DEBUG: channel: add consistency checks using BUG_ON_HOT() in some key functions
A few functions such as c_adv(), c_rew(), co_set_data() or co_skip() got a
BUG_ON_HOT() to make sure they're not used to push more data than available
in the buffer. Note that with HTX the margin can be high and will less easily
trigger, but the goal is to detect a misuse early enough.
co_data() should never be called with a wrong c->output. At least it never
happens in regtests, but we're adding a CHECK_IF_HOT() there to avoid crashing
but report it if it ever happened when the hot path checks are enabled.
diff --git a/include/haproxy/channel.h b/include/haproxy/channel.h
index 57e3d98..6829cbb 100644
--- a/include/haproxy/channel.h
+++ b/include/haproxy/channel.h
@@ -127,6 +127,7 @@
/* co_data() : returns the amount of output data in the channel's buffer */
static inline size_t co_data(const struct channel *c)
{
+ CHECK_IF_HOT(c->output > c_data(c));
return c->output;
}
@@ -170,6 +171,7 @@
static inline void c_adv(struct channel *c, size_t adv)
{
c->output += adv;
+ BUG_ON_HOT(c->output > c_data(c));
}
/* c_rew() : rewinds the channel's buffer by <adv> bytes, which means that the
@@ -179,6 +181,7 @@
*/
static inline void c_rew(struct channel *c, size_t adv)
{
+ BUG_ON_HOT(c->output < adv);
c->output -= adv;
}
@@ -191,6 +194,7 @@
/* Sets the amount of output for the channel */
static inline void co_set_data(struct channel *c, size_t output)
{
+ BUG_ON_HOT(output > c_data(c));
c->output = output;
}
@@ -932,6 +936,7 @@
*/
static inline void co_skip(struct channel *chn, int len)
{
+ BUG_ON_HOT(len > chn->output);
b_del(&chn->buf, len);
chn->output -= len;
c_realign_if_empty(chn);
@@ -946,8 +951,10 @@
struct htx_ret htxret;
htxret = htx_drain(htx, len);
- if (htxret.ret)
+ if (htxret.ret) {
+ BUG_ON_HOT(htxret.ret > chn->output);
chn->output -= htxret.ret;
+ }
}
/* Tries to copy chunk <chunk> into the channel's buffer after length controls.