Messages in this thread | | | Subject | Re: [PATCH v3 3/4] lib: logic_pio: Reject accesses to unregistered CPU MMIO regions | From | John Garry <> | Date | Thu, 4 Apr 2019 17:52:35 +0100 |
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On 04/04/2019 17:41, Guenter Roeck wrote: > On Fri, Apr 05, 2019 at 12:00:01AM +0800, John Garry wrote: >> Currently when accessing logical indirect PIO addresses in >> logic_{in, out}{,s}, we first ensure that the region is registered. >> >> However, no such check exists for CPU MMIO regions. The CPU MMIO regions >> would be registered by the PCI host - when PCI_IOBASE is defined - in >> pci_register_io_range(). >> >> We have seen scenarios when systems which don't have a PCI host or, they >> do, and the PCI host probe fails, that certain devices attempts to still >> attempt to access PCI IO ports; examples are in [1] and [2]. >> >> And even though we should protect against this by ensuring the driver >> calls request_{muxed_}region(), some don't do this: >> >> root@(none)$ insmod hwmon/f71805f.ko >> Unable to handle kernel paging request at virtual address ffff7dfffee0002e >> Mem abort info: >> ESR = 0x96000046 >> Exception class = DABT (current EL), IL = 32 bits >> SET = 0, FnV = 0 >> EA = 0, S1PTW = 0 >> Data abort info: >> ISV = 0, ISS = 0x00000046 >> CM = 0, WnR = 1 >> swapper pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____) >> [ffff7dfffee0002e] pgd=000000000141c003, pud=000000000141d003, pmd=0000000000000000 >> Internal error: Oops: 96000046 [#1] PREEMPT SMP >> Modules linked in: f71805f(+) >> CPU: 20 PID: 2736 Comm: insmod Not tainted 5.1.0-rc1-00003-g6f1bfec2a620-dirty #99 >> Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon D05 IT21 Nemo 2.0 RC0 04/18/2018 >> pstate: 80000005 (Nzcv daif -PAN -UAO) >> pc : logic_outb+0x54/0xb8 >> lr : f71805f_find+0x2c/0x1b8 [f71805f] >> sp : ffff000025fbba90 >> x29: ffff000025fbba90 x28: ffff000008b944d0 >> x27: ffff000025fbbdf0 x26: 0000000000000100 >> x25: ffff801f8c270580 x24: ffff000011420000 >> x23: ffff000025fbbb3e x22: ffff000025fbbb40 >> x21: ffff000008b991b8 x20: 0000000000000087 >> x19: 000000000000002e x18: ffffffffffffffff >> x17: 0000000000000000 x16: 0000000000000000 >> x15: ffff00001127d6c8 x14: 0000000000000000 >> x13: 0000000000000000 x12: 0000000000000000 >> x11: 0000000000010820 x10: 0000841fdac40000 >> x9 : 0000000000000001 x8 : 0000000040000000 >> x7 : 0000000000210d00 x6 : 0000000000000000 >> x5 : ffff801fb6a46040 x4 : ffff841febeaeda0 >> x3 : 0000000000ffbffe x2 : ffff000025fbbb40 >> x1 : ffff7dfffee0002e x0 : ffff7dfffee00000 >> Process insmod (pid: 2736, stack limit = 0x(____ptrval____)) >> Call trace: >> logic_outb+0x54/0xb8 >> f71805f_find+0x2c/0x1b8 [f71805f] >> f71805f_init+0x38/0xe48 [f71805f] >> do_one_initcall+0x5c/0x198 >> do_init_module+0x54/0x1b0 >> load_module+0x1dc4/0x2158 >> __se_sys_init_module+0x14c/0x1e8 >> __arm64_sys_init_module+0x18/0x20 >> el0_svc_common+0x5c/0x100 >> el0_svc_handler+0x2c/0x80 >> el0_svc+0x8/0xc >> Code: d2bfdc00 f2cfbfe0 f2ffffe0 8b000021 (39000034) >> ---[ end trace 10ea80bde051bbfc ]--- >> root@(none)$ >> >> Note that the f71805f driver does not call request_{muxed_}region(), as it >> should. >>
Hi Guenter,
> ... which is the real problem, one that is not solved by this patch. This may > result in parallel and descructive accesses if there is another device on the > LPC bus, and another driver accessing that device. Personally I'd rather have > request_muxed_region() added to the f71805f driver.
