phys_to_virt() calculates virtual address. As a important factor,
page_offset is excepted to be accurate.
Since arm64 kernel exposes va_bits through vmcore, using it.
And for 52-bits kernel, due to flipped mm layout, the PAGE_OFFSET
formula should be:
UNIT64_MAX << va_bits
instead of
UNIT64_MAX << (va_bits - 1)
Signed-off-by: Pingfan Liu <pi...@redhat.com>
Cc: Kairui Song <kas...@tencent.com>
Cc: Simon Horman <ho...@verge.net.au>
Cc: Philipp Rudo <pr...@redhat.com>
To: kexec@lists.infradead.org
---
kexec/arch/arm64/kexec-arm64.c | 34 ++++++++++++++++++++++++++++++----
util_lib/elf_info.c | 5 +++++
util_lib/include/elf_info.h | 1 +
3 files changed, 36 insertions(+), 4 deletions(-)
diff --git a/kexec/arch/arm64/kexec-arm64.c b/kexec/arch/arm64/kexec-arm64.c
index 037e51c..86aadf0 100644
--- a/kexec/arch/arm64/kexec-arm64.c
+++ b/kexec/arch/arm64/kexec-arm64.c
@@ -54,7 +54,7 @@
static bool try_read_phys_offset_from_kcore = false;
/* Machine specific details. */
-static int va_bits;
+static int va_bits = -1;
static unsigned long page_offset;
/* Global varables the core kexec routines expect. */
@@ -876,7 +876,18 @@ static inline void set_phys_offset(long v, char
*set_method)
static int get_va_bits(void)
{
- unsigned long long stext_sym_addr = get_kernel_sym("_stext");
+ unsigned long long stext_sym_addr;
+
+ /*
+ * if already got from kcore
+ */
+ if (va_bits != -1)
+ goto out;
+
+
+ /* For kernel older than v4.19 */
+ fprintf(stderr, "Warning, can't get the VA_BITS from kcore\n");
+ stext_sym_addr = get_kernel_sym("_stext");
if (stext_sym_addr == 0) {
fprintf(stderr, "Can't get the symbol of _stext.\n");
@@ -900,6 +911,7 @@ static int get_va_bits(void)
return -1;
}
+out:
dbgprintf("va_bits : %d\n", va_bits);
return 0;
@@ -917,14 +929,27 @@ int get_page_offset(unsigned long *page_offset)
if (ret < 0)
return ret;
- *page_offset = (0xffffffffffffffffUL) << (va_bits - 1);
+ if (va_bits < 52)
+ *page_offset = UINT64_MAX << (va_bits - 1);
+ else
+ *page_offset = UINT64_MAX << va_bits;
+
dbgprintf("page_offset : %lx\n", *page_offset);
return 0;
}
+static void arm64_scan_vmcoreinfo(char *pos)
+{
+ const char *str;
+
+ str = "NUMBER(VA_BITS)=";
+ if (memcmp(str, pos, strlen(str)) == 0)
+ va_bits = strtoul(pos + strlen(str), NULL, 10);
+}
+
/**
- * get_phys_offset_from_vmcoreinfo_pt_note - Helper for getting PHYS_OFFSET
+ * get_phys_offset_from_vmcoreinfo_pt_note - Helper for getting PHYS_OFFSET
(and va_bits)
* from VMCOREINFO note inside 'kcore'.
*/
@@ -937,6 +962,7 @@ static int get_phys_offset_from_vmcoreinfo_pt_note(long
*phys_offset)
return EFAILED;
}
+ arch_scan_vmcoreinfo = arm64_scan_vmcoreinfo;
ret = read_phys_offset_elf_kcore(fd, phys_offset);
close(fd);
diff --git a/util_lib/elf_info.c b/util_lib/elf_info.c
index 5574c7f..d252eff 100644
--- a/util_lib/elf_info.c
+++ b/util_lib/elf_info.c
@@ -310,6 +310,8 @@ int get_pt_load(int idx,
#define NOT_FOUND_LONG_VALUE (-1)
+void (*arch_scan_vmcoreinfo)(char *pos);
+
void scan_vmcoreinfo(char *start, size_t size)
{
char *last = start + size - 1;
@@ -551,6 +553,9 @@ void scan_vmcoreinfo(char *start, size_t size)
}
}
+ if (arch_scan_vmcoreinfo != NULL)
+ (*arch_scan_vmcoreinfo)(pos);
+
if (last_line)
break;
}
diff --git a/util_lib/include/elf_info.h b/util_lib/include/elf_info.h
index f550d86..fdf4c3d 100644
--- a/util_lib/include/elf_info.h
+++ b/util_lib/include/elf_info.h
@@ -31,5 +31,6 @@ int get_pt_load(int idx,
int read_phys_offset_elf_kcore(int fd, long *phys_off);
int read_elf(int fd);
void dump_dmesg(int fd, void (*handler)(char*, unsigned int));
+extern void (*arch_scan_vmcoreinfo)(char *pos);
#endif /* ELF_INFO_H */
--
2.31.1
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