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* xen: arm: fix build after libelf changes.4.3.0-rc5Ian Campbell2013-06-161-1/+3
| | | | | | | | | | | | | | | | ed65808a8ed4 "libelf: check all pointer accesses" caused: kernel.c: In function 'kernel_elf_load': kernel.c:162:18: error: 'struct elf_binary' has no member named 'dest' make[4]: *** [kernel.o] Error 1 The field is now called dest_base. We also need to populate dest_size. This fixes the build for me although have not tested it. I have a feeling that loading the kernel from an ELF file on ARM doesn't currently work anyway (everyone uses the zImage loader as far as I am aware). Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
* libxc: Better range check in xc_dom_alloc_segmentIan Jackson2013-06-141-1/+2
| | | | | | | | | | If seg->pfn is too large, the arithmetic in the range check might overflow, defeating the range check. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
* libxc: check blob size before proceeding in xc_dom_check_gzipMatthew Daley2013-06-141-0/+5
| | | | | | | | | | | | | This is part of the fix to a security issue, XSA-55. Signed-off-by: Matthew Daley <mattjd@gmail.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com> Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> v8: Add a comment explaining where the number 6 comes from. v6: This patch is new in v6 of the series.
* libxc: range checks in xc_dom_p2m_host and _guestIan Jackson2013-06-141-0/+4
| | | | | | | | | | | | | | | | | | | These functions take guest pfns and look them up in the p2m. They did no range checking. However, some callers, notably xc_dom_boot.c:setup_hypercall_page want to pass untrusted guest-supplied value(s). It is most convenient to detect this here and return INVALID_MFN. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Cc: Tim Deegan <tim@xen.org> Reviewed-by: George Dunlap <george.dunlap@eu.citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com> v6: Check for underflow too (thanks to Andrew Cooper).
* libxc: check return values from mallocIan Jackson2013-06-149-3/+58
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A sufficiently malformed input to libxc (such as a malformed input ELF or other guest-controlled data) might cause one of libxc's malloc() to fail. In this case we need to make sure we don't dereference or do pointer arithmetic on the result. Search for all occurrences of \b(m|c|re)alloc in libxc, and all functions which call them, and add appropriate error checking where missing. This includes the functions xc_dom_malloc*, which now print a message when they fail so that callers don't have to do so. The function xc_cpuid_to_str wasn't provided with a sane return value and has a pretty strange API, which now becomes a little stranger. There are no in-tree callers. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> v8: Move a check in xc_exchange_page to the previous patch (ie, remove it from this patch). v7: Add a missing check for a call to alloc_str. Add arithmetic overflow check in xc_dom_malloc. Coding style fix. v6: Fix a missed call `pfn_err = calloc...' in xc_domain_restore.c. Fix a missed call `new_pfn = xc_map_foreign_range...' in xc_offline_page.c v5: This patch is new in this version of the series.
* libxc: check failure of xc_dom_*_to_ptr, xc_map_foreign_rangeIan Jackson2013-06-147-0/+108
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The return values from xc_dom_*_to_ptr and xc_map_foreign_range are sometimes dereferenced, or subjected to pointer arithmetic, without checking whether the relevant function failed and returned NULL. Add an appropriate error check at every call site. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> v8: Add a missing check in xc_offline_page.c:xc_exchange_page, which was in the next patch in v7 of the series. Also improve the message. I think in this particular error case it may be that the results are a broken guest, but turning this from a possible host tools crash into a guest problem seems to solve the potential security problem. v7: Simplify an error DOMPRINTF to not use "load ? : ". Make DOMPRINTF allocation error messages consistent. Do not set elf->dest_pages in xc_dom_load_elf_kernel if xc_dom_seg_to_ptr_pages fails. v5: This patch is new in this version of the series.
* libxc: Add range checking to xc_dom_binloaderIan Jackson2013-06-141-2/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a simple binary image loader with its own metadata format. However, it is too careless with image-supplied values. Add the following checks: * That the image is bigger than the metadata table; otherwise the pointer arithmetic to calculate the metadata table location may yield undefined and dangerous values. * When clamping the end of the region to search, that we do not calculate pointers beyond the end of the image. The C specification does not permit this and compilers are becoming ever more determined to miscompile code when they can "prove" various falsehoods based on assertions from the C spec. * That the supplied image is big enough for the text we are allegedly copying from it. Otherwise we might have a read overrun and copy the results (perhaps a lot of secret data) into the guest. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: George Dunlap <george.dunlap@eu.citrix.com> v9: Use clearer code for calculating probe_end in find_table. v6: Add a missing `return -EINVAL' (Matthew Daley). Fix an error in the commit message (Matthew Daley). v5: This patch is new in this version of the series.
