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* libxc: add xc_domain_set_max_evtchn()David Vrabel2013-10-142-0/+23
| | | | | | | | | Add xc_domain_set_max_evtchn(), a wrapper around the DOMCTL_set_max_evtchn hypercall. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Keir Fraser <keir@xen.org>
* tools/migrate: Fix regression when migrating from older version of XenAndrew Cooper2013-10-103-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | Commit 00a4b65f8534c9e6521eab2e6ce796ae36037774 Sep 7 2010 "libxc: provide notification of final checkpoint to restore end" broke migration from any version of Xen using tools from prior to that commit Older tools have no idea about an XC_SAVE_ID_LAST_CHECKPOINT, causing newer tools xc_domain_restore() to start reading the qemu save record, as ctx->last_checkpoint is 0. The failure looks like: xc: error: Max batch size exceeded (1970103633). Giving up. where 1970103633 = 0x756d6551 = *(uint32_t*)"Qemu" With this fix in place, the behaviour for normal migrations is reverted to how it was before the regression; the migration is considered non-checkpointed right from the start. A XC_SAVE_ID_LAST_CHECKPOINT chunk seen in the migration stream is a nop. For checkpointed migrations the behaviour is unchanged. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Ian Campbell <Ian.Campbell@citrix.com> CC: Ian Jackson <Ian.Jackson@eu.citrix.com> Acked-by: Shriram Rajagopalan <rshriram@cs.ubc.ca> (Remus bits)
* libxc: add LZ4 decompression supportJan Beulich2013-10-074-1/+157
| | | | | | | | | | | Since there's no shared or static library to link against, this simply re-uses the hypervisor side code. However, I only audited the code added here for possible security issues, not the referenced code in the hypervisor tree. Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Keir Fraser <keir@xen.org> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* libxc: only munmap when something has actually been mapped in change_pteMatthew Daley2013-10-031-3/+3
| | | | | | Coverity-ID: 1055269 signed-off-by: Matthew Daley <mattjd@gmail.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* libxc: fix memory leak in load_p2m_frame_list error handlingMatthew Daley2013-09-251-0/+1
| | | | | | Coverity-ID: 1055885 Signed-off-by: Matthew Daley <mattjd@gmail.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* libxc: introduce xc_map_domain_meminfo (and xc_unmap_domain_meminfo)Dario Faggioli2013-09-134-155/+183
| | | | | | | | | | | | | And use it in xc_exchange_page(). This is basically because the following change need something really similar to the set of steps that are here abstracted in these two functions. Despite of the change in the interface and in the signature of some functions, this is pure code motion. No functional changes involved. Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* libxc: allow for ctxt to be NULL in xc_vcpu_setcontextDario Faggioli2013-09-131-6/+0
| | | | | | | | | Since, as can be seen in xen/common/domctl.c, that is legitimate (it results in Xen calling vcpu_reset() on the vcpu). Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* libxc: use xc_vcpu_getinfo() instead of calling do_domctl()Dario Faggioli2013-09-133-18/+14
| | | | | | | | | The wrapper is there already, so better use it in place of all the stuff required to issue a call to do_domctl() for XEN_DOMCTL_getdomaininfo. Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* libxc: use xc_vcpu_setcontext() instead of calling do_domctl()Dario Faggioli2013-09-132-15/+5
| | | | | | | | | | The wrapper is there already, so better use it in place of all the stuff required to issue a call to do_domctl() for XEN_DOMCTL_setvcpucontext. Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* libxc: introduce xc_domain_get_guest_width()Dario Faggioli2013-09-139-72/+45
| | | | | | | | | | | | | | As a wrapper to XEN_DOMCTL_get_address_size, and use it wherever the call was being issued directly via do_domctl(), saving quite some line of code. Actually, the function returns the guest width in bytes, rather than directly what XEN_DOMCTL_get_address_size provides (which is a number of bits), since that is what it is useful almost everywhere. Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* libxc/x86: fix page table creation for huge guestsJan Beulich2013-09-121-8/+16
