Re: [PATCH 2/6] treewide: remove using list iterator after loop body as a ptr
From: Matthew Wilcox <willy@infradead.org>
Date: 2022-03-01 19:01:41
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Subsystem:
scheduler, the rest · Maintainers:
Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot, Linus Torvalds
On Tue, Mar 01, 2022 at 10:14:07AM -0800, Kees Cook wrote:
On Mon, Feb 28, 2022 at 04:45:11PM -0800, Linus Torvalds wrote:quoted
Really. The "-Wshadow doesn't work on the kernel" is not some new issue, because you have to do completely insane things to the source code to enable it.The first big glitch with -Wshadow was with shadowed global variables. GCC 4.8 fixed that, but it still yells about shadowed functions. What _almost_ works is -Wshadow=local. At first glace, all the warnings look solvable, but then one will eventually discover __wait_event() and associated macros that mix when and how deeply it intentionally shadows variables. :)
Well, that's just disgusting. Macros fundamentally shouldn't be referring to things that aren't in their arguments. The first step to cleaning this up is ... I'll take a look at the rest of cleaning this up soon. From 28ffe35d56223d4242b915832299e5acc926737e Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" <willy@infradead.org> Date: Tue, 1 Mar 2022 13:47:07 -0500 Subject: [PATCH] wait: Parameterize the return variable to ___wait_event() Macros should not refer to variables which aren't in their arguments. Pass the name from its callers. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- include/linux/swait.h | 12 ++++++------ include/linux/wait.h | 32 ++++++++++++++++---------------- include/linux/wait_bit.h | 4 ++-- 3 files changed, 24 insertions(+), 24 deletions(-)
diff --git a/include/linux/swait.h b/include/linux/swait.h
index 6a8c22b8c2a5..5e8e9b13be2d 100644
--- a/include/linux/swait.h
+++ b/include/linux/swait.h@@ -191,14 +191,14 @@ do { \ } while (0) #define __swait_event_timeout(wq, condition, timeout) \ - ___swait_event(wq, ___wait_cond_timeout(condition), \ + ___swait_event(wq, ___wait_cond_timeout(condition, __ret), \ TASK_UNINTERRUPTIBLE, timeout, \ __ret = schedule_timeout(__ret)) #define swait_event_timeout_exclusive(wq, condition, timeout) \ ({ \ long __ret = timeout; \ - if (!___wait_cond_timeout(condition)) \ + if (!___wait_cond_timeout(condition, __ret)) \ __ret = __swait_event_timeout(wq, condition, timeout); \ __ret; \ })
@@ -216,14 +216,14 @@ do { \ }) #define __swait_event_interruptible_timeout(wq, condition, timeout) \ - ___swait_event(wq, ___wait_cond_timeout(condition), \ + ___swait_event(wq, ___wait_cond_timeout(condition, __ret), \ TASK_INTERRUPTIBLE, timeout, \ __ret = schedule_timeout(__ret)) #define swait_event_interruptible_timeout_exclusive(wq, condition, timeout)\ ({ \ long __ret = timeout; \ - if (!___wait_cond_timeout(condition)) \ + if (!___wait_cond_timeout(condition, __ret)) \ __ret = __swait_event_interruptible_timeout(wq, \ condition, timeout); \ __ret; \
@@ -252,7 +252,7 @@ do { \ } while (0) #define __swait_event_idle_timeout(wq, condition, timeout) \ - ___swait_event(wq, ___wait_cond_timeout(condition), \ + ___swait_event(wq, ___wait_cond_timeout(condition, __ret), \ TASK_IDLE, timeout, \ __ret = schedule_timeout(__ret))
@@ -278,7 +278,7 @@ do { \ #define swait_event_idle_timeout_exclusive(wq, condition, timeout) \ ({ \ long __ret = timeout; \ - if (!___wait_cond_timeout(condition)) \ + if (!___wait_cond_timeout(condition, __ret)) \ __ret = __swait_event_idle_timeout(wq, \ condition, timeout); \ __ret; \
diff --git a/include/linux/wait.h b/include/linux/wait.h
index 851e07da2583..890cce3c0f2e 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h@@ -271,7 +271,7 @@ static inline void wake_up_pollfree(struct wait_queue_head *wq_head) __wake_up_pollfree(wq_head); } -#define ___wait_cond_timeout(condition) \ +#define ___wait_cond_timeout(condition, __ret) \ ({ \ bool __cond = (condition); \ if (__cond && !__ret) \
@@ -386,7 +386,7 @@ do { \ }) #define __wait_event_timeout(wq_head, condition, timeout) \ - ___wait_event(wq_head, ___wait_cond_timeout(condition), \ + ___wait_event(wq_head, ___wait_cond_timeout(condition, __ret), \ TASK_UNINTERRUPTIBLE, 0, timeout, \ __ret = schedule_timeout(__ret))
