* [PATCH 08/13] module: remove each_symbol_in_section
From: Christoph Hellwig @ 2021-01-28 18:14 UTC (permalink / raw)
To: Frederic Barrat, Andrew Donnellan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, David Airlie, Daniel Vetter,
Jessica Yu, Josh Poimboeuf, Jiri Kosina, Miroslav Benes,
Petr Mladek, Joe Lawrence
Cc: Michal Marek, linux-kbuild, Masahiro Yamada, linux-kernel,
dri-devel, live-patching, linuxppc-dev
In-Reply-To: <20210128181421.2279-1-hch@lst.de>
each_symbol_in_section just contains a trivial loop over its arguments.
Just open code the loop in the two callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
kernel/module.c | 29 +++++++----------------------
1 file changed, 7 insertions(+), 22 deletions(-)
diff --git a/kernel/module.c b/kernel/module.c
index 5152fae1fc9406..945fe94b81fd92 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -433,30 +433,13 @@ extern const s32 __start___kcrctab_unused_gpl[];
#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
#endif
-static bool each_symbol_in_section(const struct symsearch *arr,
- unsigned int arrsize,
- struct module *owner,
- bool (*fn)(const struct symsearch *syms,
- struct module *owner,
- void *data),
- void *data)
-{
- unsigned int j;
-
- for (j = 0; j < arrsize; j++) {
- if (fn(&arr[j], owner, data))
- return true;
- }
-
- return false;
-}
-
/* Returns true as soon as fn returns true, otherwise false. */
static bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
struct module *owner,
void *data),
void *data)
{
+ unsigned int i;
struct module *mod;
static const struct symsearch arr[] = {
{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
@@ -479,8 +462,9 @@ static bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
module_assert_mutex_or_preempt();
- if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
- return true;
+ for (i = 0; i < ARRAY_SIZE(arr); i++)
+ if (fn(&arr[i], NULL, data))
+ return true;
list_for_each_entry_rcu(mod, &modules, list,
lockdep_is_held(&module_mutex)) {
@@ -509,8 +493,9 @@ static bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
if (mod->state == MODULE_STATE_UNFORMED)
continue;
- if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
- return true;
+ for (i = 0; i < ARRAY_SIZE(arr); i++)
+ if (fn(&arr[i], mod, data))
+ return true;
}
return false;
}
--
2.29.2
^ permalink raw reply related
* [PATCH 06/13] kallsyms: only build {, module_}kallsyms_on_each_symbol when required
From: Christoph Hellwig @ 2021-01-28 18:14 UTC (permalink / raw)
To: Frederic Barrat, Andrew Donnellan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, David Airlie, Daniel Vetter,
Jessica Yu, Josh Poimboeuf, Jiri Kosina, Miroslav Benes,
Petr Mladek, Joe Lawrence
Cc: Michal Marek, linux-kbuild, Masahiro Yamada, linux-kernel,
dri-devel, live-patching, linuxppc-dev
In-Reply-To: <20210128181421.2279-1-hch@lst.de>
kallsyms_on_each_symbol and module_kallsyms_on_each_symbol are only used
by the livepatching code, so don't build them if livepatching is not
enabled.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
include/linux/kallsyms.h | 17 ++++-------------
include/linux/module.h | 16 ++++------------
kernel/kallsyms.c | 2 ++
kernel/module.c | 2 ++
4 files changed, 12 insertions(+), 25 deletions(-)
diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
index 481273f0c72d42..465060acc9816f 100644
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h
@@ -71,15 +71,14 @@ static inline void *dereference_symbol_descriptor(void *ptr)
return ptr;
}
-#ifdef CONFIG_KALLSYMS
-/* Lookup the address for a symbol. Returns 0 if not found. */
-unsigned long kallsyms_lookup_name(const char *name);
-
-/* Call a function on each kallsyms symbol in the core kernel */
int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
unsigned long),
void *data);
+#ifdef CONFIG_KALLSYMS
+/* Lookup the address for a symbol. Returns 0 if not found. */
+unsigned long kallsyms_lookup_name(const char *name);
+
extern int kallsyms_lookup_size_offset(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset);