| | | | | | | | | | | The switch-over logic from one page directory to the next was wrong; it needs to be deferred until we actually reach the last page within a given region, instead of being done when the last entry of a page directory gets started with. Signed-off-by: Jan Beulich <jbeulich@suse.com> Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
* libxc/pm: Fix NULL pointer checks.Andrew Cooper2013-09-101-7/+7
| | | | | | | | | | | | | | | | Discovered by Coverity, CIDs 1054968 1054969 1054970 1054971 1054972 1054973 10549704 This was broken by c/s 5cc436c1d2b3b0 which did a blanket change of 'int xc_handle' -> 'xc_interface *xch'. The types got updated, but error conditions were left as-were. (I suspect some sed was involved originally) Also while playing around in this area, fix up some of the bracketing style to match the Xen coding style. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: Ian Campbell <Ian.Campbell@citrix.com> CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
* xen: only expose start_info on architectures which have a PV boot pathIan Campbell2013-08-201-3/+2
| | | | | | | | | Most of this struct is PV MMU specific and it is not used on ARM at all. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Jan Beulich <JBeulich@suse.com> Acked-by: Keir Fraser <keir@xen.org> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
* libxc: silence HVM domain creation messagesMatthew Daley2013-08-201-2/+2
| | | | | | | | | | | There's no need for xl to output these messages on HVM domain creation to stderr by default. Change their loglevels from XTL_INFO to XTL_DETAIL; then the messages output by xl are the same as those for PV domain creation. These now-silenced messages can still be seen using verbose (-v) mode. Signed-off-by: Matthew Daley <mattjd@gmail.com>
* libxc: xc_evtchn_open does not return -1 on error.Vincent Bernardoff2013-06-281-2/+2
| | | | | Signed-off-by: Vincent Bernardoff <vincent.bernardoff@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* tools/libxc: Fix memory leaks in xc_domain_save()Andrew Cooper2013-06-261-0/+9
| | | | | | | | Introduces outbuf_free() to mirror the currently existing outbuf_init(). Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: George Dunlap <george.dunlap@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* libxc: Fix guest boot on ARM after XSA-55Julien Grall2013-06-262-4/+7
| | | | | | | | XSA-55 has exposed errors for guest creation on ARM: - domain virt_base was not defined; - xc_dom_alloc_segment allocates pfn from 0 instead of the RAM base address. Signed-off-by: Julien Grall <julien.grall@linaro.org>
* tools/libxc: Fix memory leaks in xc_domain_restore()Andrew Cooper2013-06-241-0/+3
| | | | | | Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Acked-by: George Dunlap <george.dunlap@eu.citrix.com> (re 4.3 release) Acked-by: Ian Jackson <ian.jackson@eu.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 Jackson2013-06-141-4/+4
| | | | | | | | | | | | | | | | 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 Jackson2013-06-141-9/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Jackson2013-06-143-24/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Jackson2013-06-141-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Jackson2013-06-142-4/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Jackson2013-06-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | 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 Jackson2013-06-142-11/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: introduce macros for memory access and pointer handlingIan Jackson2013-06-142-16/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* 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 Jackson2013-06-141-1/+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>
* fix XSA-46 regression with xend/xmJan Beulich2013-05-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The hypervisor side changes for XSA-46 require the tool stack to now always map the guest pIRQ before granting access permission to the underlying host IRQ (GSI). This in particular requires that pciif.py no longer can skip this step (assuming qemu would do it) for HVM guests. This in turn exposes, however, an inconsistency between xend and qemu: The former wants to always establish 1:1 mappings between pIRQ and host IRQ (for non-MSI only of course), while the latter always wants to allocate an arbitrary mapping. Since the whole tool stack obviously should always agree on the mapping model, make libxc enforce the 1:1 mapping as the more natural one (as well as being the one that