Re: [Crash-utility] [External Mail]Re: [PATCH] Fix for the determination of the ARM64 SECTION_SIZE_BITS
by 陈启武
Hi Dave,
I resend the email with the patch attached. It’s a bugfix for the determination of the ARM64 SECTION_SIZE_BITS.
For some ARM64 arch platforms such as qcom 8150/8250 boards, they define their own section size bits in kernel config to support
memory hotplug, which is not same as ARM64 default SECTION_SIZE_BITS value: 30. The SECTION_SIZE_BITS definition in qcom's linux-4.14 code as below:
[arch/arm64/include/asm/sparsemem.h]
#ifdef CONFIG_SPARSEMEM
#define MAX_PHYSMEM_BITS 48
#ifndef CONFIG_MEMORY_HOTPLUG
#define SECTION_SIZE_BITS 30
#else
#define SECTION_SIZE_BITS CONFIG_HOTPLUG_SIZE_BITS
#endif
#endif
Without the patch, after load ramdump by crash tool, the warning message maybe displayed:
crash> kmem -P 0x80000000
kmem: WARNING: cannot find mem_map page for address: fffffffe80000000
kmem: cannot determine page for 80000000
80000000: physical address not found in mem map
So I introduce this patch to fix it, we can determine SECTION_SIZE_BITS either by reading VMCOREINFO or the kernel config,
otherwise borrow the 64-bit ARM default definiton.
diff --git a/arm64.c b/arm64.c
index 6b34b5f..31c03d4 100644
--- a/arm64.c
+++ b/arm64.c
@@ -32,6 +32,7 @@ static int verify_kimage_voffset(void);
static void arm64_calc_kimage_voffset(void);
static void arm64_calc_phys_offset(void);
static void arm64_calc_virtual_memory_ranges(void);
+static void arm64_get_section_size_bits(void);
static int arm64_kdump_phys_base(ulong *);
static ulong arm64_processor_speed(void);
static void arm64_init_kernel_pgd(void);
@@ -375,7 +376,11 @@ arm64_init(int when)
case POST_GDB:
arm64_calc_virtual_memory_ranges();
- machdep->section_size_bits = _SECTION_SIZE_BITS;
+ arm64_get_section_size_bits();
+ if (CRASHDEBUG(1)) {
+ fprintf(fp, "SECTION_SIZE_BITS: %ld\n", machdep->section_size_bits);
+ }
+
if (!machdep->max_physmem_bits) {
if ((string = pc->read_vmcoreinfo("NUMBER(MAX_PHYSMEM_BITS)"))) {
machdep->max_physmem_bits = atol(string);
@@ -1055,6 +1060,32 @@ arm64_calc_phys_offset(void)
fprintf(fp, "using %lx as phys_offset\n", ms->phys_offset);
}
+/*
+ * Determine SECTION_SIZE_BITS either by reading VMCOREINFO or the kernel
+ * config, otherwise borrow the 64-bit ARM default definiton.
+ */
+static void
+arm64_get_section_size_bits(void)
+{
+ int ret;
+ char *string;
+
+ if ((string = pc->read_vmcoreinfo("NUMBER(SECTION_SIZE_BITS)"))) {
+ machdep->section_size_bits = atol(string);
+ free(string);
+ return;
+ }
+
+ if ((ret = get_kernel_config("CONFIG_MEMORY_HOTPLUG", NULL)) == IKCONFIG_Y) {
+ if ((ret = get_kernel_config("CONFIG_HOTPLUG_SIZE_BITS", &string)) == IKCONFIG_STR) {
+ machdep->section_size_bits = atol(string);
+ free(string);
+ return;
+ }
+ }
+
+ machdep->section_size_bits = _SECTION_SIZE_BITS;
+}
Thanks for your review. I’m looking forward to your favourable reply!
Best regards,
Qiwu
-----Original Message-----
From: Dave Anderson <anderson(a)redhat.com>
Sent: Wednesday, September 18, 2019 9:32 PM
To: 陈启武 <chenqiwu(a)xiaomi.com>
Cc: crash-utility(a)redhat.com
Subject: Re: [External Mail]Re: [PATCH] Fix a segfault in setup_ikconfig.
