Date: Sat, 29 Aug 2020 04:04:55 -0600 From: Warner Losh <imp@bsdimp.com> To: Mateusz Guzik <mjguzik@gmail.com> Cc: Warner Losh <imp@freebsd.org>, src-committers <src-committers@freebsd.org>, svn-src-all <svn-src-all@freebsd.org>, svn-src-head <svn-src-head@freebsd.org> Subject: Re: svn commit: r364946 - head/sys/kern Message-ID: <CANCZdfqXtKhKhh33ovFQ4_a3tiesRi8-6ZuMTp0yW%2BMzkxWLzA@mail.gmail.com> In-Reply-To: <CAGudoHFAkrAykin6ngH=04254J4AmhHk2NmDyGfrUE=wJcxH2A@mail.gmail.com> References: <202008290430.07T4UCM4007928@repo.freebsd.org> <CAGudoHFAkrAykin6ngH=04254J4AmhHk2NmDyGfrUE=wJcxH2A@mail.gmail.com>
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On Sat, Aug 29, 2020 at 1:09 AM Mateusz Guzik <mjguzik@gmail.com> wrote: > This crashes on boot for me: > I wasn't able to get it to crash on boot for me, but I was able to recreate it. Fixed in r364949. I think it didn't crash on boot for me because kldxref failed due to the segment thing so devmatch didn't run which would have triggered this bug. devinfo did trigger a very similar crash, and r364949 fixes that crash. Even a new kldxref failed due to the too many segments thing, so I can't confirm that's what you hit, but I'm pretty sure it is... Warner > atal trap 12: page fault while in kernel mode > cpuid = 0; apic id = 00 > fault virtual address = 0x0 > fault code = supervisor read data, page not present > instruction pointer = 0x20:0xffffffff805b0a7f > stack pointer = 0x28:0xfffffe002366a7f0 > frame pointer = 0x28:0xfffffe002366a7f0 > code segment = base 0x0, limit 0xfffff, type 0x1b > = DPL 0, pres 1, long 1, def32 0, gran 1 > processor eflags = interrupt enabled, resume, IOPL = 0 > current process = 89 (devmatch) > trap number = 12 > panic: page fault > cpuid = 0 > time = 1598692135 > KDB: stack backtrace: > db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame > 0xfffffe002366a4a0 > vpanic() at vpanic+0x182/frame 0xfffffe002366a4f0 > panic() at panic+0x43/frame 0xfffffe002366a550 > trap_fatal() at trap_fatal+0x387/frame 0xfffffe002366a5b0 > trap_pfault() at trap_pfault+0x4f/frame 0xfffffe002366a610 > trap() at trap+0x27d/frame 0xfffffe002366a720 > calltrap() at calltrap+0x8/frame 0xfffffe002366a720 > --- trap 0xc, rip = 0xffffffff805b0a7f, rsp = 0xfffffe002366a7f0, rbp > = 0xfffffe002366a7f0 --- > strlen() at strlen+0x1f/frame 0xfffffe002366a7f0 > sbuf_cat() at sbuf_cat+0x15/frame 0xfffffe002366a810 > sysctl_devices() at sysctl_devices+0x104/frame 0xfffffe002366a8a0 > sysctl_root_handler_locked() at sysctl_root_handler_locked+0x91/frame > 0xfffffe002366a8f0 > sysctl_root() at sysctl_root+0x249/frame 0xfffffe002366a970 > userland_sysctl() at userland_sysctl+0x170/frame 0xfffffe002366aa20 > sys___sysctl() at sys___sysctl+0x5f/frame 0xfffffe002366aad0 > amd64_syscall() at amd64_syscall+0x10c/frame 0xfffffe002366abf0 > fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe002366abf0 > --- syscall (202, FreeBSD ELF64, sys___sysctl), rip = 0x80041c0ea, rsp > = 0x7fffffffda78, rbp = 0x7fffffffdab0 --- > KDB: enter: panic > [ thread pid 89 tid 100067 ] > Stopped at kdb_enter+0x37: movq $0,0x7e2616(%rip) > > > On 8/29/20, Warner Losh <imp@freebsd.org> wrote: > > Author: imp > > Date: Sat Aug 29 04:30:12 2020 > > New Revision: 364946 > > URL: https://svnweb.freebsd.org/changeset/base/364946 > > > > Log: > > Move to using sbuf for some sysctl in newbus > > > > Convert two different sysctl to using sbuf. First, for all the default > > sysctls we implement for each device driver that's attached. This is a > > pure sbuf conversion. > > > > Second, convert sysctl_devices to fill its buffer with sbuf rather > > than a hand-rolled crappy thing I wrote years ago. > > > > Reviewed by: cem, markj > > Differential Revision: https://reviews.freebsd.org/D26206 > > > > Modified: > > head/sys/kern/subr_bus.c > > > > Modified: head/sys/kern/subr_bus.c > > > ============================================================================== > > --- head/sys/kern/subr_bus.c Sat Aug 29 04:30:06 2020 (r364945) > > +++ head/sys/kern/subr_bus.c Sat Aug 29 04:30:12 2020 (r364946) > > @@ -260,36 +260,33 @@ enum { > > static int > > device_sysctl_handler(SYSCTL_HANDLER_ARGS) > > { > > + struct sbuf sb; > > device_t dev = (device_t)arg1; > > - const char *value; > > - char *buf; > > int error; > > > > - buf = NULL; > > + sbuf_new_for_sysctl(&sb, NULL, 1024, req); > > switch (arg2) { > > case DEVICE_SYSCTL_DESC: > > - value = dev->desc ? dev->desc : ""; > > + sbuf_cpy(&sb, dev->desc ? dev->desc : ""); > > break; > > case DEVICE_SYSCTL_DRIVER: > > - value = dev->driver ? dev->driver->name : ""; > > + sbuf_cpy(&sb, dev->driver ? dev->driver->name : ""); > > break; > > case DEVICE_SYSCTL_LOCATION: > > - value = buf = malloc(1024, M_BUS, M_WAITOK | M_ZERO); > > - bus_child_location_str(dev, buf, 1024); > > + bus_child_location_sb(dev, &sb); > > break; > > case DEVICE_SYSCTL_PNPINFO: > > - value = buf = malloc(1024, M_BUS, M_WAITOK | M_ZERO); > > - bus_child_pnpinfo_str(dev, buf, 1024); > > + bus_child_pnpinfo_sb(dev, &sb); > > break; > > case DEVICE_SYSCTL_PARENT: > > - value = dev->parent ? dev->parent->nameunit : ""; > > + sbuf_cpy(&sb, dev->parent ? dev->parent->nameunit : ""); > > break; > > default: > > + sbuf_delete(&sb); > > return (EINVAL); > > } > > - error = SYSCTL_OUT_STR(req, value); > > - if (buf != NULL) > > - free(buf, M_BUS); > > + error = sbuf_finish(&sb); > > + sbuf_delete(&sb); > > return (error); > > } > > > > @@ -5464,13 +5461,13 @@ SYSCTL_PROC(_hw_bus, OID_AUTO, info, > CTLTYPE_STRUCT > > | > > static int > > sysctl_devices(SYSCTL_HANDLER_ARGS) > > { > > + struct sbuf sb; > > int *name = (int *)arg1; > > u_int namelen = arg2; > > int index; > > device_t dev; > > struct u_device *udev; > > int error; > > - char *walker, *ep; > > > > if (namelen != 2) > > return (EINVAL); > > @@ -5501,34 +5498,21 @@ sysctl_devices(SYSCTL_HANDLER_ARGS) > > udev->dv_devflags = dev->devflags; > > udev->dv_flags = dev->flags; > > udev->dv_state = dev->state; > > - walker = udev->dv_fields; > > - ep = walker + sizeof(udev->dv_fields); > > -#define CP(src) \ > > - if ((src) == NULL) \ > > - *walker++ = '\0'; \ > > - else { \ > > - strlcpy(walker, (src), ep - walker); \ > > - walker += strlen(walker) + 1; \ > > - } \ > > - if (walker >= ep) \ > > - break; > > - > > - do { > > - CP(dev->nameunit); > > - CP(dev->desc); > > - CP(dev->driver != NULL ? dev->driver->name : NULL); > > - bus_child_pnpinfo_str(dev, walker, ep - walker); > > - walker += strlen(walker) + 1; > > - if (walker >= ep) > > - break; > > - bus_child_location_str(dev, walker, ep - walker); > > - walker += strlen(walker) + 1; > > - if (walker >= ep) > > - break; > > - *walker++ = '\0'; > > - } while (0); > > -#undef CP > > - error = SYSCTL_OUT(req, udev, sizeof(*udev)); > > + sbuf_new(&sb, udev->dv_fields, sizeof(udev->dv_fields), > SBUF_FIXEDLEN); > > + sbuf_cat(&sb, dev->nameunit); > > + sbuf_putc(&sb, '\0'); > > + sbuf_cat(&sb, dev->desc); > > + sbuf_putc(&sb, '\0'); > > + sbuf_cat(&sb, dev->driver != NULL ? dev->driver->name : '\0'); > > + sbuf_putc(&sb, '\0'); > > + bus_child_pnpinfo_sb(dev, &sb); > > + sbuf_putc(&sb, '\0'); > > + bus_child_location_sb(dev, &sb); > > + sbuf_putc(&sb, '\0'); > > + error = sbuf_finish(&sb); > > + if (error == 0) > > + error = SYSCTL_OUT(req, udev, sizeof(*udev)); > > + sbuf_delete(&sb); > > free(udev, M_BUS); > > return (error); > > } > > > > > -- > Mateusz Guzik <mjguzik gmail.com> >
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