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author | Viktor Prutyanov <viktor.prutyanov@virtuozzo.com> | 2018-05-17 19:23:40 +0300 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-06-29 13:02:48 +0200 |
commit | 92d1b3d5086c182bab66fd1814c4a04ba1e59337 (patch) | |
tree | ed13b9c838769f8f75e71bf68ffc37925bce6499 /win_dump.c | |
parent | 2da91b54fe98faa8676264ac6e5a3aac5b69bec2 (diff) | |
download | qemu-92d1b3d5086c182bab66fd1814c4a04ba1e59337.zip qemu-92d1b3d5086c182bab66fd1814c4a04ba1e59337.tar.gz qemu-92d1b3d5086c182bab66fd1814c4a04ba1e59337.tar.bz2 |
dump: use system context in Windows dump
We use CPU #0 to access guest virtual memory, but it can execute user
thread at that moment. So, switch CR3 to PageDirectoryBase from header
and restore original value at the end.
Signed-off-by: Viktor Prutyanov <viktor.prutyanov@virtuozzo.com>
Message-Id: <20180517162342.4330-3-viktor.prutyanov@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'win_dump.c')
-rw-r--r-- | win_dump.c | 26 |
1 files changed, 17 insertions, 9 deletions
@@ -111,12 +111,6 @@ static void patch_header(WinDumpHeader64 *h) h->PhysicalMemoryBlock.unused = 0; h->unused1 = 0; - /* - * We assume h->DirectoryBase and current CR3 are the same when we access - * memory by virtual address. In other words, we suppose current context - * is system context. It is definetely true in case of BSOD. - */ - patch_mm_pfn_database(h, &local_err); if (local_err) { warn_report_err(local_err); @@ -171,6 +165,8 @@ void create_win_dump(DumpState *s, Error **errp) { WinDumpHeader64 *h = (WinDumpHeader64 *)(s->guest_note + VMCOREINFO_ELF_NOTE_HDR_SIZE); + X86CPU *first_x86_cpu = X86_CPU(first_cpu); + uint64_t saved_cr3 = first_x86_cpu->env.cr[3]; Error *local_err = NULL; if (s->guest_note_size != sizeof(WinDumpHeader64) + @@ -185,10 +181,17 @@ void create_win_dump(DumpState *s, Error **errp) return; } + /* + * Further access to kernel structures by virtual addresses + * should be made from system context. + */ + + first_x86_cpu->env.cr[3] = h->DirectoryTableBase; + check_kdbg(h, &local_err); if (local_err) { error_propagate(errp, local_err); - return; + goto out_cr3; } patch_header(h); @@ -198,12 +201,17 @@ void create_win_dump(DumpState *s, Error **errp) s->written_size = qemu_write_full(s->fd, h, sizeof(*h)); if (s->written_size != sizeof(*h)) { error_setg(errp, QERR_IO_ERROR); - return; + goto out_cr3; } write_runs(s, h, &local_err); if (local_err) { error_propagate(errp, local_err); - return; + goto out_cr3; } + +out_cr3: + first_x86_cpu->env.cr[3] = saved_cr3; + + return; } |