Further extend struct pcpu_hot with the hard and soft irq stack pointers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111145.599170752@infradead.org
Remove the CONFIG_PREEMPT_RT symbol from the ifdef around do_softirq_own_stack() and move it to Kconfig instead. Enable softirq stacks based on SOFTIRQ_ON_OWN_STACK which depends on HAVE_SOFTIRQ_ON_OWN_STACK and its default value is set to !PREEMPT_RT. This ensures that softirq stacks are not used on PREEMPT_RT and avoids a 'select' statement on an option which has a 'depends' statement. Link: https://lore.kernel.org/YvN5E%2FPrHfUhggr7@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Because we need a variant for .S files too. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/Yi9gOW9f1GGwwUD6@hirez.programming.kicks-ass.net
vmlinux.o: warning: objtool: page_fault_oops()+0x13c: unreachable instruction 0000 000000000005b460 <page_fault_oops>: ... 0128 5b588: 49 89 23 mov %rsp,(%r11) 012b 5b58b: 4c 89 dc mov %r11,%rsp 012e 5b58e: 4c 89 f2 mov %r14,%rdx 0131 5b591: 48 89 ee mov %rbp,%rsi 0134 5b594: 4c 89 e7 mov %r12,%rdi 0137 5b597: e8 00 00 00 00 call 5b59c <page_fault_oops+0x13c> 5b598: R_X86_64_PLT32 handle_stack_overflow-0x4 013c 5b59c: 5c pop %rsp vmlinux.o: warning: objtool: sysvec_reboot()+0x6d: unreachable instruction 0000 00000000000033f0 <sysvec_reboot>: ... 005d 344d: 4c 89 dc mov %r11,%rsp 0060 3450: e8 00 00 00 00 call 3455 <sysvec_reboot+0x65> 3451: R_X86_64_PLT32 irq_enter_rcu-0x4 0065 3455: 48 89 ef mov %rbp,%rdi 0068 3458: e8 00 00 00 00 call 345d <sysvec_reboot+0x6d> 3459: R_X86_64_PC32 .text+0x47d0c 006d 345d: e8 00 00 00 00 call 3462 <sysvec_reboot+0x72> 345e: R_X86_64_PLT32 irq_exit_rcu-0x4 0072 3462: 5c pop %rsp Both cases are due to a call_on_stack() calling a __noreturn function. Since that's an inline asm, GCC can't do anything about the instructions after the CALL. Therefore put in an explicit ASM_REACHABLE annotation to make sure objtool and gcc are consistently confused about control flow. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154319.468805622@infradead.org
Pull x86 core updates from Borislav Petkov: - Do not #GP on userspace use of CLI/STI but pretend it was a NOP to keep old userspace from breaking. Adjust the corresponding iopl selftest to that. - Improve stack overflow warnings to say which stack got overflowed and raise the exception stack sizes to 2 pages since overflowing the single page of exception stack is very easy to do nowadays with all the tracing machinery enabled. With that, rip out the custom mapping of AMD SEV's too. - A bunch of changes in preparation for FGKASLR like supporting more than 64K section headers in the relocs tool, correct ORC lookup table size to cover the whole kernel .text and other adjustments. * tag 'x86_core_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: selftests/x86/iopl: Adjust to the faked iopl CLI/STI usage vmlinux.lds.h: Have ORC lookup cover entire _etext - _stext x86/boot/compressed: Avoid duplicate malloc() implementations x86/boot: Allow a "silent" kaslr random byte fetch x86/tools/relocs: Support >64K section headers x86/sev: Make the #VC exception stacks part of the default stacks storage x86: Increase exception stack sizes x86/mm/64: Improve stack overflow warnings x86/iopl: Fake iopl(3) CLI/STI usage
Pull x86 cleanups from Borislav Petkov: "The usual round of random minor fixes and cleanups all over the place" * tag 'x86_cleanups_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/Makefile: Remove unneeded whitespaces before tabs x86/of: Kill unused early_init_dt_scan_chosen_arch() x86: Fix misspelled Kconfig symbols x86/Kconfig: Remove references to obsolete Kconfig symbols x86/smp: Remove unnecessary assignment to local var freq_scale
Fix misspelled Kconfig symbols as detected by scripts/checkkconfigsymbols.py. [ bp: Combine into a single patch. ] Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210803113531.30720-7-lukas.bulwahn@gmail.com
PREEMPT_RT preempts softirqs and the current implementation avoids do_softirq_own_stack() and only uses __do_softirq(). Disable the unused softirqs stacks on PREEMPT_RT to safe some memory and ensure that do_softirq_own_stack() is not used which is not expected. [ bigeasy: commit description. ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210924161245.2357247-1-bigeasy@linutronix.de
Current code has an explicit check for hitting the task stack guard; but overflowing any of the other stacks will get you a non-descript general #DF warning. Improve matters by using get_stack_info_noinstr() to detetrmine if and which stack guard page got hit, enabling a better stack warning. In specific, Michael Wang reported what turned out to be an NMI exception stack overflow, which is now clearly reported as such: [] BUG: NMI stack guard page was hit at 0000000085fd977b (stack is 000000003a55b09e..00000000d8cce1a5) Reported-by: Michael Wang <yun.wang@linux.alibaba.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Michael Wang <yun.wang@linux.alibaba.com> Link: https://lkml.kernel.org/r/YUTE/NuqnaWbST8n@hirez.programming.kicks-ass.net
Fix ~144 single-word typos in arch/x86/ code comments. Doing this in a single commit should reduce the churn. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: linux-kernel@vger.kernel.org