Added handler of fs/gs register. It tries to find and check KPCR and version address.
Signed-off-by: Mihail Abakumov <mikhail.abaku...@ispras.ru> Signed-off-by: Pavel Dovgalyuk <dovga...@ispras.ru> Signed-off-by: Dmitriy Koltunov <koltu...@ispras.ru> --- include/exec/windbgstub-utils.h | 8 ++++++ target/i386/windbgstub.c | 49 ++++++++++++++++++++++++++++++++++++++- windbgstub-utils.c | 13 ++++++++++ windbgstub.c | 10 ++++++++ 4 files changed, 79 insertions(+), 1 deletion(-) diff --git a/include/exec/windbgstub-utils.h b/include/exec/windbgstub-utils.h index 825d58b76b..ff260287dc 100755 --- a/include/exec/windbgstub-utils.h +++ b/include/exec/windbgstub-utils.h @@ -50,6 +50,14 @@ _t; \ }) +typedef struct InitedAddr { + target_ulong addr; + bool is_init; +} InitedAddr; + +InitedAddr *windbg_get_KPCR(void); +InitedAddr *windbg_get_version(void); + bool windbg_on_load(void); #endif diff --git a/target/i386/windbgstub.c b/target/i386/windbgstub.c index f2f83423a0..83e80bdfc8 100755 --- a/target/i386/windbgstub.c +++ b/target/i386/windbgstub.c @@ -12,7 +12,54 @@ #include "qemu/osdep.h" #include "exec/windbgstub-utils.h" +#ifdef TARGET_X86_64 +# define OFFSET_SELF_PCR 0x18 +# define OFFSET_VERS 0x108 +#else +# define OFFSET_SELF_PCR 0x1C +# define OFFSET_VERS 0x34 +#endif + bool windbg_on_load(void) { - return false; + CPUState *cpu = qemu_get_cpu(0); + CPUArchState *env = cpu->env_ptr; + InitedAddr *KPCR = windbg_get_KPCR(); + InitedAddr *version = windbg_get_version(); + + if (!KPCR->is_init) { + + #ifdef TARGET_X86_64 + KPCR->addr = env->segs[R_GS].base; + #else + KPCR->addr = env->segs[R_FS].base; + #endif + + static target_ulong prev_KPCR; + if (!KPCR->addr || prev_KPCR == KPCR->addr) { + return false; + } + prev_KPCR = KPCR->addr; + + if (KPCR->addr != READ_VMEM(cpu, KPCR->addr + OFFSET_SELF_PCR, + target_ulong)) { + return false; + } + + KPCR->is_init = true; + } + + if (!version->is_init && KPCR->is_init) { + version->addr = READ_VMEM(cpu, KPCR->addr + OFFSET_VERS, + target_ulong); + if (!version->addr) { + return false; + } + version->is_init = true; + } + + WINDBG_DEBUG("windbg_on_load: KPCR " FMT_ADDR, KPCR->addr); + WINDBG_DEBUG("windbg_on_load: version " FMT_ADDR, version->addr); + + return true; } diff --git a/windbgstub-utils.c b/windbgstub-utils.c index dc5e505c63..347c61553a 100755 --- a/windbgstub-utils.c +++ b/windbgstub-utils.c @@ -10,3 +10,16 @@ */ #include "exec/windbgstub-utils.h" + +static InitedAddr KPCR; +static InitedAddr version; + +InitedAddr *windbg_get_KPCR(void) +{ + return &KPCR; +} + +InitedAddr *windbg_get_version(void) +{ + return &version; +} diff --git a/windbgstub.c b/windbgstub.c index a2a6eb81b4..e9aabd807b 100755 --- a/windbgstub.c +++ b/windbgstub.c @@ -17,6 +17,7 @@ #include "exec/windbgstub.h" #include "exec/windbgstub-utils.h" #include "sysemu/kvm.h" +#include "sysemu/reset.h" typedef struct WindbgState { bool is_loaded; @@ -46,6 +47,13 @@ static void windbg_exit(void) g_free(windbg_state); } +static void windbg_handle_reset(void *opaque) +{ + windbg_state->is_loaded = false; + windbg_get_KPCR()->is_init = false; + windbg_get_version()->is_init = false; +} + void windbg_try_load(void) { if (windbg_state && !windbg_state->is_loaded) { @@ -85,6 +93,8 @@ int windbg_server_start(const char *device) qemu_chr_fe_set_handlers(&windbg_state->chr, windbg_chr_can_receive, windbg_chr_receive, NULL, NULL, NULL, NULL, true); + qemu_register_reset(windbg_handle_reset, NULL); + atexit(windbg_exit); return 0; }