diff options
| author | James Morse <james.morse@arm.com> | 2017-11-02 12:12:38 +0000 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2017-11-02 15:55:41 +0000 |
| commit | 84d0fb1bb6257d5d5d45f5e3554ab441b4ff5a74 (patch) | |
| tree | 3054c4b315f1b3963b0ceeeeea140f6d85503933 /arch/arm64 | |
| parent | 8d66772e869e79ffb94eed7492ca3d2267e150e8 (diff) | |
arm64: entry.S: Remove disable_dbg
enable_step_tsk is the only user of disable_dbg, which doesn't respect
our 'dai' order for exception masking. enable_step_tsk may enable
single-step, so previously needed to mask debug exceptions to prevent us
from single-stepping kernel_exit. enable_step_tsk is called at the end
of the ret_to_user loop, which has already masked all exceptions so this
is no longer needed.
Remove disable_dbg, add a comment that enable_step_tsk's caller should
have masked debug.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/include/asm/assembler.h | 9 |
1 files changed, 1 insertions, 8 deletions
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index a4aa22241dd1..8bc63fc98752 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -69,13 +69,6 @@ msr daif, \flags .endm -/* - * Enable and disable debug exceptions. - */ - .macro disable_dbg - msr daifset, #8 - .endm - .macro enable_dbg msr daifclr, #8 .endm @@ -89,9 +82,9 @@ 9990: .endm + /* call with daif masked */ .macro enable_step_tsk, flgs, tmp tbz \flgs, #TIF_SINGLESTEP, 9990f - disable_dbg mrs \tmp, mdscr_el1 orr \tmp, \tmp, #DBG_MDSCR_SS msr mdscr_el1, \tmp |