Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH] x86: pad assembly functions with INT3 | Date | Thu, 10 May 2018 16:39:55 +0000 |
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From: Alexey Dobriyan > Sent: 07 May 2018 22:38 > > Use INT3 instead of NOP. All that padding between functions is > an illegal area, no legitimate code should jump into it. > > I've checked x86_64 allyesconfig disassembly, all changes looks sane: > INT3 is only used after RET or unconditional JMP.
I thought there was a performance penalty (on at least some cpu) depending on the number of and the actual instructions used for padding.
I believe that is why gcc generates a small number of very long 'nop' instructions when padding code.
David
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