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>
This commit is contained in:
Nicolas Pitre 2017-07-28 15:35:35 -04:00
parent 569dbb88e8
commit 8fcd6c45f5
2 changed files with 4 additions and 0 deletions

View File

@ -35,5 +35,6 @@
#define __ARM_NR_usr26 (__ARM_NR_BASE+3) #define __ARM_NR_usr26 (__ARM_NR_BASE+3)
#define __ARM_NR_usr32 (__ARM_NR_BASE+4) #define __ARM_NR_usr32 (__ARM_NR_BASE+4)
#define __ARM_NR_set_tls (__ARM_NR_BASE+5) #define __ARM_NR_set_tls (__ARM_NR_BASE+5)
#define __ARM_NR_get_tls (__ARM_NR_BASE+6)
#endif /* _UAPI__ASM_ARM_UNISTD_H */ #endif /* _UAPI__ASM_ARM_UNISTD_H */

View File

@ -647,6 +647,9 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs)
set_tls(regs->ARM_r0); set_tls(regs->ARM_r0);
return 0; return 0;
case NR(get_tls):
return current_thread_info()->tp_value[0];
default: default:
/* Calls 9f00xx..9f07ff are defined to return -ENOSYS /* Calls 9f00xx..9f07ff are defined to return -ENOSYS
if not implemented, rather than raising SIGILL. This if not implemented, rather than raising SIGILL. This