From 80eff6c484799722736471d15ff9cc86b64cae7a Mon Sep 17 00:00:00 2001 From: Balbir Singh Date: Mon, 30 Oct 2017 22:01:12 +1100 Subject: powerpc/xmon: Support dumping software pagetables 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 [mpe: Bike shed the output format, show the pgdir, fix build failures] Signed-off-by: Michael Ellerman --- arch/powerpc/xmon/xmon.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 116 insertions(+) (limited to 'arch/powerpc/xmon') diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index 6b1236b85622..1b2d8cb49abb 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include @@ -127,6 +128,7 @@ static void byterev(unsigned char *, int); static void memex(void); static int bsesc(void); static void dump(void); +static void show_pte(unsigned long); static void prdump(unsigned long, long); static int ppc_inst_dump(unsigned long, long, int); static void dump_log_buf(void); @@ -234,6 +236,7 @@ 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 +2616,9 @@ dump(void) dump_log_buf(); } else if (c == 'o') { dump_opal_msglog(); + } else if (c == 'v') { + /* dump virtual to physical translation */ + show_pte(adrs); } else if (c == 'r') { scanhex(&ndump); if (ndump == 0) @@ -2946,6 +2952,116 @@ 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; -- cgit v1.2.3