* [PATCH v5] powerpc/xmon: Support dumping software pagetables
@ 2017-10-30 11:01 Balbir Singh
2017-11-02 10:44 ` kbuild test robot
2017-11-14 11:12 ` [v5] " Michael Ellerman
0 siblings, 2 replies; 3+ messages in thread
From: Balbir Singh @ 2017-10-30 11:01 UTC (permalink / raw)
To: mpe; +Cc: linuxppc-dev, Balbir Singh
It would be nice to be able to dump page tables in a particular
context.
eg: dumping vmalloc space:
0:mon> dv 0xd00037fffff00000
pgd @ 0xc0000000017c0000
pgdp @ 0xc0000000017c00d8 = 0x00000000f10b1000
pudp @ 0xc0000000f10b13f8 = 0x00000000f10d0000
pmdp @ 0xc0000000f10d1ff8 = 0x00000000f1102000
ptep @ 0xc0000000f1102780 = 0xc0000000f1ba018e
Maps physical address = 0x00000000f1ba0000
Flags = Accessed Dirty Read Write
This patch does not replicate the complex code of dump_pagetable and
has no support for bolted linear mapping, thats why I've it's called
dump virtual page table support. The format of the PTE can be expanded
even further to add more useful information about the flags in the PTE
if required.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Bike shed the output format, show the pgdir]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
Changelog v5
- Remove dependence on CONFIG_HUGETLB_PAGE and
make the changes PPC_BOOK3S_64 dependent.
arch/powerpc/xmon/xmon.c | 122 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 122 insertions(+)
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 83e7faf5b3d3..9d9899c85d7c 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -28,6 +28,7 @@
#include <linux/bug.h>
#include <linux/nmi.h>
#include <linux/ctype.h>
+#include <linux/highmem.h>
#include <asm/debugfs.h>
#include <asm/ptrace.h>
@@ -127,6 +128,9 @@ static void byterev(unsigned char *, int);
static void memex(void);
static int bsesc(void);
static void dump(void);
+#ifdef CONFIG_PPC_BOOK3S_64
+static void show_pte(unsigned long);
+#endif
static void prdump(unsigned long, long);
static int ppc_inst_dump(unsigned long, long, int);
static void dump_log_buf(void);
@@ -234,6 +238,7 @@ Commands:\n\
#endif
"\
dr dump stream of raw bytes\n\
+ dv dump virtual address translation \n\
dt dump the tracing buffers (uses printk)\n\
dtc dump the tracing buffers for current CPU (uses printk)\n\
"
@@ -2613,6 +2618,11 @@ dump(void)
dump_log_buf();
} else if (c == 'o') {
dump_opal_msglog();
+ } else if (c == 'v') {
+#ifdef CONFIG_PPC_BOOK3S_64
+ /* dump virtual to physical translation */
+ show_pte(adrs);
+#endif
} else if (c == 'r') {
scanhex(&ndump);
if (ndump == 0)
@@ -2946,6 +2956,118 @@ static void show_task(struct task_struct *tsk)
tsk->comm);
}
+#ifdef CONFIG_PPC_BOOK3S_64
+void format_pte(void *ptep, unsigned long pte)
+{
+ printf("ptep @ 0x%016lx = 0x%016lx\n", (unsigned long)ptep, pte);
+ printf("Maps physical address = 0x%016lx\n", pte & PTE_RPN_MASK);
+
+ printf("Flags = %s%s%s%s%s\n",
+ (pte & _PAGE_ACCESSED) ? "Accessed " : "",
+ (pte & _PAGE_DIRTY) ? "Dirty " : "",
+ (pte & _PAGE_READ) ? "Read " : "",
+ (pte & _PAGE_WRITE) ? "Write " : "",
+ (pte & _PAGE_EXEC) ? "Exec " : "");
+}
+
+static void show_pte(unsigned long addr)
+{
+ unsigned long tskv = 0;
+ struct task_struct *tsk = NULL;
+ struct mm_struct *mm;
+ pgd_t *pgdp, *pgdir;
+ pud_t *pudp;
+ pmd_t *pmdp;
+ pte_t *ptep;
+
+ if (!scanhex(&tskv))
+ mm = &init_mm;
+ else
+ tsk = (struct task_struct *)tskv;
+
+ if (tsk == NULL)
+ mm = &init_mm;
+ else
+ mm = tsk->active_mm;
+
+ if (setjmp(bus_error_jmp) != 0) {
+ catch_memory_errors = 0;
+ printf("*** Error dumping pte for task %p\n", tsk);
+ return;
+ }
+
+ catch_memory_errors = 1;
+ sync();
+
+ if (mm == &init_mm) {
+ pgdp = pgd_offset_k(addr);
+ pgdir = pgd_offset_k(0);
+ } else {
+ pgdp = pgd_offset(mm, addr);
+ pgdir = pgd_offset(mm, 0);
+ }
+
+ if (pgd_none(*pgdp)) {
+ printf("no linux page table for address\n");
+ return;
+ }
+
+ printf("pgd @ 0x%016lx\n", pgdir);
+
+ if (pgd_huge(*pgdp)) {
+ format_pte(pgdp, pgd_val(*pgdp));
+ return;
+ }
+ printf("pgdp @ 0x%016lx = 0x%016lx\n", pgdp, pgd_val(*pgdp));
