Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH v2 2/6] x86-64: Convert stack protector to normal percpu variable | Date | Wed, 1 Dec 2021 09:50:57 +0000 |
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From: Brian Gerst > Sent: 30 November 2021 20:56 > > Older versions of GCC fixed the location of the stack protector canary > at %gs:40. This constraint forced the percpu section to be linked at > virtual address 0 so that the canary could be the first data object in > the percpu section. Supporting the zero-based percpu section requires > additional code to handle relocations for RIP-relative references to > percpu data, extra complexity to kallsyms, and workarounds for linker > bugs due to the use of absolute symbols. > > Since version 8.1, GCC has options to configure the location of the > canary value. This allows the canary to be turned into a normal > percpu variable and removes the constraint that the percpu section > be zero-based.
I didn't think the minimum gcc version has been raised as far as 8.1?
David
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