@@ -413,13 +413,13 @@ do { \ ({ \ long __ret = timeout; \ might_sleep(); \ - if (!___wait_cond_timeout(condition)) \ + if (!___wait_cond_timeout(condition, __ret)) \ __ret = __wait_event_timeout(wq_head, condition, timeout); \ __ret; \ }) #define __wait_event_freezable_timeout(wq_head, condition, timeout) \ - ___wait_event(wq_head, ___wait_cond_timeout(condition), \ + ___wait_event(wq_head, ___wait_cond_timeout(condition, __ret), \ TASK_INTERRUPTIBLE, 0, timeout, \ __ret = freezable_schedule_timeout(__ret))
@@ -431,7 +431,7 @@ do { \ ({ \ long __ret = timeout; \ might_sleep(); \ - if (!___wait_cond_timeout(condition)) \ + if (!___wait_cond_timeout(condition, __ret)) \ __ret = __wait_event_freezable_timeout(wq_head, condition, timeout); \ __ret; \ })
@@ -503,7 +503,7 @@ do { \ }) #define __wait_event_interruptible_timeout(wq_head, condition, timeout) \ - ___wait_event(wq_head, ___wait_cond_timeout(condition), \ + ___wait_event(wq_head, ___wait_cond_timeout(condition, __ret), \ TASK_INTERRUPTIBLE, 0, timeout, \ __ret = schedule_timeout(__ret))
@@ -531,7 +531,7 @@ do { \ ({ \ long __ret = timeout; \ might_sleep(); \ - if (!___wait_cond_timeout(condition)) \ + if (!___wait_cond_timeout(condition, __ret)) \ __ret = __wait_event_interruptible_timeout(wq_head, \ condition, timeout); \ __ret; \
@@ -698,7 +698,7 @@ do { \ } while (0) #define __wait_event_idle_timeout(wq_head, condition, timeout) \ - ___wait_event(wq_head, ___wait_cond_timeout(condition), \ + ___wait_event(wq_head, ___wait_cond_timeout(condition, __ret), \ TASK_IDLE, 0, timeout, \ __ret = schedule_timeout(__ret))
@@ -725,13 +725,13 @@ do { \ ({ \ long __ret = timeout; \ might_sleep(); \ - if (!___wait_cond_timeout(condition)) \ + if (!___wait_cond_timeout(condition, __ret)) \ __ret = __wait_event_idle_timeout(wq_head, condition, timeout); \ __ret; \ }) #define __wait_event_idle_exclusive_timeout(wq_head, condition, timeout) \ - ___wait_event(wq_head, ___wait_cond_timeout(condition), \ + ___wait_event(wq_head, ___wait_cond_timeout(condition, __ret), \ TASK_IDLE, 1, timeout, \ __ret = schedule_timeout(__ret))
@@ -762,7 +762,7 @@ do { \ ({ \ long __ret = timeout; \ might_sleep(); \ - if (!___wait_cond_timeout(condition)) \ + if (!___wait_cond_timeout(condition, __ret)) \ __ret = __wait_event_idle_exclusive_timeout(wq_head, condition, timeout);\ __ret; \ })
@@ -932,7 +932,7 @@ extern int do_wait_intr_irq(wait_queue_head_t *, wait_queue_entry_t *); }) #define __wait_event_killable_timeout(wq_head, condition, timeout) \ - ___wait_event(wq_head, ___wait_cond_timeout(condition), \ + ___wait_event(wq_head, ___wait_cond_timeout(condition, __ret), \ TASK_KILLABLE, 0, timeout, \ __ret = schedule_timeout(__ret))
@@ -962,7 +962,7 @@ extern int do_wait_intr_irq(wait_queue_head_t *, wait_queue_entry_t *); ({ \ long __ret = timeout; \ might_sleep(); \ - if (!___wait_cond_timeout(condition)) \ + if (!___wait_cond_timeout(condition, __ret)) \ __ret = __wait_event_killable_timeout(wq_head, \ condition, timeout); \ __ret; \
@@ -1107,7 +1107,7 @@ do { \ }) #define __wait_event_lock_irq_timeout(wq_head, condition, lock, timeout, state) \ - ___wait_event(wq_head, ___wait_cond_timeout(condition), \ + ___wait_event(wq_head, ___wait_cond_timeout(condition, __ret), \ state, 0, timeout, \ spin_unlock_irq(&lock); \ __ret = schedule_timeout(__ret); \
@@ -1141,7 +1141,7 @@ do { \ timeout) \ ({ \ long __ret = timeout; \ - if (!___wait_cond_timeout(condition)) \ + if (!___wait_cond_timeout(condition, __ret)) \ __ret = __wait_event_lock_irq_timeout( \ wq_head, condition, lock, timeout, \ TASK_INTERRUPTIBLE); \
@@ -1151,7 +1151,7 @@ do { \ #define wait_event_lock_irq_timeout(wq_head, condition, lock, timeout) \ ({ \ long __ret = timeout; \ - if (!___wait_cond_timeout(condition)) \ + if (!___wait_cond_timeout(condition, __ret)) \ __ret = __wait_event_lock_irq_timeout( \ wq_head, condition, lock, timeout, \ TASK_UNINTERRUPTIBLE); \
diff --git a/include/linux/wait_bit.h b/include/linux/wait_bit.h
index 7dec36aecbd9..227e6a20a978 100644
--- a/include/linux/wait_bit.h
+++ b/include/linux/wait_bit.h@@ -292,7 +292,7 @@ do { \ }) #define __wait_var_event_timeout(var, condition, timeout) \ - ___wait_var_event(var, ___wait_cond_timeout(condition), \ + ___wait_var_event(var, ___wait_cond_timeout(condition, __ret), \ TASK_UNINTERRUPTIBLE, 0, timeout, \ __ret = schedule_timeout(__ret))
@@ -300,7 +300,7 @@ do { \ ({ \ long __ret = timeout; \ might_sleep(); \ - if (!___wait_cond_timeout(condition)) \ + if (!___wait_cond_timeout(condition, __ret)) \ __ret = __wait_var_event_timeout(var, condition, timeout); \ __ret; \ })
--
2.34.1