@@ -108,14 +107,6 @@ static inline unsigned long kallsyms_lookup_name(const char *name)
return 0;
}
-static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *,
- struct module *,
- unsigned long),
- void *data)
-{
- return 0;
-}
-
static inline int kallsyms_lookup_size_offset(unsigned long addr,
unsigned long *symbolsize,
unsigned long *offset)
diff --git a/include/linux/module.h b/include/linux/module.h
index a64aa84d1b182c..3ea4ffae608f97 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -608,10 +608,6 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
/* Look for this name: can be of form module:name. */
unsigned long module_kallsyms_lookup_name(const char *name);
-int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
- struct module *, unsigned long),
- void *data);
-
extern void __noreturn __module_put_and_exit(struct module *mod,
long code);
#define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code)
@@ -795,14 +791,6 @@ static inline unsigned long module_kallsyms_lookup_name(const char *name)
return 0;
}
-static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
- struct module *,
- unsigned long),
- void *data)
-{
- return 0;
-}
-
static inline int register_module_notifier(struct notifier_block *nb)
{
/* no events will happen anyway, so this can always succeed */
@@ -891,4 +879,8 @@ static inline bool module_sig_ok(struct module *module)
}
#endif /* CONFIG_MODULE_SIG */
+int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
+ struct module *, unsigned long),
+ void *data);
+
#endif /* _LINUX_MODULE_H */
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index a0d3f0865916f9..8043a90aa50ed3 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -177,6 +177,7 @@ unsigned long kallsyms_lookup_name(const char *name)
return module_kallsyms_lookup_name(name);
}
+#ifdef CONFIG_LIVEPATCH
/*
* Iterate over all symbols in vmlinux. For symbols from modules use
* module_kallsyms_on_each_symbol instead.
@@ -198,6 +199,7 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
}
return 0;
}
+#endif /* CONFIG_LIVEPATCH */
static unsigned long get_symbol_pos(unsigned long addr,
unsigned long *symbolsize,
diff --git a/kernel/module.c b/kernel/module.c
index ae9045c5292a78..856df9e17ff3d0 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4371,6 +4371,7 @@ unsigned long module_kallsyms_lookup_name(const char *name)
return ret;
}
+#ifdef CONFIG_LIVEPATCH
int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
struct module *, unsigned long),
void *data)
@@ -4401,6 +4402,7 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
mutex_unlock(&module_mutex);
return ret;
}
+#endif /* CONFIG_LIVEPATCH */
#endif /* CONFIG_KALLSYMS */
/* Maximum number of characters written by module_flags() */
--
2.29.2
^ permalink raw reply related
* [PATCH 05/13] kallsyms: refactor {,module_}kallsyms_on_each_symbol
From: Christoph Hellwig @ 2021-01-28 18:14 UTC (permalink / raw)
To: Frederic Barrat, Andrew Donnellan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, David Airlie, Daniel Vetter,
Jessica Yu, Josh Poimboeuf, Jiri Kosina, Miroslav Benes,
Petr Mladek, Joe Lawrence
Cc: Michal Marek, linux-kbuild, Masahiro Yamada, linux-kernel,
dri-devel, live-patching, linuxppc-dev
In-Reply-To: <20210128181421.2279-1-hch@lst.de>
Require an explicit call to module_kallsyms_on_each_symbol to look
for symbols in modules instead of the call from kallsyms_on_each_symbol,
and acquire module_mutex inside of module_kallsyms_on_each_symbol instead
of leaving that up to the caller.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
kernel/kallsyms.c | 6 +++++-
kernel/livepatch/core.c | 6 +-----
kernel/module.c | 8 ++++----
3 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index fe9de067771c34..a0d3f0865916f9 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -177,6 +177,10 @@ unsigned long kallsyms_lookup_name(const char *name)
return module_kallsyms_lookup_name(name);
}
+/*
+ * Iterate over all symbols in vmlinux. For symbols from modules use
+ * module_kallsyms_on_each_symbol instead.