* libelf: abolish obsolete macrosIan Jackson2013-06-146-68/+44
| | | | | | | | | | | | | | | | Abolish ELF_PTRVAL_[CONST_]{CHAR,VOID}; change uses to elf_ptrval. Abolish ELF_HANDLE_DECL_NONCONST; change uses to ELF_HANDLE_DECL. Abolish ELF_OBSOLETE_VOIDP_CAST; simply remove all uses. No functional change. (Verified by diffing assembler output.) This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> v2: New patch.
* libelf: check loops for running awayIan Jackson2013-06-145-29/+135
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ensure that libelf does not have any loops which can run away indefinitely even if the input is bogus. (Grepped for \bfor, \bwhile and \bgoto in libelf and xc_dom_*loader*.c.) Changes needed: * elf_note_next uses the note's unchecked alleged length, which might wrap round. If it does, return ELF_MAX_PTRVAL (0xfff..fff) instead, which will be beyond the end of the section and so terminate the caller's loop. Also check that the returned psuedopointer is sane. * In various loops over section and program headers, check that the calculated header pointer is still within the image, and quit the loop if it isn't. * Some fixed limits to avoid potentially O(image_size^2) loops: - maximum length of strings: 4K (longer ones ignored totally) - maximum total number of ELF notes: 65536 (any more are ignored) * Check that the total program contents (text, data) we copy or initialise doesn't exceed twice the output image area size. * Remove an entirely useless loop from elf_xen_parse (!) * Replace a nested search loop in in xc_dom_load_elf_symtab in xc_dom_elfloader.c by a precomputation of a bitmap of referenced symtabs. We have not changed loops which might, in principle, iterate over the whole image - even if they might do so one byte at a time with a nontrivial access check function in the middle. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> v8: Fix the two loops in libelf-dominfo.c; the comment about PT_NOTE and SHT_NOTE wasn't true because the checks did "continue", not "break". Add a comment about elf_note_next's expectations of the caller's loop conditions (which most plausible callers will follow anyway). v5: Fix regression due to wrong image size loop limit calculation. Check return value from xc_dom_malloc. v4: Fix regression due to misplacement of test in elf_shdr_by_name (uninitialised variable). Introduce fixed limits. Avoid O(size^2) loops. Check returned psuedopointer from elf_note_next is correct. A few style fixes. v3: Fix a whitespace error. v2: BUGFIX: elf_shdr_by_name, elf_note_next: Reject new <= old, not just <. elf_shdr_by_name: Change order of checks to be a bit clearer. elf_load_bsdsyms: shdr loop check, improve chance of brokenness detection. Style fixes.
* libelf: use only unsigned integersIan Jackson2013-06-149-87/+105
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed integers have undesirable undefined behaviours on overflow. Malicious compilers can turn apparently-correct code into code with security vulnerabilities etc. So use only unsigned integers. Exceptions are booleans (which we have already changed) and error codes. We _do_ change all the chars which aren't fixed constants from our own text segment, but not the char*s. This is because it is safe to access an arbitrary byte through a char*, but not necessarily safe to convert an arbitrary value to a char. As a consequence we need to compile libelf with -Wno-pointer-sign. It is OK to change all the signed integers to unsigned because all the inequalities in libelf are in contexts where we don't "expect" negative numbers. In libelf-dominfo.c:elf_xen_parse we rename a variable "rc" to "more_notes" as it actually contains a note count derived from the input image. The "error" return value from elf_xen_parse_notes is changed from -1 to ~0U. grepping shows only one occurrence of "PRId" or "%d" or "%ld" in libelf and xc_dom_elfloader.c (a "%d" which becomes "%u"). This is part of the fix to a security issue, XSA-55. For those concerned about unintentional functional changes, the following rune produces a version of the patch which is much smaller and eliminates only non-functional changes: GIT_EXTERNAL_DIFF=.../unsigned-differ git-diff <before>..<after> where <before> and <after> are git refs for the code before and after this patch, and unsigned-differ is this shell script: #!/bin/bash set -e seddery () { perl -pe 's/\b(?:elf_errorstatus|elf_negerrnoval)\b/int/g' } path="$1" in="$2" out="$5" set +e diff -pu --label "$path~" <(seddery <"$in") --label "$path" <(seddery <"$out") rc=$? set -e if [ $rc = 1 ]; then rc=0; fi exit $rc Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Reviewed-by: George Dunlap <george.dunlap@eu.citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> v8: Use "?!?!" to express consternation instead of a ruder phrase. v5: Introduce ELF_NOTE_INVALID, instead of using a literal ~0U. v4: Fix regression in elf_round_up; use uint64_t here. v3: Changes to booleans split off into separate patch. v2: BUGFIX: Eliminate conversion to int of return from elf_xen_parse_notes. BUGFIX: Fix the one printf format thing which needs changing. Remove irrelevant change to constify note_desc.name in libelf-dominfo.c. In xc_dom_load_elf_symtab change one sizeof(int) to sizeof(unsigned). Do not change type of 2nd argument to memset. Provide seddery for easier review. Style fix.
