[PATCH -tip 1/4] x86: Add in_entry_text() helper function
From: mhiramat@kernel.org (Masami Hiramatsu)
Date: 2017-08-17 07:14:47
Also in:
linux-arch, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit), x86 stack unwinding · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Josh Poimboeuf, Peter Zijlstra
Add in_entry_text() helper function to cleanup entry/irqentry section checking code in kprobes and unwind_frame. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> --- arch/x86/include/asm/sections.h | 15 +++++++++++++++ arch/x86/kernel/kprobes/opt.c | 5 +---- arch/x86/kernel/unwind_frame.c | 15 +-------------- 3 files changed, 17 insertions(+), 18 deletions(-)
diff --git a/arch/x86/include/asm/sections.h b/arch/x86/include/asm/sections.h
index 2f75f30cb2f6..bb72ea0f4367 100644
--- a/arch/x86/include/asm/sections.h
+++ b/arch/x86/include/asm/sections.h@@ -11,4 +11,19 @@ extern struct exception_table_entry __stop___ex_table[]; extern char __end_rodata_hpage_align[]; #endif +/** + * in_entry_text - check if an address is in entry_text or irqentry_text + * @addr: virtual address to be checked + * + * Returns: true if the address specified by @addr is in the entry_text or + * irqentry_text, false otherwise. + */ +static inline bool in_entry_text(unsigned long addr) +{ + return memory_contains(__entry_text_start, __entry_text_end, + (void *)addr, 0) || + memory_contains(__irqentry_text_start, __irqentry_text_end, + (void *)addr, 0); +} + #endif /* _ASM_X86_SECTIONS_H */
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index 4f98aad38237..74c5ad55ba6a 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c@@ -254,10 +254,7 @@ static int can_optimize(unsigned long paddr) * Do not optimize in the entry code due to the unstable * stack handling and registers setup. */ - if (((paddr >= (unsigned long)__entry_text_start) && - (paddr < (unsigned long)__entry_text_end)) || - ((paddr >= (unsigned long)__irqentry_text_start) && - (paddr < (unsigned long)__irqentry_text_end))) + if (in_entry_text(paddr)) return 0; /* Check there is enough space for a relative jump. */
diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c
index d145a0b1f529..508cef8904f4 100644
--- a/arch/x86/kernel/unwind_frame.c
+++ b/arch/x86/kernel/unwind_frame.c@@ -77,19 +77,6 @@ static size_t regs_size(struct pt_regs *regs) return sizeof(*regs); } -static bool in_entry_code(unsigned long ip) -{ - char *addr = (char *)ip; - - if (addr >= __entry_text_start && addr < __entry_text_end) - return true; - - if (addr >= __irqentry_text_start && addr < __irqentry_text_end) - return true; - - return false; -} - static inline unsigned long *last_frame(struct unwind_state *state) { return (unsigned long *)task_pt_regs(state->task) - 2;
@@ -321,7 +308,7 @@ bool unwind_next_frame(struct unwind_state *state) * Don't warn if the unwinder got lost due to an interrupt in entry * code or in the C handler before the first frame pointer got set up: */ - if (state->got_irq && in_entry_code(state->ip)) + if (state->got_irq && in_entry_text(state->ip)) goto the_end; if (state->regs && state->regs->sp >= (unsigned long)last_aligned_frame(state) &&