+ */
int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
unsigned long),
void *data)
@@ -192,7 +196,7 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
if (ret != 0)
return ret;
}
- return module_kallsyms_on_each_symbol(fn, data);
+ return 0;
}
static unsigned long get_symbol_pos(unsigned long addr,
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 262cd9b003b9f0..f591dac5e86ef4 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -164,12 +164,8 @@ static int klp_find_object_symbol(const char *objname, const char *name,
.pos = sympos,
};
- mutex_lock(&module_mutex);
- if (objname)
+ if (objname || !kallsyms_on_each_symbol(klp_find_callback, &args))
module_kallsyms_on_each_symbol(klp_find_callback, &args);
- else
- kallsyms_on_each_symbol(klp_find_callback, &args);
- mutex_unlock(&module_mutex);
/*
* Ensure an address was found. If sympos is 0, ensure symbol is unique;
diff --git a/kernel/module.c b/kernel/module.c
index 6772fb2680eb3e..ae9045c5292a78 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4379,8 +4379,7 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
unsigned int i;
int ret;
- module_assert_mutex();
-
+ mutex_lock(&module_mutex);
list_for_each_entry(mod, &modules, list) {
/* We hold module_mutex: no need for rcu_dereference_sched */
struct mod_kallsyms *kallsyms = mod->kallsyms;
@@ -4396,10 +4395,11 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
ret = fn(data, kallsyms_symbol_name(kallsyms, i),
mod, kallsyms_symbol_value(sym));
if (ret != 0)
- return ret;
+ break;
}
}
- return 0;
+ mutex_unlock(&module_mutex);
+ return ret;
}
#endif /* CONFIG_KALLSYMS */
--
2.29.2
^ permalink raw reply related
* [PATCH 03/13] module: unexport find_module and module_mutex
From: Christoph Hellwig @ 2021-01-28 18:14 UTC (permalink / raw)
To: Frederic Barrat, Andrew Donnellan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, David Airlie, Daniel Vetter,
Jessica Yu, Josh Poimboeuf, Jiri Kosina, Miroslav Benes,
Petr Mladek, Joe Lawrence
Cc: Michal Marek, linux-kbuild, Masahiro Yamada, linux-kernel,
dri-devel, live-patching, linuxppc-dev
In-Reply-To: <20210128181421.2279-1-hch@lst.de>
find_module is not used by modular code any more, and random driver code
has no business calling it to start with.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
kernel/module.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/kernel/module.c b/kernel/module.c
index 4bf30e4b3eaaa1..981302f616b411 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -88,7 +88,6 @@
* (delete and add uses RCU list operations).
*/
DEFINE_MUTEX(module_mutex);
-EXPORT_SYMBOL_GPL(module_mutex);
static LIST_HEAD(modules);
/* Work queue for freeing init sections in success case */
@@ -672,7 +671,6 @@ struct module *find_module(const char *name)
module_assert_mutex();
return find_module_all(name, strlen(name), false);
}
-EXPORT_SYMBOL_GPL(find_module);
#ifdef CONFIG_SMP
--
2.29.2
^ permalink raw reply related
* [PATCH 04/13] module: use RCU to synchronize find_module
From: Christoph Hellwig @ 2021-01-28 18:14 UTC (permalink / raw)
To: Frederic Barrat, Andrew Donnellan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, David Airlie, Daniel Vetter,
Jessica Yu, Josh Poimboeuf, Jiri Kosina, Miroslav Benes,
Petr Mladek, Joe Lawrence
Cc: Michal Marek, linux-kbuild, Masahiro Yamada, linux-kernel,
dri-devel, live-patching, linuxppc-dev
In-Reply-To: <20210128181421.2279-1-hch@lst.de>
Allow for a RCU-sched critical section around find_module, following
the lower level find_module_all helper, and switch the two callers
outside of module.c to use such a RCU-sched critical section instead
of module_mutex.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
include/linux/module.h | 2 +-
kernel/livepatch/core.c | 5 +++--
kernel/module.c | 1 -
kernel/trace/trace_kprobe.c | 4 ++--
4 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/include/linux/module.h b/include/linux/module.h
index 7a0bcb5b1ffccd..a64aa84d1b182c 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -586,7 +586,7 @@ static inline bool within_module(unsigned long addr, const struct module *mod)
