[Crash-utility] Re: [PATCH] gdb bt: multiple stacks support (x86_64)

On Mon, Nov 11, 2024 at 2:54 PM <devel-request(a)lists.crash-utility.osci.io&gt; wrote: > > Date: Mon, 11 Nov 2024 16:24:25 +1300 > From: Tao Liu <ltao(a)redhat.com&gt; > Subject: [Crash-utility] Re: [PATCH] gdb bt: multiple stacks support > (x86_64) > To: Alexey Makhalov <alexey.makhalov(a)broadcom.com&gt; > Cc: devel(a)lists.crash-utility.osci.io > Message-ID: > <CAO7dBbWO84Uhw=i6yFOJT-gbQ=CQ6QTzj-g+tQG9+B4TK-Kw-Q(a)mail.gmail.com&gt; > Content-Type: text/plain; charset="UTF-8" > > Hi Alexey, > > Thanks a lot for your improvement! This is a feature which I planned > to support for the next crash release, and you have provided a good > start for it. > > I have tried your patch over the weekend, and currently I'm working on > an improvement, and will send it upstream later. Do you mean you will post an improved patchset based on the current patch to support this feature on X86 64/aarch64/ppc64 arches? Should we ignore the current patch from Alex(no need to review this one)?

Thanks Lianbo > > > On Sat, Nov 9, 2024 at 2:12 PM Alexey Makhalov > <alexey.makhalov(a)broadcom.com&gt; wrote: > > > > gdb target analyzes only one task at a time and it backtraces > > only straight C stack until end of the stack. If stacks were concatenated > > during exceptions or interrupts, gdb bt will show only the topmost one. > > > > Introduce multiple stacks support in gdb target, which can be observed > > as a different threads from gdb perspective. > > 'gdb info threads' - to see list of in-kenrel stacks to given task. > > 'gdb thread <Id>' - to switch. > > 'gdb bt' - to show it. > > I like the idea, this is really nice! > > > > > Implmentation is machine specific. In x86_64, I use cmd_bt() to add > > additional gdb threads (gdb_add_substack(stack_id) call). Once added, > > gdb will may call machdep->get_current_task_reg() with corresonding > > stack_id (sid: new argument). > > Note: crash 'bt' command must be called for addition threads to appear. > > > I guess this is not very user-friendly, I'm trying to improve that. > > > No threads/stacks support for arm64 and ppc64, x86_64 only. > > > > Example of #GP fault in the kernel caught by SCTP task.. > > > > crash> bt > > PID: 94228 TASK: ffff96a6766a8000 CPU: 31 COMMAND: "SCTP" > > #0 [ffffbb67437e7220] panic at ffffffff99b4f60b > > #1 [ffffbb67437e72c0] die_addr at ffffffff99033650 > > #2 [ffffbb67437e72f0] exc_general_protection at ffffffff99b9194b > > #3 [ffffbb67437e7390] asm_exc_general_protection at ffffffff99c00b47 > > [exception RIP: crypto_aead_encrypt+9] > > RIP: ffffffff995ce269 RSP: ffffbb67437e7440 RFLAGS: 00010246 > > RAX: 0fdd59d2b3d89ecb RBX: 0000000000000000 RCX: 0000000000000c90 > > RDX: ffff96a368508110 RSI: 0000000000000000 RDI: ffff96a348352060 > > RBP: ffffbb67437e7650 R8: 0000000000000001 R9: ffff96a3685080c8 > > R10: ffff96a348351c78 R11: 00000000d5a09e53 R12: 0000000000000008 > > R13: ffff96a348352010 R14: ffff96a348352000 R15: 0000000000000001 > > ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 > > #4 [ffffbb67437e7440] echainiv_encrypt at ffffffffc0ae82c2 [echainiv] > > #5 [ffffbb67437e7658] crypto_aead_encrypt at ffffffff995ce27c > > #6 [ffffbb67437e7668] esp_output_tail at ffffffffc0add3fc [esp4] > > #7 [ffffbb67437e76f8] esp_output at ffffffffc0addedf [esp4] > > #8 [ffffbb67437e7760] xfrm_output_resume at ffffffff99a9186a > > #9 [ffffbb67437e77e0] xfrm_output at ffffffff99a91fba > > #10 [ffffbb67437e7810] __xfrm4_output at ffffffff99a7b0e6 > > #11 [ffffbb67437e7820] xfrm4_output at ffffffff99a7b172 > > #12 [ffffbb67437e7890] ip_local_out at ffffffff99a000ef > > #13 [ffffbb67437e78b8] __ip_queue_xmit at ffffffff99a0028e > > #14 [ffffbb67437e7918] sctp_v4_xmit at ffffffffc0afe0f8 [sctp] > > #15 [ffffbb67437e79f0] sctp_packet_singleton at ffffffffc0b0bc47 [sctp] > > #16 [ffffbb67437e7a60] sctp_outq_flush at ffffffffc0b0c636 [sctp] > > #17 [ffffbb67437e7b08] sctp_outq_uncork at ffffffffc0b0d85c [sctp] > > #18 [ffffbb67437e7b18] sctp_do_sm at ffffffffc0afbaa6 [sctp] > > #19 [ffffbb67437e7d08] __sctp_connect at ffffffffc0b17893 [sctp] > > #20 [ffffbb67437e7d78] __sctp_setsockopt_connectx at ffffffffc0b17a6d [sctp] > > #21 [ffffbb67437e7da8] sctp_getsockopt at ffffffffc0b1c892 [sctp] > > #22 [ffffbb67437e7eb8] sock_common_getsockopt at ffffffff9993c6e7 > > #23 [ffffbb67437e7ec8] __sys_getsockopt at ffffffff9993afac > > #24 [ffffbb67437e7f18] __x64_sys_getsockopt at ffffffff9993b0bf > > #25 [ffffbb67437e7f28] x64_sys_call at ffffffff99004ca5 > > #26 [ffffbb67437e7f38] do_syscall_64 at ffffffff99b90e34 > > #27 [ffffbb67437e7f50] entry_SYSCALL_64_after_hwframe at ffffffff99c00126 > > RIP: 00007f12c63028ea RSP: 00007f10e41d9b28 RFLAGS: 00000206 > > RAX: ffffffffffffffda RBX: 0000000000000050 RCX: 00007f12c63028ea > > RDX: 000000000000006f RSI: 0000000000000084 RDI: 0000000000000050 > > RBP: 00007f10a00009b0 R8: 00007f10e41d9b3c R9: 00007f10ac000a5c > > R10: 00007f10e41d9b40 R11: 0000000000000206 R12: 00007f10e41db120 > > R13: 0000000000000050 R14: 0000000000000010 R15: 000000000289e070 > > ORIG_RAX: 0000000000000037 CS: 0033 SS: 002b > > > > crash> gdb bt > > #0 0xffffffff998eaadf in __inb (port=100) at ./arch/x86/include/asm/shared/io.h:22 > > #1 i8042_read_status () at drivers/input/serio/i8042-acpipnpio.h:54 > > #2 i8042_panic_blink (state=<optimized out>) at drivers/input/serio/i8042.c:1137 > > #3 0xffffffff99b4f60b in panic (fmt=fmt@entry=0xffffffff9a42c4cb "Fatal exception") at kernel/panic.c:460 > > #4 0xffffffff99b49b84 in oops_end (flags=<optimized out>, flags@entry=582, regs=<optimized out>, regs@entry=0xffffbb67437e7398, signr=<optimized out>) at arch/x86/kernel/dumpstack.c:382 > > #5 0xffffffff99033650 in die_addr (str=str@entry=0xffffbb67437e7304 "general protection fault, probably for non-canonical address 0xfdd59d2b3d89edb", regs=regs@entry=0xffffbb67437e7398, err=err@entry=0, gp_addr=<optimized out>) at arch/x86/kernel/dumpstack.c:462 > > #6 0xffffffff99b9194b in __exc_general_protection (error_code=0, regs=0xffffbb67437e7398) at arch/x86/kernel/traps.c:784 > > #7 exc_general_protection (regs=0xffffbb67437e7398, error_code=0) at arch/x86/kernel/traps.c:729 > > #8 0xffffffff99c00b47 in asm_exc_general_protection () at ./arch/x86/include/asm/idtentry.h:564 > > > > crash> gdb info threads > > Id Target Id Frame > > * 1 94228 SCTP (stack 0) 0xffffffff998eaadf in __inb (port=100) at ./arch/x86/include/asm/shared/io.h:22 > > 2 94228 SCTP (stack 1) crypto_aead_encrypt (req=req@entry=0xffff96a348352060) at crypto/aead.c:86 > > The stack(0,1) doesn't make sense for users, I prefer to set marks for > each threads, as the follows: > > crash> info threads > Detaching from process 18613 > Id Target Id Frame > * 1 18336 insmod crash_setup_regs (oldregs=<optimized > out>, newregs=<optimized out>) at ./arch/x86/include/asm/kexec.h:134 > 2 18336 insmod "eframe" 0xffffffffa008300e in ?? () > > So the user will know what kind of stack the thread is... > > Anyway, please wait a while and let's work this out together. > > Thanks, > Tao Liu > > > > > crash> gdb thread 2 > > [Switching to thread 2 (94228 SCTP (stack 1))] > > #0 crypto_aead_encrypt (req=req@entry=0xffff96a348352060) at crypto/aead.c:86 > > 86 crypto/aead.c: No such file or directory. > > > > crash> gdb bt > > #0 crypto_aead_encrypt (req=req@entry=0xffff96a348352060) at crypto/aead.c:86 > > #1 0xffffffffc0ae82c2 in echainiv_encrypt (req=0xffff96a348352010) at crypto/echainiv.c:82 > > #2 0xffffffff995ce27c in crypto_aead_encrypt (req=0xffff96a348352060) at crypto/aead.c:94 > > #3 0xffffffffc0add3fc in esp_output_tail () > > #4 0xffffffffc0addedf in esp_output () > > #5 0xffffffff99a9186a in xfrm_output_one (err=0, skb=0xffff96a3c852b300) at net/xfrm/xfrm_output.c:553 > > #6 xfrm_output_resume (sk=sk@entry=0xffff96a348368000, skb=skb@entry=0xffff96a3c852b300, err=<optimized out>, err@entry=1) at net/xfrm/xfrm_output.c:588 > > #7 0xffffffff99a91fba in xfrm_output2 (skb=0xffff96a3c852b300, sk=0xffff96a348368000, net=0xffff96a365582580) at net/xfrm/xfrm_output.c:615 > > #8 xfrm_output (sk=0xffff96a348368000, skb=0xffff96a3c852b300) at net/xfrm/xfrm_output.c:765 > > #9 0xffffffff99a7b0e6 in __xfrm4_output (net=<optimized out>, sk=<optimized out>, skb=<optimized out>) at net/ipv4/xfrm4_output.c:28 > > #10 0xffffffff99a7b172 in NF_HOOK_COND (pf=2 '\002', hook=4, okfn=0xffffffff99a7b0c0 <__xfrm4_output>, cond=<optimized out>, out=0xffff96a496ff2000, in=0x0, skb=0xffff96a3c852b300, sk=0xffff96a348368000, net=0xffff96a365582580) at ./include/linux/netfilter.h:291 > > #11 xfrm4_output (net=0xffff96a365582580, sk=0xffff96a348368000, skb=0xffff96a3c852b300) at net/ipv4/xfrm4_output.c:33 > > #12 0xffffffff99a000ef in dst_output (skb=0xffff96a368508110, sk=0x0, net=0xffff96a348352060) at ./include/net/dst.h:444 > > #13 ip_local_out (net=0xffff96a348352060, sk=0x0, skb=0xffff96a368508110) at net/ipv4/ip_output.c:126 > > #14 0xffffffff99a0028e in __ip_queue_xmit (sk=sk@entry=0xffff96a348368000, skb=skb@entry=0xffff96a3c852b300, fl=fl@entry=0xffff96a348351830, tos=tos@entry=186 '\272') at net/ipv4/ip_output.c:532 > > #15 0xffffffffc0afe0f8 in sctp_v4_xmit (skb=0xffff96a3c852b300, t=0xffff96a348351800) at net/sctp/protocol.c:1071 > > #16 0xffffffffc0b1f553 in sctp_packet_transmit (packet=packet@entry=0xffffbb67437e79f8, gfp=gfp@entry=3264) at net/sctp/output.c:653 > > #17 