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Commit 8fcd6c45 authored Jul 28, 2017 by Nicolas Pitre

ARM: implement get_tls syscall



When there is no dedicated register to hold the tp value and no MMU
to provide a fixed address kuser helper entry point, all that is
left as fallback is a syscall.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Mickael GUENE <mickael.guene@st.com>
Tested-by: Vincent Abriou <vincent.abriou@st.com>
Tested-by: Andras Szemzo <szemzo.andras@gmail.com>

parent 569dbb88

arch/arm/include/uapi/asm/unistd.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -35,5 +35,6 @@
		#define __ARM_NR_usr26 (__ARM_NR_BASE+3)
		#define __ARM_NR_usr32 (__ARM_NR_BASE+4)
		#define __ARM_NR_set_tls (__ARM_NR_BASE+5)
		#define __ARM_NR_get_tls (__ARM_NR_BASE+6)

		#endif /* _UAPI__ASM_ARM_UNISTD_H */

arch/arm/kernel/traps.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -647,6 +647,9 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs)
		set_tls(regs->ARM_r0);
		return 0;

		case NR(get_tls):
		return current_thread_info()->tp_value[0];

		default:
		/* Calls 9f00xx..9f07ff are defined to return -ENOSYS
		if not implemented, rather than raising SIGILL. This