* libelf: use C99 bool for booleansIan Jackson2013-06-146-21/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We want to remove uses of "int" because signed integers have undesirable undefined behaviours on overflow. Malicious compilers can turn apparently-correct code into code with security vulnerabilities etc. In this patch we change all the booleans in libelf to C99 bool, from <stdbool.h>. For the one visible libelf boolean in libxc's public interface we retain the use of int to avoid changing the ABI; libxc converts it to a bool for consumption by libelf. It is OK to change all values only ever used as booleans to _Bool (bool) because conversion from any scalar type to a _Bool works the same as the boolean test in if() or ?: and is always defined (C99 6.3.1.2). But we do need to check that all these variables really are only ever used that way. (It is theoretically possible that the old code truncated some 64-bit values to 32-bit ints which might become zero depending on the value, which would mean a behavioural change in this patch, but it seems implausible that treating 0x????????00000000 as false could have been intended.) This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: George Dunlap <george.dunlap@eu.citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> v3: Use <stdbool.h>'s bool (or _Bool) instead of defining elf_bool. Split this into a separate patch.
* libelf: Make all callers call elf_check_brokenIan Jackson2013-06-145-11/+58
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This arranges that if the new pointer reference error checking tripped, we actually get a message about it. In this patch these messages do not change the actual return values from the various functions: so pointer reference errors do not prevent loading. This is for fear that some existing kernels might cause the code to make these wild references, which would then break, which is not a good thing in a security patch. In xen/arch/x86/domain_build.c we have to introduce an "out" label and change all of the "return rc" beyond the relevant point into "goto out". This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Reviewed-by: George Dunlap <george.dunlap@eu.citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> v5: Fix two whitespace errors. v3.1: Add error check to xc_dom_parse_elf_kernel. Move check in xc_hvm_build_x86.c:setup_guest to right place. v2 was Acked-by: Ian Campbell <ian.campbell@citrix.com> v2 was Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> v2: Style fixes.
* libelf: Check pointer references in elf_is_elfbinaryIan Jackson2013-06-145-8/+13
| | | | | | | | | | | | | | | | | | | | | | elf_is_elfbinary didn't take a length parameter and could potentially access out of range when provided with a very short image. We only need to check the size is enough for the actual dereference in elf_is_elfbinary; callers are just using it to check the magic number and do their own checks (usually via the new elf_ptrval system) before dereferencing other parts of the header. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> v7: Add a comment about the limited function of elf_is_elfbinary. v2: Style fix. Fix commit message subject.
* libelf: check all pointer accessesIan Jackson2013-06-148-85/+312
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We change the ELF_PTRVAL and ELF_HANDLE types and associated macros: * PTRVAL becomes a uintptr_t, for which we provide a typedef elf_ptrval. This means no arithmetic done on it can overflow so the compiler cannot do any malicious invalid pointer arithmetic "optimisations". It also means that any places where we dereference one of these pointers without using the appropriate macros or functions become a compilation error. So we can be sure that we won't miss any memory accesses. All the PTRVAL variables were previously void* or char*, so the actual address calculations are unchanged. * ELF_HANDLE becomes a union, one half of which keeps the pointer value and the other half of which is just there to record the type. The new type is not a pointer type so there can be no address calculations on it whose meaning would change. Every assignment or access has to go through one of our macros. * The distinction between const and non-const pointers and char*s and void*s in libelf goes away. This was not important (and anyway libelf tended to cast away const in various places). * The fields elf->image and elf->dest are renamed. That proves that we haven't missed any unchecked uses of these actual pointer values. * The caller may fill in elf->caller_xdest_base and _size to specify another range of memory which is safe for libelf to access, besides the input and output images. * When accesses fail due to being out of range, we mark the elf "broken". This will be checked and used for diagnostics in a following patch. We do not check for write accesses to the input image. This is because libelf actually does this in a number of places. So we simply permit that. * Each caller of libelf which used to set dest now sets dest_base and dest_size. * In xc_dom_load_elf_symtab we provide a new actual-pointer value hdr_ptr which we get from mapping the guest's kernel area and use (checking carefully) as the caller_xdest area. * The STAR(h) macro in libelf-dominfo.c now uses elf_access_unsigned. * elf-init uses the new elf_uval_3264 accessor to access the 32-bit fields, rather than an unchecked field