From: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; Kernel commit fb799447ae29 ("x86,objtool: Split UNWIND_HINT_EMPTY in two"), which is contained in Linux 6.4 and later kernels, changed ORC_TYPE_CALL macro from 0 to 2. As a result, the "bt" command cannot use ORC entries, and can display stale entries in a call trace. crash> bt 1 PID: 1 TASK: ffff93cd06294180 CPU: 51 COMMAND: "systemd" #0 [ffffb72bc00cbc98] __schedule at ffffffff86e52aae #1 [ffffb72bc00cbd00] schedule at ffffffff86e52f6a #2 [ffffb72bc00cbd18] schedule_hrtimeout_range_clock at ffffffff86e58ef5 #3 [ffffb72bc00cbd88] ep_poll at ffffffff8669624d #4 [ffffb72bc00cbe28] do_epoll_wait at ffffffff86696371 #5 [ffffb72bc00cbe30] do_timerfd_settime at ffffffff8669902b << #6 [ffffb72bc00cbe60] __x64_sys_epoll_wait at ffffffff86696bf0 #7 [ffffb72bc00cbeb0] do_syscall_64 at ffffffff86e3feb9 #8 [ffffb72bc00cbee0] __task_pid_nr_ns at ffffffff863330d7 << #9 [ffffb72bc00cbf08] syscall_exit_to_user_mode at ffffffff86e466b2 << stale entries #10 [ffffb72bc00cbf18] do_syscall_64 at ffffffff86e3fec9 << #11 [ffffb72bc00cbf50] entry_SYSCALL_64_after_hwframe at ffffffff870000aa Also, kernel commit ffb1b4a41016 added a member to struct orc_entry. Although this does not affect the crash's unwinder, its debugging information can be displayed incorrectly. To fix these, (1) introduce "kernel_orc_entry_6_4" structure corresponding to 6.4 and abstruction layer "orc_entry" structure in crash, (2) switch ORC_TYPE_CALL to 2 or 0 with kernel's orc_entry structure. Related orc_entry history: v4.14 39358a033b2e introduced struct orc_entry v4.19 d31a580266ee added orc_entry.end member v6.3 ffb1b4a41016 added orc_entry.signal member v6.4 fb799447ae29 removed end member and changed type member to 3 bits Signed-off-by: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; --- v2: - better debugging information for orc_entry.{signal,end}. defs.h | 27 ++++++++++++- x86_64.c | 119 +++++++++++++++++++++++++++++++++++++++++++------------ 2 files changed, 118 insertions(+), 28 deletions(-) diff --git a/defs.h b/defs.h index 21cc760444d1..c1ac347c8e26 100644 --- a/defs.h +++ b/defs.h @@ -6354,9 +6354,29 @@ typedef struct __attribute__((__packed__)) { unsigned int sp_reg:4; unsigned int bp_reg:4; unsigned int type:2; + unsigned int signal:1; unsigned int end:1; } kernel_orc_entry; +typedef struct __attribute__((__packed__)) { + signed short sp_offset; + signed short bp_offset; + unsigned int sp_reg:4; + unsigned int bp_reg:4; + unsigned int type:3; + unsigned int signal:1; +} kernel_orc_entry_6_4; + +typedef struct orc_entry { + signed short sp_offset; + signed short bp_offset; + unsigned int sp_reg; + unsigned int bp_reg; + unsigned int type; + unsigned int signal; + unsigned int end; +} orc_entry; + struct ORC_data { int module_ORC; uint lookup_num_blocks; @@ -6367,10 +6387,12 @@ struct ORC_data { ulong orc_lookup; ulong ip_entry; ulong orc_entry; - kernel_orc_entry kernel_orc_entry; + orc_entry orc_entry_data; + int has_signal; + int has_end; }; -#define ORC_TYPE_CALL 0 +#define ORC_TYPE_CALL ((machdep->flags & ORC_6_4) ? 