return within_module_init(addr, mod) || within_module_core(addr, mod);
}
-/* Search for module by name: must hold module_mutex. */
+/* Search for module by name: must be in a RCU-sched critical section. */
struct module *find_module(const char *name);
struct symsearch {
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index f76fdb9255323d..262cd9b003b9f0 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -19,6 +19,7 @@
#include <linux/moduleloader.h>
#include <linux/completion.h>
#include <linux/memory.h>
+#include <linux/rcupdate.h>
#include <asm/cacheflush.h>
#include "core.h"
#include "patch.h"
@@ -57,7 +58,7 @@ static void klp_find_object_module(struct klp_object *obj)
if (!klp_is_module(obj))
return;
- mutex_lock(&module_mutex);
+ rcu_read_lock_sched();
/*
* We do not want to block removal of patched modules and therefore
* we do not take a reference here. The patches are removed by
@@ -74,7 +75,7 @@ static void klp_find_object_module(struct klp_object *obj)
if (mod && mod->klp_alive)
obj->mod = mod;
- mutex_unlock(&module_mutex);
+ rcu_read_unlock_sched();
}
static bool klp_initialized(void)
diff --git a/kernel/module.c b/kernel/module.c
index 981302f616b411..6772fb2680eb3e 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -668,7 +668,6 @@ static struct module *find_module_all(const char *name, size_t len,
struct module *find_module(const char *name)
{
- module_assert_mutex();
return find_module_all(name, strlen(name), false);
}
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index e6fba1798771b4..3137992baa5e7a 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -124,9 +124,9 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
if (!p)
return true;
*p = '\0';
- mutex_lock(&module_mutex);
+ rcu_read_lock_sched();
ret = !!find_module(tk->symbol);
- mutex_unlock(&module_mutex);
+ rcu_read_unlock_sched();
*p = ':';
return ret;
--
2.29.2
^ permalink raw reply related
* [PATCH 02/13] drm: remove drm_fb_helper_modinit
From: Christoph Hellwig @ 2021-01-28 18:14 UTC (permalink / raw)
To: Frederic Barrat, Andrew Donnellan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, David Airlie, Daniel Vetter,
Jessica Yu, Josh Poimboeuf, Jiri Kosina, Miroslav Benes,
Petr Mladek, Joe Lawrence
Cc: Michal Marek, linux-kbuild, Masahiro Yamada, linux-kernel,
dri-devel, live-patching, linuxppc-dev
In-Reply-To: <20210128181421.2279-1-hch@lst.de>
drm_fb_helper_modinit has a lot of boilerplate for what is not very
simple functionality. Just open code it in the only caller using
IS_ENABLED and IS_MODULE, and skip the find_module check as a
request_module is harmless if the module is already loaded (and not
other caller has this find_module check either).
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/gpu/drm/drm_crtc_helper_internal.h | 10 ---------
drivers/gpu/drm/drm_fb_helper.c | 21 ------------------
drivers/gpu/drm/drm_kms_helper_common.c | 25 +++++++++++-----------
3 files changed, 12 insertions(+), 44 deletions(-)
diff --git a/drivers/gpu/drm/drm_crtc_helper_internal.h b/drivers/gpu/drm/drm_crtc_helper_internal.h
index 25ce42e799952c..61e09f8a8d0ff0 100644
--- a/drivers/gpu/drm/drm_crtc_helper_internal.h
+++ b/drivers/gpu/drm/drm_crtc_helper_internal.h
@@ -32,16 +32,6 @@
#include <drm/drm_encoder.h>
#include <drm/drm_modes.h>
-/* drm_fb_helper.c */
-#ifdef CONFIG_DRM_FBDEV_EMULATION
-int drm_fb_helper_modinit(void);
-#else
-static inline int drm_fb_helper_modinit(void)
-{
- return 0;
-}
-#endif
-
/* drm_dp_aux_dev.c */
#ifdef CONFIG_DRM_DP_AUX_CHARDEV
int drm_dp_aux_dev_init(void);
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 4b81195106875d..0b9f1ae1b7864c 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -2499,24 +2499,3 @@ void drm_fbdev_generic_setup(struct drm_device *dev,
drm_client_register(&fb_helper->client);
}
EXPORT_SYMBOL(drm_fbdev_generic_setup);
-
-/* The Kconfig DRM_KMS_HELPER selects FRAMEBUFFER_CONSOLE (if !EXPERT)
- * but the module doesn't depend on any fb console symbols. At least
- * attempt to load fbcon to avoid leaving the system without a usable console.