access (ie, unchecked pointer access). * elf_uval has been reworked to use elf_uval_3264. Both of these macros are essentially new in this patch (although they are derived from the old elf_uval) and need careful review. * ELF_ADVANCE_DEST is now safe in the sense that you can use it to chop parts off the front of the dest area but if you chop more than is available, the dest area is simply set to be empty, preventing future accesses. * We introduce some #defines for memcpy, memset, memmove and strcpy: - We provide elf_memcpy_safe and elf_memset_safe which take PTRVALs and do checking on the supplied pointers. - Users inside libelf must all be changed to either elf_mem*_unchecked (which are just like mem*), or elf_mem*_safe (which take PTRVALs) and are checked. Any unchanged call sites become compilation errors. * We do _not_ at this time fix elf_access_unsigned so that it doesn't make unaligned accesses. We hope that unaligned accesses are OK on every supported architecture. But it does check the supplied pointer for validity. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> v7: Remove a spurious whitespace change. v5: Use allow_size value from xc_dom_vaddr_to_ptr to set xdest_size correctly. If ELF_ADVANCE_DEST advances past the end, mark the elf broken. Always regard NULL allowable region pointers (e.g. dest_base) as invalid (since NULL pointers don't point anywhere). v4: Fix ELF_UNSAFE_PTR to work on 32-bit even when provided 64-bit values. Fix xc_dom_load_elf_symtab not to call XC_DOM_PAGE_SIZE unnecessarily if load is false. This was a regression. v3.1: Introduce a change to elf_store_field to undo the effects of the v3.1 change to the previous patch (the definition there is not compatible with the new types). v3: Fix a whitespace error. v2 was Acked-by: Ian Campbell <ian.campbell@citrix.com> v2: BUGFIX: elf_strval: Fix loop termination condition to actually work. BUGFIX: elf_strval: Fix return value to not always be totally wild. BUGFIX: xc_dom_load_elf_symtab: do proper check for small header size. xc_dom_load_elf_symtab: narrow scope of `hdr_ptr'. xc_dom_load_elf_symtab: split out uninit'd symtab.class ref fix. More comments on the lifetime/validity of elf-> dest ptrs etc. libelf.h: write "obsolete" out in full libelf.h: rename "dontuse" to "typeonly" and add doc comment elf_ptrval_in_range: Document trustedness of arguments. Style and commit message fixes.
* libelf: check nul-terminated strings properlyIan Jackson2013-06-144-11/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is not safe to simply take pointers into the ELF and use them as C pointers. They might not be properly nul-terminated (and the pointers might be wild). So we are going to introduce a new function elf_strval for safely getting strings. This will check that the addresses are in range and that there is a proper nul-terminated string. Of course it might discover that there isn't. In that case, it will be made to fail. This means that elf_note_name might fail, too. For the benefit of call sites which are just going to pass the value to a printf-like function, we provide elf_strfmt which returns "(invalid)" on failure rather than NULL. In this patch we introduce dummy definitions of these functions. We introduce calls to elf_strval and elf_strfmt everywhere, and update all the call sites with appropriate error checking. There is not yet any semantic change, since before this patch all the places where we introduce elf_strval dereferenced the value anyway, so it mustn't have been NULL. In future patches, when elf_strval is made able return NULL, when it does so it will mark the elf "broken" so that an appropriate diagnostic can be printed. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> v7: Change readnotes.c check to use two if statements rather than ||. v2: Fix coding style, in one "if" statement.
* tools/xcutils/readnotes: adjust print_l1_mfn_valid_noteIan Jackson2013-06-141-5/+6
| | | | | | | | | | | | | | | | | | | | Use the new PTRVAL macros and elf_access_unsigned in print_l1_mfn_valid_note. No functional change unless the input is wrong, or we are reading a file for a different endianness. Separated out from the previous patch because this change does produce a difference in the generated code. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com> v2: Split out into its own patch.
* libelf: introduce macros for memory access and pointer handlingIan Jackson2013-06-147-163/+312
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We introduce a collection of macros which abstract away all the pointer arithmetic and dereferences used for accessing the input ELF and the output area(s). We use the new macros everywhere. For now, these macros are semantically identical to the code they replace, so this patch has no functional change. elf_is_elfbinary is an exception: since it doesn't take an elf*, we need to handle it differently. In a future patch we will change it to take, and check, a length parameter. For now we just mark it with a fixme. That this patch has no functional change can be verified as follows: 0. Copy the scripts "comparison-generate" and "function-filter" out of this commit message. 1. Check out the tree before this patch. 2. Run the script ../comparison-generate .... ../before 3. Check out the tree after this patch. 4. Run the script ../comparison-generate .... ../after 5. diff --exclude=\*.