forked from Minki/linux
97efebf1bc
There are two basic things that can happen as the result of a bounds exception (#BR): 1. We allocate a new bounds table 2. We pass up a bounds exception to userspace. This patch adds a trace point for the case where we are passing the exception up to userspace with a signal. We are also explicit that we're printing out the inverse of the 'upper' that we encounter. If you want to filter, for instance, you need to ~ the value first. The reason we do this is because of how 'upper' is stored in the bounds table. If a pointer's range is: 0x1000 -> 0x2000 it is stored in the bounds table as (32-bits here for brevity): lower: 0x00001000 upper: 0xffffdfff That is so that an all 0's entry: lower: 0x00000000 upper: 0x00000000 corresponds to the "init" bounds which store a *range* of: 0x00000000 -> 0xffffffff That is, by far, the common case, and that lets us use the zero page, or deduplicate the memory, etc... The 'upper' stored in the table is gibberish to print by itself, so we print ~upper to get the *actual*, logical, human-readable value printed out. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dave Hansen <dave@sr71.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20150607183703.027BB9B0@viggo.jf.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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| exceptions.h | ||
| irq_vectors.h | ||
| mpx.h | ||