From f4661d293eb2d01dfc742982761a36fafe456d46 Mon Sep 17 00:00:00 2001 From: Jacek Tomaka Date: Sat, 25 Aug 2018 11:50:39 +0800 Subject: x86/microcode: Make revision and processor flags world-readable The microcode revision is already readable for non-root users via /proc/cpuinfo. Thus, there's no reason to keep the same information readable by root only in /sys/devices/system/cpu/cpuX/microcode/. Make .../processor_flags world-readable too, while at it. Reported-by: Tim Burgess Signed-off-by: Jacek Tomaka Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Link: http://lkml.kernel.org/r/20180825035039.14409-1-jacekt@dugeo.com --- arch/x86/kernel/cpu/microcode/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c index b9bc8a1a584e..2637ff09d6a0 100644 --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -666,8 +666,8 @@ static ssize_t pf_show(struct device *dev, } static DEVICE_ATTR_WO(reload); -static DEVICE_ATTR(version, 0400, version_show, NULL); -static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL); +static DEVICE_ATTR(version, 0444, version_show, NULL); +static DEVICE_ATTR(processor_flags, 0444, pf_show, NULL); static struct attribute *mc_default_attrs[] = { &dev_attr_version.attr, -- cgit v1.2.3-55-g7522 From d2266bbfa9e3e32e3b642965088ca461bd24a94f Mon Sep 17 00:00:00 2001 From: Feng Tang Date: Wed, 3 Oct 2018 00:49:21 +0800 Subject: x86/earlyprintk: Add a force option for pciserial device The "pciserial" earlyprintk variant helps much on many modern x86 platforms, but unfortunately there are still some platforms with PCI UART devices which have the wrong PCI class code. In that case, the current class code check does not allow for them to be used for logging. Add a sub-option "force" which overrides the class code check and thus the use of such device can be enforced. [ bp: massage formulations. ] Suggested-by: Borislav Petkov Signed-off-by: Feng Tang Signed-off-by: Borislav Petkov Cc: "H. Peter Anvin" Cc: "Stuart R . Anderson" Cc: Bjorn Helgaas Cc: David Rientjes Cc: Feng Tang Cc: Frederic Weisbecker Cc: Greg Kroah-Hartman Cc: H Peter Anvin Cc: Ingo Molnar Cc: Jiri Kosina Cc: Jonathan Corbet Cc: Kai-Heng Feng Cc: Kate Stewart Cc: Konrad Rzeszutek Wilk Cc: Peter Zijlstra Cc: Philippe Ombredanne Cc: Thomas Gleixner Cc: Thymo van Beers Cc: alan@linux.intel.com Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/20181002164921.25833-1-feng.tang@intel.com --- Documentation/admin-guide/kernel-parameters.txt | 6 ++++- arch/x86/kernel/early_printk.c | 29 ++++++++++++++++--------- 2 files changed, 24 insertions(+), 11 deletions(-) (limited to 'arch/x86') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 92eb1f42240d..34e6800dea0e 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1063,7 +1063,7 @@ earlyprintk=serial[,0x...[,baudrate]] earlyprintk=ttySn[,baudrate] earlyprintk=dbgp[debugController#] - earlyprintk=pciserial,bus:device.function[,baudrate] + earlyprintk=pciserial[,force],bus:device.function[,baudrate] earlyprintk=xdbc[xhciController#] earlyprintk is useful when the kernel crashes before @@ -1095,6 +1095,10 @@ The sclp output can only be used on s390. + The optional "force" to "pciserial" enables use of a + PCI device even when its classcode is not of the + UART class. + edac_report= [HW,EDAC] Control how to report EDAC event Format: {"on" | "off" | "force"} on: enable EDAC to report H/W event. May be overridden diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c index 5e801c8c8ce7..374a52fa5296 100644 --- a/arch/x86/kernel/early_printk.c +++ b/arch/x86/kernel/early_printk.c @@ -213,8 +213,9 @@ static unsigned int mem32_serial_in(unsigned long addr, int offset) * early_pci_serial_init() * * This function is invoked when the early_printk param starts with "pciserial" - * The rest of the param should be ",B:D.F,baud" where B, D & F describe the - * location of a PCI device that must be a UART device. + * The rest of the param should be "[force],B:D.F,baud", where B, D & F describe + * the location of a PCI device that must be a UART device. "force" is optional + * and overrides the use of an UART device with a wrong PCI class code. */ static __init void early_pci_serial_init(char *s) { @@ -224,17 +225,23 @@ static __init void early_pci_serial_init(char *s) u32 classcode, bar0; u16 cmdreg; char *e; + int force = 0; - - /* - * First, part the param to get the BDF values - */ if (*s == ',') ++s; if (*s == 0) return; + /* Force the use of an UART device with wrong class code */ + if (!strncmp(s, "force,", 6)) { + force = 1; + s += 6; + } + + /* + * Part the param to get the BDF values + */ bus = (u8)simple_strtoul(s, &e, 16); s = e; if (*s != ':') @@ -253,7 +260,7 @@ static __init void early_pci_serial_init(char *s) s++; /* - * Second, find the device from the BDF + * Find the device from the BDF */ cmdreg = read_pci_config(bus, slot, func, PCI_COMMAND); classcode = read_pci_config(bus, slot, func, PCI_CLASS_REVISION); @@ -264,8 +271,10 @@ static __init void early_pci_serial_init(char *s) */ if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) && (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) || - (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */ - return; + (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */ { + if (!force) + return; + } /* * Determine if it is IO or memory mapped @@ -289,7 +298,7 @@ static __init void early_pci_serial_init(char *s) } /* - * Lastly, initialize the hardware + * Initialize the hardware */ if (*s) { if (strcmp(s, "nocfg") == 0) -- cgit v1.2.3-55-g7522