Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

LoongArch: Fix bitflag conflict for TIF_FIXADE

After LoongArch was converted to use the generic TIF bits in commit
f9629891d407 ("loongarch: Use generic TIF bits"), its TIF_FIXADE flag
takes the same bit with TIF_RESTORE_SIGMASK in thread_info.flags.

Such conflict causes TIF_FIXADE being considered cleared when
TIF_RESTORE_SIGMASK is cleared during deliver of a signal. And since
TIF_FIXADE determines whether unaligned access emulation works for a
task, userspace making use of unaligned access will receive unexpected
SIGBUS (and likely terminate) after receiving its first signal.

This conflict looks like a simple typo, switch it to the free bit 19.

Fixes: f9629891d407 ("loongarch: Use generic TIF bits")
Signed-off-by: Yao Zi <ziyao@disroot.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Wentao Guan <guanwentao@uniontech.com>

authored by

Yao Zi and committed by
Thomas Gleixner
3ec09344 41e871f2

+1 -1
+1 -1
arch/loongarch/include/asm/thread_info.h
··· 77 77 #define TIF_NOHZ 16 /* in adaptive nohz mode */ 78 78 #define TIF_USEDFPU 17 /* FPU was used by this task this quantum (SMP) */ 79 79 #define TIF_USEDSIMD 18 /* SIMD has been used this quantum */ 80 - #define TIF_FIXADE 10 /* Fix address errors in software */ 80 + #define TIF_FIXADE 19 /* Fix address errors in software */ 81 81 #define TIF_LOGADE 20 /* Log address errors to syslog */ 82 82 #define TIF_32BIT_REGS 21 /* 32-bit general purpose registers */ 83 83 #define TIF_32BIT_ADDR 22 /* 32-bit address space */