Re: [Crash-utility] [PATCH v2] struct: Fix handing of percpu symbols (when symbolic argument only)
On Thu 2016-09-29 12:37 -0400, Dave Anderson wrote:
[ ... ]
Given that you are essentially specifying a completely new argument
type to the struct command, I'm going to have to NAK this patch.
That's OK.
To do what you want, honestly I don't really feel that it's
asking too much
to make it a two-step process, i.e, get the address first, and then apply it
to the struct command.
Agreed.
However, if you really feel it's worth it, I suppose you could
create a
new "indirect-pointer-argument-type" for the struct command that explicitly
specifies that it is a pointer to the target address.
No, it's not worth it actually. Perhaps a warning instead?
For e.g. something like this:
Subject: [PATCH] struct: warn if percpu symbol is of type pointer
---
symbols.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/symbols.c b/symbols.c
index 8b0d8b9..6447fad 100644
--- a/symbols.c
+++ b/symbols.c
@@ -81,6 +81,7 @@ static void cmd_datatype_common(ulong);
static void do_datatype_addr(struct datatype_member *, ulong, int,
ulong, char **, int);
static void process_gdb_output(char *, unsigned, const char *, int);
+static char *expr_type_name(const char *);
static int display_per_cpu_info(struct syment *, int, char *);
static struct load_module *get_module_percpu_sym_owner(struct syment *);
static int is_percpu_symbol(struct syment *);
@@ -6112,6 +6113,7 @@ cmd_datatype_common(ulong flags)
char *separator;
char *structname, *members;
char *memberlist[MAXARGS];
+ char *typename;
dm = &datatype_member;
count = 0xdeadbeef;
@@ -6122,6 +6124,7 @@ cmd_datatype_common(ulong flags)
separator = members = NULL;
cpuspec = NULL;
cpus = NULL;
+ typename = NULL;
while ((c = getopt(argcnt, args, "pxdhfuc:rvol:")) != EOF) {
switch (c)
@@ -6245,6 +6248,12 @@ cmd_datatype_common(ulong flags)
sp->name);
cpuspec = NULL;
}
+ typename = expr_type_name(sp->name);
+ if (cpuspec && typename &&
+ LASTCHAR(typename) == '*' ? 1 : 0)
+ error(WARNING,
+ "percpu symbol %s is of type pointer.\n",
+ sp->name);
addr = sp->value;
aflag++;
} else {
@@ -6364,6 +6373,9 @@ freebuf:
if (cpus)
FREEBUF(cpus);
+
+ if (typename)
+ FREEBUF(typename);
}
static void
--
2.5.5
--
Aaron Tomlin