ARC: fix CONFIG_HARDENED_USERCOPY
Currently enabling this triggers a warning | usercopy: Kernel memory overwrite attempt detected to kernel text (offset 155633, size 11)! | usercopy: BUG: failure at mm/usercopy.c:99/usercopy_abort()! | |gcc generated __builtin_trap |Path: /bin/busybox |CPU: 0 PID: 84 Comm: init Not tainted 5.4.22 | |[ECR ]: 0x00090005 => gcc generated __builtin_trap |[EFA ]: 0x9024fcaa |[BLINK ]: usercopy_abort+0x8a/0x8c |[ERET ]: memfd_fcntl+0x0/0x470 |[STAT32]: 0x80080802 : IE K |... |... |Stack Trace: | memfd_fcntl+0x0/0x470 | usercopy_abort+0x8a/0x8c | __check_object_size+0x10e/0x138 | copy_strings+0x1f4/0x38c | __do_execve_file+0x352/0x848 | EV_Trap+0xcc/0xd0 The issue is triggered by an allocation in "init reclaimed" region. ARC _stext emcompasses the init region (for historical reasons we wanted the init.text to be under .text as well). This however trips up __check_object_size()->check_kernel_text_object() which treats this as object bleeding into kernel text. Fix that by rezoning _stext to start from regular kernel .text and leave out .init altogether. Fixes: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/15 Reported-by:Evgeniy Didin <didin@synopsys.com> Reviewed-by:
Kees Cook <keescook@chromium.org> Signed-off-by:
Vineet Gupta <vgupta@synopsys.com>
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96f1b001
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