[PATCH v6 2/4] x86/syscalls: Specific usage of verify_pre_usermode_state
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From: H. Peter Anvin <hpa@zytor.com>
Date: 2017-04-04 18:35:16
Also in:
linux-api, linux-s390, lkml
On 04/04/17 10:47, Thomas Garnier wrote:
Implement specific usage of verify_pre_usermode_state for user-mode returns for x86. Signed-off-by: Thomas Garnier <redacted> + /* + * If address limit is not based on user-mode, jump to slow path for + * additional security checks. + */ + movq $TASK_SIZE_MAX, %rcx + cmp %rcx, TASK_addr_limit(%r11) + jnz 1f + LOCKDEP_SYS_EXIT
Nitpick: use jne not jnz when comparing for equality. Same instruction but more readable. -hpa