----- Original Message -----
> Hi Dave,
> 1. I'm requesting the arm64.c change as well. Because some chip makers
> would like to define their own section size bits in kernel config to
> support memory hotplug, which is not same as ARM64 default SECTION_SIZE_BITS value:
> 30, such as QCOM SDM8150 or 8250 borads. Although linux kernel
> maintain line still define default SECTION_SIZE_BITS value: 30 as
> section_size_bits for sparsemem. The patch has detailed descript in
> the email "[PATCH] Fix for the determination of the ARM64 SECTION_SIZE_BITS".
I never received an email with that header. Can you please resend the email with the patch attached (i.e., not inlined)?
Thanks,
Dave
> 2. The output of "sys config" for my dumpfile has been uploaded, which
> shows the last line is empty. it occurs a segment fault when add the
> last empty line into ikconfig entry. I agree that the use of STRNEQ()
> is better than strncmp().
>
> Best regards,
> Qiwu
>
>
>
> -----Original Message-----
> From: Dave Anderson <anderson(a)redhat.com>
> Sent: Wednesday, September 18, 2019 3:22 AM
> To: 陈启武 <chenqiwu(a)xiaomi.com>
> Cc: crash-utility(a)redhat.com
> Subject: [External Mail]Re: [PATCH] Fix a segfault in setup_ikconfig.
>
>
>
> ----- Original Message -----
> >
> > Hi Anderson,
> > I want to introduce a patch to your crash tool project. It’s a
> > bugfix for a segfault in setup_ikconfig.
> > We add an ikconfig entry only if ent[0] != '#', it is not an
> > advisable condition because there is a potential segfault risk if ent is gibberish.
>
> Using your dumpfile that has the bogus "ent" string, can you show me
> what the output of "sys config" looks like?
>
> Dave
>
> > I explain the reproducing steps about this segfault case:
> > I try to apply the following patch to crash 7.2.6++ code for a test.
> > --- a/arm64.c
> > +++ b/arm64.c
> > @@ -32,6 +32,7 @@ static int verify_kimage_voffset(void); static
> > void arm64_calc_kimage_voffset(void); static void
> > arm64_calc_phys_offset(void); static void
> > arm64_calc_virtual_memory_ranges(void);
> > +static void arm64_get_section_size_bits(void);
> > static int arm64_kdump_phys_base(ulong *); static ulong
> > arm64_processor_speed(void); static void
> > arm64_init_kernel_pgd(void); @@ -375,7 +376,11 @@ arm64_init(int
> > when)
> >
> > case POST_GDB:
> > arm64_calc_virtual_memory_ranges();
> > - machdep->section_size_bits = _SECTION_SIZE_BITS;
> > + arm64_get_section_size_bits();
> > + if (CRASHDEBUG(1)) {
> > + fprintf(fp, "SECTION_SIZE_BITS: %ld\n",
> > machdep->section_size_bits);
> > + }
> > +
> > if (!machdep->max_physmem_bits) {
> > if ((string =
> > pc->read_vmcoreinfo("NUMBER(MAX_PHYSMEM_BITS)"))) {
> > machdep->max_physmem_bits =
> > atol(string); @@ -1055,6 +1060,32 @@ arm64_calc_phys_offset(void)
> > fprintf(fp, "using %lx as phys_offset\n",
> > ms->phys_offset); }
> >
> > +/*
> > + * Determine SECTION_SIZE_BITS either by reading VMCOREINFO or the
> > +kernel
> > + * config, otherwise borrow the 64-bit ARM default definiton.
> > + */
> > +static void
> > +arm64_get_section_size_bits(void)
> > +{
> > + int ret;
> > + char *string;
> > +
> > + if ((string = pc->read_vmcoreinfo("NUMBER(SECTION_SIZE_BITS)"))) {
> > + machdep->section_size_bits = atol(string);
> > + free(string);
> > + return;
> > + }
> > +
> > + if ((ret = get_kernel_config("CONFIG_MEMORY_HOTPLUG", NULL))
> > + ==
> > IKCONFIG_Y) {
> > + if ((ret =
> > + get_kernel_config("CONFIG_HOTPLUG_SIZE_BITS",
> > &string)) == IKCONFIG_STR) {
> > + machdep->section_size_bits = atol(string);
> > + free(string);
> > + return;
> > + }
> > + } else {
> > + machdep->section_size_bits = _SECTION_SIZE_BITS;
> > + }
> > +}
> >
> > Then I make and load the dumpfiles by crash, it occurs a segment
> > fault as
> > below:
> > crash[31000]: segfault at 0 ip 00007f0fb24d98d1 sp 00007fff1703f7e8
> > error 4 in libc-2.26.so[7f0fb235b000+1d6000]
> >
> > So I add debug to find out the segfault reason, It occurred in
> > setup_ikconfig-> add_ikconfig_entry.
