user/sven/linux.git/kernel/livepatch, branch v5.15.44

livepatch: Fix build failure on 32 bits processors

2022-04-08T12:23:29Z

[ Upstream commit 2f293651eca3eacaeb56747dede31edace7329d2 ] Trying to build livepatch on powerpc/32 results in: kernel/livepatch/core.c: In function 'klp_resolve_symbols': kernel/livepatch/core.c:221:23: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] 221 | sym = (Elf64_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info); | ^ kernel/livepatch/core.c:221:21: error: assignment to 'Elf32_Sym *' {aka 'struct elf32_sym *'} from incompatible pointer type 'Elf64_Sym *' {aka 'struct elf64_sym *'} [-Werror=incompatible-pointer-types] 221 | sym = (Elf64_Sym *)sechdrs[symndx].sh_addr + ELF_R_SYM(relas[i].r_info); | ^ kernel/livepatch/core.c: In function 'klp_apply_section_relocs': kernel/livepatch/core.c:312:35: error: passing argument 1 of 'klp_resolve_symbols' from incompatible pointer type [-Werror=incompatible-pointer-types] 312 | ret = klp_resolve_symbols(sechdrs, strtab, symndx, sec, sec_objname); | ^~~~~~~ | | | Elf32_Shdr * {aka struct elf32_shdr *} kernel/livepatch/core.c:193:44: note: expected 'Elf64_Shdr *' {aka 'struct elf64_shdr *'} but argument is of type 'Elf32_Shdr *' {aka 'struct elf32_shdr *'} 193 | static int klp_resolve_symbols(Elf64_Shdr *sechdrs, const char *strtab, | ~~~~~~~~~~~~^~~~~~~ Fix it by using the right types instead of forcing 64 bits types. Fixes: 7c8e2bdd5f0d ("livepatch: Apply vmlinux-specific KLP relocations early") Signed-off-by: Christophe Leroy Acked-by: Petr Mladek Acked-by: Joe Lawrence Acked-by: Miroslav Benes Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/5288e11b018a762ea3351cc8fb2d4f15093a4457.1640017960.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin

livepatch: Replace deprecated CPU-hotplug functions.

2021-08-19T10:00:24Z

The functions get_online_cpus() and put_online_cpus() have been deprecated during the CPU hotplug rework. They map directly to cpus_read_lock() and cpus_read_unlock(). Replace deprecated CPU-hotplug functions with the official version. The behavior remains unchanged. Cc: Josh Poimboeuf Cc: Jiri Kosina Cc: Miroslav Benes Cc: Petr Mladek Cc: Joe Lawrence Cc: live-patching@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Petr Mladek Signed-off-by: Jiri Kosina

Merge tag 'livepatching-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching

2021-04-28T01:14:38Z

Pull livepatching update from Petr Mladek: - Use TIF_NOTIFY_SIGNAL infrastructure instead of the fake signal * tag 'livepatching-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching: livepatch: Replace the fake signal sending with TIF_NOTIFY_SIGNAL infrastructure

livepatch: Replace the fake signal sending with TIF_NOTIFY_SIGNAL infrastructure

2021-03-30T07:40:21Z

Livepatch sends a fake signal to all remaining blocking tasks of a running transition after a set period of time. It uses TIF_SIGPENDING flag for the purpose. Commit 12db8b690010 ("entry: Add support for TIF_NOTIFY_SIGNAL") added a generic infrastructure to achieve the same. Replace our bespoke solution with the generic one. Reviewed-by: Jens Axboe Reviewed-by: Petr Mladek Acked-by: Joe Lawrence Signed-off-by: Miroslav Benes Signed-off-by: Jiri Kosina

kallsyms: refactor {,module_}kallsyms_on_each_symbol

2021-02-08T11:22:08Z

Require an explicit call to module_kallsyms_on_each_symbol to look for symbols in modules instead of the call from kallsyms_on_each_symbol, and acquire module_mutex inside of module_kallsyms_on_each_symbol instead of leaving that up to the caller. Note that this slightly changes the behavior for the livepatch code in that the symbols from vmlinux are not iterated anymore if objname is set, but that actually is the desired behavior in this case. Reviewed-by: Petr Mladek Acked-by: Miroslav Benes Signed-off-by: Christoph Hellwig Signed-off-by: Jessica Yu

