arm64: compat: Alloc separate pages for vectors and sigpage
authorVincenzo Frascino <vincenzo.frascino@arm.com>
Mon, 15 Apr 2019 09:49:34 +0000 (10:49 +0100)
committerWill Deacon <will.deacon@arm.com>
Tue, 23 Apr 2019 17:01:31 +0000 (18:01 +0100)
commit0d747f6585954d7285a3995058e7dfeae7236cf9
tree6e0ceb723e3d0d5cbc41d993c3419f58f50cde04
parent36a2ba07757df790b4a874efb1a105b9330a9ae7
arm64: compat: Alloc separate pages for vectors and sigpage

For AArch32 tasks, we install a special "[vectors]" page that contains
the sigreturn trampolines and kuser helpers, which is mapped at a fixed
address specified by the kuser helpers ABI.

Having the sigreturn trampolines in the same page as the kuser helpers
makes it impossible to disable the kuser helpers independently.

Follow the Arm implementation, by moving the signal trampolines out of
the "[vectors]" page and into their own "[sigpage]".

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
[will: tweaked comments and fixed sparse warning]
Signed-off-by: Will Deacon <will.deacon@arm.com>
arch/arm64/include/asm/elf.h
arch/arm64/include/asm/signal32.h
arch/arm64/kernel/signal32.c
arch/arm64/kernel/vdso.c