> > add_ikconfig_entry: ▒▒▒U //The last ent is a gibberish, lead
> > to segfault
> >
> > I think the most advisable judgement is if an ikconfig entry start
> > with "CONFIG_". I debug by the following patch and never reproduce
> > segfault again.
> > diff --git a/kernel.c b/kernel.c
> > index 7804aef..d023c87 100644
> > --- a/kernel.c
> > +++ b/kernel.c
> > @@ -10144,7 +10144,7 @@ static int setup_ikconfig(char *config)
> > while (whitespace(*ent))
> > ent++;
> >
> > - if (ent[0] != '#') {
> > + if (!strncmp(ent, "CONFIG_", strlen("CONFIG_"))) {
> > add_ikconfig_entry(ent,
> > &ikconfig_all[kt->ikconfig_ents++]);
> > if (kt->ikconfig_ents == IKCONFIG_MAX) {
> >
> > Thanks for your review. I’m looking forward to your favourable reply!
> >
> > Best regards,
> > Qiwu
> >
> >
> >
> >
> > #/******本邮件及其附件含有小米公司的保密信息，仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用（包括但不限于
> > 全部
> > 或部分地泄露、复制、或散发）本邮件中的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本邮件！
> > This e-mail and its attachments contain confidential information
> > from XIAOMI, which is intended only for the person or entity whose
> > address is listed above. Any use of the information contained herein
> > in any way (including, but not limited to, total or partial
> > disclosure, reproduction, or dissemination) by persons other than
> > the intended
> > recipient(s) is prohibited. If you receive this e-mail in error,
> > please notify the sender by phone or email immediately and delete
> > it!******/#
> >
> #/******本邮件及其附件含有小米公司的保密信息，仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部
> 或部分地泄露、复制、或散发）本邮件中的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本邮件！
> This e-mail and its attachments contain confidential information from
> XIAOMI, which is intended only for the person or entity whose address
> is listed above. Any use of the information contained herein in any
> way (including, but not limited to, total or partial disclosure,
> reproduction, or dissemination) by persons other than the intended
> recipient(s) is prohibited. If you receive this e-mail in error,
> please notify the sender by phone or email immediately and delete
> it!******/#
>
#/******本邮件及其附件含有小米公司的保密信息，仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制、或散发）本邮件中的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本邮件！ This e-mail and its attachments contain confidential information from XIAOMI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!******/#
5 years, 1 month
- 2
- 1
[PATCH] Fix a segfault in setup_ikconfig.
by 陈启武
Hi Anderson,
I want to introduce a patch to your crash tool project. It’s a bugfix for a segfault in setup_ikconfig.
We add an ikconfig entry only if ent[0] != '#', it is not an advisable condition because there is a potential segfault risk if ent is gibberish.
I explain the reproducing steps about this segfault case:
I try to apply the following patch to crash 7.2.6++ code for a test.
--- a/arm64.c
+++ b/arm64.c
@@ -32,6 +32,7 @@ static int verify_kimage_voffset(void);
static void arm64_calc_kimage_voffset(void);
static void arm64_calc_phys_offset(void);
static void arm64_calc_virtual_memory_ranges(void);
+static void arm64_get_section_size_bits(void);
static int arm64_kdump_phys_base(ulong *);
static ulong arm64_processor_speed(void);
static void arm64_init_kernel_pgd(void);
@@ -375,7 +376,11 @@ arm64_init(int when)
case POST_GDB:
arm64_calc_virtual_memory_ranges();
- machdep->section_size_bits = _SECTION_SIZE_BITS;
+ arm64_get_section_size_bits();
+ if (CRASHDEBUG(1)) {
+ fprintf(fp, "SECTION_SIZE_BITS: %ld\n", machdep->section_size_bits);
+ }
+
if (!machdep->max_physmem_bits) {
if ((string = pc->read_vmcoreinfo("NUMBER(MAX_PHYSMEM_BITS)"))) {
machdep->max_physmem_bits = atol(string);
@@ -1055,6 +1060,32 @@ arm64_calc_phys_offset(void)
fprintf(fp, "using %lx as phys_offset\n", ms->phys_offset);
}
+/*
+ * Determine SECTION_SIZE_BITS either by reading VMCOREINFO or the kernel
+ * config, otherwise borrow the 64-bit ARM default definiton.
