10:23 a.m.
I ever sent the patch 1 in the link:
https://patchwork.kernel.org/project/linux-riscv/patch/20220708073150.352...
And patch 2,3 in the link:
https://patchwork.kernel.org/project/linux-riscv/patch/20220714113300.367...
https://patchwork.kernel.org/project/linux-riscv/patch/20220714113300.367...
This patch series just put these patches together, and with two new patch 4, 5.
these five patches are the fixups for machine_kexec, kernel mode PC for vmcore
and improvements for vmcoreinfo and memory layout dump.
The main changes in the five patchs as below,
Patch 1: use __smp_processor_id() instead of smp_processor_id() to cleanup
the console prints.
Patch 2: Add VM layout, va bits, ram base to vmcoreinfo, which can simplify
the development of crash tool as ARM64 already did
(arch/arm64/kernel/crash_core.c).
Patch 3: Add modules to virtual kernel memory layout dump.
Patch 4: Fixup to get correct kernel mode PC for vmcore.
Patch 5: Updates vmcoreinfo.rst.
With these 5 patches(patch 2 is must), crash tool can work well to analyze
a vmcore. The patches for crash tool for RISCV64 is in the link:
https://lore.kernel.org/linux-riscv/20220718025346.411758-1-xianting.tian...
Changes v1 -> v2:
1, remove the patch "Add a fast call path of crash_kexec()" from this series
of patches, as it already applied to riscv git.
https://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git/commit/?h...
2, add 'Reviewed-by' based on the comments of v1.
Xianting Tian (5):
RISC-V: use __smp_processor_id() instead of smp_processor_id()
RISC-V: Add arch_crash_save_vmcoreinfo support
riscv: Add modules to virtual kernel memory layout dump
RISC-V: Fixup getting correct current pc
riscv64: crash_core: Export kernel vm layout, phys_ram_base
.../admin-guide/kdump/vmcoreinfo.rst | 31 +++++++++++++++++++
arch/riscv/kernel/Makefile | 1 +
arch/riscv/kernel/crash_core.c | 29 +++++++++++++++++
arch/riscv/kernel/crash_save_regs.S | 2 +-
arch/riscv/kernel/machine_kexec.c | 2 +-
arch/riscv/mm/init.c | 4 +++
6 files changed, 67 insertions(+), 2 deletions(-)
create mode 100644 arch/riscv/kernel/crash_core.c
--
2.17.1
10:23 a.m.
New subject: [PATCH V2 1/5] RISC-V: use __smp_processor_id() instead of smp_processor_id()
Use __smp_processor_id() to avoid check the preemption context when
CONFIG_DEBUG_PREEMPT enabled, as we will enter crash kernel and no
return.
Without the patch,
[ 103.781044] sysrq: Trigger a crash
[ 103.784625] Kernel panic - not syncing: sysrq triggered crash
[ 103.837634] CPU1: off
[ 103.889668] CPU2: off
[ 103.933479] CPU3: off
[ 103.939424] Starting crashdump kernel...
[ 103.943442] BUG: using smp_processor_id() in preemptible [00000000] code: sh/346
[ 103.950884] caller is debug_smp_processor_id+0x1c/0x26
[ 103.956051] CPU: 0 PID: 346 Comm: sh Kdump: loaded Not tainted
5.10.113-00002-gce03f03bf4ec-dirty #149
[ 103.965355] Call Trace:
[ 103.967805] [<ffffffe00020372a>] walk_stackframe+0x0/0xa2
[ 103.973206] [<ffffffe000bcf1f4>] show_stack+0x32/0x3e
[ 103.978258] [<ffffffe000bd382a>] dump_stack_lvl+0x72/0x8e
[ 103.983655] [<ffffffe000bd385a>] dump_stack+0x14/0x1c
[ 103.988705] [<ffffffe000bdc8fe>] check_preemption_disabled+0x9e/0xaa
[ 103.995057] [<ffffffe000bdc926>] debug_smp_processor_id+0x1c/0x26
[ 104.001150] [<ffffffe000206c64>] machine_kexec+0x22/0xd0
[ 104.006463] [<ffffffe000291a7e>] __crash_kexec+0x6a/0xa4
[ 104.011774] [<ffffffe000bcf3fa>] panic+0xfc/0x2b0
[ 104.016480] [<ffffffe000656ca4>] sysrq_reset_seq_param_set+0x0/0x70
[ 104.022745] [<ffffffe000657310>] __handle_sysrq+0x8c/0x154
[ 104.028229] [<ffffffe0006577e8>] write_sysrq_trigger+0x5a/0x6a
[ 104.034061] [<ffffffe0003d90e0>] proc_reg_write+0x58/0xd4
[ 104.039459] [<ffffffe00036cff4>] vfs_write+0x7e/0x254
[ 104.044509] [<ffffffe00036d2f6>] ksys_write+0x58/0xbe
[ 104.049558] [<ffffffe00036d36a>] sys_write+0xe/0x16
[ 104.054434] [<ffffffe000201b9a>] ret_from_syscall+0x0/0x2
[ 104.067863] Will call new kernel at ecc00000 from hart id 0
[ 104.074939] FDT image at fc5ee000
[ 104.079523] Bye...