[soi] -ruN before/ after/ |less Expect these differences: * stubdom/zlib-x86_64/ztest*.s2 The filename of this test file apparently contains the pid. * xen/common/version.s2 The xen build timestamp appears in two diff hunks. Verification that this is all that's needed: In a completely built xen.git, find * -name .*.d -type f | xargs grep -l libelf\.h Expect results in: xen/arch/x86: Checked above. tools/libxc: Checked above. tools/xcutils/readnotes: Checked above. tools/xenstore: Checked above. xen/common/libelf: This is the build for the hypervisor; checked in B above. stubdom: We have one stubdom which reads ELFs using our libelf, pvgrub, which is checked above. I have not done this verification for ARM. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> v7: Add uintptr_t cast to ELF_UNSAFE_PTR. Still verifies. Use git foo not git-foo in commit message verification script. v4: Fix elf_load_binary's phdr message to be correct on 32-bit. Fix ELF_OBSOLETE_VOIDP_CAST to work on 32-bit. Indent scripts in commit message. v3.1: Change elf_store_field to verify correctly on 32-bit. comparison-generate copes with Xen 4.1's lack of ./configure. v2: Use Xen style for multi-line comments. Postpone changes to readnotes.c:print_l1_mfn_valid_note. Much improved verification instructions with new script. Fixed commit message subject. -8<- comparison-generate -8<- #!/bin/bash # usage: # cd xen.git # .../comparison-generate OUR-CONFIG BUILD-RUNE-PREFIX ../before|../after # eg: # .../comparison-generate ~/work/.config 'schroot -pc64 --' ../before set -ex test $# = 3 || need-exactly-three-arguments our_config=$1 build_rune_prefix=$2 result_dir=$3 git clean -x -d -f cp "$our_config" . cat <<END >>.config debug_symbols=n CFLAGS += -save-temps END perl -i~ -pe 's/ -g / -g0 / if m/^CFLAGS/' xen/Rules.mk if [ -f ./configure ]; then $build_rune_prefix ./configure fi $build_rune_prefix make -C xen $build_rune_prefix make -C tools/include $build_rune_prefix make -C stubdom grub $build_rune_prefix make -C tools/libxc $build_rune_prefix make -C tools/xenstore $build_rune_prefix make -C tools/xcutils rm -rf "$result_dir" mkdir "$result_dir" set +x for f in `find xen tools stubdom -name \*.[soi]`; do mkdir -p "$result_dir"/`dirname $f` cp $f "$result_dir"/${f} case $f in *.s) ../function-filter <$f >"$result_dir"/${f}2 ;; esac done echo ok. -8<- -8<- function-filter -8<- #!/usr/bin/perl -w # function-filter # script for massaging gcc-generated labels to be consistent use strict; our @lines; my $sedderybody = "sub seddery () {\n"; while (<>) { push @lines, $_; if (m/^(__FUNCTION__|__func__)\.(\d+)\:/) { $sedderybody .= " s/\\b$1\\.$2\\b/__XSA55MANGLED__$1.$./g;\n"; } } $sedderybody .= "}\n1;\n"; eval $sedderybody or die $@; foreach (@lines) { seddery(); print or die $!; } -8<-
* libelf/xc_dom_load_elf_symtab: Do not use "syms" uninitialisedIan Jackson2013-06-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | xc_dom_load_elf_symtab (with load==0) calls elf_round_up, but it mistakenly used the uninitialised variable "syms" when calculating dom->bsd_symtab_start. This should be a reference to "elf". This change might have the effect of rounding the value differently. Previously if the uninitialised value (a single byte on the stack) was ELFCLASS64 (ie, 2), the alignment would be to 8 bytes, otherwise to 4. However, the value is calculated from dom->kernel_seg.vend so this could only make a difference if that value wasn't already aligned to 8 bytes. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com> v2: Split this change into its own patch for proper review.
* libelf: move include of <asm/guest_access.h> to top of fileIan Jackson2013-06-141-1/+4
| | | | | | | | | | | | | | | | | | | | libelf-loader.c #includes <asm/guest_access.h>, when being compiled for Xen. Currently it does this in the middle of the file. Move this #include to the top of the file, before libelf-private.h. This is necessary because in forthcoming patches we will introduce private #defines of memcpy etc. which would interfere with definitions in headers #included from guest_access.h. No semantic or functional change in this patch. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com>
* libelf: abolish elf_sval and elf_access_signedIan Jackson2013-06-142-39/+0
| | | | | | | | | | | These are not used anywhere. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com>
* libelf: add `struct elf_binary*' parameter to elf_load_imageIan Jackson2013-06-141-3/+5
| | | | | | | | | | | | | | | The meat of this function is going to need a copy of the elf pointer, in forthcoming patches. No functional change in this patch. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com>
* libxc: Fix range checking in xc_dom_pfn_to_ptr etc.Ian Jackson2013-06-144-5/+38
| | | | | | | | | | | | | | | | | | | | | * Ensure that xc_dom_pfn_to_ptr (when called with count==0) does not return a previously-allocated block which is entirely before the requested pfn (!) * Provide a version of xc_dom_pfn_to_ptr, xc_dom_pfn_to_ptr_retcount, which provides the length of the mapped region via an out parameter. * Change xc_dom_vaddr_to_ptr to always provide the length of the mapped region and change the call site in xc_dom_binloader.c to check it. The call site in xc_dom_load_elf_symtab will be corrected in a forthcoming patch, and for now ignores the returned length. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> v5: This patch is new in v5 of the series.
