Hi, Pingfan
Thanks for the fix.
在 2021年03月18日 09:36, Pingfan Liu 写道:
> 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@xxxxxxxxxx>
> Cc: Lianbo Jiang <lijiang@xxxxxxxxxx>
> To: crash-utility@xxxxxxxxxx
> ---
> 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;
Is that possible to explicitly use the following ways instead of the magic number? For example:
((UL(1) << (52))) - ((UL(1) << (48))) or ((UL(1) << (VA_BITS))) something?
Thanks.
Lianbo
> + 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;
>
--
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