- */
-int __init drm_fb_helper_modinit(void)
-{
-#if defined(CONFIG_FRAMEBUFFER_CONSOLE_MODULE) && !defined(CONFIG_EXPERT)
- const char name[] = "fbcon";
- struct module *fbcon;
-
- mutex_lock(&module_mutex);
- fbcon = find_module(name);
- mutex_unlock(&module_mutex);
-
- if (!fbcon)
- request_module_nowait(name);
-#endif
- return 0;
-}
-EXPORT_SYMBOL(drm_fb_helper_modinit);
diff --git a/drivers/gpu/drm/drm_kms_helper_common.c b/drivers/gpu/drm/drm_kms_helper_common.c
index 221a8528c9937a..f933da1656eb52 100644
--- a/drivers/gpu/drm/drm_kms_helper_common.c
+++ b/drivers/gpu/drm/drm_kms_helper_common.c
@@ -64,19 +64,18 @@ MODULE_PARM_DESC(edid_firmware,
static int __init drm_kms_helper_init(void)
{
- int ret;
-
- /* Call init functions from specific kms helpers here */
- ret = drm_fb_helper_modinit();
- if (ret < 0)
- goto out;
-
- ret = drm_dp_aux_dev_init();
- if (ret < 0)
- goto out;
-
-out:
- return ret;
+ /*
+ * The Kconfig DRM_KMS_HELPER selects FRAMEBUFFER_CONSOLE (if !EXPERT)
+ * but the module doesn't depend on any fb console symbols. At least
+ * attempt to load fbcon to avoid leaving the system without a usable
+ * console.
+ */
+ if (IS_ENABLED(CONFIG_DRM_FBDEV_EMULATION) &&
+ IS_MODULE(CONFIG_FRAMEBUFFER_CONSOLE) &&
+ !IS_ENABLED(CONFIG_EXPERT))
+ request_module_nowait("fbcon");
+
+ return drm_dp_aux_dev_init();
}
static void __exit drm_kms_helper_exit(void)
--
2.29.2
^ permalink raw reply related
* module loader dead code removal and cleanups v2
From: Christoph Hellwig @ 2021-01-28 18:14 UTC (permalink / raw)
To: Frederic Barrat, Andrew Donnellan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, David Airlie, Daniel Vetter,
Jessica Yu, Josh Poimboeuf, Jiri Kosina, Miroslav Benes,
Petr Mladek, Joe Lawrence
Cc: Michal Marek, linux-kbuild, Masahiro Yamada, linux-kernel,
dri-devel, live-patching, linuxppc-dev
Hi all,
this series removes support for long term unused export types and
cleans up various loose ends in the module loader.
Changes since v1:
- move struct symsearch to module.c
- rework drm to not call find_module at all
- llow RCU-sched locking for find_module
- keep find_module as a public API instead of module_loaded
- update a few comments and commit logs
Diffstat:
arch/arm/configs/bcm2835_defconfig | 1
arch/arm/configs/mxs_defconfig | 1
arch/mips/configs/nlm_xlp_defconfig | 1
arch/mips/configs/nlm_xlr_defconfig | 1
arch/parisc/configs/generic-32bit_defconfig | 1
arch/parisc/configs/generic-64bit_defconfig | 1
arch/powerpc/configs/ppc6xx_defconfig | 1
arch/powerpc/platforms/powernv/pci-cxl.c | 22 -
arch/s390/configs/debug_defconfig | 1
arch/s390/configs/defconfig | 1
arch/sh/configs/edosk7760_defconfig | 1
arch/sh/configs/sdk7780_defconfig | 1
arch/x86/configs/i386_defconfig | 1
arch/x86/configs/x86_64_defconfig | 1
arch/x86/tools/relocs.c | 4
drivers/gpu/drm/drm_crtc_helper_internal.h | 10
drivers/gpu/drm/drm_fb_helper.c | 21 -
drivers/gpu/drm/drm_kms_helper_common.c | 25 +-
include/asm-generic/vmlinux.lds.h | 42 ---
include/linux/export.h | 9
include/linux/kallsyms.h | 17 -
include/linux/module.h | 48 ----
init/Kconfig | 17 -
kernel/kallsyms.c | 8
kernel/livepatch/core.c | 11
kernel/module.c | 310 +++++++++-------------------
kernel/trace/trace_kprobe.c | 4
lib/bug.c | 3
scripts/checkpatch.pl | 6
scripts/mod/modpost.c | 50 ----
scripts/mod/modpost.h | 3
scripts/module.lds.S | 6
tools/include/linux/export.h | 3
33 files changed, 142 insertions(+), 490 deletions(-)
^ permalink raw reply
* [PATCH 01/13] powerpc/powernv: remove get_cxl_module
From: Christoph Hellwig @ 2021-01-28 18:14 UTC (permalink / raw)
To: Frederic Barrat, Andrew Donnellan, Maarten Lankhorst,
Maxime Ripard, Thomas Zimmermann, David Airlie, Daniel Vetter,
