From 21f585073d6347651f2262da187606fa1c4ee16d Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Tue, 29 Apr 2014 15:25:17 -0400 Subject: powerpc: Fix smp_processor_id() in preemptible splat in set_breakpoint Currently, on 8641D, which doesn't set CONFIG_HAVE_HW_BREAKPOINT we get the following splat: BUG: using smp_processor_id() in preemptible [00000000] code: login/1382 caller is set_breakpoint+0x1c/0xa0 CPU: 0 PID: 1382 Comm: login Not tainted 3.15.0-rc3-00041-g2aafe1a4d451 #1 Call Trace: [decd5d80] [c0008dc4] show_stack+0x50/0x158 (unreliable) [decd5dc0] [c03c6fa0] dump_stack+0x7c/0xdc [decd5de0] [c01f8818] check_preemption_disabled+0xf4/0x104 [decd5e00] [c00086b8] set_breakpoint+0x1c/0xa0 [decd5e10] [c00d4530] flush_old_exec+0x2bc/0x588 [decd5e40] [c011c468] load_elf_binary+0x2ac/0x1164 [decd5ec0] [c00d35f8] search_binary_handler+0xc4/0x1f8 [decd5ef0] [c00d4ee8] do_execve+0x3d8/0x4b8 [decd5f40] [c001185c] ret_from_syscall+0x0/0x38 --- Exception: c01 at 0xfeee554 LR = 0xfeee7d4 The call path in this case is: flush_thread --> set_debug_reg_defaults --> set_breakpoint --> __get_cpu_var Since preemption is enabled in the cleanup of flush thread, and there is no need to disable it, introduce the distinction between set_breakpoint and __set_breakpoint, leaving only the flush_thread instance as the current user of set_breakpoint. Signed-off-by: Paul Gortmaker Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/xmon/xmon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/powerpc/xmon') diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index 08504e7..d3759b7 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -759,7 +759,7 @@ static void insert_cpu_bpts(void) brk.address = dabr.address; brk.type = (dabr.enabled & HW_BRK_TYPE_DABR) | HW_BRK_TYPE_PRIV_ALL; brk.len = 8; - set_breakpoint(&brk); + __set_breakpoint(&brk); } if (iabr && cpu_has_feature(CPU_FTR_IABR)) mtspr(SPRN_IABR, iabr->address -- cgit v1.1