allows for easier debugging, since there no need to find out the extra mapping). Users of libxc that want to establish a particular (rather than an allocated) mapping are still free to do so, as well as tool stacks not based on libxc wanting to implement an allocation based model (which is why it's not the hypervisor that's being changed to enforce either model). Since libxl, like xend, already uses a 1:1 model, it's unaffected by the libxc change (and it being unaffected by the original hypervisor side changes is - afaict - simply due to qemu getting spawned at a later point in time compared to the xend event flow). Signed-off-by: Jan Beulich <jbeulich@suse.com> Tested-by: Andreas Falck <falck.andreas.lists@gmail.com> (on 4.1) Tested-by: Gordan Bobic <gordan@bobich.net> (on 4.2) Acked-by: Ian Campbell <ian.campbell@citrix.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
* hypervisor/xen/tools: Remove the XENMEM_get_oustanding_pages and provide the ↵Konrad Rzeszutek Wilk2013-05-142-11/+0
| | | | | | | | | | | | | | | | | | | | | | | | data via xc_phys_info During the review of the patches it was noticed that there exists a race wherein the 'free_memory' value consists of information from two hypercalls. That is the XEN_SYSCTL_physinfo and XENMEM_get_outstanding_pages. The free memory the host has available for guest is the difference between the 'free_pages' (from XEN_SYSCTL_physinfo) and 'outstanding_pages'. As they are two hypercalls many things can happen in between the execution of them. This patch resolves this by eliminating the XENMEM_get_outstanding_pages hypercall and providing the free_pages and outstanding_pages information via the xc_phys_info structure. It also removes the XSM hooks and adds locking as needed. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Reviewed-by: Tim Deegan <tim@xen.org> Acked-by: Keir Fraser <keir.xen@gmail.com>
* tools: Bump some library sonamesIan Jackson2013-05-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | libxc (libxenctrl, libxenguest): New claim_enabled field in struct xc_dom_image; New nr_outstanding_pages field in struct xc_dominfo; New fields in struct xc_hvm_build_args (xenguest.h). libxl: new fields in dominfo domain_build_info device_vfb device_vkb device_disk etc. etc. etc. libxlu #includes libxl headers so needs to inherit its new soname Use Xen version for new sonames since we don't in fact guarantee ABI (as opposed to API) stability across releases. xenstore (libxenstore): New flag XS_UNWATCH_FILTER, so bump minor version only. This was the result of reviewing the output from: git-checkout staging cd tools git-diff RELEASE-4.2.2 `find -name \*.h` Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* libxl: write IO ABI for disk frontendsWei Liu2013-04-263-0/+51
| | | | | | | | | | | | | | | This is a patch to forward-port a Xend behaviour. Xend writes IO ABI used for all frontends. Blkfront before 2.6.26 relies on this behaviour otherwise guest cannot boot when running in 32-on-64 mode. Blkfront after 2.6.26 writes that node itself, in which case it's just an overwrite to an existing node which should be OK. In fact Xend writes the ABI for all frontends including console and vif. But nowadays only old disk frontends rely on that behaviour so that we only write the ABI for disk frontends in libxl, minimizing the impact. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>
* libxc: Add unsafe decompressorsBastian Blank2013-04-228-0/+221
| | | | | | | | | | | | | | | | | | | | Add decompressors based on hypervisor code. This are used in mini-os by pv-grub. This enables pv-grub to boot kernels compressed with e.g. xz, which are becoming more common. Signed-off-by: Bastian Blank <waldi@debian.org> Adjusted to use terminology "unsafe" rather than "trusted" to indicate that the user had better sanitise the data (or not care, as in stub domains) as suggested by Tim Deegan. This was effectively a sed script. Minimise the changes to hypervisor code by moving the "compat layer" into the relevant libxc source files (which include the Xen ones). Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
* libxc: allow for explicitly specifying node-affinityDario Faggioli2013-04-172-0/+103
| | | | | | | | | By providing the proper get/set interface and wiring them to the new domctl-s from the previous commit. Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com> Acked-by: Juergen Gross <juergen.gross@ts.fujitsu.com> Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
