[Crash-utility] [PATCH v2 1/2] arm64: add tag_mask machdep option
Raw ramdumps without vmcoreinfo does not work currently
with pointer authentication enabled. The arm capability
array can be queried but that creates a dependency on
the bits identifying the capabilities. Add a machdep
option instead to mask the tags when PAC is enabled.
Signed-off-by: Vinayak Menon <vinayakm.list(a)gmail.com>
---
arm64.c | 20 +++++++++++++++-----
crash.8 | 1 +
defs.h | 1 +
help.c | 1 +
4 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/arm64.c b/arm64.c
index 37aed07..5b59972 100644
--- a/arm64.c
+++ b/arm64.c
@@ -763,6 +763,8 @@ arm64_parse_machdep_arg_l(char *argstring, char *param, ulong *value)
*value = dtol(p, flags, &err);
} else if (STRNEQ(argstring, "vabits_actual")) {
*value = dtol(p, flags, &err);
+ } else if (STRNEQ(argstring, "tag_mask")) {
+ *value = htol(p, flags, &err);
} else if (megabytes) {
*value = dtol(p, flags, &err);
if (!err)
@@ -796,7 +798,6 @@ arm64_parse_cmdline_args(void)
for (index = 0; index < MAX_MACHDEP_ARGS; index++) {
if (!machdep->cmdline_args[index])
break;
-
if (!strstr(machdep->cmdline_args[index], "=")) {
error(WARNING, "ignoring --machdep option: %x\n",
machdep->cmdline_args[index]);
@@ -838,6 +839,12 @@ arm64_parse_cmdline_args(void)
"setting vabits_actual to: %ld\n\n",
machdep->machspec->VA_BITS_ACTUAL);
continue;
+ } else if (arm64_parse_machdep_arg_l(arglist[i], "tag_mask",
+ &machdep->machspec->tag_mask)) {
+ error(NOTE,
+ "setting tag_mask to: %lx\n\n",
+ machdep->machspec->tag_mask);
+ continue;
}
error(WARNING, "ignoring --machdep option: %s\n",
@@ -4124,16 +4131,19 @@ arm64_swp_offset(ulong pte)
static void arm64_calc_KERNELPACMASK(void)
{
- ulong value;
+ ulong value = 0;
char *string;
if ((string = pc->read_vmcoreinfo("NUMBER(KERNELPACMASK)"))) {
value = htol(string, QUIET, NULL);
free(string);
- machdep->machspec->CONFIG_ARM64_KERNELPACMASK = value;
- if (CRASHDEBUG(1))
- fprintf(fp, "CONFIG_ARM64_KERNELPACMASK: %lx\n", value);
+ } else if (machdep->machspec->tag_mask) {
+ value = machdep->machspec->tag_mask;
}
+
+ machdep->machspec->CONFIG_ARM64_KERNELPACMASK = value;
+ if (CRASHDEBUG(1))
+ fprintf(fp, "CONFIG_ARM64_KERNELPACMASK: %lx\n", value);
}
#endif /* ARM64 */
diff --git a/crash.8 b/crash.8
index 5020ce1..de32bdb 100644
--- a/crash.8
+++ b/crash.8
@@ -289,6 +289,7 @@ ARM64:
kimage_voffset=<kimage_voffset-value>
max_physmem_bits=<value>
vabits_actual=<value>
+ tag_mask=<value>
X86:
page_offset=<CONFIG_PAGE_OFFSET-value>
.fi
diff --git a/defs.h b/defs.h
index 35b983a..d406f5f 100644
--- a/defs.h
+++ b/defs.h
@@ -3331,6 +3331,7 @@ struct machine_specific {
ulong VA_START;
ulong CONFIG_ARM64_KERNELPACMASK;
ulong physvirt_offset;
+ ulong tag_mask;
};
struct arm64_stackframe {
diff --git a/help.c b/help.c
index 531f50a..7f619d5 100644
--- a/help.c
+++ b/help.c
@@ -182,6 +182,7 @@ char *program_usage_info[] = {
" kimage_voffset=<kimage_voffset-value>",
" max_physmem_bits=<value>",
" vabits_actual=<value>",
+ " tag_mask=<value>",
" X86:",
" page_offset=<CONFIG_PAGE_OFFSET-value>",
"",