Re: [Crash-utility] [PATCH] arm64: store phy_offset and memstart_addr separately

With kernel commit 7bc1a0f9e176 ("arm64: mm: use single quantity to represent the PA to VA translation"), memstart_addr can be negative, which makes it different from real phy_offset. In crash utility, PTOV() needs memstart_addr, while getting PFN offset in a dumpfile, phy_offset is required. So storing them separately for different purpose. Signed-off-by: Pingfan Liu <piliu(a)redhat.com&gt; Cc: Lianbo Jiang <lijiang(a)redhat.com&gt; To: crash-utility(a)redhat.com --- arm64.c | 22 +++++++++++++++++++--- defs.h | 1 + 2 files changed, 20 insertions(+), 3 deletions(-) diff --git a/arm64.c b/arm64.c index 37aed07..e560d07 100644 --- a/arm64.c +++ b/arm64.c @@ -687,6 +687,7 @@ arm64_dump_machdep_table(ulong arg) fprintf(fp, " kimage_voffset: %016lx\n", ms->kimage_voffset); } fprintf(fp, " phys_offset: %lx\n", ms->phys_offset); + fprintf(fp, " memstart_addr: %lx\n", ms->memstart_addr); fprintf(fp, "__exception_text_start: %lx\n", ms->__exception_text_start); fprintf(fp, " __exception_text_end: %lx\n", ms->__exception_text_end); fprintf(fp, " __irqentry_text_start: %lx\n", ms->__irqentry_text_start); @@ -987,7 +988,7 @@ arm64_calc_physvirt_offset(void) ulong physvirt_offset; struct syment *sp; - ms->physvirt_offset = ms->phys_offset - ms->page_offset; + ms->physvirt_offset = ms->memstart_addr - ms->page_offset; if ((sp = kernel_symbol_search("physvirt_offset")) && machdep->machspec->kimage_voffset) { @@ -1028,7 +1029,11 @@ arm64_calc_phys_offset(void) ms->kimage_voffset && (sp = kernel_symbol_search("memstart_addr"))) { if (pc->flags & PROC_KCORE) { if ((string = pc->read_vmcoreinfo("NUMBER(PHYS_OFFSET)"))) { - ms->phys_offset = htol(string, QUIET, NULL); + ms->memstart_addr = htol(string, QUIET, NULL); + if (ms->memstart_addr < 0) + ms->phys_offset = ms->memstart_addr + 0xffff000000000000 - 0xfff0000000000000;

+ else + ms->phys_offset = ms->memstart_addr; free(string); return; } @@ -1080,7 +1085,18 @@ arm64_calc_phys_offset(void) } else if (DISKDUMP_DUMPFILE() && diskdump_phys_base(&phys_offset)) { ms->phys_offset = phys_offset; } else if (KDUMP_DUMPFILE() && arm64_kdump_phys_base(&phys_offset)) { - ms->phys_offset = phys_offset; + /* + * When running a 52bits kernel on 48bits hardware. Kernel plays a trick: + * if (IS_ENABLED(CONFIG_ARM64_VA_BITS_52) && (vabits_actual != 52)) + * memstart_addr -= _PAGE_OFFSET(48) - _PAGE_OFFSET(52); + * + * In crash, this should be detected to get a real physical start address. + */ + ms->memstart_addr = phys_offset; + if ((long)phys_offset < 0) + ms->phys_offset = phys_offset + 0xffff000000000000 - 0xfff0000000000000; + else + ms->phys_offset = phys_offset; } else { error(WARNING, "phys_offset cannot be determined from the dumpfile.\n"); diff --git a/defs.h b/defs.h index 35b983a..64f2bcb 100644 --- a/defs.h +++ b/defs.h @@ -3290,6 +3290,7 @@ struct machine_specific { ulong modules_vaddr; ulong modules_end; ulong phys_offset; + long memstart_addr; ulong __exception_text_start; ulong __exception_text_end; struct arm64_pt_regs *panic_task_regs;