From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Jim Cromie <jim.cromie@gmail.com>,
jbaron@akamai.com,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 4.14 19/22] dyndbg: fix a BUG_ON in ddebug_describe_flags
Date: Mon, 10 Aug 2020 15:13:41 -0400 [thread overview]
Message-ID: <20200810191345.3795166-19-sashal@kernel.org> (raw)
In-Reply-To: <20200810191345.3795166-1-sashal@kernel.org>
From: Jim Cromie <jim.cromie@gmail.com>
[ Upstream commit f678ce8cc3cb2ad29df75d8824c74f36398ba871 ]
ddebug_describe_flags() currently fills a caller provided string buffer,
after testing its size (also passed) in a BUG_ON. Fix this by
replacing them with a known-big-enough string buffer wrapped in a
struct, and passing that instead.
Also simplify ddebug_describe_flags() flags parameter from a struct to
a member in that struct, and hoist the member deref up to the caller.
This makes the function reusable (soon) where flags are unpacked.
Acked-by: <jbaron@akamai.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20200719231058.1586423-8-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
lib/dynamic_debug.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index c7c96bc7654af..91c451e0f4741 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -85,22 +85,22 @@ static struct { unsigned flag:8; char opt_char; } opt_array[] = {
{ _DPRINTK_FLAGS_NONE, '_' },
};
+struct flagsbuf { char buf[ARRAY_SIZE(opt_array)+1]; };
+
/* format a string into buf[] which describes the _ddebug's flags */
-static char *ddebug_describe_flags(struct _ddebug *dp, char *buf,
- size_t maxlen)
+static char *ddebug_describe_flags(unsigned int flags, struct flagsbuf *fb)
{
- char *p = buf;
+ char *p = fb->buf;
int i;
- BUG_ON(maxlen < 6);
for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
- if (dp->flags & opt_array[i].flag)
+ if (flags & opt_array[i].flag)
*p++ = opt_array[i].opt_char;
- if (p == buf)
+ if (p == fb->buf)
*p++ = '_';
*p = '\0';
- return buf;
+ return fb->buf;
}
#define vpr_info(fmt, ...) \
@@ -142,7 +142,7 @@ static int ddebug_change(const struct ddebug_query *query,
struct ddebug_table *dt;
unsigned int newflags;
unsigned int nfound = 0;
- char flagbuf[10];
+ struct flagsbuf fbuf;
/* search for matching ddebugs */
mutex_lock(&ddebug_lock);
@@ -199,8 +199,7 @@ static int ddebug_change(const struct ddebug_query *query,
vpr_info("changed %s:%d [%s]%s =%s\n",
trim_prefix(dp->filename), dp->lineno,
dt->mod_name, dp->function,
- ddebug_describe_flags(dp, flagbuf,
- sizeof(flagbuf)));
+ ddebug_describe_flags(dp->flags, &fbuf));
}
}
mutex_unlock(&ddebug_lock);
@@ -779,7 +778,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
{
struct ddebug_iter *iter = m->private;
struct _ddebug *dp = p;
- char flagsbuf[10];
+ struct flagsbuf flags;
vpr_info("called m=%p p=%p\n", m, p);
@@ -792,7 +791,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
seq_printf(m, "%s:%u [%s]%s =%s \"",
trim_prefix(dp->filename), dp->lineno,
iter->table->mod_name, dp->function,
- ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));
+ ddebug_describe_flags(dp->flags, &flags));
seq_escape(m, dp->format, "\t\r\n\"");
seq_puts(m, "\"\n");
--
2.25.1
next prev parent reply other threads:[~2020-08-10 19:14 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-10 19:13 [PATCH AUTOSEL 4.14 01/22] drm/tilcdc: fix leak & null ref in panel_connector_get_modes Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 02/22] Bluetooth: add a mutex lock to avoid UAF in do_enale_set Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 03/22] fs/btrfs: Add cond_resched() for try_release_extent_mapping() stalls Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 04/22] drm/radeon: Fix reference count leaks caused by pm_runtime_get_sync Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 05/22] video: fbdev: neofb: fix memory leak in neo_scan_monitor() Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 06/22] md-cluster: fix wild pointer of unlock_all_bitmaps() Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 07/22] arm64: dts: hisilicon: hikey: fixes to comply with adi, adv7533 DT binding Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 08/22] drm/nouveau: fix multiple instances of reference count leaks Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 09/22] drm/debugfs: fix plain echo to connector "force" attribute Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 10/22] irqchip/irq-mtk-sysirq: Replace spinlock with raw_spinlock Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 11/22] mm/mmap.c: Add cond_resched() for exit_mmap() CPU stalls Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 12/22] brcmfmac: To fix Bss Info flag definition Bug Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 13/22] brcmfmac: set state of hanger slot to FREE when flushing PSQ Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 14/22] iwlegacy: Check the return value of pcie_capability_read_*() Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 15/22] gpu: host1x: debug: Fix multiple channels emitting messages simultaneously Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 16/22] usb: gadget: net2280: fix memory leak on probe error handling paths Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 17/22] bdc: Fix bug causing crash after multiple disconnects Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 18/22] usb: bdc: Halt controller on suspend Sasha Levin
2020-08-10 19:13 ` Sasha Levin [this message]
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 20/22] dyndbg: prefer declarative init in caller, to memset in callee Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 21/22] bcache: fix super block seq numbers comparision in register_cache_set() Sasha Levin
2020-08-10 19:13 ` [PATCH AUTOSEL 4.14 22/22] ACPICA: Do not increment operation_region reference counts for field units Sasha Levin
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