With the patch we can got clear output,
[ 67.740553] sysrq: Trigger a crash
[ 67.744166] Kernel panic - not syncing: sysrq triggered crash
[ 67.809123] CPU1: off
[ 67.865210] CPU2: off
[ 67.909075] CPU3: off
[ 67.919123] Starting crashdump kernel...
[ 67.924900] Will call new kernel at ecc00000 from hart id 0
[ 67.932045] FDT image at fc5ee000
[ 67.935560] Bye...
Fixes: 0e105f1d0037 ("riscv: use hart id instead of cpu id on machine_kexec")
Reviewed-by: Guo Ren <guoren(a)kernel.org>
Reviewed-by: Heiko Stuebner <heiko(a)sntech.de>
Reviewed-by: Atish Patra <atishp(a)rivosinc.com>
Signed-off-by: Xianting Tian <xianting.tian(a)linux.alibaba.com>
---
arch/riscv/kernel/machine_kexec.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/riscv/kernel/machine_kexec.c b/arch/riscv/kernel/machine_kexec.c
index df8e24559035..86d1b5f9dfb5 100644
--- a/arch/riscv/kernel/machine_kexec.c
+++ b/arch/riscv/kernel/machine_kexec.c
@@ -171,7 +171,7 @@ machine_kexec(struct kimage *image)
struct kimage_arch *internal = &image->arch;
unsigned long jump_addr = (unsigned long) image->start;
unsigned long first_ind_entry = (unsigned long) &image->head;
- unsigned long this_cpu_id = smp_processor_id();
+ unsigned long this_cpu_id = __smp_processor_id();
unsigned long this_hart_id = cpuid_to_hartid_map(this_cpu_id);
unsigned long fdt_addr = internal->fdt_addr;
void *control_code_buffer = page_address(image->control_code_page);
--
2.17.1
10:23 a.m.
New subject: [PATCH V2 2/5] RISC-V: Add arch_crash_save_vmcoreinfo support
Add arch_crash_save_vmcoreinfo(), which exports VM layout(MODULES, VMALLOC,
VMEMMAP and KERNEL_LINK_ADDR ranges), va bits and ram base to vmcore.
Default pagetable levels and PAGE_OFFSET aren't same for different kernel
version as below. For default pagetable levels, it sets sv57 on defaultly
in latest kernel and do fallback to try to set sv48 on boot time if sv57
is not supported in current hardware.
For ram base, the default value is 0x80200000 for qemu riscv64 env, 0x200000
for riscv64 SoC platform(eg, SoC platform of RISC-V XuanTie 910 CPU).
* Linux Kernel 5.18 ~
* PGTABLE_LEVELS = 5
* PAGE_OFFSET = 0xff60000000000000
* Linux Kernel 5.17 ~
* PGTABLE_LEVELS = 4
* PAGE_OFFSET = 0xffffaf8000000000
* Linux Kernel 4.19 ~
* PGTABLE_LEVELS = 3
* PAGE_OFFSET = 0xffffffe000000000
Since these configurations change from time to time and version to version,
it is preferable to export them via vmcoreinfo than to change the crash's
code frequently, it can simplify the development of crash tool.
