[Crash-utility] [PATCHv5 3/3] crash-utility/arm64: assign page_offset with kernel configure value

On RHEL9, crash hits a bug when executing "crash /proc/kcore" : seek error: kernel virtual address: ffff6a0f3fff0000 type: "pmd page" The kernel virtual address does not vary with va_actual bits, instead, is determined by configuration value. But crash does not observe this fact. Since this disagreement only happens if 52-bits kernel on 48 bits platform, it can be handled only if "phys_offset_nominal < 0". Signed-off-by: Pingfan Liu <piliu(a)redhat.com&gt; Cc: HAGIO KAZUHITO <k-hagio-ab(a)nec.com&gt; Cc: Lianbo Jiang <lijiang(a)redhat.com&gt; Cc: Bhupesh Sharma <bhupesh.sharma(a)linaro.org&gt; To: crash-utility(a)redhat.com --- arm64.c | 10 +++++++++- defs.h | 1 + 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/arm64.c b/arm64.c index f1bac84..7cc19e8 100644 --- a/arm64.c +++ b/arm64.c @@ -221,7 +221,15 @@ arm64_init(int when) arm64_calc_VA_BITS(); arm64_calc_KERNELPACMASK(); ms = machdep->machspec; - if (ms->VA_BITS_ACTUAL) { + /* For 52-bits kernel running on 48 bits platform */ + if (ms->phys_offset_nominal < 0) { + ms->page_offset = ARM64_FLIP_PAGE_OFFSET; + /* useless on arm64 */ + machdep->identity_map_base = ARM64_FLIP_PAGE_OFFSET; + machdep->kvbase = ARM64_FLIP_PAGE_OFFSET; + ms->userspace_top = ARM64_USERSPACE_TOP_ACTUAL; + /* For 52-bits on 52-bits platform, or 48-bits on 48 */ + } else if (ms->VA_BITS_ACTUAL) { ms->page_offset = ARM64_FLIP_PAGE_OFFSET_ACTUAL; machdep->identity_map_base = ARM64_FLIP_PAGE_OFFSET_ACTUAL; machdep->kvbase = ARM64_FLIP_PAGE_OFFSET_ACTUAL; diff --git a/defs.h b/defs.h index 1007c69..f804212 100644 --- a/defs.h +++ b/defs.h @@ -3224,6 +3224,7 @@ typedef signed int s32; #define ARM64_PAGE_OFFSET ((0xffffffffffffffffUL) \ << (machdep->machspec->VA_BITS - 1)) /* kernels > v5.4 the kernel VA space is flipped */ +#define ARM64_FLIP_PAGE_OFFSET (-(1UL) << machdep->machspec->CONFIG_ARM64_VA_BITS) #define ARM64_FLIP_PAGE_OFFSET_ACTUAL ((0xffffffffffffffffUL) \ - ((1UL) << machdep->machspec->VA_BITS_ACTUAL) + 1) -- 2.29.2