module: use RCU to synchronize find_module

2021-02-08T11:21:40Z

Allow for a RCU-sched critical section around find_module, following the lower level find_module_all helper, and switch the two callers outside of module.c to use such a RCU-sched critical section instead of module_mutex. Reviewed-by: Petr Mladek Acked-by: Miroslav Benes Signed-off-by: Christoph Hellwig Signed-off-by: Jessica Yu

livepatch: Use the default ftrace_ops instead of REGS when ARGS is available

2020-11-13T17:15:28Z

When CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS is available, the ftrace call will be able to set the ip of the calling function. This will improve the performance of live kernel patching where it does not need all the regs to be stored just to change the instruction pointer. If all archs that support live kernel patching also support HAVE_DYNAMIC_FTRACE_WITH_ARGS, then the architecture specific function klp_arch_set_pc() could be made generic. It is possible that an arch can support HAVE_DYNAMIC_FTRACE_WITH_ARGS but not HAVE_DYNAMIC_FTRACE_WITH_REGS and then have access to live patching. Cc: Josh Poimboeuf Cc: Jiri Kosina Cc: live-patching@vger.kernel.org Acked-by: Peter Zijlstra (Intel) Acked-by: Miroslav Benes Signed-off-by: Steven Rostedt (VMware)

ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs

2020-11-13T17:14:55Z

In preparation to have arguments of a function passed to callbacks attached to functions as default, change the default callback prototype to receive a struct ftrace_regs as the forth parameter instead of a pt_regs. For callbacks that set the FL_SAVE_REGS flag in their ftrace_ops flags, they will now need to get the pt_regs via a ftrace_get_regs() helper call. If this is called by a callback that their ftrace_ops did not have a FL_SAVE_REGS flag set, it that helper function will return NULL. This will allow the ftrace_regs to hold enough just to get the parameters and stack pointer, but without the worry that callbacks may have a pt_regs that is not completely filled. Acked-by: Peter Zijlstra (Intel) Reviewed-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

ftrace: Add recording of functions that caused recursion

2020-11-06T13:42:26Z

This adds CONFIG_FTRACE_RECORD_RECURSION that will record to a file "recursed_functions" all the functions that caused recursion while a callback to the function tracer was running. Link: https://lkml.kernel.org/r/20201106023548.102375687@goodmis.org Cc: Masami Hiramatsu Cc: Andrew Morton Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Jonathan Corbet Cc: Guo Ren Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: Thomas Gleixner Cc: Borislav Petkov Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: Kees Cook Cc: Anton Vorontsov Cc: Colin Cross Cc: Tony Luck Cc: Josh Poimboeuf Cc: Jiri Kosina Cc: Miroslav Benes Cc: Petr Mladek Cc: Joe Lawrence Cc: Kamalesh Babulal Cc: Mauro Carvalho Chehab Cc: Sebastian Andrzej Siewior Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-csky@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: live-patching@vger.kernel.org Signed-off-by: Steven Rostedt (VMware)

livepatch: Trigger WARNING if livepatch function fails due to recursion

2020-11-06T13:41:47Z

If for some reason a function is called that triggers the recursion detection of live patching, trigger a warning. By not executing the live patch code, it is possible that the old unpatched function will be called placing the system into an unknown state. Link: https://lore.kernel.org/r/20201029145709.GD16774@alley Link: https://lkml.kernel.org/r/20201106023547.312639435@goodmis.org Cc: Masami Hiramatsu Cc: Andrew Morton Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Josh Poimboeuf Cc: Jiri Kosina Cc: Joe Lawrence Cc: live-patching@vger.kernel.org Suggested-by: Miroslav Benes Reviewed-by: Petr Mladek Acked-by: Miroslav Benes Signed-off-by: Steven Rostedt (VMware)