Messages in this thread |  | | From | Keith Owens <> | Subject | Re: Oops in 2.4.0-ac5 | Date | Thu, 11 Jan 2001 09:29:07 +1100 |
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On Wed, 10 Jan 2001 15:23:14 -0500, Nathan Walp <faceprint@faceprint.com> wrote: >Here it is... I opted to cut out the 1200-odd warnings, which from the >look of them were all because i'm running it under 2.4.0-ac4 (which >boots fine).
ksymoops defaults to using /proc entries from the current system. This is fine for most people but you have to override the default when decoding an oops from another kernel.
ksymoops -KL -m /boot/System.map-2.4.0-ac5
ignores the running ksyms and lsmod files, removing your warnings.
>>>EIP; c01129ba <setup_apic_nmi_watchdog+a/90> <===== >Trace; c0100191 <L6+0/2> >Code; c01129ba <setup_apic_nmi_watchdog+a/90> >00000000 <_EIP>: >Code; c01129ba <setup_apic_nmi_watchdog+a/90> <===== > 0: 0f 30 wrmsr <===== >Code; c01129bc <setup_apic_nmi_watchdog+c/90>
This is why my original NMI for UP code in kdb uses wrmsr_eio() instead of wrmsr. wrmsr_eio() catches errors where the APIC does not support the msr and returns EIO instead of oopsing and taking the kernel with it. I could never persuade Ingo to use wrmsr_eio() and check the return code, maybe this will change his mind. Extract from kdb v1.7.
/* * {rd,wr}msr_eio by HPA, moved from arch/i386/msr.c to here. * Keith Owens. */
/* Note: "err" is handled in a funny way below. Otherwise one version of gcc or another breaks. */
extern inline int wrmsr_eio(u32 reg, u32 eax, u32 edx) { int err;
asm volatile( "1: wrmsr\n" "2:\n" ".section .fixup,\"ax\"\n" "3: movl %4,%0\n" " jmp 2b\n" ".previous\n" ".section __ex_table,\"a\"\n" " .align 4\n" " .long 1b,3b\n" ".previous" : "=&bDS" (err) : "a" (eax), "d" (edx), "c" (reg), "i" (-EIO), "0" (0));
return err; }
.....
/* * Activate or deactivate NMI watchdog via a local APIC. */
int setup_apic_nmi_watchdog(int value) { int ret, eax;
if (!test_bit(X86_FEATURE_APIC, &boot_cpu_data.x86_capability)) return(-EIO); if (nmi_watchdog_source && nmi_watchdog_source != 1) return(0); /* Not using local APIC */ /* Disable performance counters 0, 1 for all NMI changes */ nmi_watchdog = proc_nmi_watchdog = nmi_watchdog_source = 0; if ((ret = wrmsr_eio(EVNTSEL0, 0, 0)) || (ret = wrmsr_eio(EVNTSEL1, 0, 0)) || (ret = wrmsr_eio(PERFCTR0, 0, 0)) || (ret = wrmsr_eio(PERFCTR1, 0, 0))) goto exit; if (!value) return(0); /* Must set before activation to catch first NMI */ nmi_watchdog = proc_nmi_watchdog = nmi_watchdog_source = 1; eax = 1 << 20 /* Interrupt on overflow */ | 1 << 17 /* OS mode */ | 1 << 16 /* User mode */ | 0x79; /* Event, cpu clocks not halted */ if ((ret = wrmsr_eio(EVNTSEL1, eax, 0)) || (ret = set_nmi_counter_local())) goto exit; apic_write_around(APIC_LVTPC, APIC_DM_NMI); eax = 1 << 22; /* Enable performance counters, only using ctr1 */ ret = wrmsr_eio(EVNTSEL0, eax, 0); exit: if (ret) nmi_watchdog = proc_nmi_watchdog = nmi_watchdog_source = 0; else printk(KERN_INFO "Activated NMI via local APIC\n"); return(ret); }
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