0xffffffffc0b0bc47 in sctp_packet_singleton (transport=<optimized out>, chunk=chunk@entry=0xffff96a34c96f500, gfp=3264) at net/sctp/outqueue.c:783 > > #18 0xffffffffc0b0c636 in sctp_outq_flush_ctrl (ctx=0xffffbb67437e7aa0) at net/sctp/outqueue.c:914 > > #19 sctp_outq_flush (q=0xffff96a3483585b8, rtx_timeout=rtx_timeout@entry=0, gfp=<optimized out>) at net/sctp/outqueue.c:1212 > > #20 0xffffffffc0b0d85c in sctp_outq_uncork (q=q@entry=0xffff96a3483585b8, gfp=gfp@entry=3264) at net/sctp/outqueue.c:764 > > #21 0xffffffffc0afbaa6 in sctp_cmd_interpreter (state=<optimized out>, status=<optimized out>, gfp=<optimized out>, commands=0xffffbb67437e7b68, event_arg=<optimized out>, asoc=0xffff96a348358000, ep=<optimized out>, subtype=..., event_type=<optimized out>) at net/sctp/sm_sideeffect.c:1819 > > #22 sctp_side_effects (gfp=<optimized out>, commands=0xffffbb67437e7b68, status=<optimized out>, event_arg=<optimized out>, asoc=<synthetic pointer>, ep=<optimized out>, state=<optimized out>, subtype=..., event_type=<optimized out>) at net/sctp/sm_sideeffect.c:1199 > > #23 sctp_do_sm (net=<optimized out>, event_type=event_type@entry=SCTP_EVENT_T_PRIMITIVE, subtype=..., subtype@entry=..., state=<optimized out>, ep=<optimized out>, asoc=<optimized out>, event_arg=<optimized out>, gfp=<optimized out>) at net/sctp/sm_sideeffect.c:1170 > > #24 0xffffffffc0b1e2f0 in sctp_primitive_ASSOCIATE (net=<optimized out>, asoc=asoc@entry=0xffff96a348358000, arg=arg@entry=0x0) at net/sctp/primitive.c:73 > > #25 0xffffffffc0b17893 in __sctp_connect (sk=sk@entry=0xffff96a348368000, kaddrs=kaddrs@entry=0xffff96a342085030, addrs_size=addrs_size@entry=16, flags=2050, assoc_id=assoc_id@entry=0xffffbb67437e7df4) at ./include/net/net_namespace.h:369 > > #26 0xffffffffc0b17a6d in __sctp_setsockopt_connectx (sk=sk@entry=0xffff96a348368000, kaddrs=kaddrs@entry=0xffff96a342085030, addrs_size=16, assoc_id=assoc_id@entry=0xffffbb67437e7df4) at net/sctp/socket.c:1334 > > #27 0xffffffffc0b1c892 in sctp_getsockopt_connectx3 (optlen=0x7f10e41d9b3c, optval=0x7f10e41d9b40 <error: Cannot access memory at address 0x7f10e41d9b40>, len=16, sk=0xffff96a348368000) at net/sctp/socket.c:1419 > > #28 sctp_getsockopt (sk=0xffff96a348368000, level=<optimized out>, optname=<optimized out>, optval=0x7f10e41d9b40 <error: Cannot access memory at address 0x7f10e41d9b40>, optlen=<optimized out>) at net/sctp/socket.c:8124 > > #29 0xffffffff9993c6e7 in sock_common_getsockopt (sock=<optimized out>, level=0, optname=1750106384, optval=0xc90 <error: Cannot access memory at address 0xc90>, optlen=0x1) at net/core/sock.c:3652 > > #30 0xffffffff9993afac in __sys_getsockopt (fd=<optimized out>, level=132, optname=111, optval=0x7f10e41d9b40 <error: Cannot access memory at address 0x7f10e41d9b40>, optlen=<optimized out>) at net/socket.c:2327 > > #31 0xffffffff9993b0bf in __do_sys_getsockopt (optlen=<optimized out>, optval=<optimized out>, optname=<optimized out>, level=<optimized out>, fd=<optimized out>) at net/socket.c:2342 > > #32 __se_sys_getsockopt (optlen=<optimized out>, optval=<optimized out>, optname=<optimized out>, level=<optimized out>, fd=<optimized