Signed-off-by: Xianting Tian <xianting.tian(a)linux.alibaba.com>
---
arch/riscv/kernel/Makefile | 1 +
arch/riscv/kernel/crash_core.c | 29 +++++++++++++++++++++++++++++
2 files changed, 30 insertions(+)
create mode 100644 arch/riscv/kernel/crash_core.c
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index 33bb60a354cd..5e149df58176 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -81,6 +81,7 @@ obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_KEXEC_CORE) += kexec_relocate.o crash_save_regs.o machine_kexec.o
obj-$(CONFIG_KEXEC_FILE) += elf_kexec.o machine_kexec_file.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
+obj-$(CONFIG_CRASH_CORE) += crash_core.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
diff --git a/arch/riscv/kernel/crash_core.c b/arch/riscv/kernel/crash_core.c
new file mode 100644
index 000000000000..8d7f5ff108da
--- /dev/null
+++ b/arch/riscv/kernel/crash_core.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/crash_core.h>
+#include <linux/pagemap.h>
+
+void arch_crash_save_vmcoreinfo(void)
+{
+ VMCOREINFO_NUMBER(VA_BITS);
+ VMCOREINFO_NUMBER(phys_ram_base);
+
+ vmcoreinfo_append_str("NUMBER(PAGE_OFFSET)=0x%lx\n", PAGE_OFFSET);
+ vmcoreinfo_append_str("NUMBER(VMALLOC_START)=0x%lx\n", VMALLOC_START);
+ vmcoreinfo_append_str("NUMBER(VMALLOC_END)=0x%lx\n", VMALLOC_END);
+ vmcoreinfo_append_str("NUMBER(VMEMMAP_START)=0x%lx\n", VMEMMAP_START);
+ vmcoreinfo_append_str("NUMBER(VMEMMAP_END)=0x%lx\n", VMEMMAP_END);
+#ifdef CONFIG_64BIT
+ vmcoreinfo_append_str("NUMBER(MODULES_VADDR)=0x%lx\n", MODULES_VADDR);
+ vmcoreinfo_append_str("NUMBER(MODULES_END)=0x%lx\n", MODULES_END);
+#endif
+
+ if (IS_ENABLED(CONFIG_64BIT)) {
+#ifdef CONFIG_KASAN
+ vmcoreinfo_append_str("NUMBER(KASAN_SHADOW_START)=0x%lx\n",
KASAN_SHADOW_START);
+ vmcoreinfo_append_str("NUMBER(KASAN_SHADOW_END)=0x%lx\n", KASAN_SHADOW_END);
+#endif
+ vmcoreinfo_append_str("NUMBER(KERNEL_LINK_ADDR)=0x%lx\n", KERNEL_LINK_ADDR);
+ vmcoreinfo_append_str("NUMBER(ADDRESS_SPACE_END)=0x%lx\n",
ADDRESS_SPACE_END);
+ }
+}
--
2.17.1
10:23 a.m.
New subject: [PATCH V2 3/5] riscv: Add modules to virtual kernel memory layout dump
Modules always live before the kernel, MODULES_END is fixed but
MODULES_VADDR isn't fixed, it depends on the kernel size.
Let's add it to virtual kernel memory layout dump.
As MODULES is only defined for CONFIG_64BIT, so we dump it when
CONFIG_64BIT=y.
eg,
MODULES_VADDR - MODULES_END
0xffffffff01133000 - 0xffffffff80000000
Reviewed-by: Guo Ren <guoren(a)kernel.org>
Reviewed-by: Heiko Stuebner <heiko(a)sntech.de>
Signed-off-by: Xianting Tian <xianting.tian(a)linux.alibaba.com>
---
arch/riscv/mm/init.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index d466ec670e1f..2c4a64e97aec 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -135,6 +135,10 @@ static void __init print_vm_layout(void)
(unsigned long)VMEMMAP_END);
print_ml("vmalloc", (unsigned long)VMALLOC_START,
(unsigned long)VMALLOC_END);
+#ifdef CONFIG_64BIT
+ print_ml("modules", (unsigned long)MODULES_VADDR,
+ (unsigned long)MODULES_END);
+#endif
print_ml("lowmem", (unsigned long)PAGE_OFFSET,
(unsigned long)high_memory);
if (IS_ENABLED(CONFIG_64BIT)) {
--
2.17.1
10:23 a.m.
