Date: Sun, 22 Mar 2015 19:25:55 +0800 From: Tiwei Bie <btw@mail.ustc.edu.cn> To: Mateusz Guzik <mjguzik@gmail.com> Cc: Konstantin Belousov <kostikbel@gmail.com>, freebsd-hackers@freebsd.org Subject: Re: [PATCH] Finish the task 'Validate coredump format string' Message-ID: <20150322112555.GA44277@freebsd> In-Reply-To: <20150322101401.GH14650@dft-labs.eu> References: <1426946345-67889-1-git-send-email-btw@mail.ustc.edu.cn> <20150321200500.GC14650@dft-labs.eu> <20150322091853.GA89976@freebsd> <20150322101401.GH14650@dft-labs.eu>
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On Sun, Mar 22, 2015 at 11:14:01AM +0100, Mateusz Guzik wrote:
> On Sun, Mar 22, 2015 at 05:19:40PM +0800, Tiwei Bie wrote:
[..]
>
> A dedicated sysinit func could fetch and validate the tunable, if any.
> If no tunable was provided it would alloc memory for the default.
>
My new patch, that uses a dedicated sysinit func to fetch and validate
the tunable:
---
sys/kern/kern_sig.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 59 insertions(+), 1 deletion(-)
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index 8410d9d..e2a00ba 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -3096,19 +3096,77 @@ static int compress_user_cores = 0;
static char corefilename[MAXPATHLEN] = {"%N.core"};
+static bool
+corefilename_check(const char *format)
+{
+ int i, counti;
+
+ counti = 0;
+ for (i = 0; format[i] != '\0'; i++) {
+ if (format[i] == '%') {
+ i++;
+ switch (format[i]) {
+ case 'I':
+ counti++;
+ if (counti > 1) {
+ printf("Too many index flags specified "
+ "in corename `%s'\n", format);
+ return (false);
+ }
+ case '%':
+ case 'H':
+ case 'N':
+ case 'P':
+ case 'U':
+ break;
+ default:
+ printf("Unknown format character %c in "
+ "corename `%s'\n", format[i], format);
+ return (false);
+ }
+ }
+ }
+
+ return (true);
+}
+
+static void
+corefilename_init(void *arg)
+{
+ char *format = kern_getenv("kern.corefile");
+
+ if (format != NULL && corefilename_check(format))
+ strncpy(corefilename, format, sizeof(corefilename));
+}
+SYSINIT(corefilename, SI_SUB_KMEM, SI_ORDER_FIRST, corefilename_init, 0);
+
static int
sysctl_kern_corefile(SYSCTL_HANDLER_ARGS)
{
+ char *format;
int error;
+ format = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
+
+ sx_slock(&corefilename_lock);
+ strncpy(format, corefilename, MAXPATHLEN);
+ sx_sunlock(&corefilename_lock);
+
+ error = sysctl_handle_string(oidp, format, MAXPATHLEN, req);
+ if (error != 0 || strcmp(format, corefilename) == 0 ||
+ !corefilename_check(format))
+ goto out;
+
sx_xlock(&corefilename_lock);
error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename),
req);
sx_xunlock(&corefilename_lock);
+out:
+ free(format, M_TEMP);
return (error);
}
-SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RWTUN |
+SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW |
CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A",
"Process corefile name format string");
--
2.1.2
Best regards,
Tiwei Bie
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