user/sven/linux.git/kernel/module.c, branch v4.14.281

Revert "module, async: async_synchronize_full() on module init iff async is used"

2022-02-23T10:57:33Z

[ Upstream commit 67d6212afda218d564890d1674bab28e8612170f ] This reverts commit 774a1221e862b343388347bac9b318767336b20b. We need to finish all async code before the module init sequence is done. In the reverted commit the PF_USED_ASYNC flag was added to mark a thread that called async_schedule(). Then the PF_USED_ASYNC flag was used to determine whether or not async_synchronize_full() needs to be invoked. This works when modprobe thread is calling async_schedule(), but it does not work if module dispatches init code to a worker thread which then calls async_schedule(). For example, PCI driver probing is invoked from a worker thread based on a node where device is attached: if (cpu < nr_cpu_ids) error = work_on_cpu(cpu, local_pci_probe, &ddi); else error = local_pci_probe(&ddi); We end up in a situation where a worker thread gets the PF_USED_ASYNC flag set instead of the modprobe thread. As a result, async_synchronize_full() is not invoked and modprobe completes without waiting for the async code to finish. The issue was discovered while loading the pm80xx driver: (scsi_mod.scan=async) modprobe pm80xx worker ... do_init_module() ... pci_call_probe() work_on_cpu(local_pci_probe) local_pci_probe() pm8001_pci_probe() scsi_scan_host() async_schedule() worker->flags |= PF_USED_ASYNC; ... < return from worker > ... if (current->flags & PF_USED_ASYNC) <--- false async_synchronize_full(); Commit 21c3c5d28007 ("block: don't request module during elevator init") fixed the deadlock issue which the reverted commit 774a1221e862 ("module, async: async_synchronize_full() on module init iff async is used") tried to fix. Since commit 0fdff3ec6d87 ("async, kmod: warn on synchronous request_module() from async workers") synchronous module loading from async is not allowed. Given that the original deadlock issue is fixed and it is no longer allowed to call synchronous request_module() from async we can remove PF_USED_ASYNC flag to make module init consistently invoke async_synchronize_full() unless async module probe is requested. Signed-off-by: Igor Pylypiv Reviewed-by: Changyuan Lyu Reviewed-by: Luis Chamberlain Acked-by: Tejun Heo Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

modules: inherit TAINT_PROPRIETARY_MODULE

2021-05-22T08:57:24Z

commit 262e6ae7081df304fc625cf368d5c2cbba2bb991 upstream. If a TAINT_PROPRIETARY_MODULE exports symbol, inherit the taint flag for all modules importing these symbols, and don't allow loading symbols from TAINT_PROPRIETARY_MODULE modules if the module previously imported gplonly symbols. Add a anti-circumvention devices so people don't accidentally get themselves into trouble this way. Comment from Greg: "Ah, the proven-to-be-illegal "GPL Condom" defense :)" [jeyu: pr_info -> pr_err and pr_warn as per discussion] Link: http://lore.kernel.org/r/20200730162957.GA22469@lst.de Acked-by: Daniel Vetter Reviewed-by: Greg Kroah-Hartman Signed-off-by: Christoph Hellwig Signed-off-by: Jessica Yu Signed-off-by: Greg Kroah-Hartman

modules: return licensing information from find_symbol

2021-05-22T08:57:24Z

commit ef1dac6021cc8ec5de02ce31722bf26ac4ed5523 upstream. Report the GPLONLY status through a new argument. Signed-off-by: Christoph Hellwig Signed-off-by: Jessica Yu Signed-off-by: Greg Kroah-Hartman

modules: rename the licence field in struct symsearch to license

2021-05-22T08:57:23Z

commit cd8732cdcc37d7077c4fa2c966b748c0662b607e upstream. Use the same spelling variant as the rest of the file. Signed-off-by: Christoph Hellwig Signed-off-by: Jessica Yu Signed-off-by: Greg Kroah-Hartman

modules: unexport __module_address

2021-05-22T08:57:23Z

commit 34e64705ad415ed7a816e60ef62b42fe6d1729d9 upstream. __module_address is only used by built-in code. Signed-off-by: Christoph Hellwig Signed-off-by: Jessica Yu Signed-off-by: Greg Kroah-Hartman

modules: unexport __module_text_address

2021-05-22T08:57:23Z

commit 3fe1e56d0e68b623dd62d8d38265d2a052e7e185 upstream. __module_text_address is only used by built-in code. Signed-off-by: Christoph Hellwig Signed-off-by: Jessica Yu Signed-off-by: Greg Kroah-Hartman

modules: mark each_symbol_section static

2021-05-22T08:57:23Z

commit a54e04914c211b5678602a46b3ede5d82ec1327d upstream. each_symbol_section is only used inside of module.c. Signed-off-by: Christoph Hellwig Signed-off-by: Jessica Yu Signed-off-by: Greg Kroah-Hartman

modules: mark find_symbol static

2021-05-22T08:57:23Z

commit 773110470e2fa3839523384ae014f8a723c4d178 upstream. find_symbol is only used in module.c. Signed-off-by: Christoph Hellwig Signed-off-by: Jessica Yu Signed-off-by: Greg Kroah-Hartman

modules: mark ref_module static

2021-05-22T08:57:23Z

commit 7ef5264de773279b9f23b6cc8afb5addb30e970b upstream. ref_module isn't used anywhere outside of module.c. Signed-off-by: Christoph Hellwig Signed-off-by: Jessica Yu Signed-off-by: Greg Kroah-Hartman

module: Ignore _GLOBAL_OFFSET_TABLE_ when warning for undefined symbols

2021-03-03T17:22:54Z

commit ebfac7b778fac8b0e8e92ec91d0b055f046b4604 upstream. clang-12 -fno-pic (since https://github.com/llvm/llvm-project/commit/a084c0388e2a59b9556f2de0083333232da3f1d6) can emit `call __stack_chk_fail@PLT` instead of `call __stack_chk_fail` on x86. The two forms should have identical behaviors on x86-64 but the former causes GNU as<2.37 to produce an unreferenced undefined symbol _GLOBAL_OFFSET_TABLE_. (On x86-32, there is an R_386_PC32 vs R_386_PLT32 difference but the linker behavior is identical as far as Linux kernel is concerned.) Simply ignore _GLOBAL_OFFSET_TABLE_ for now, like what scripts/mod/modpost.c:ignore_undef_symbol does. This also fixes the problem for gcc/clang -fpie and -fpic, which may emit `call foo@PLT` for external function calls on x86. Note: ld -z defs and dynamic loaders do not error for unreferenced undefined symbols so the module loader is reading too much. If we ever need to ignore more symbols, the code should be refactored to ignore unreferenced symbols. Cc: Link: https://github.com/ClangBuiltLinux/linux/issues/1250 Link: https://sourceware.org/bugzilla/show_bug.cgi?id=27178 Reported-by: Marco Elver Reviewed-by: Nick Desaulniers Reviewed-by: Nathan Chancellor Tested-by: Marco Elver Signed-off-by: Fangrui Song Signed-off-by: Jessica Yu Signed-off-by: Greg Kroah-Hartman