Right, we should and will still fix f71805f. If you recall, I did have the f71805f fix in the v1 series, but you committed that it was orthogonal, so I decided to take it out of this work for now.
And even if we fix up f71805f and other known drivers which don't call request_muxed_region(), we still need to police against these rogue accesses, which is what this patch attempts to do.
Thanks, John
> > Guenter > >> This patch adds a check to ensure that the CPU MMIO region is registered >> prior to accessing the PCI IO ports. >> >> [1] https://lore.kernel.org/linux-pci/56F209A9.4040304@huawei.com >> [2] https://lore.kernel.org/linux-arm-kernel/e6995b4a-184a-d8d4-f4d4-9ce75d8f47c0@huawei.com/ >> >> This patch includes some other tidy-up. >> >> Signed-off-by: John Garry <john.garry@huawei.com> >> --- >> lib/logic_pio.c | 103 +++++++++++++++++++++++++++++++++++------------- >> 1 file changed, 75 insertions(+), 28 deletions(-) >> >> diff --git a/lib/logic_pio.c b/lib/logic_pio.c >> index 431cd8d99236..3d8d986e9dcb 100644 >> --- a/lib/logic_pio.c >> +++ b/lib/logic_pio.c >> @@ -193,95 +193,135 @@ unsigned long logic_pio_trans_cpuaddr(resource_size_t addr) >> >> #if defined(PCI_IOBASE) >> #if defined(CONFIG_INDIRECT_PIO) >> +#define INVALID_RANGE(range) \ >> + (!(range) || ((range)->flags == LOGIC_PIO_INDIRECT && !(range)->ops)) >> + >> #define BUILD_LOGIC_IO(bw, type) \ >> type logic_in##bw(unsigned long addr) \ >> { \ >> type ret = (type)~0; \ >> + struct logic_pio_hwaddr *range = find_io_range(addr); \ >> + \ >> + if (INVALID_RANGE(range)) { \ >> + WARN_ON_ONCE(1); \ >> + return ret; \ >> + } \ >> \ >> if (addr < MMIO_UPPER_LIMIT) { \ >> ret = read##bw(PCI_IOBASE + addr); \ >> } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \ >> - struct logic_pio_hwaddr *entry = find_io_range(addr); \ >> size_t sz = sizeof(type); \ >> + void *hostdata = range->hostdata; \ >> \ >> - if (entry && entry->ops) \ >> - ret = entry->ops->in(entry->hostdata, addr, sz);\ >> - else \ >> - WARN_ON_ONCE(1); \ >> + if (range->ops->in) \ >> + ret = range->ops->in(hostdata, addr, sz); \ >> } \ >> return ret; \ >> } \ >> \ >> -void logic_out##bw(type value, unsigned long addr) \ >> +void logic_out##bw(type val, unsigned long addr) \ >> { \ >> + struct logic_pio_hwaddr *range = find_io_range(addr); \ >> + \ >> + if (INVALID_RANGE(range)) { \ >> + WARN_ON_ONCE(1); \ >> + return; \ >> + } \ >> + \ >> if (addr < MMIO_UPPER_LIMIT) { \ >> - write##bw(value, PCI_IOBASE + addr); \ >> + write##bw(val, PCI_IOBASE + addr); \ >> } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \ >> - struct logic_pio_hwaddr *entry = find_io_range(addr); \ >> size_t sz = sizeof(type); \ >> + void *hostdata = range->hostdata; \ >> \ >> - if (entry && entry->ops) \ >> - entry->ops->out(entry->hostdata, \ >> - addr, value, sz); \ >> - else \ >> - WARN_ON_ONCE(1); \ >> + if (range->ops->out) \ >> + range->ops->out(hostdata, addr, val, sz); \ >> } \ >> } \ >> \ >> void logic_ins##bw(unsigned long addr, void *buf, unsigned int cnt) \ >> { \ >> + struct logic_pio_hwaddr *range = find_io_range(addr); \ >> + \ >> + if (INVALID_RANGE(range)) { \ >> + WARN_ON_ONCE(1); \ >> + return; \ >> + } \ >> + \ >> if (addr < MMIO_UPPER_LIMIT) { \ >> reads##bw(PCI_IOBASE + addr, buf, cnt); \ >> } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \ >> - struct logic_pio_hwaddr *entry = find_io_range(addr); \ >> size_t sz = sizeof(type); \ >> + void *hostdata = range->hostdata; \ >> \ >> - if (entry && entry->ops) \ >> - entry->ops->ins(entry->hostdata, \ >> - addr, buf, sz, cnt); \ >> - else \ >> - WARN_ON_ONCE(1); \ >> + if (range->ops->ins) \ >> + range->ops->ins(hostdata, addr, buf, sz, cnt); \ >> } \ >> - \ >> } \ >> \ >> void logic_outs##bw(unsigned long addr, const void *buf, \ >> unsigned int cnt) \ >> { \ >> + struct logic_pio_hwaddr *range = find_io_range(addr); \ >> + \ >> + if (INVALID_RANGE(range)) { \ >> + WARN_ON_ONCE(1); \ >> + return; \ >> + } \ >> + \ >> if (addr < MMIO_UPPER_LIMIT) { \ >> writes##bw(PCI_IOBASE + addr, buf, cnt); \ >> } else if (addr >= MMIO_UPPER_LIMIT && addr < IO_SPACE_LIMIT) { \ >> - struct logic_pio_hwaddr *entry = find_io_range(addr); \ >> size_t sz = sizeof(type); \ >> + void *hostdata = range->hostdata; \ >> \ >> - if (entry && entry->ops) \ >> - entry->ops->outs(entry->hostdata, \ >> - addr, buf, sz, cnt); \ >> - else \ >> - WARN_ON_ONCE(1); \ >> + if (range->ops->outs) \ >> + range->ops->outs(hostdata, addr, buf, sz, cnt); \ >> } \ >> } >> >> #else /* CONFIG_INDIRECT_PIO */ >> >> +#define INVALID_RANGE(range) (!(range)) >> + >> #define BUILD_LOGIC_IO(bw, type) \ >> type logic_in##bw(unsigned long addr) \ >> { \ >> type ret = (type)~0; \ >> + struct logic_pio_hwaddr *range = find_io_range(addr); \ >> + \ >> + if (INVALID_RANGE(range)) { \ >> + WARN_ON_ONCE(1); \ >> + return ret; \ >> + } \ >> \ >> if (addr < MMIO_UPPER_LIMIT) \ >> ret = read##bw(PCI_IOBASE + addr); \ >> return ret; \ >> } \ >> \ >> -void logic_out##bw(type value, unsigned long addr) \ >> +void logic_out##bw(type val, unsigned long addr) \ >> { \ >> + struct logic_pio_hwaddr *range = find_io_range(addr); \ >> + \ >> + if (INVALID_RANGE(range)) { \ >> + WARN_ON_ONCE(1); \ >> + return; \ >> + } \ >> + \ >> if (addr < MMIO_UPPER_LIMIT) \ >> - write##bw(value, PCI_IOBASE + addr); \ >> + write##bw(val, PCI_IOBASE + addr); \ >> } \ >> \ >> void logic_ins##bw(unsigned long addr, void *buf, unsigned int cnt) \ >> { \ >> + struct logic_pio_hwaddr *range = find_io_range(addr); \ >> + \ >> + if (INVALID_RANGE(range)) { \ >> + WARN_ON_ONCE(1); \ >> + return; \ >> + } \ >> + \ >> if (addr < MMIO_UPPER_LIMIT) \ >> reads##bw(PCI_IOBASE + addr, buf, cnt); \ >> } \ >> @@ -289,6 +329,13 @@ void logic_ins##bw(unsigned long addr, void *buf, unsigned int cnt) \ >> void logic_outs##bw(unsigned long addr, const void *buf, \ >> unsigned int cnt) \ >> { \ >> + struct logic_pio_hwaddr *range = find_io_range(addr); \ >> + \ >> + if (INVALID_RANGE(range)) { \ >> + WARN_ON_ONCE(1); \ >> + return; \ >> + } \ >> + \ >> if (addr < MMIO_UPPER_LIMIT) \ >> writes##bw(PCI_IOBASE + addr, buf, cnt); \ >> } >> -- >> 2.17.1 >> > > . >
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