New subject: [PATCH V2 4/5] RISC-V: Fixup getting correct current pc
When use 'echo c > /proc/sysrq-trigger' to trigger kdump,
riscv_crash_save_regs()
will be called to save regs to vmcore, we found "epc" value 00ffffffa5537400
is not a valid kernel virtual address, but is a user virtual address. Other
regs(eg, ra, sp, gp...) are correct kernel virtual address.
Actually 0x00ffffffb0dd9400 is the user mode PC of 'PID: 113 Comm: sh', which
is saved in the task's stack.
[ 21.201701] CPU: 0 PID: 113 Comm: sh Kdump: loaded Not tainted 5.18.9 #45
[ 21.201979] Hardware name: riscv-virtio,qemu (DT)
[ 21.202160] epc : 00ffffffa5537400 ra : ffffffff80088640 sp : ff20000010333b90
[ 21.202435] gp : ffffffff810dde38 tp : ff6000000226c200 t0 : ffffffff8032be7c
[ 21.202707] t1 : 0720072007200720 t2 : 30203a7375746174 s0 : ff20000010333cf0
[ 21.202973] s1 : 0000000000000000 a0 : ff20000010333b98 a1 : 0000000000000001
[ 21.203243] a2 : 0000000000000010 a3 : 0000000000000000 a4 : 28c8f0aeffea4e00
[ 21.203519] a5 : 28c8f0aeffea4e00 a6 : 0000000000000009 a7 : ffffffff8035c9b8
[ 21.203794] s2 : ffffffff810df0a8 s3 : ffffffff810df718 s4 : ff20000010333b98
[ 21.204062] s5 : 0000000000000000 s6 : 0000000000000007 s7 : ffffffff80c4a468
[ 21.204331] s8 : 00ffffffef451410 s9 : 0000000000000007 s10: 00aaaaaac0510700
[ 21.204606] s11: 0000000000000001 t3 : ff60000001218f00 t4 : ff60000001218f00
[ 21.204876] t5 : ff60000001218000 t6 : ff200000103338b8
[ 21.205079] status: 0000000200000020 badaddr: 0000000000000000 cause: 0000000000000008
With the incorrect PC, the backtrace showed by crash tool as below, the first
stack frame is abnormal,
crash> bt
PID: 113 TASK: ff60000002269600 CPU: 0 COMMAND: "sh"
#0 [ff2000001039bb90] __efistub_.Ldebug_info0 at 00ffffffa5537400 <-- Abnormal
#1 [ff2000001039bcf0] panic at ffffffff806578ba
#2 [ff2000001039bd50] sysrq_reset_seq_param_set at ffffffff8038c030
#3 [ff2000001039bda0] __handle_sysrq at ffffffff8038c5f8
#4 [ff2000001039be00] write_sysrq_trigger at ffffffff8038cad8
#5 [ff2000001039be20] proc_reg_write at ffffffff801b7edc
#6 [ff2000001039be40] vfs_write at ffffffff80152ba6
#7 [ff2000001039be80] ksys_write at ffffffff80152ece
#8 [ff2000001039bed0] sys_write at ffffffff80152f46
With the patch, we can get current kernel mode PC, the output as below,
[ 17.607658] CPU: 0 PID: 113 Comm: sh Kdump: loaded Not tainted 5.18.9 #42
[ 17.607937] Hardware name: riscv-virtio,qemu (DT)
[ 17.608150] epc : ffffffff800078f8 ra : ffffffff8008862c sp : ff20000010333b90
[ 17.608441] gp : ffffffff810dde38 tp : ff6000000226c200 t0 : ffffffff8032be68
[ 17.608741] t1 : 0720072007200720 t2 : 666666666666663c s0 : ff20000010333cf0
[ 17.609025] s1 : 0000000000000000 a0 : ff20000010333b98 a1 : 0000000000000001
[ 17.609320] a2 : 0000000000000010 a3 : 0000000000000000 a4 : 0000000000000000
[ 17.609601] a5 : ff60000001c78000 a6 : 000000000000003c a7 : ffffffff8035c9a4
[ 17.609894] s2 : ffffffff810df0a8 s3 : ffffffff810df718 s4 : ff20000010333b98
[ 17.610186] s5 : 0000000000000000 s6 : 0000000000000007 s7 : ffffffff80c4a468
[ 17.610469] s8 : 00ffffffca281410 s9 : 0000000000000007 s10: 00aaaaaab5bb6700
[ 17.610755] s11: 0000000000000001 t3 : ff60000001218f00 t4 : ff60000001218f00
