[PATCHv2 00/19] arm64: invoke syscalls with pt_regs

From: Mark Rutland
Date: Fri Jun 01 2018 - 07:24:56 EST


This series reworks arm64's syscall handling to minimize the propagation
of user-controlled register values into speculated code paths. As with
x86 [1], a wrapper is generated for each syscall, which extracts the
argument from a struct pt_regs. During kernel entry from userspace,
registers are zeroed.

The arm64 kernel code directly invokes some syscalls which the x86 code
doesn't, so I've added ksys_* wrappers for these, following the x86
example. The rest of the series is arm64-specific.

I've pushed the series out to my arm64/syscall-regs branch [2] on
kernel.org.

Since v1 [3]:
* Rebase atop of arm64 for-next/core (for SSBD conflicts)
* Move ksys_personality logic into <linux/syscalls.h>
* Move kcompat_sys_* wrappers to <linux/compat.h>
* Fix scno bounds check to use unisgned comparison
* Fix sve_user_reset() call in el0_svc_handler()
* Add BUILD_BUG() to the !CONFIG_ARM64_SVE stubs
* Accumulate acked-by / reviewed-by tags

Thanks,
Mark.

[1] https://lkml.kernel.org/r/20180330093720.6780-1-linux@xxxxxxxxxxxxxxxxxxxx
[2] git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git
[3] https://lkml.kernel.org/r/20180514094640.27569-1-mark.rutland@xxxxxxx

Mark Rutland (19):
arm64: consistently use unsigned long for thread flags
arm64: move SCTLR_EL{1,2} assertions to <asm/sysreg.h>
arm64: introduce sysreg_clear_set()
arm64: kill config_sctlr_el1()
arm64: kill change_cpacr()
arm64: move sve_user_{enable,disable} to <asm/fpsimd.h>
arm64: remove sigreturn wrappers
arm64: convert raw syscall invocation to C
arm64: convert syscall trace logic to C
arm64: convert native/compat syscall entry to C
arm64: don't reload GPRs after apply_ssbd
arm64: zero GPRs upon entry from EL0
kernel: add ksys_personality()
kernel: add kcompat_sys_{f,}statfs64()
arm64: remove in-kernel call to sys_personality()
arm64: use {COMPAT,}SYSCALL_DEFINE0 for sigreturn
arm64: use SYSCALL_DEFINE6() for mmap
arm64: convert compat wrappers to C
arm64: implement syscall wrappers

arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/fpsimd.h | 17 +++-
arch/arm64/include/asm/syscall_wrapper.h | 80 +++++++++++++++++
arch/arm64/include/asm/sysreg.h | 33 ++++---
arch/arm64/include/asm/unistd32.h | 26 +++---
arch/arm64/kernel/Makefile | 5 +-
arch/arm64/kernel/armv8_deprecated.c | 8 +-
arch/arm64/kernel/cpu_errata.c | 3 +-
arch/arm64/kernel/entry.S | 145 ++++---------------------------
arch/arm64/kernel/entry32.S | 121 --------------------------
arch/arm64/kernel/fpsimd.c | 19 ----
arch/arm64/kernel/signal.c | 5 +-
arch/arm64/kernel/signal32.c | 6 +-
arch/arm64/kernel/sys.c | 19 ++--
arch/arm64/kernel/sys32.c | 127 ++++++++++++++++++++++++---
arch/arm64/kernel/syscall.c | 114 ++++++++++++++++++++++++
arch/arm64/kernel/traps.c | 4 +-
arch/arm64/mm/fault.c | 2 +-
fs/statfs.c | 14 ++-
include/linux/compat.h | 11 +++
include/linux/syscalls.h | 11 +++
21 files changed, 437 insertions(+), 334 deletions(-)
create mode 100644 arch/arm64/include/asm/syscall_wrapper.h
delete mode 100644 arch/arm64/kernel/entry32.S
create mode 100644 arch/arm64/kernel/syscall.c

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2.11.0