* libxc: introduce xc_dom_seg_to_ptr_pagesIan Jackson2013-06-141-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | | Provide a version of xc_dom_seg_to_ptr which returns the number of guest pages it has actually mapped. This is useful for callers who want to do range checking; we will use this later in this series. This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com> v7: xc_dom_seg_to_ptr_pages now always expects pages_out!=NULL. (It seems silly to have it tolerate NULL when all the real callers pass non-NULL and there's a version which doesn't need pages_out anyway. Fix the call in xc_dom_seg_to_ptr to have a dummy pages for pages_out.) v5: xc_dom_seg_to_ptr_pages sets *pages_out=0 if it returns NULL. v4 was: Acked-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
* libelf: abolish libelf-relocate.cIan Jackson2013-06-142-373/+1
| | | | | | | | | | | | | | | | | This file is not actually used. It's not built in Xen's instance of libelf; in libxc's it's built but nothing in it is called. Do not compile it in libxc, and delete it. This reduces the amount of work we need to do in forthcoming patches to libelf (particularly since as libelf-relocate.c is not used it is probably full of bugs). This is part of the fix to a security issue, XSA-55. Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Chuck Anderson <chuck.anderson@oracle.com>
* Update QEMU_UPSTREAM_REVISIONIan Jackson2013-06-141-1/+1
| | | | Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
* xen/arm: Use the right GICD register to initialize IRQs routingJulien Grall2013-06-131-1/+1
| | | | | | | | | Currently IRQs routing is initialized to the wrong register and overwrites interrupt configuration register (ICFGRn). Reported-by: Sander Bogaert <sander.bogaert@elis.ugent.be> Signed-off-by: Julien Grall <julien.grall@linaro.org> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* xen/arm: define PAGE_HYPERVISOR as WRITEALLOCStefano Stabellini2013-06-131-1/+1
| | | | | | | | Use stage 1 attribute indexes for PAGE_HYPERVISOR, the appriopriate one for normal memory hypervisor mappings in Xen is WRITEALLOC. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* xen/arm64: fix stack dump in show_traceIan Campbell2013-06-131-25/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On aarch64 the frame pointer points to the next frame pointer and the return address is the previous stack slot (so below on the downward growing stack, therefore above in memory): |<RETURN ADDR> ^addresses grow up FP -> |<NEXT FP> | | | v | stack grows down. This is contrary to aarch32 where the frame pointer points to the return address and the next frame pointer is the next stack slot (so above on the downward growing stack, below in memory): FP -> |<RETURN ADDR> ^addresses grow up |<NEXT FP> | | | v | stack grows down. In addition print out LR as part of the trace, since it may contain the penultimate return address e.g. if the ultimate function is a leaf function. Lastly nuke some unnecessary braces. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
* tmem: Don't use map_domain_page for long-life-time pagesKonrad Rzeszutek Wilk2013-06-131-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When using tmem with Xen 4.3 (and debug build) we end up with: (XEN) Xen BUG at domain_page.c:143 (XEN) ----[ Xen-4.3-unstable x86_64 debug=y Not tainted ]---- (XEN) CPU: 3 (XEN) RIP: e008:[<ffff82c4c01606a7>] map_domain_page+0x61d/0x6e1 .. (XEN) Xen call trace: (XEN) [<ffff82c4c01606a7>] map_domain_page+0x61d/0x6e1 (XEN) [<ffff82c4c01373de>] cli_get_page+0x15e/0x17b (XEN) [<ffff82c4c01377c4>] tmh_copy_from_client+0x150/0x284 (XEN) [<ffff82c4c0135929>] do_tmem_put+0x323/0x5c4 (XEN) [<ffff82c4c0136510>] do_tmem_op+0x5a0/0xbd0 (XEN) [<ffff82c4c022391b>] syscall_enter+0xeb/0x145 (XEN) A bit of debugging revealed that the map_domain_page and unmap_domain_page are meant for short life-time mappings. And that those mappings are finite. In the 2 VCPU guest we only have 32 entries and once we have exhausted those we trigger the BUG_ON condition. The two functions - tmh_persistent_pool_page_[get,put] are used by the xmem_pool when xmem_pool_[alloc,free] are called. These xmem_pool_* function are wrapped in macro and functions - the entry points are via: tmem_malloc and tmem_page_alloc. In both cases the users are in the hypervisor and they do not seem to suffer from using the hypervisor virtual addresses. Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* x86: fix map_domain_page() last resort fallbackJan Beulich2013-06-131-5/+5
| | | | | | | | | | | | | | | | | | Guests with vCPU count not divisible by 4 have unused bits in the last word of their inuse bitmap, and the garbage collection code therefore would get mislead believing that some entries were actually recoverable for use. Also use an earlier established local variable in mapcache_vcpu_init() instead of re-calculating the value (noticed while investigating the generally better option of setting those overhanging bits once during setup - this didn't work out in a simple enough fashion because the mapping getting established there isn't in the current address space, and hence the bitmap isn't directly accessible there). Reported-by: Konrad Wilk <konrad.wilk@oracle.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Keir Fraser <keir@xen.org>
* x86: drop setup_idle_pagetable()Jan Beulich2013-06-123-10/+0
