diff options
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/fault.c | 33 | ||||
| -rw-r--r-- | arch/x86/mm/pageattr.c | 14 |
2 files changed, 30 insertions, 17 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index a92c4c999787..8e5722992677 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1025,8 +1025,12 @@ static inline bool smap_violation(int error_code, struct pt_regs *regs) * This routine handles page faults. It determines the address, * and the problem, and then passes it off to one of the appropriate * routines. + * + * This function must have noinline because both callers + * {,trace_}do_page_fault() have notrace on. Having this an actual function + * guarantees there's a function trace entry. */ -static void __kprobes +static void __kprobes noinline __do_page_fault(struct pt_regs *regs, unsigned long error_code, unsigned long address) { @@ -1250,31 +1254,38 @@ good_area: up_read(&mm->mmap_sem); } -dotraplinkage void __kprobes +dotraplinkage void __kprobes notrace do_page_fault(struct pt_regs *regs, unsigned long error_code) { + unsigned long address = read_cr2(); /* Get the faulting address */ enum ctx_state prev_state; - /* Get the faulting address: */ - unsigned long address = read_cr2(); + + /* + * We must have this function tagged with __kprobes, notrace and call + * read_cr2() before calling anything else. To avoid calling any kind + * of tracing machinery before we've observed the CR2 value. + * + * exception_{enter,exit}() contain all sorts of tracepoints. + */ prev_state = exception_enter(); __do_page_fault(regs, error_code, address); exception_exit(prev_state); } -static void trace_page_fault_entries(struct pt_regs *regs, +#ifdef CONFIG_TRACING +static void trace_page_fault_entries(unsigned long address, struct pt_regs *regs, unsigned long error_code) { if (user_mode(regs)) - trace_page_fault_user(read_cr2(), regs, error_code); + trace_page_fault_user(address, regs, error_code); else - trace_page_fault_kernel(read_cr2(), regs, error_code); + trace_page_fault_kernel(address, regs, error_code); } -dotraplinkage void __kprobes +dotraplinkage void __kprobes notrace trace_do_page_fault(struct pt_regs *regs, unsigned long error_code) { - enum ctx_state prev_state; /* * The exception_enter and tracepoint processing could * trigger another page faults (user space callchain @@ -1282,9 +1293,11 @@ trace_do_page_fault(struct pt_regs *regs, unsigned long error_code) * the faulting address now. */ unsigned long address = read_cr2(); + enum ctx_state prev_state; prev_state = exception_enter(); - trace_page_fault_entries(regs, error_code); + trace_page_fault_entries(address, regs, error_code); __do_page_fault(regs, error_code, address); exception_exit(prev_state); } +#endif /* CONFIG_TRACING */ diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 1585da3b9b85..ae242a7c11c7 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -126,8 +126,8 @@ within(unsigned long addr, unsigned long start, unsigned long end) * @vaddr: virtual start address * @size: number of bytes to flush * - * clflush is an unordered instruction which needs fencing with mfence - * to avoid ordering issues. + * clflushopt is an unordered instruction which needs fencing with mfence or + * sfence to avoid ordering issues. */ void clflush_cache_range(void *vaddr, unsigned int size) { @@ -136,11 +136,11 @@ void clflush_cache_range(void *vaddr, unsigned int size) mb(); for (; vaddr < vend; vaddr += boot_cpu_data.x86_clflush_size) - clflush(vaddr); + clflushopt(vaddr); /* * Flush any possible final partial cacheline: */ - clflush(vend); + clflushopt(vend); mb(); } @@ -1393,10 +1393,10 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages, cache = cache_attr(mask_set); /* - * On success we use clflush, when the CPU supports it to - * avoid the wbindv. If the CPU does not support it and in the + * On success we use CLFLUSH, when the CPU supports it to + * avoid the WBINVD. If the CPU does not support it and in the * error case we fall back to cpa_flush_all (which uses - * wbindv): + * WBINVD): */ if (!ret && cpu_has_clflush) { if (cpa.flags & (CPA_PAGES_ARRAY | CPA_ARRAY)) { |