Jessica Yu, Josh Poimboeuf, Jiri Kosina, Miroslav Benes,
Petr Mladek, Joe Lawrence
Cc: Michal Marek, linux-kbuild, Masahiro Yamada, linux-kernel,
dri-devel, live-patching, linuxppc-dev
In-Reply-To: <20210128181421.2279-1-hch@lst.de>
The static inline get_cxl_module function is entirely unused since commit
8bf6b91a5125a ("Revert "powerpc/powernv: Add support for the cxl kernel
api on the real phb"), so remove it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
---
arch/powerpc/platforms/powernv/pci-cxl.c | 22 ----------------------
1 file changed, 22 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/pci-cxl.c b/arch/powerpc/platforms/powernv/pci-cxl.c
index 8c739c94ed28d6..53172862d23bd3 100644
--- a/arch/powerpc/platforms/powernv/pci-cxl.c
+++ b/arch/powerpc/platforms/powernv/pci-cxl.c
@@ -150,25 +150,3 @@ int pnv_cxl_ioda_msi_setup(struct pci_dev *dev, unsigned int hwirq,
return 0;
}
EXPORT_SYMBOL(pnv_cxl_ioda_msi_setup);
-
-#if IS_MODULE(CONFIG_CXL)
-static inline int get_cxl_module(void)
-{
- struct module *cxl_module;
-
- mutex_lock(&module_mutex);
-
- cxl_module = find_module("cxl");
- if (cxl_module)
- __module_get(cxl_module);
-
- mutex_unlock(&module_mutex);
-
- if (!cxl_module)
- return -ENODEV;
-
- return 0;
-}
-#else
-static inline int get_cxl_module(void) { return 0; }
-#endif
--
2.29.2
^ permalink raw reply related
* Re: [PATCH] powerpc/sstep: Fix array out of bound warning
From: Naveen N. Rao @ 2021-01-28 17:20 UTC (permalink / raw)
To: Ravi Bangoria; +Cc: naveen.n.rao, paulus, linuxppc-dev, jniethe5
In-Reply-To: <20210115061620.692500-1-ravi.bangoria@linux.ibm.com>
On 2021/01/15 11:46AM, Ravi Bangoria wrote:
> Compiling kernel with -Warray-bounds throws below warning:
>
> In function 'emulate_vsx_store':
> warning: array subscript is above array bounds [-Warray-bounds]
> buf.d[2] = byterev_8(reg->d[1]);
> ~~~~~^~~
> buf.d[3] = byterev_8(reg->d[0]);
> ~~~~~^~~
>
> Fix it by converting local variable 'union vsx_reg buf' into an array.
> Also consider function argument 'union vsx_reg *reg' as array instead
> of pointer because callers are actually passing an array to it.
I think you should change the function prototype to reflect this.
However, while I agree with this change in principle, it looks to be a
lot of code churn for a fairly narrow use. Perhaps we should just
address the specific bug. Something like the below (not tested)?
@@ -818,13 +818,15 @@ void emulate_vsx_store(struct instruction_op *op, const union vsx_reg *reg,
break;
if (rev) {
/* reverse 32 bytes */
- buf.d[0] = byterev_8(reg->d[3]);
- buf.d[1] = byterev_8(reg->d[2]);
- buf.d[2] = byterev_8(reg->d[1]);
- buf.d[3] = byterev_8(reg->d[0]);
- reg = &buf;
+ union vsx_reg buf32[2];
+ buf32[0].d[0] = byterev_8(reg[1].d[1]);
+ buf32[0].d[1] = byterev_8(reg[1].d[0]);
+ buf32[1].d[0] = byterev_8(reg[0].d[1]);
+ buf32[1].d[1] = byterev_8(reg[0].d[0]);
+ memcpy(mem, buf32, size);
+ } else {
+ memcpy(mem, reg, size);
}
- memcpy(mem, reg, size);
break;
case 16:
/* stxv, stxvx, stxvl, stxvll */
- Naveen
^ permalink raw reply
* Re: [PATCH 03/13] livepatch: refactor klp_init_object
From: Christoph Hellwig @ 2021-01-28 16:24 UTC (permalink / raw)
To: Petr Mladek
Cc: Jiri Kosina, Andrew Donnellan, linux-kbuild, David Airlie,
Masahiro Yamada, Josh Poimboeuf, Maarten Lankhorst, linux-kernel,
Maxime Ripard, live-patching, Michal Marek, Joe Lawrence,
dri-devel, Thomas Zimmermann, Jessica Yu, Frederic Barrat,
Daniel Vetter, Miroslav Benes, linuxppc-dev, Christoph Hellwig
In-Reply-To: <20210128162240.GA3417@lst.de>
On Thu, Jan 28, 2021 at 05:22:40PM +0100, Christoph Hellwig wrote:
> > We need to either update the function description or keep this check.