out>) at net/socket.c:2339 > > #33 __x64_sys_getsockopt (regs=<optimized out>) at net/socket.c:2339 > > #34 0xffffffff99004ca5 in x64_sys_call (regs=regs@entry=0xffffbb67437e7f58, nr=<optimized out>) at ./arch/x86/include/generated/asm/syscalls_64.h:56 > > #35 0xffffffff99b90e34 in do_syscall_x64 (nr=<optimized out>, regs=0xffffbb67437e7f58) at arch/x86/entry/common.c:51 > > #36 do_syscall_64 (regs=0xffffbb67437e7f58, nr=<optimized out>) at arch/x86/entry/common.c:81 > > #37 0xffffffff99c00126 in entry_SYSCALL_64 () at arch/x86/entry/entry_64.S:121 > > > > Now we can use GDB to see the root cause. > > > > Signed-off-by: Alexey Makhalov <alexey.makhalov(a)broadcom.com&gt; > > --- > > arm64.c | 2 +- > > crash_target.c | 25 ++++++++++++++++++---- > > defs.h | 3 ++- > > gdb_interface.c | 6 +++--- > > ppc64.c | 2 +- > > x86_64.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++-- > > 6 files changed, 81 insertions(+), 12 deletions(-) > > > > diff --git a/arm64.c b/arm64.c > > index 608b19d..62f91d8 100644 > > --- a/arm64.c > > +++ b/arm64.c > > @@ -204,7 +204,7 @@ out: > > > > static int > > arm64_get_current_task_reg(int regno, const char *name, > > - int size, void *value) > > + int size, void *value, int unused) > > { > > struct bt_info bt_info, bt_setup; > > struct task_context *tc; > > diff --git a/crash_target.c b/crash_target.c > > index 1080976..8b17ef8 100644 > > --- a/crash_target.c > > +++ b/crash_target.c > > @@ -27,8 +27,9 @@ void crash_target_init (void); > > > > extern "C" int gdb_readmem_callback(unsigned long, void *, int, int); > > extern "C" int crash_get_current_task_reg (int regno, const char *regname, > > - int regsize, void *val); > > + int regsize, void *val, int sid); > > extern "C" int gdb_change_thread_context (void); > > +extern "C" int gdb_add_substack (int sid); > > extern "C" void crash_get_current_task_info(unsigned long *pid, char **comm); > > > > /* The crash target. */ > > @@ -64,9 +65,10 @@ public: > > unsigned long pid; > > char *comm; > > crash_get_current_task_info(&pid, &comm); > > - return string_printf ("%ld %s", pid, comm); > > + if (thread_count(this) == 1) > > + return string_printf ("%ld %s", pid, comm); > > + return string_printf ("%ld %s (stack %ld)", pid, comm, ptid.tid()); > > } > > - > > }; > > > > static void supply_registers(struct regcache *regcache, int regno) > > @@ -79,7 +81,7 @@ static void supply_registers(struct regcache *regcache, int regno) > > if (regsize > sizeof (regval)) > > error (_("fatal error: buffer size is not enough to fit register value")); > > > > - if (crash_get_current_task_reg (regno, regname, regsize, (void *)&regval)) > > + if (crash_get_current_task_reg (regno, regname, regsize, (void *)&regval, inferior_thread()->ptid.tid())) > > regcache->raw_supply (regno, regval); > > else > > regcache->raw_supply (regno, NULL); > > @@ -144,7 +146,22 @@ crash_target_init (void) > > extern "C" int > > gdb_change_thread_context (void) > > { > > + for (thread_info *tp : current_inferior()->threads_safe()) > > + if (tp->ptid.tid_p()) > > + delete_thread (tp); > > target_fetch_registers(get_current_regcache(), -1); > > reinit_frame_cache(); > > return