Date: Fri, 31 May 2024 17:19:39 +0800
From: Tao Liu <ltao@redhat.com>
Subject: [Crash-utility] [PATCH v4 16/16] arm64: Add gdb stack
unwinding support
To: devel@lists.crash-utility.osci.io
Cc: Mahesh J Salgaonkar <mahesh@linux.ibm.com>, "Naveen N . Rao"
<naveen.n.rao@linux.vnet.ibm.com>, Lianbo Jiang <lijiang@redhat.com>,
Alexey Makhalov <alexey.makhalov@broadcom.com>
Message-ID: <20240531091939.97828-17-ltao@redhat.com>
Content-Type: text/plain; charset=UTF-8
Cc: Sourabh Jain <sourabhjain@linux.ibm.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Mahesh J Salgaonkar <mahesh@linux.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Lianbo Jiang <lijiang@redhat.com>
Cc: HAGIO KAZUHITO(萩尾 一仁) <k-hagio-ab@nec.com>
Cc: Tao Liu <ltao@redhat.com>
Cc: Alexey Makhalov <alexey.makhalov@broadcom.com>
Signed-off-by: Tao Liu <ltao@redhat.com>
---
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;
+ }
+
The above switch-case code block can be defined as a separate static function to do the sanity check, as mentioned in another thread.
Please refer to the comment here:
Hmm, basically the current patch is similar to the code design of [patch v4 08/16], so I won't comment on the following code one by one, can you try to improve this one based on the previous comments? (See the above link).
Thanks.
Lianbo
+ tc = CURRENT_CONTEXT();
+ 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