rest is made constant and simply includes those two. - mk_... helpers are gone now that we don't need to generate these headers - arch/um/include2 removed since everything under arch/um/include/sysdep is constant now and symlink can point straight to source tree. - dependencies seriously simplified.Signed-off-by: Al Viro Signed-off-by: Linus Torvalds List of files: /linux-6.15/arch/um/kernel/skas/Makefile

e32dacb9 - [PATCH] uml: system call path cleanup

Sat, 03 Sep 2005 22:57:42 +0000

[PATCH] uml: system call path cleanupThis merges two sets of files which had no business being split apart in thefirst place.Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux-6.15/arch/um/kernel/skas/Makefile

9786a8f3 - [PATCH] uml: Proper clone support for skas0

Fri, 08 Jul 2005 00:56:50 +0000

[PATCH] uml: Proper clone support for skas0This patch implements the clone-stub mechanism, which allows skas0 to runwith proc_mm==0, even if the clib in UML uses modify_ldt.Note: There is a bug in skas3.v7 host patch, that avoids UML-skas fromrunning properly on a SMP-box. In full skas3, I never really saw problems,but in skas0 they showed up.More commentary by jdike - What this patch does is makes sure that the hostparent of each new host process matches the UML parent of the correspondingUML process. This ensures that any changed LDTs are inherited. This isdone by having clone actually called by the UML process from its stub,rather than by the kernel. We have special syscall stubs that are loadedonto the stub code page because that code must be completelyself-contained. These stubs are given C interfaces, and used like normal Cfunctions, but there are subtleties. Principally, we have to be carefulabout stack variables in stub_clone_handler after the clone. The code iswritten so that there aren't any - everything boils down to a fixedaddress. If there were any locals, references to them after the clonewould be wrong because the stack just changed.Signed-off-by: Bodo Stroesser Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds List of files: /linux-6.15/arch/um/kernel/skas/Makefile