x86/traps: Prepare for using DEFINE_IDTENTRY (218e31b6) · Commits · 戴 / test

Prepare for using IDTENTRY to define the C exception/trap entry points. It would be possible to glue this into the existing macro maze, but it's simpler and better to read at the end to just make them distinct. Provide a trivial inline helper to read the trap address and add a comment explaining the logic behind it. The existing macros will be removed once all instances are converted. Signed-off-by:

Thomas Gleixner <tglx@linutronix.de> Reviewed-by:

Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by:

Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200505134904.556327833@linutronix.de

arch/x86/kernel/traps.c

+15 −0

Original line number	Diff line number	Diff line
		@@ -205,6 +205,21 @@ static void do_error_trap(struct pt_regs regs, long error_code, char str,
		}
		}

		/*
		* Posix requires to provide the address of the faulting instruction for
		* SIGILL (#UD) and SIGFPE (#DE) in the si_addr member of siginfo_t.
		*
		* This address is usually regs->ip, but when an uprobe moved the code out
		* of line then regs->ip points to the XOL code which would confuse
		* anything which analyzes the fault address vs. the unmodified binary. If
		* a trap happened in XOL code then uprobe maps regs->ip back to the
		* original instruction address.
		*/
		static __always_inline void __user error_get_trap_addr(struct pt_regs regs)
		{
		return (void __user *)uprobe_get_trap_addr(regs);
		}

		#define IP ((void __user *)uprobe_get_trap_addr(regs))
		#define DO_ERROR(trapnr, signr, sicode, addr, str, name) \
		dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \

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