+
+ pudp = pud_offset(pgdp, addr);
+
+ if (pud_none(*pudp)) {
+ printf("No valid PUD\n");
+ return;
+ }
+
+ if (pud_huge(*pudp)) {
+ format_pte(pudp, pud_val(*pudp));
+ return;
+ }
+
+ printf("pudp @ 0x%016lx = 0x%016lx\n", pudp, pud_val(*pudp));
+
+ pmdp = pmd_offset(pudp, addr);
+
+ if (pmd_none(*pmdp)) {
+ printf("No valid PMD\n");
+ return;
+ }
+
+ if (pmd_huge(*pmdp)) {
+ format_pte(pmdp, pmd_val(*pmdp));
+ return;
+ }
+ printf("pmdp @ 0x%016lx = 0x%016lx\n", pmdp, pmd_val(*pmdp));
+
+ ptep = pte_offset_map(pmdp, addr);
+ if (pte_none(*ptep)) {
+ printf("no valid PTE\n");
+ return;
+ }
+
+ format_pte(ptep, pte_val(*ptep));
+
+ sync();
+ __delay(200);
+ catch_memory_errors = 0;
+}
+#else
+
+static void show_pte(unsigned long addr)
+{
+ printf("show_pte not yet implemented\n");
+}
+
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
static void show_tasks(void)
{
unsigned long tskv;
--
2.13.6
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v5] powerpc/xmon: Support dumping software pagetables
2017-10-30 11:01 [PATCH v5] powerpc/xmon: Support dumping software pagetables Balbir Singh
@ 2017-11-02 10:44 ` kbuild test robot
2017-11-14 11:12 ` [v5] " Michael Ellerman
1 sibling, 0 replies; 3+ messages in thread
From: kbuild test robot @ 2017-11-02 10:44 UTC (permalink / raw)
To: Balbir Singh; +Cc: kbuild-all, mpe, linuxppc-dev
[-- Attachment #1: Type: text/plain, Size: 1415 bytes --]
Hi Balbir,
I love your patch! Yet something to improve:
[auto build test ERROR on powerpc/next]
[also build test ERROR on v4.14-rc7 next-20171018]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Balbir-Singh/powerpc-xmon-Support-dumping-software-pagetables/20171102-071230
base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc-currituck_defconfig (attached as .config)
compiler: powerpc-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=powerpc
All errors (new ones prefixed by >>):
>> arch/powerpc/xmon/xmon.c:3064:13: error: 'show_pte' defined but not used [-Werror=unused-function]
static void show_pte(unsigned long addr)
^~~~~~~~
cc1: all warnings being treated as errors
vim +/show_pte +3064 arch/powerpc/xmon/xmon.c
3063
> 3064 static void show_pte(unsigned long addr)
3065 {
3066 printf("show_pte not yet implemented\n");
3067 }
3068
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 15103 bytes --]
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [v5] powerpc/xmon: Support dumping software pagetables
2017-10-30 11:01 [PATCH v5] powerpc/xmon: Support dumping software pagetables Balbir Singh
2017-11-02 10:44 ` kbuild test robot
@ 2017-11-14 11:12 ` Michael Ellerman
1 sibling, 0 replies; 3+ messages in thread
From: Michael Ellerman @ 2017-11-14 11:12 UTC (permalink / raw)
To: Balbir Singh; +Cc: linuxppc-dev
On Mon, 2017-10-30 at 11:01:12 UTC, Balbir Singh wrote:
> It would be nice to be able to dump page tables in a particular
> context.
>
> eg: dumping vmalloc space:
>
> 0:mon> dv 0xd00037fffff00000
> pgd @ 0xc0000000017c0000
> pgdp @ 0xc0000000017c00d8 = 0x00000000f10b1000
> pudp @ 0xc0000000f10b13f8 = 0x00000000f10d0000
> pmdp @ 0xc0000000f10d1ff8 = 0x00000000f1102000
> ptep @ 0xc0000000f1102780 = 0xc0000000f1ba018e
> Maps physical address = 0x00000000f1ba0000
> Flags = Accessed Dirty Read Write
>
> This patch does not replicate the complex code of dump_pagetable and
> has no support for bolted linear mapping, thats why I've it's called
> dump virtual page table support. The format of the PTE can be expanded
> even further to add more useful information about the flags in the PTE
> if required.
>
> Signed-off-by: Balbir Singh <bsingharora@gmail.com>
> [mpe: Bike shed the output format, show the pgdir]
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/80eff6c484799722736471d15ff9cc
cheers
^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-11-02 10:44 ` kbuild test robot
2017-11-14 11:12 ` [v5] " Michael Ellerman
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