| | | | | | | | | | | With vcpu->domain->arch.perdomain_l3_pg no longer getting set up for the idle domain, this creates an invalid L4 entry (due to translating a NULL struct page_info pointer to a physical address). Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Keir Fraser <keir@xen.org> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
* docs: Make note for the scheduler "cap" option warning about power ↵George Dunlap2013-06-123-0/+39
| | | | | | | | | management effects Suggested-by: Massimo Canonico <mex@di.unipmn.it> Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com> Reviewed-by: Dario Faggioli <dario.faggioli@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* libxl: add LIBXL_HAVE_<foo> for outstanding_pages and outstanding_memkbDario Faggioli2013-06-121-0/+18
| | | | | | | | | | | | Commits d0782481 ("xl: export 'outstanding_pages' value from xcinfo") and bec8f17e ("xen: Remove the XENMEM_get_oustanding_pages and provide the data via xc_phys_info") added these two fields in libxl_physinfo and in libxl_dominfo, respectively, but did not include the needed LIBXL_HAVE_<foo> runes. Adding them. Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
* flask/policy: device model stubdom fixesDaniel De Graaf2013-06-121-1/+1
| | | | | | | | | This fixes framebuffer support for device model stubdoms after 3f28d007 which added the target_hack permission but did not allow the permission to the stubdom it was created for. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* io/ring.h: drop unused and broken *_RING_ATTACH() macrosJan Beulich2013-06-121-15/+0
| | | | | | | | | | Initializing r*_prod_pvt and r*_cons from independent shared ring fields is broken, as other macros in this header rely on them being coupled. Furthermore using the backend variant would also imply a security vulnerability. Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Keir Fraser <keir@xen.org>
* io/ring.h: new macro to detect whether there are too many requests on the ringJan Beulich2013-06-121-0/+4
| | | | | | | | | | | | | | Backends may need to protect themselves against an insane number of produced requests stored by a frontend, in case they iterate over requests until reaching the req_prod value. There can't be more requests on the ring than the difference between produced requests and produced (but possibly not yet published) responses. This is a more strict alternative to a patch previously posted by Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>. Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Keir Fraser <keir@xen.org>
* x86/HVM: fix initialization of wallclock time for PVHVM on migrationRoger Pau Monné2013-06-121-19/+14
| | | | | | | | | | | | | | | Call update_domain_wallclock_time on hvm_latch_shinfo_size even if the bitness of the guest has already been set, this fixes the problem with the wallclock not being set for PVHVM guests on resume from migration. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Clean up the resulting code and retain the (slightly adjusted) original comment. Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Keir Fraser <keir@xen.org>
* x86/HVM: fix x2APIC APIC_ID read emulationZhenguo Wang2013-06-111-3/+20
| | | | | | | | | | | | | | | | | | APIC and x2APIC have different format for APIC_ID register. Need translation. Signed-off-by: Zhenguo Wang <wangzhenguo@huawei.com> Signed-off-by: Xiaowei Yang <xiaowei.yang@huawei.com> Convert code to use switch(), fixing coding style issue at once, and use GET_xAPIC_ID() on the value read instead of VLAPIC_ID() (reading the field again). In the course of this also properly reject both read and writes on the non-existing MSR corresponding to APIC_ICR2. Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Keir Fraser <keir@xen.org>
* gnttab: drop unused GNTCOPY_can_fail4.3.0-rc4Jan Beulich2013-06-101-2/+0
| | | | | Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Keir Fraser <keir@xen.org>
* Revert "irq: Add extra debugging to help track down why an assertion is failing"Jan Beulich2013-06-101-15/+1
| | | | | | | | | | | | | This reverts commits 2ae8b9173fb2388af6514c730d620ed5f450bc34 and 98e10364bde098e12104caa4f566b17d05f8b791. This was never reported to be hit, and we assume to have taken care of the problem by excluding legacy IRQs from the IRQ move cleanup logic. Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
* AMD/IOMMU: revert "SR56x0 Erratum 64 - Reset all head & tail pointers"Jan Beulich2013-06-051-19/+6
| | | | | | | | | | The code this patch added is redundant with already present code in set_iommu_{command_buffer,{event,ppr}_log}_control(). Just switch those ones from using writel() to writeq() for consistency. Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
* x86/vtsc: update vcpu_time in hvm_set_guest_timeRoger Pau Monné2013-06-051-1/+13
| | | | | | | | | | | When using a vtsc, hvm_set_guest_time changes hvm_vcpu.stime_offset, which is used in the vcpu time structure to calculate the tsc_timestamp, so after updating stime_offset we need to propagate the change to vcpu_time in order for the guest to get the right time if using the PV clock. Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: George Dunlap <george.dunlap@eu.citrix.com>
* x86: fix XCR0 handlingJan Beulich2013-06-049-55/+69
