From 86effd0dc675c36caed7b954d7f4f63b77c353b5 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Mon, 19 Sep 2016 16:42:25 -0700 Subject: ARC: dw2 unwind: enable cfi pseudo ops in string lib This uses a new set of annoations viz. ENTRY_CFI/END_CFI to enabel cfi ops generation. Note that we didn't change the normal ENTRY/EXIT as we don't actually want unwind info in the trap/exception/interrutp handlers which use these, as unwinder then gets confused (it keeps recursing vs. stopping). Semantically these are leaf routines and unwinding should stop when it hits those routines. Before ------ 28.52% 1.19% 9929 hackbench libuClibc-1.0.17.so [.] __write_nocancel | ---__write_nocancel |--8.95%--EV_Trap | --8.25%--sys_write | |--3.93%--sock_write_iter ... |--2.62%--memset <==== [LEAF entry as no unwind info] ^^^^^^ After ----- 29.46% 1.24% 13622 hackbench libuClibc-1.0.17.so [.] __write_nocancel | ---__write_nocancel |--9.31%--EV_Trap | --8.62%--sys_write | |--4.17%--sock_write_iter ... |--6.19%--sys_write | --6.19%--sock_write_iter | unix_stream_sendmsg | |--1.62%--sock_alloc_send_pskb | |--0.89%--sock_def_readable | |--0.88%--_raw_spin_unlock_irqrestore | |--0.69%--memset | | ^^^^^^ <==== [now in proper callframe] | | | --0.52%--skb_copy_datagram_from_iter Signed-off-by: Vineet Gupta --- arch/arc/kernel/ctx_sw_asm.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/arc/kernel/ctx_sw_asm.S') diff --git a/arch/arc/kernel/ctx_sw_asm.S b/arch/arc/kernel/ctx_sw_asm.S index e6890b1f8650..7c1f365ef3d2 100644 --- a/arch/arc/kernel/ctx_sw_asm.S +++ b/arch/arc/kernel/ctx_sw_asm.S @@ -23,6 +23,7 @@ .global __switch_to .type __switch_to, @function __switch_to: + CFI_STARTPROC /* Save regs on kernel mode stack of task */ st.a blink, [sp, -4] @@ -59,4 +60,4 @@ __switch_to: ld.ab blink, [sp, 4] j [blink] -END(__switch_to) +END_CFI(__switch_to) -- cgit v1.2.1