On 07/25/2018 05:09 AM, Tamar Christina wrote: > Hi All, > > Attached an updated patch which documents what the test cases are expecting > as requested. > > Ok for trunk? > > Thanks, > Tamar > > gcc/ > 2018-07-25 Tamar Christina <tamar.christ...@arm.com> > > PR target/86486 > * config/aarch64/aarch64.h (STACK_CLASH_OUTGOING_ARGS, > STACK_DYNAMIC_OFFSET): New. > * config/aarch64/aarch64.c (aarch64_layout_frame): > Update outgoing args size. > (aarch64_stack_clash_protection_alloca_probe_range, > TARGET_STACK_CLASH_PROTECTION_ALLOCA_PROBE_RANGE): New. > > gcc/testsuite/ > 2018-07-25 Tamar Christina <tamar.christ...@arm.com> > > PR target/86486 > * gcc.target/aarch64/stack-check-alloca-1.c: New. > * gcc.target/aarch64/stack-check-alloca-10.c: New. > * gcc.target/aarch64/stack-check-alloca-2.c: New. > * gcc.target/aarch64/stack-check-alloca-3.c: New. > * gcc.target/aarch64/stack-check-alloca-4.c: New. > * gcc.target/aarch64/stack-check-alloca-5.c: New. > * gcc.target/aarch64/stack-check-alloca-6.c: New. > * gcc.target/aarch64/stack-check-alloca-7.c: New. > * gcc.target/aarch64/stack-check-alloca-8.c: New. > * gcc.target/aarch64/stack-check-alloca-9.c: New. > * gcc.target/aarch64/stack-check-alloca.h: New. > * gcc.target/aarch64/stack-check-14.c: New. > * gcc.target/aarch64/stack-check-15.c: New. > >> -----Original Message----- >> From: Tamar Christina >> Sent: Friday, July 13, 2018 17:36 >> To: Tamar Christina <tamar.christ...@arm.com>; gcc-patches@gcc.gnu.org >> Cc: nd <n...@arm.com>; James Greenhalgh <james.greenha...@arm.com>; >> Richard Earnshaw <richard.earns...@arm.com>; Marcus Shawcroft >> <marcus.shawcr...@arm.com> >> Subject: RE: [PATCH][GCC][AArch64] Ensure that outgoing argument size is at >> least 8 bytes when alloca and stack-clash. [Patch (3/6)] >> >> Hi All, >> >> I'm sending an updated patch which updates a testcase that hits one of our >> corner cases. >> This is an assembler scan only update in a testcase. >> >> Regards, >> Tamar >> >>> -----Original Message----- >>> From: Tamar Christina <tamar.christ...@arm.com> >>> Sent: Wednesday, July 11, 2018 12:21 >>> To: gcc-patches@gcc.gnu.org >>> Cc: nd <n...@arm.com>; James Greenhalgh <james.greenha...@arm.com>; >>> Richard Earnshaw <richard.earns...@arm.com>; Marcus Shawcroft >>> <marcus.shawcr...@arm.com> >>> Subject: [PATCH][GCC][AArch64] Ensure that outgoing argument size is >>> at least 8 bytes when alloca and stack-clash. [Patch (3/6)] >>> >>> Hi All, >>> >>> This patch adds a requirement that the number of outgoing arguments >>> for a function is at least 8 bytes when using stack-clash protection. >>> >>> By using this condition we can avoid a check in the alloca code and so >>> have smaller and simpler code there. >>> >>> A simplified version of the AArch64 stack frames is: >>> >>> +-----------------------+ >>> | | >>> | | >>> | | >>> +-----------------------+ >>> |LR | >>> +-----------------------+ >>> |FP | >>> +-----------------------+ >>> |dynamic allocations | ---- expanding area which will push the >>> outgoing >>> +-----------------------+ args down during each allocation. >>> |padding | >>> +-----------------------+ >>> |outgoing stack args | ---- safety buffer of 8 bytes (aligned) >>> +-----------------------+ >>> >>> By always defining an outgoing argument, alloca(0) effectively is safe >>> to probe at $sp due to the reserved buffer being there. It will never >>> corrupt the stack. >>> >>> This is also safe for alloca(x) where x is 0 or x % page_size == 0. >>> In the former it is the same case as alloca(0) while the latter is >>> safe because any allocation pushes the outgoing stack args down: >>> >>> |FP | >>> +-----------------------+ >>> | | >>> |dynamic allocations | ---- alloca (x) >>> | | >>> +-----------------------+ >>> |padding | >>> +-----------------------+ >>> |outgoing stack args | ---- safety buffer of 8 bytes (aligned) >>> +-----------------------+ >>> >>> Which means when you probe for the residual, if it's 0 you'll again >>> just probe in the outgoing stack args range, which we know is non-zero (at >> least 8 bytes). >>> >>> Bootstrapped Regtested on aarch64-none-linux-gnu and no issues. >>> Target was tested with stack clash on and off by default. >>> >>> Ok for trunk? >>> >>> Thanks, >>> Tamar >>> >>> gcc/ >>> 2018-07-11 Tamar Christina <tamar.christ...@arm.com> >>> >>> PR target/86486 >>> * config/aarch64/aarch64.h (STACK_CLASH_OUTGOING_ARGS, >>> STACK_DYNAMIC_OFFSET): New. >>> * config/aarch64/aarch64.c (aarch64_layout_frame): >>> Update outgoing args size. >>> (aarch64_stack_clash_protection_alloca_probe_range, >>> TARGET_STACK_CLASH_PROTECTION_ALLOCA_PROBE_RANGE): >>> New. >>> >>> gcc/testsuite/ >>> 2018-07-11 Tamar Christina <tamar.christ...@arm.com> >>> >>> PR target/86486 >>> * gcc.target/aarch64/stack-check-alloca-1.c: New. >>> * gcc.target/aarch64/stack-check-alloca-10.c: New. >>> * gcc.target/aarch64/stack-check-alloca-2.c: New. >>> * gcc.target/aarch64/stack-check-alloca-3.c: New. >>> * gcc.target/aarch64/stack-check-alloca-4.c: New. >>> * gcc.target/aarch64/stack-check-alloca-5.c: New. >>> * gcc.target/aarch64/stack-check-alloca-6.c: New. >>> * gcc.target/aarch64/stack-check-alloca-7.c: New. >>> * gcc.target/aarch64/stack-check-alloca-8.c: New. >>> * gcc.target/aarch64/stack-check-alloca-9.c: New. >>> * gcc.target/aarch64/stack-check-alloca.h: New. >>> * gcc.target/aarch64/stack-check-14.c: New. >>> * gcc.target/aarch64/stack-check-15.c: New. >>> >>> -- Likewise -- no concerns on my end. AArch64 maintainers have the final say.
jeff