TRUE; > > } > > + > > +/* Add a thread for each additional stack. Use stack ID as a thread ID */ > > +extern "C" int > > +gdb_add_substack (int sid) > > +{ > > + ptid_t ptid = ptid_t(CRASH_INFERIOR_PID, 0, sid); > > + > > + thread_info *tp = find_thread_ptid (current_inferior(), ptid); > > + if (tp == nullptr) > > + add_thread_silent (current_inferior()->process_target(), ptid); > > + return TRUE; > > +} > > diff --git a/defs.h b/defs.h > > index b93a7a6..bb2bc20 100644 > > --- a/defs.h > > +++ b/defs.h > > @@ -1081,7 +1081,7 @@ struct machdep_table { > > void (*get_irq_affinity)(int); > > void (*show_interrupts)(int, ulong *); > > int (*is_page_ptr)(ulong, physaddr_t *); > > - int (*get_current_task_reg)(int, const char *, int, void *); > > + int (*get_current_task_reg)(int, const char *, int, void *, int); > > int (*is_cpu_prstatus_valid)(int cpu); > > }; > > > > @@ -8301,5 +8301,6 @@ enum ppc64_regnum { > > > > /* crash_target.c */ > > extern int gdb_change_thread_context (void); > > +extern int gdb_add_substack (int sid); > > > > #endif /* !GDB_COMMON */ > > diff --git a/gdb_interface.c b/gdb_interface.c > > index 315711e..c138c94 100644 > > --- a/gdb_interface.c > > +++ b/gdb_interface.c > > @@ -1074,12 +1074,12 @@ unsigned long crash_get_kaslr_offset(void) > > > > /* Callbacks for crash_target */ > > int crash_get_current_task_reg (int regno, const char *regname, > > - int regsize, void *value); > > + int regsize, void *value, int sid); > > int crash_get_current_task_reg (int regno, const char *regname, > > - int regsize, void *value) > > + int regsize, void *value, int sid) > > { > > if (!machdep->get_current_task_reg) > > return FALSE; > > - return machdep->get_current_task_reg(regno, regname, regsize, value); > > + return machdep->get_current_task_reg(regno, regname, regsize, value, sid); > > } > > > > diff --git a/ppc64.c b/ppc64.c > > index 782107b..1cf06e3 100644 > > --- a/ppc64.c > > +++ b/ppc64.c > > @@ -2512,7 +2512,7 @@ ppc64_print_eframe(char *efrm_str, struct ppc64_pt_regs *regs, > > > > static int > > ppc64_get_current_task_reg(int regno, const char *name, int size, > > - void *value) > > + void *value, int unused) > > { > > struct bt_info bt_info, bt_setup; > > struct task_context *tc; > > diff --git a/x86_64.c b/x86_64.c > > index e7f8fe2..2e7cde4 100644 > > --- a/x86_64.c > > +++ b/x86_64.c > > @@ -126,7 +126,7 @@ static int x86_64_get_framesize(struct bt_info *, ulong, ulong, char *); > > static void x86_64_framesize_debug(struct bt_info *); > > static void x86_64_get_active_set(void); > > static int x86_64_get_kvaddr_ranges(struct vaddr_range *); > > -static int x86_64_get_current_task_reg(int, const char *, int, void *); > > +static int x86_64_get_current_task_reg(int, const char *, int, void *, int); > > static int x86_64_verify_paddr(uint64_t); > > static void GART_init(void); > > static void x86_64_exception_stacks_init(void); > > @@ -143,6 +143,14 @@ struct machine_specific x86_64_machine_specific = { 0 }; > > static const char *exception_functions_orig[]; > > static const char *exception_functions_5_8[]; > > > > +/* > > + * Additional