| | | | | | | | | | | | | | - both VMX and SVM ignored the ECX input to XSETBV - both SVM and VMX used the full 64-bit RAX when calculating the input mask to XSETBV - faults on XSETBV did not get recovered from Also consolidate the handling for PV and HVM into a single function, and make the per-CPU variable "xcr0" static to xstate.c. Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Keir Fraser <keir@xen.org> Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
* x86: preserve FPU selectors for 32-bit guest codeJan Beulich2013-06-045-60/+191
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Doing {,F}X{SAVE,RSTOR} unconditionally with 64-bit operand size leads to the selector values associated with the last instruction/data pointers getting lost. This, besides being inconsistent and not compatible with native hardware behavior especially for 32-bit guests, leads to bug checks in 32-bit Windows when running with "Driver verifier" (see e.g. http://support.microsoft.com/kb/244617). In a first try I made the code figure out the current guest mode, but that has the disadvantage of only taking care of the issue when the guest executes in the mode for which the state currently is (i.e. namely not in the case of a 64-bit guest running a 32-bit application, but being in kernle [64-bit] mode). The solution presented here is to conditionally execute an auxiliary FNSTENV and use the selectors from there. In either case the determined word size gets stored in the last byte of the FPU/SSE save area, which is available for software use (and I verified is being cleared to zero by all versions of Xen, i.e. will not present a problem when migrating guests from older to newer hosts), and evaluated for determining the operand size {,F}XRSTOR is to be issued with. Note that I did check whether using a second FXSAVE or a partial second XSAVE would be faster than FNSTENV - neither on my Westmere (FXSAVE) nor on my Romley (XSAVE) they are. I was really tempted to use branches into the middle of instructions (i.e. past the REX64 prefixes) here, as that would have allowed to collapse the otherwise identical fault recovery blocks. I stayed away from doing so just because I expect others to dislike such slightly subtle/tricky code. Reported-by: Ben Guthro <Benjamin.Guthro@citrix.com> Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Keir Fraser <keir@xen.org> Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
* x86/xsave: properly check guest input to XSETBVJan Beulich2013-06-041-0/+5
| | | | | | | | | | Other than the HVM emulation path, the PV case so far failed to check that YMM state requires SSE state to be enabled, allowing for a #GP to occur upon passing the inputs to XSETBV inside the hypervisor. This is CVE-2013-2078 / XSA-54. Signed-off-by: Jan Beulich <jbeulich@suse.com>
* x86/xsave: recover from faults on XRSTORJan Beulich2013-06-042-5/+20
| | | | | | | | | | | | | | Just like FXRSTOR, XRSTOR can raise #GP if bad content is being passed to it in the memory block (i.e. aspects not under the control of the hypervisor, other than e.g. proper alignment of the block). Also correct the comment explaining why FXRSTOR needs exception recovery code to not wrongly state that this can only be a result of the control tools passing a bad image. This is CVE-2013-2077 / XSA-53. Signed-off-by: Jan Beulich <jbeulich@suse.com>
* x86/xsave: fix information leak on AMD CPUsJan Beulich2013-06-041-0/+15
| | | | | | | | | | | | | | | | | | | | | | | Just like for FXSAVE/FXRSTOR, XSAVE/XRSTOR also don't save/restore the last instruction and operand pointers as well as the last opcode if there's no pending unmasked exception (see CVE-2006-1056 and commit 9747:4d667a139318). While the FXSR solution sits in the save path, I prefer to have this in the restore path because there the handling is simpler (namely in the context of the pending changes to properly save the selector values for 32-bit guest code). Also this is using FFREE instead of EMMS, as it doesn't seem unlikely that in the future we may see CPUs with x87 and SSE/AVX but no MMX support. The goal here anyway is just to avoid an FPU stack overflow. I would have preferred to use FFREEP instead of FFREE (freeing two stack slots at once), but AMD doesn't document that instruction. This is CVE-2013-2076 / XSA-52. Signed-off-by: Jan Beulich <jbeulich@suse.com> Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
* x86/MCE: disable if MCE banks are not presentAravindh Puthiyaparambil2013-06-031-1/+8
| | | | | | | | | | | | | | | | | When booting Xen on VMware ESX 5.1 and Workstation 9, you hit a GPF during MCE initialization. The culprit is line 631 in set_poll_bankmask(): bitmap_copy(mb->bank_map, mca_allbanks->bank_map, nr_mce_banks); What is happening is that in mca_cap_init(), nr_mce_banks is being set to 0. This causes the allocation of bank_map to be set to ZERO_BLOCK_PTR which is the return value for zero-size allocation by xzalloc_array()/_xmalloc(). This results in the bitmap_copy() to fail disastrously. The following patch fixes this issue. Signed-off-by: Aravindh Puthiyaparambil <aravindp@cisco.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Christoph Egger <chegger@amazon.de>
* tools/libxl: fix array subscript has type 'char'Christoph Egger2013-05-311-1/+1
| | | | Signed-off-by: Christoph Egger <chegger@amazon.de>
* blkif.h: Document the physical-sector-size extensionStefan Bader2013-05-311-4/+10
| | | | Signed-off-by: Stefan Bader <stefan.bader@canonical.com>