diff options
| author |   Ard Biesheuvel <ardb@kernel.org> | 2021-09-18 10:44:34 +0200 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2021-09-27 16:54:01 +0200 |
| commit | dfbdcda280eb762bae2184145cc0702932d41798 (patch) | |
| tree | 412a5d96995d2b0cb4d41409dd51476e3a7da8ea /arch/arm/include/asm | |
| parent | Linux 5.15-rc1 (diff) | |
| download | linux-dev-dfbdcda280eb762bae2184145cc0702932d41798.tar.xz linux-dev-dfbdcda280eb762bae2184145cc0702932d41798.zip | |
gcc-plugins: arm-ssp: Prepare for THREAD_INFO_IN_TASK support
We will be enabling THREAD_INFO_IN_TASK support for ARM, which means
that we can no longer load the stack canary value by masking the stack
pointer and taking the copy that lives in thread_info. Instead, we will
be able to load it from the task_struct directly, by using the TPIDRURO
register which will hold the current task pointer when
THREAD_INFO_IN_TASK is in effect. This is much more straight-forward,
and allows us to declutter this code a bit while at it.
Note that this means that ARMv6 (non-v6K) SMP systems can no longer use
this feature, but those are quite rare to begin with, so this is a
reasonable trade off.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Diffstat (limited to 'arch/arm/include/asm')
| -rw-r--r-- | arch/arm/include/asm/stackprotector.h | 2 | ||||
| -rw-r--r-- | arch/arm/include/asm/thread_info.h | 3 |
2 files changed, 0 insertions, 5 deletions
diff --git a/arch/arm/include/asm/stackprotector.h b/arch/arm/include/asm/stackprotector.h index 72a20c3a0a90..088d03161be5 100644 --- a/arch/arm/include/asm/stackprotector.h +++ b/arch/arm/include/asm/stackprotector.h @@ -39,8 +39,6 @@ static __always_inline void boot_init_stack_canary(void) current->stack_canary = canary; #ifndef CONFIG_STACKPROTECTOR_PER_TASK __stack_chk_guard = current->stack_canary; -#else - current_thread_info()->stack_canary = current->stack_canary; #endif } diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h index 9a18da3e10cc..f0cacc733231 100644 --- a/arch/arm/include/asm/thread_info.h +++ b/arch/arm/include/asm/thread_info.h @@ -55,9 +55,6 @@ struct thread_info { struct task_struct *task; /* main task structure */ __u32 cpu; /* cpu */ __u32 cpu_domain; /* cpu domain */ -#ifdef CONFIG_STACKPROTECTOR_PER_TASK - unsigned long stack_canary; -#endif struct cpu_context_save cpu_context; /* cpu context */ __u32 abi_syscall; /* ABI type and syscall nr */ __u8 used_cp[16]; /* thread used copro */ |