* xen, libxc: introduce xc_nodemap_tDario Faggioli2013-04-172-1/+24
| | | | | | | | | And its handling functions, following suit from xc_cpumap_t. Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com> Acked-by: George Dunlap <george.dunlap@eu.citrix.com> Acked-by: Juergen Gross <juergen.gross@ts.fujitsu.com> Acked-by: Keir Fraser <keir@xen.org>
* xen, libxc: rename xenctl_cpumap to xenctl_bitmapDario Faggioli2013-04-173-5/+5
| | | | | | | | | | | | | | | | | | More specifically: 1. replaces xenctl_cpumap with xenctl_bitmap 2. provides bitmap_to_xenctl_bitmap and the reverse; 3. re-implement cpumask_to_xenctl_bitmap with bitmap_to_xenctl_bitmap and the reverse; Other than #3, no functional changes. Interface only slightly afected. This is in preparation of introducing NUMA node-affinity maps. Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com> Acked-by: George Dunlap <george.dunlap@eu.citrix.com> Acked-by: Juergen Gross <juergen.gross@ts.fujitsu.com> Acked-by: Keir Fraser <keir@xen.org>
* xc: export outstanding_pages value in xc_dominfo structure.Dan Magenheimer2013-04-162-0/+2
| | | | | | | | | | | | | | | | | | This patch provides the value of the currently outstanding pages claimed for a specific domain. This is a value that influences the global outstanding claims value (See patch: "xl: 'xl info' print outstanding claims if enabled") returned via xc_domain_get_outstanding_pages hypercall. This domain value decrements as the memory is populated for the guest and eventually reaches zero. This patch is neccessary for "xl: export 'outstanding_pages' value from xcinfo" patch. Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> [v2: s/unclaimed_pages/outstanding_pages/ per Tim's suggestion] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
* xc: use XENMEM_claim_pages hypercall during guest creation.Dan Magenheimer2013-04-166-4/+70
| | | | | | | | | | | | | | | | | | | | | | We add an extra parameter to the structures passed to the PV routine (arch_setup_meminit) and HVM routine (setup_guest) that determines whether the claim hypercall is to be done. The contents of the 'claim_enabled' is defined as an 'int' in case the hypercall expands in the future with extra flags (for example for per-NUMA allocation). For right now the proper values are: 0 to disable it or 1 to enable it. If the hypervisor does not support this function, the xc_domain_claim_pages and xc_domain_get_outstanding_pages will silently return 0 (and set errno to zero). Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> [v2: Updated per Ian's recommendations] [v3: Added support for out-of-sync hypervisor] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
* tools: libxc: arm64 supportIan Campbell2013-04-112-1/+5
| | | | | Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Tim Deegan <tim@xen.org>
* tools/xentoollog: update tty detection in stdiostream_progressOlaf Hering2013-02-281-1/+3
| | | | | | | | | As suggested by IanJ: Check isatty only once to preserve the errno of ->progress users, and to reduce the noice in strace output. Signed-off-by: Olaf Hering <olaf@aepfle.de> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
* doc: Improve xc_domain_restore inline documentationFrediano Ziglio2013-02-221-0/+2
| | | | | | Was not clear that xc_domain_restore did not resume the machine. Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com>
* xen: arm: separate guest user regs from internal guest state.Ian Campbell2013-02-221-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | struct cpu_user_regs is currently used as both internal state (specifically at the base of the stack) and a guest/toolstack visible API (via struct vcpu_guest_context used by XEN_DOMCTL_{g,s}etvcpucontext and VCPUOP_initialise). This causes problems when we want to make the API 64-bit clean since we don't really want to change the size of the on-stack struct. So split into vcpu_guest_core_regs which is the API facing struct and keep cpu_user_regs purely internal, translate between the two. In the user API arrange for both 64- and 32-bit registers to be included in a layout which does not differ depending on toolstack architecture. Also switch to using the more formal banked register names (e.g. with the _usr suffix) for clarity. This is an ABI change. Note that the kernel doesn't currently use this data structure so it affects the tools interface only. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Tim Deegan <tim@xen.org>