[ 17.611041] t5 : ff60000001218000 t6 : ff20000010333988
[ 17.611255] status: 0000000200000020 badaddr: 0000000000000000 cause: 0000000000000008
With the correct PC, the backtrace showed by crash tool as below,
crash> bt
PID: 113 TASK: ff6000000226c200 CPU: 0 COMMAND: "sh"
#0 [ff20000010333b90] riscv_crash_save_regs at ffffffff800078f8 <--- Normal
#1 [ff20000010333cf0] panic at ffffffff806578c6
#2 [ff20000010333d50] sysrq_reset_seq_param_set at ffffffff8038c03c
#3 [ff20000010333da0] __handle_sysrq at ffffffff8038c604
#4 [ff20000010333e00] write_sysrq_trigger at ffffffff8038cae4
#5 [ff20000010333e20] proc_reg_write at ffffffff801b7ee8
#6 [ff20000010333e40] vfs_write at ffffffff80152bb2
#7 [ff20000010333e80] ksys_write at ffffffff80152eda
#8 [ff20000010333ed0] sys_write at ffffffff80152f52
Fixes: e53d28180d4d ("RISC-V: Add kdump support")
Co-developed-by: Guo Ren <guoren(a)kernel.org>
Signed-off-by: Xianting Tian <xianting.tian(a)linux.alibaba.com>
---
arch/riscv/kernel/crash_save_regs.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/riscv/kernel/crash_save_regs.S b/arch/riscv/kernel/crash_save_regs.S
index 7832fb763aba..b2a1908c0463 100644
--- a/arch/riscv/kernel/crash_save_regs.S
+++ b/arch/riscv/kernel/crash_save_regs.S
@@ -44,7 +44,7 @@ SYM_CODE_START(riscv_crash_save_regs)
REG_S t6, PT_T6(a0) /* x31 */
csrr t1, CSR_STATUS
- csrr t2, CSR_EPC
+ auipc t2, 0x0
csrr t3, CSR_TVAL
csrr t4, CSR_CAUSE
--
2.17.1
10:23 a.m.
New subject: [PATCH V2 5/5] riscv64: crash_core: Export kernel vm layout, phys_ram_base
These infos are needed by the kdump crash tool. Since these values change
from time to time, it is preferable to export them via vmcoreinfo than to
change the crash's code frequently.
Signed-off-by: Xianting Tian <xianting.tian(a)linux.alibaba.com>
---
.../admin-guide/kdump/vmcoreinfo.rst | 31 +++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst
b/Documentation/admin-guide/kdump/vmcoreinfo.rst
index 8419019b6a88..7d89a9d041c4 100644
--- a/Documentation/admin-guide/kdump/vmcoreinfo.rst
+++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst
@@ -595,3 +595,34 @@ X2TLB
-----
Indicates whether the crashed kernel enabled SH extended mode.
+
+RISCV64
+=====
+
+VA_BITS
+-------
+
+The maximum number of bits for virtual addresses. Used to compute the
+virtual memory ranges.
+
+PAGE_OFFSET
+-----------
+
+Indicates the virtual kernel start address of direct-mapped RAM region.
+
+phys_ram_base
+------------
+
+Indicates the start physical RAM address.
+
+MODULES_VADDR|MODULES_END|VMALLOC_START|VMALLOC_END|VMEMMAP_START|VMEMMAP_END
+-----------------------------------------------------------------------------
+KASAN_SHADOW_START|KASAN_SHADOW_END|KERNEL_LINK_ADDR|ADDRESS_SPACE_END
+----------------------------------------------------------------------
+
+Used to get the correct ranges:
+ MODULES_VADDR ~ MODULES_END : Kernel module space.
+ VMALLOC_START ~ VMALLOC_END : vmalloc() / ioremap() space.
+ VMEMMAP_START ~ VMEMMAP_END : vmemmap region, used for struct page array.
+ KASAN_SHADOW_START ~ KASAN_SHADOW_END : kasan shadow space.
+ KERNEL_LINK_ADDR ~ ADDRESS_SPACE_END : Kernel link and BPF space.
--
2.17.1
708
days inactive
708
days old
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Xianting Tian