stacks entry registers for gdb target. > > + * See 'gdb info threads' > > + */ > > +#define MAX_STACKS_NUM 5 > > +ulong stack_idx; > > +ulong stacks_regs[MAX_STACKS_NUM][SS_REGNUM + 1]; > > + > > /* Use this hardwired version -- sometimes the > > * debuginfo doesn't pick this up even though > > * it exists in the kernel; it shouldn't change. > > @@ -3551,6 +3559,7 @@ x86_64_low_budget_back_trace_cmd(struct bt_info *bt_in) > > irq_eframe = 0; > > last_process_stack_eframe = 0; > > bt->call_target = NULL; > > + stack_idx = 0; > > rsp = bt->stkptr; > > ms = machdep->machspec; > > > > @@ -4159,6 +4168,7 @@ x86_64_dwarf_back_trace_cmd(struct bt_info *bt_in) > > last_process_stack_eframe = 0; > > bt->call_target = NULL; > > bt->bptr = 0; > > + stack_idx = 0; > > rsp = bt->stkptr; > > if (!rsp) { > > error(INFO, "cannot determine starting stack pointer\n"); > > @@ -4799,6 +4809,36 @@ x86_64_exception_frame(ulong flags, ulong kvaddr, char *local, > > } else if (machdep->flags & ORC) > > bt->bptr = rbp; > > > > + > > + /* > > + * Preserve registers set for each additional in-kernel stack > > + * up to MAX_STACKS_NUM. > > + */ > > + if (!(cs & 3) && verified && stack_idx < MAX_STACKS_NUM) { > > + stacks_regs[stack_idx][RAX_REGNUM] = rax; > > + stacks_regs[stack_idx][RBX_REGNUM] = rbx; > > + stacks_regs[stack_idx][RCX_REGNUM] = rcx; > > + stacks_regs[stack_idx][RDX_REGNUM] = rdx; > > + stacks_regs[stack_idx][RSI_REGNUM] = rsi; > > + stacks_regs[stack_idx][RDI_REGNUM] = rdi; > > + stacks_regs[stack_idx][RBP_REGNUM] = rbp; > > + stacks_regs[stack_idx][RSP_REGNUM] = rsp; > > + stacks_regs[stack_idx][R8_REGNUM] = r8; > > + stacks_regs[stack_idx][R9_REGNUM] = r9; > > + stacks_regs[stack_idx][R10_REGNUM] = r10; > > + stacks_regs[stack_idx][R11_REGNUM] = r11; > > + stacks_regs[stack_idx][R12_REGNUM] = r12; > > + stacks_regs[stack_idx][R13_REGNUM] = r13; > > + stacks_regs[stack_idx][R14_REGNUM] = r14; > > + stacks_regs[stack_idx][R15_REGNUM] = r15; > > + stacks_regs[stack_idx][RIP_REGNUM] = rip; > > + stacks_regs[stack_idx][EFLAGS_REGNUM] = rflags; > > + stacks_regs[stack_idx][CS_REGNUM] = cs; > > + stacks_regs[stack_idx][SS_REGNUM] = ss; > > + /* Skip stack 0 (main stack), start with index 1 */ > > + gdb_add_substack (stack_idx + 1); > > + stack_idx++; > > + } > > if (kvaddr) > > FREEBUF(pt_regs_buf); > > > > @@ -9236,7 +9276,7 @@ x86_64_get_kvaddr_ranges(struct vaddr_range *vrp) > > > > static int > > x86_64_get_current_task_reg(int regno, const char *name, > > - int size, void *value) > > + int size, void *value, int sid) > > { > > struct bt_info bt_info, bt_setup; > > struct task_context *tc; > > @@ -9256,6 +9296,17 @@ x86_64_get_current_task_reg(int regno, const char *name, > > if (!tc) > > return FALSE; > > > > + /* Non zero stack ID, use saved regs */ > > + if (sid && sid <= MAX_STACKS_NUM) { > > + switch (regno) { > > + case RAX_REGNUM ... SS_REGNUM: > > + memcpy(value, &stacks_regs[sid - 1][regno], size > 8 ? 8 : size); > > + return TRUE; > > + default: > > + return FALSE; > > + } > > + } > > + > > /* > > * Task is active, grab CPU's registers > > */ > > -- > > 2.43.5