[Crash-utility] Re: [PATCH v4 16/16] arm64: Add gdb stack unwinding support

Date: Fri, 31 May 2024 17:19:39 +0800 From: Tao Liu <ltao(a)redhat.com&gt; Subject: [Crash-utility] [PATCH v4 16/16] arm64: Add gdb stack unwinding support To: devel(a)lists.crash-utility.osci.io Cc: Mahesh J Salgaonkar <mahesh(a)linux.ibm.com&gt;, "Naveen N . Rao" <naveen.n.rao(a)linux.vnet.ibm.com&gt;, Lianbo Jiang < lijiang(a)redhat.com&gt;, Alexey Makhalov <alexey.makhalov(a)broadcom.com&gt; Message-ID: <20240531091939.97828-17-ltao(a)redhat.com&gt; Content-Type: text/plain; charset=UTF-8 Cc: Sourabh Jain <sourabhjain(a)linux.ibm.com&gt; Cc: Hari Bathini <hbathini(a)linux.ibm.com&gt; Cc: Mahesh J Salgaonkar <mahesh(a)linux.ibm.com&gt; Cc: Naveen N. Rao <naveen.n.rao(a)linux.vnet.ibm.com&gt; Cc: Lianbo Jiang <lijiang(a)redhat.com&gt; Cc: HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab(a)nec.com&gt; Cc: Tao Liu <ltao(a)redhat.com&gt; Cc: Alexey Makhalov <alexey.makhalov(a)broadcom.com&gt; Signed-off-by: Tao Liu <ltao(a)redhat.com&gt; --- arm64.c | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++++--- defs.h | 36 ++++++++++++++++++ 2 files changed, 145 insertions(+), 5 deletions(-) diff --git a/arm64.c b/arm64.c index af0e0d7..5f9be82 100644 --- a/arm64.c +++ b/arm64.c @@ -116,6 +116,23 @@ static void arm64_get_struct_page_size(struct machine_specific *ms); #define mte_tag_reset(addr) (((ulong)addr & ~mte_tag_shifted(KASAN_TAG_KERNEL)) | \ mte_tag_shifted(KASAN_TAG_KERNEL)) +struct user_regs_bitmap_struct { + struct { + union { + struct arm64_user_pt_regs user_regs; + struct { + u64 regs[31]; + u64 sp; + u64 pc; + u64 pstate; + }; + }; + u64 orig_x0; + u64 syscallno; + }; + ulong bitmap; +}; + static inline bool is_mte_kvaddr(ulong addr) { /* check for ARM64_MTE enabled */ @@ -174,6 +191,85 @@ arm64_vmemmap_is_page_ptr(ulong addr, physaddr_t *phys) return FALSE; } +static int +arm64_get_current_task_reg(int regno, const char *name, + int size, void *value) +{ + struct bt_info bt_info, bt_setup; + struct task_context *tc; + struct user_regs_bitmap_struct *ur_bitmap; + ulong ip, sp; + bool ret = FALSE; + + switch (regno) { + case X0_REGNUM ... PC_REGNUM: + break; + default: + return FALSE; + } +

+ if (!tc) + return FALSE; + BZERO(&bt_setup, sizeof(struct bt_info)); + clone_bt_info(&bt_setup, &bt_info, tc); + fill_stackbuf(&bt_info); + + get_dumpfile_regs(&bt_info, &sp, &ip); + if (bt_info.stackbuf) + FREEBUF(bt_info.stackbuf); + ur_bitmap = (struct user_regs_bitmap_struct *)bt_info.machdep; + if (!ur_bitmap) + return FALSE; + + if (!bt_info.need_free) { + goto get_all; + } + switch (ur_bitmap->bitmap) { + case 0x1a0000000: + switch (regno) { + case X29_REGNUM: + case SP_REGNUM: + case PC_REGNUM: + break; + default: + return FALSE; + } + break; + } + +get_all: + switch (regno) { + case X0_REGNUM ... X30_REGNUM: + if (size != sizeof(ur_bitmap->regs[regno])) { + ret = FALSE; break; + } else { + memcpy(value, &ur_bitmap->regs[regno], size); + ret = TRUE; break; + } + case SP_REGNUM: + if (size != sizeof(ur_bitmap->sp)) { + ret = FALSE; break; + } else { + memcpy(value, &ur_bitmap->sp, size); + ret = TRUE; break; + } + case PC_REGNUM: + if (size != sizeof(ur_bitmap->pc)) { + ret = FALSE; break; + } else { + memcpy(value, &ur_bitmap->pc, size); + ret = TRUE; break; + } + } + + if (bt_info.need_free) { + FREEBUF(ur_bitmap); + bt_info.need_free = FALSE; + } + return ret; +} + /* * Do all necessary machine-specific setup here. This is called several times * during initialization. @@ -472,6 +568,7 @@ arm64_init(int when) machdep->dumpfile_init = NULL; machdep->verify_line_number = NULL; machdep->init_kernel_pgd = arm64_init_kernel_pgd; + machdep->get_current_task_reg = arm64_get_current_task_reg; /* use machdep parameters */ arm64_calc_phys_offset(); @@ -3785,6 +3882,7 @@ arm64_get_dumpfile_stackframe(struct bt_info *bt, struct arm64_stackframe *frame try_kernel: frame->sp = ptregs->sp; frame->fp = ptregs->regs[29]; + bt->machdep = ptregs; } if (arm64_in_kdump_text(bt, frame) || @@ -3814,21 +3912,27 @@ static void arm64_get_stack_frame(struct bt_info *bt, ulong *pcp, ulong *spp) { int ret; + struct user_regs_bitmap_struct *ur_bitmap; struct arm64_stackframe stackframe = { 0 }; if (DUMPFILE() && is_task_active(bt->task)) { ret = arm64_get_dumpfile_stackframe(bt, &stackframe); + bt->need_free = FALSE; } else { if (bt->flags & BT_SKIP_IDLE) bt->flags &= ~BT_SKIP_IDLE; ret = arm64_get_stackframe(bt, &stackframe); - } - if (!ret) - error(WARNING, - "cannot determine starting stack frame for task %lx\n", - bt->task); + ur_bitmap = (struct user_regs_bitmap_struct *)GETBUF(sizeof(*ur_bitmap)); + memset(ur_bitmap, 0, sizeof(*ur_bitmap)); + ur_bitmap->pc = stackframe.pc; + ur_bitmap->sp = stackframe.sp; + ur_bitmap->regs[29] = stackframe.fp; + ur_bitmap->bitmap += 0x1a0000000; + bt->machdep = ur_bitmap; + bt->need_free = TRUE; + } bt->frameptr = stackframe.fp; if (pcp) diff --git a/defs.h b/defs.h index fd00462..05d8e14 100644 --- a/defs.h +++ b/defs.h @@ -8073,6 +8073,42 @@ enum x86_64_regnum { LAST_REGNUM }; +enum arm64_regnum { + X0_REGNUM, + X1_REGNUM, + X2_REGNUM, + X3_REGNUM, + X4_REGNUM, + X5_REGNUM, + X6_REGNUM, + X7_REGNUM, + X8_REGNUM, + X9_REGNUM, + X10_REGNUM, + X11_REGNUM, + X12_REGNUM, + X13_REGNUM, + X14_REGNUM, + X15_REGNUM, + X16_REGNUM, + X17_REGNUM, + X18_REGNUM, + X19_REGNUM, + X20_REGNUM, + X21_REGNUM, + X22_REGNUM, + X23_REGNUM, + X24_REGNUM, + X25_REGNUM, + X26_REGNUM, + X27_REGNUM, + X28_REGNUM, + X29_REGNUM, + X30_REGNUM, + SP_REGNUM, + PC_REGNUM, +}; + /* * Register numbers to make crash_target->fetch_registers() * ---> machdep->get_current_task_reg() work properly. -- 2.40.1