user/sven/linux.git/kernel/module.c, branch v4.19.54

jump_label: move 'asm goto' support test to Kconfig

2019-06-04T06:02:34Z

commit e9666d10a5677a494260d60d1fa0b73cc7646eb3 upstream. Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label". The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this: #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO. Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability. Signed-off-by: Masahiro Yamada Acked-by: Michael Ellerman (powerpc) Tested-by: Sedat Dilek [nc: Fix trivial conflicts in 4.19 arch/xtensa/kernel/jump_label.c doesn't exist yet Ensured CC_HAVE_ASM_GOTO and HAVE_JUMP_LABEL were sufficiently eliminated] Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

x86/modules: Avoid breaking W^X while loading modules

2019-05-31T13:46:12Z

[ Upstream commit f2c65fb3221adc6b73b0549fc7ba892022db9797 ] When modules and BPF filters are loaded, there is a time window in which some memory is both writable and executable. An attacker that has already found another vulnerability (e.g., a dangling pointer) might be able to exploit this behavior to overwrite kernel code. Prevent having writable executable PTEs in this stage. In addition, avoiding having W+X mappings can also slightly simplify the patching of modules code on initialization (e.g., by alternatives and static-key), as would be done in the next patch. This was actually the main motivation for this patch. To avoid having W+X mappings, set them initially as RW (NX) and after they are set as RO set them as X as well. Setting them as executable is done as a separate step to avoid one core in which the old PTE is cached (hence writable), and another which sees the updated PTE (executable), which would break the W^X protection. Suggested-by: Thomas Gleixner Suggested-by: Andy Lutomirski Signed-off-by: Nadav Amit Signed-off-by: Rick Edgecombe Signed-off-by: Peter Zijlstra (Intel) Cc: Cc: Cc: Cc: Cc: Cc: Cc: Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Jessica Yu Cc: Kees Cook Cc: Linus Torvalds Cc: Masami Hiramatsu Cc: Rik van Riel Link: https://lkml.kernel.org/r/20190426001143.4983-12-namit@vmware.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin

kobject: return error code if writing /sys/.../uevent fails

2019-02-12T18:47:06Z

[ Upstream commit df44b479654f62b478c18ee4d8bc4e9f897a9844 ] Propagate error code back to userspace if writing the /sys/.../uevent file fails. Before, the write operation always returned with success, even if we failed to recognize the input string or if we failed to generate the uevent itself. With the error codes properly propagated back to userspace, we are able to react in userspace accordingly by not assuming and awaiting a uevent that is not delivered. Signed-off-by: Peter Rajnoha Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

module: use relative references for __ksymtab entries

2018-08-22T17:52:47Z

An ordinary arm64 defconfig build has ~64 KB worth of __ksymtab entries, each consisting of two 64-bit fields containing absolute references, to the symbol itself and to a char array containing its name, respectively. When we build the same configuration with KASLR enabled, we end up with an additional ~192 KB of relocations in the .init section, i.e., one 24 byte entry for each absolute reference, which all need to be processed at boot time. Given how the struct kernel_symbol that describes each entry is completely local to module.c (except for the references emitted by EXPORT_SYMBOL() itself), we can easily modify it to contain two 32-bit relative references instead. This reduces the size of the __ksymtab section by 50% for all 64-bit architectures, and gets rid of the runtime relocations entirely for architectures implementing KASLR, either via standard PIE linking (arm64) or using custom host tools (x86). Note that the binary search involving __ksymtab contents relies on each section being sorted by symbol name. This is implemented based on the input section names, not the names in the ksymtab entries, so this patch does not interfere with that. Given that the use of place-relative relocations requires support both in the toolchain and in the module loader, we cannot enable this feature for all architectures. So make it dependent on whether CONFIG_HAVE_ARCH_PREL32_RELOCATIONS is defined. Link: http://lkml.kernel.org/r/20180704083651.24360-4-ard.biesheuvel@linaro.org Signed-off-by: Ard Biesheuvel Acked-by: Jessica Yu Acked-by: Michael Ellerman Reviewed-by: Will Deacon Acked-by: Ingo Molnar Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: Bjorn Helgaas Cc: Catalin Marinas Cc: James Morris Cc: James Morris Cc: Josh Poimboeuf Cc: Kees Cook Cc: Nicolas Pitre Cc: Paul Mackerras Cc: Petr Mladek Cc: Russell King Cc: "Serge E. Hallyn" Cc: Sergey Senozhatsky Cc: Steven Rostedt Cc: Thomas Garnier Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'modules-for-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

2018-08-17T17:51:22Z

Pull modules updates from Jessica Yu: "Summary of modules changes for the 4.19 merge window: - Fix modules kallsyms for livepatch. Livepatch modules can have SHN_UNDEF symbols in their module symbol tables for later symbol resolution, but kallsyms shouldn't be returning these symbols - Some code cleanups and minor reshuffling in load_module() were done to log the module name when module signature verification fails" * tag 'modules-for-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: kernel/module: Use kmemdup to replace kmalloc+memcpy ARM: module: fix modsign build error modsign: log module name in the event of an error module: replace VMLINUX_SYMBOL_STR() with __stringify() or string literal module: print sensible error code module: setup load info before module_sig_check() module: make it clear when we're handling the module copy in info->hdr module: exclude SHN_UNDEF symbols from kallsyms api

kernel/module: Use kmemdup to replace kmalloc+memcpy

2018-08-02T16:03:17Z

we prefer to the kmemdup rather than kmalloc+memcpy. so just replace them. Signed-off-by: zhong jiang Signed-off-by: Jessica Yu

module: replace the existing LSM hook in init_module

2018-07-16T19:31:57Z

Both the init_module and finit_module syscalls call either directly or indirectly the security_kernel_read_file LSM hook. This patch replaces the direct call in init_module with a call to the new security_kernel_load_data hook and makes the corresponding changes in SELinux, LoadPin, and IMA. Signed-off-by: Mimi Zohar Cc: Jeff Vander Stoep Cc: Casey Schaufler Cc: Kees Cook Acked-by: Jessica Yu Acked-by: Paul Moore Acked-by: Kees Cook Signed-off-by: James Morris

modsign: log module name in the event of an error

2018-07-02T09:36:17Z

Now that we have the load_info struct all initialized (including info->name, which contains the name of the module) before module_sig_check(), make the load_info struct and hence module name available to mod_verify_sig() so that we can log the module name in the event of an error. Signed-off-by: Jessica Yu

module: replace VMLINUX_SYMBOL_STR() with __stringify() or string literal

2018-06-25T09:18:29Z

With the special case handling for Blackfin and Metag was removed by commit 94e58e0ac312 ("export.h: remove code for prefixing symbols with underscore"), VMLINUX_SYMBOL_STR() is now equivalent to __stringify(). Replace the remaining usages to prepare for the entire removal of VMLINUX_SYMBOL_STR(). Signed-off-by: Masahiro Yamada Signed-off-by: Jessica Yu

module: print sensible error code

2018-06-25T08:37:08Z

Printing "err 0" to the user in the warning message is not particularly useful, especially when this gets transformed into a -ENOENT for the remainder of the call chain. Signed-off-by: Jason A. Donenfeld Signed-off-by: Jessica Yu