2 : 0) #define ORC_TYPE_REGS 1 #define ORC_TYPE_REGS_IRET 2 #define UNWIND_HINT_TYPE_SAVE 3 @@ -6447,6 +6469,7 @@ struct machine_specific { #define ORC (0x4000) #define KPTI (0x8000) #define L1TF (0x10000) +#define ORC_6_4 (0x20000) #define VM_FLAGS (VM_ORIG|VM_2_6_11|VM_XEN|VM_XEN_RHEL4|VM_5LEVEL) diff --git a/x86_64.c b/x86_64.c index 5019c69e452e..74d38106bb3c 100644 --- a/x86_64.c +++ b/x86_64.c @@ -132,9 +132,9 @@ static void GART_init(void); static void x86_64_exception_stacks_init(void); static int in_START_KERNEL_map(ulong); static ulong orc_ip(ulong); -static kernel_orc_entry *__orc_find(ulong, ulong, uint, ulong); -static kernel_orc_entry *orc_find(ulong); -static kernel_orc_entry *orc_module_find(ulong); +static orc_entry *__orc_find(ulong, ulong, uint, ulong); +static orc_entry *orc_find(ulong); +static orc_entry *orc_module_find(ulong); static ulong ip_table_to_vaddr(ulong); static void orc_dump(ulong); @@ -806,6 +806,8 @@ x86_64_dump_machdep_table(ulong arg) fprintf(fp, "%sFRAMESIZE_DEBUG", others++ ? "|" : ""); if (machdep->flags & ORC) fprintf(fp, "%sORC", others++ ? "|" : ""); + if (machdep->flags & ORC_6_4) + fprintf(fp, "%sORC_6_4", others++ ? "|" : ""); if (machdep->flags & FRAMEPOINTER) fprintf(fp, "%sFRAMEPOINTER", others++ ? "|" : ""); if (machdep->flags & GART_REGION) @@ -980,6 +982,8 @@ x86_64_dump_machdep_table(ulong arg) fprintf(fp, " ORC_data: %s", machdep->flags & ORC ? "\n" : "(unused)\n"); if (machdep->flags & ORC) { fprintf(fp, " module_ORC: %s\n", ms->orc.module_ORC ? "TRUE" : "FALSE"); + fprintf(fp, " has_signal: %s\n", ms->orc.has_signal ? "TRUE" : "FALSE"); + fprintf(fp, " has_end: %s\n", ms->orc.has_end ? "TRUE" : "FALSE"); fprintf(fp, " lookup_num_blocks: %d\n", ms->orc.lookup_num_blocks); fprintf(fp, " __start_orc_unwind_ip: %lx\n", ms->orc.__start_orc_unwind_ip); fprintf(fp, " __stop_orc_unwind_ip: %lx\n", ms->orc.__stop_orc_unwind_ip); @@ -988,14 +992,18 @@ x86_64_dump_machdep_table(ulong arg) fprintf(fp, " orc_lookup: %lx\n", ms->orc.orc_lookup); fprintf(fp, " ip_entry: %lx\n", ms->orc.ip_entry); fprintf(fp, " orc_entry: %lx\n", ms->orc.orc_entry); - fprintf(fp, " kernel_orc_entry:\n"); - fprintf(fp, " sp_offset: %d\n", ms->orc.kernel_orc_entry.sp_offset); - fprintf(fp, " bp_offset: %d\n", ms->orc.kernel_orc_entry.bp_offset); - fprintf(fp, " sp_reg: %d\n", ms->orc.kernel_orc_entry.sp_reg); - fprintf(fp, " bp_reg: %d\n", ms->orc.kernel_orc_entry.bp_reg); - fprintf(fp, " type: %d\n", ms->orc.kernel_orc_entry.type); - if (MEMBER_EXISTS("orc_entry", "end")) - fprintf(fp, " end: %d\n", ms->orc.kernel_orc_entry.end); + fprintf(fp, " orc_entry_data:\n"); + fprintf(fp, " sp_offset: %d\n", ms->orc.orc_entry_data.sp_offset); + fprintf(fp, " bp_offset: %d\n", ms->orc.orc_entry_data.bp_offset); + fprintf(fp, " sp_reg: %d\n", ms->orc.orc_entry_data.sp_reg); + fprintf(fp, " bp_reg: %d\n", ms->orc.orc_entry_data.bp_reg); + fprintf(fp, " type: %d\n", ms->orc.orc_entry_data.type); + if (ms->orc.has_signal) + fprintf(fp, " signal: %d\n", ms->orc.orc_entry_data.signal); + else + fprintf(fp, " signal: (n/a)\n"); + if (ms->orc.has_end) + fprintf(fp, " end: %d\n", ms->orc.orc_entry_data.end); else fprintf(fp, " end: (n/a)\n"); } @@ -6439,6 +6447,12 @@ x86_64_ORC_init(void) MEMBER_OFFSET_INIT(inactive_task_frame_bp, "inactive_task_frame", "bp"); MEMBER_OFFSET_INIT(inactive_task_frame_ret_addr, "inactive_task_frame", "ret_addr"); + orc->has_signal = MEMBER_EXISTS("orc_entry", "signal"); /* added at 6.3 */ + orc->has_end = MEMBER_EXISTS("orc_entry", "end"); /* removed at 6.4 */ + + if (orc->has_signal && !orc->has_end) + machdep->flags |= ORC_6_4; + machdep->flags |= ORC; } @@ -8521,7 +8535,7 @@ x86_64_get_framesize(struct bt_info *bt, ulong textaddr, ulong rsp, char *stack_ int reterror; int arg_exists; int exception; - kernel_orc_entry *korc; + orc_entry *korc; if (!(bt->flags & BT_FRAMESIZE_DEBUG)) { if ((bt->flags & BT_FRAMESIZE_IGNORE_MASK) || @@ -8607,11 +8621,14 @@ x86_64_get_framesize(struct bt_info *bt, ulong textaddr, ulong rsp, char *stack_ if ((machdep->flags & ORC) && (korc = orc_find(textaddr))) { if (CRASHDEBUG(1)) { + struct ORC_data *orc = &machdep->machspec->orc; fprintf(fp, "rsp: %lx textaddr: %lx -> spo: %d bpo: %d spr: %d bpr: %d type: %d", rsp, textaddr, korc->sp_offset, korc->bp_offset, korc->sp_reg, korc->bp_reg, korc->type); - if (MEMBER_EXISTS("orc_entry", "end")) + if (orc->has_signal) + fprintf(fp, " signal: %d", korc->signal); + if (orc->has_end) fprintf(fp, " end: %d", korc->end); fprintf(fp, "\n"); } @@ -9117,7 +9134,53 @@ orc_ip(ulong ip) return (ip + ip_entry); } -static kernel_orc_entry * +static orc_entry * +orc_get_entry(struct ORC_data *orc) +{ + struct orc_entry *entry = &orc->orc_entry_data; + + if (machdep->flags & ORC_6_4) { + kernel_orc_entry_6_4 korc; + + if (!readmem(orc->orc_entry, KVADDR, &korc, sizeof(kernel_orc_entry_6_4), + "kernel orc_entry", RETURN_ON_ERROR|QUIET)) + return NULL; + + entry->sp_offset = korc.sp_offset; + entry->bp_offset = korc.bp_offset; + entry->sp_reg = korc.sp_reg; + entry->bp_reg = korc.bp_reg; + entry->type = korc.type; + entry->signal = korc.signal; + } else { + kernel_orc_entry korc; + + if (!readmem(orc->orc_entry, KVADDR, &korc, sizeof(kernel_orc_entry), + "kernel orc_entry", RETURN_ON_ERROR|QUIET)) + return NULL; + + entry->sp_offset = korc.sp_offset; + entry->bp_offset = korc.bp_offset; + entry->sp_reg = korc.sp_reg; + entry->bp_reg = korc.bp_reg; + entry->type = korc.type; + if (orc->has_end) { + /* + * orc_entry.signal was inserted before orc_entry.end. + * see