+ */
+static void
+arm64_get_section_size_bits(void)
+{
+ int ret;
+ char *string;
+
+ if ((string = pc->read_vmcoreinfo("NUMBER(SECTION_SIZE_BITS)"))) {
+ machdep->section_size_bits = atol(string);
+ free(string);
+ return;
+ }
+
+ if ((ret = get_kernel_config("CONFIG_MEMORY_HOTPLUG", NULL)) == IKCONFIG_Y) {
+ if ((ret = get_kernel_config("CONFIG_HOTPLUG_SIZE_BITS", &string)) == IKCONFIG_STR) {
+ machdep->section_size_bits = atol(string);
+ free(string);
+ return;
+ }
+ } else {
+ machdep->section_size_bits = _SECTION_SIZE_BITS;
+ }
+}
Then I make and load the dumpfiles by crash, it occurs a segment fault as below:
crash[31000]: segfault at 0 ip 00007f0fb24d98d1 sp 00007fff1703f7e8 error 4 in libc-2.26.so[7f0fb235b000+1d6000]
So I add debug to find out the segfault reason, It occurred in setup_ikconfig-> add_ikconfig_entry.
add_ikconfig_entry: ▒▒▒U //The last ent is a gibberish, lead to segfault
I think the most advisable judgement is if an ikconfig entry start with "CONFIG_". I debug by the following patch and never reproduce segfault again.
diff --git a/kernel.c b/kernel.c
index 7804aef..d023c87 100644
--- a/kernel.c
+++ b/kernel.c
@@ -10144,7 +10144,7 @@ static int setup_ikconfig(char *config)
while (whitespace(*ent))
ent++;
- if (ent[0] != '#') {
+ if (!strncmp(ent, "CONFIG_", strlen("CONFIG_"))) {
add_ikconfig_entry(ent,
&ikconfig_all[kt->ikconfig_ents++]);
if (kt->ikconfig_ents == IKCONFIG_MAX) {
Thanks for your review. I’m looking forward to your favourable reply!
Best regards,
Qiwu
#/******本邮件及其附件含有小米公司的保密信息，仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制、或散发）本邮件中的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本邮件！ This e-mail and its attachments contain confidential information from XIAOMI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!******/#
5 years, 1 month
- 3
- 5
Problem with "timer" command on RHEL7.6
by Kazuhito Hagio
Hi Dave,
I noticed that the "timer" command prints somewhat wrongly for RHEL7.6 or
later kernels (not including RHEL8 / upstream) and found that it is because
struct tvec and tvec_root have an array of list_head, instead of hlist_head
in upstream kernels.
So the following patch looks good only for RHEL7, but I don't know how we
should determine the list type in order to switch the size, etc in this case.
What do you think?
Thanks,
Kazu
---
diff --git a/kernel.c b/kernel.c
index a79e5a3010ea..419cca3ac7ae 100644
--- a/kernel.c
+++ b/kernel.c
@@ -8376,7 +8376,7 @@ dump_timer_data_tvec_bases_v3(const ulong *cpus)
char buf4[BUFSIZE];
vec_root_size = vec_size = 0;
- head_size = SIZE(hlist_head);
+ head_size = SIZE(list_head);
if ((i = get_array_length("tvec_root.vec", NULL, head_size)))
vec_root_size = i;
@@ -8804,19 +8804,19 @@ do_timer_list_v3(ulong vec_kvaddr,
tdx++;
}
- readmem(vec_kvaddr, KVADDR, vec, SIZE(hlist_head) * size,
+ readmem(vec_kvaddr, KVADDR, vec, SIZE(list_head) * size,
"timer_list vec array", FAULT_ON_ERROR);
ld = &list_data;
timer_list_buf = GETBUF(SIZE(timer_list));
- for (i = count = 0; i < size; i++, vec_kvaddr += SIZE(hlist_head)) {
+ for (i = count = 0; i < size; i++, vec_kvaddr += SIZE(list_head)) {
- if (vec[i] == 0)
+ if (vec[i*2] == vec_kvaddr)
continue;
BZERO(ld, sizeof(struct list_data));
- ld->start = vec[i];
+ ld->start = vec[i*2];
ld->list_head_offset = OFFSET(timer_list_entry);
ld->end = vec_kvaddr;
ld->flags = RETURN_ON_LIST_ERROR;
5 years, 1 month
- 2
- 8