[Crash-utility] [PATCH] arm64: fix page size calculation
As for v4.16-rc1, crash for arm64 fails to analyze the core dump,
with a message: cannot determine page size.
There seems to be a couple of reasons for this:
[1] splits a 64-bit field of image header, _kernel_flags_le, into two
32-bit values and in turn they have got a bit different names.
[2] and more recent [3] can possibly add extra space between idmap_pg_dir
and swapper_pg_dir.
This patch addresses both of changes.
[1] commit 6ad1fe5d9077 ("arm64: avoid R_AARCH64_ABS64 relocations for
Image header fields")
[2] commit 1e1b8c04fa34 ("arm64: entry: Move the trampoline to be before PAN")
[3] commit 4b65a5db3627 ("arm64: Introduce uaccess_{disable,enable}
functionality based on TTBR0_EL1")
Signed-off-by: AKASHI Takahiro <takahiro.akashi(a)linaro.org>
---
arm64.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/arm64.c b/arm64.c
index 7904f65..7f87d5b 100644
--- a/arm64.c
+++ b/arm64.c
@@ -172,8 +172,14 @@ arm64_init(int when)
if (!machdep->pagesize &&
kernel_symbol_exists("swapper_pg_dir") &&
kernel_symbol_exists("idmap_pg_dir")) {
- value = symbol_value("swapper_pg_dir") -
- symbol_value("idmap_pg_dir");
+ if (kernel_symbol_exists("tramp_pg_dir"))
+ value = symbol_value("tramp_pg_dir");
+ else if (kernel_symbol_exists("reserved_ttbr0"))
+ value = symbol_value("reserved_ttbr0");
+ else
+ value = symbol_value("swapper_pg_dir");
+
+ value -= symbol_value("idmap_pg_dir");
/*
* idmap_pg_dir is 2 pages prior to 4.1,
* and 3 pages thereafter. Only 4K and 64K
@@ -436,6 +442,12 @@ arm64_verify_symbol(const char *name, ulong value, char type)
if ((type == 'A') && STREQ(name, "_kernel_flags_le"))
machdep->machspec->kernel_flags = le64toh(value);
+ if ((type == 'A') && STREQ(name, "_kernel_flags_le_hi32"))
+ machdep->machspec->kernel_flags |= (le32toh(value) << 32);
+
+ if ((type == 'A') && STREQ(name, "_kernel_flags_le_lo32"))
+ machdep->machspec->kernel_flags |= le32toh(value);
+
if (((type == 'A') || (type == 'a')) && (highest_bit_long(value)
!= 63))
return FALSE;
--
2.15.1