ffb1b4a41016. + */ + if (orc->has_signal) { + entry->signal = korc.signal; + entry->end = korc.end; + } else + entry->end = korc.signal; /* on purpose */ + } + } + + return entry; +} + +static orc_entry * __orc_find(ulong ip_table_ptr, ulong u_table_ptr, uint num_entries, ulong ip) { int index; @@ -9127,7 +9190,7 @@ __orc_find(ulong ip_table_ptr, ulong u_table_ptr, uint num_entries, ulong ip) int *ip_table = (int *)ip_table_ptr; struct ORC_data *orc = &machdep->machspec->orc; ulong vaddr; - kernel_orc_entry *korc; + orc_entry *korc; if (CRASHDEBUG(2)) { int i, ip_entry; @@ -9171,18 +9234,20 @@ __orc_find(ulong ip_table_ptr, ulong u_table_ptr, uint num_entries, ulong ip) orc->ip_entry = (ulong)found; orc->orc_entry = u_table_ptr + (index * SIZE(orc_entry)); - if (!readmem(orc->orc_entry, KVADDR, &orc->kernel_orc_entry, - sizeof(kernel_orc_entry), "kernel orc_entry", RETURN_ON_ERROR|QUIET)) + + if (!orc_get_entry(orc)) return NULL; - korc = &orc->kernel_orc_entry; + korc = &orc->orc_entry_data; if (CRASHDEBUG(2)) { fprintf(fp, " found: %lx index: %d\n", (ulong)found, index); fprintf(fp, " orc_entry: %lx sp_offset: %d bp_offset: %d sp_reg: %d bp_reg: %d type: %d", orc->orc_entry, korc->sp_offset, korc->bp_offset, korc->sp_reg, korc->bp_reg, korc->type); - if (MEMBER_EXISTS("orc_entry", "end")) + if (orc->has_signal) + fprintf(fp, " signal: %d", korc->signal); + if (orc->has_end) fprintf(fp, " end: %d", korc->end); fprintf(fp, "\n"); } @@ -9195,7 +9260,7 @@ __orc_find(ulong ip_table_ptr, ulong u_table_ptr, uint num_entries, ulong ip) #define LOOKUP_START_IP (unsigned long)kt->stext #define LOOKUP_STOP_IP (unsigned long)kt->etext -static kernel_orc_entry * +static orc_entry * orc_find(ulong ip) { unsigned int idx, start, stop; @@ -9265,7 +9330,7 @@ orc_find(ulong ip) orc->__start_orc_unwind + (start * SIZE(orc_entry)), stop - start, ip); } -static kernel_orc_entry * +static orc_entry * orc_module_find(ulong ip) { struct load_module *lm; @@ -9312,7 +9377,7 @@ static void orc_dump(ulong ip) { struct ORC_data *orc = &machdep->machspec->orc; - kernel_orc_entry *korc; + orc_entry *korc; ulong vaddr, offset; struct syment *sp, *orig; @@ -9335,13 +9400,15 @@ next_in_func: fprintf(fp, "%s+%ld -> ", sp->name, offset); else fprintf(fp, "(unresolved) -> "); - if (!readmem(orc->orc_entry, KVADDR, &orc->kernel_orc_entry, sizeof(kernel_orc_entry), - "kernel orc_entry", RETURN_ON_ERROR)) + + if (!orc_get_entry(orc)) error(FATAL, "cannot read orc_entry\n"); - korc = &orc->kernel_orc_entry; + korc = &orc->orc_entry_data; fprintf(fp, "orc: %lx spo: %d bpo: %d spr: %d bpr: %d type: %d", orc->orc_entry, korc->sp_offset, korc->bp_offset, korc->sp_reg, korc->bp_reg, korc->type); - if (MEMBER_EXISTS("orc_entry", "end")) + if (orc->has_signal) + fprintf(fp, " signal: %d", korc->signal); + if (orc->has_end) fprintf(fp, " end: %d", korc->end); fprintf(fp, "\n"); -- 2.31.1