Commit 218e31b6 authored by Thomas Gleixner's avatar Thomas Gleixner

x86/traps: Prepare for using DEFINE_IDTENTRY

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: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarAlexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: default avatarPeter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200505134904.556327833@linutronix.de



parent 0ba50e86
...@@ -205,6 +205,21 @@ static void do_error_trap(struct pt_regs *regs, long error_code, char *str, ...@@ -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 IP ((void __user *)uprobe_get_trap_addr(regs))
#define DO_ERROR(trapnr, signr, sicode, addr, str, name) \ #define DO_ERROR(trapnr, signr, sicode, addr, str, name) \
dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \
......
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