> >
> > I prefer to keep the check. The function does the right thing also
> > for the object "vmlinux". Also the livepatch code includes many
> > similar paranoid checks that makes the code less error prone
> > against any further changes.
>
> Well, the check is in the caller now where we have a conditional for
> it. So I'd be tempted to either update the comment, or just drop the
> patch.
Also even without the check I think it will do the right thing when
called for vmlinux given that it simplify won't find a module called
vmlinux..
^ permalink raw reply
* Re: [PATCH 03/13] livepatch: refactor klp_init_object
From: Christoph Hellwig @ 2021-01-28 16:22 UTC (permalink / raw)
To: Petr Mladek
Cc: Jiri Kosina, Andrew Donnellan, linux-kbuild, David Airlie,
Masahiro Yamada, Josh Poimboeuf, Maarten Lankhorst, linux-kernel,
Maxime Ripard, live-patching, Michal Marek, Joe Lawrence,
dri-devel, Thomas Zimmermann, Jessica Yu, Frederic Barrat,
Daniel Vetter, Miroslav Benes, linuxppc-dev, Christoph Hellwig
In-Reply-To: <YBFjbbuQ7sn4T7yT@alley>
On Wed, Jan 27, 2021 at 01:58:21PM +0100, Petr Mladek wrote:
> > --- a/kernel/livepatch/core.c
> > +++ b/kernel/livepatch/core.c
> > @@ -54,9 +54,6 @@ static void klp_find_object_module(struct klp_object *obj)
> > {
> > struct module *mod;
> >
> > - if (!klp_is_module(obj))
> > - return;
> > -
>
> We need to either update the function description or keep this check.
>
> I prefer to keep the check. The function does the right thing also
> for the object "vmlinux". Also the livepatch code includes many
> similar paranoid checks that makes the code less error prone
> against any further changes.
Well, the check is in the caller now where we have a conditional for
it. So I'd be tempted to either update the comment, or just drop the
patch.
^ permalink raw reply
* Re: [PATCH 13/13] module: remove EXPORY_UNUSED_SYMBOL*
From: Christoph Hellwig @ 2021-01-28 16:09 UTC (permalink / raw)
To: Jessica Yu
Cc: Petr Mladek, Joe Lawrence, Andrew Donnellan, linux-kbuild,
David Airlie, Masahiro Yamada, Jiri Kosina, Maarten Lankhorst,
linux-kernel, Maxime Ripard, live-patching, Michal Marek,
dri-devel, Thomas Zimmermann, Josh Poimboeuf, Frederic Barrat,
Daniel Vetter, Miroslav Benes, linuxppc-dev, Christoph Hellwig
In-Reply-To: <YBFvcmUiHRjkucbf@gunter>
On Wed, Jan 27, 2021 at 02:49:38PM +0100, Jessica Yu wrote:
>> #ifdef CONFIG_MODULE_SIG
>> /* Signature was verified. */
>> bool sig_ok;
>> @@ -592,7 +580,6 @@ struct symsearch {
>> GPL_ONLY,
>> WILL_BE_GPL_ONLY,
>> } license;
>> - bool unused;
>> };
> Thanks for the cleanups. While we're here, I noticed that struct
> symsearch is only used internally in kernel/module.c, so I don't think
> it actually needs to be in include/linux/module.h. I don't see it used
> anywhere else. We could move maybe that to kernel/module-internal.h.
I've added a patch to just move it directly into module.c.
^ permalink raw reply
* Re: [PATCH] powerpc/fault: fix wrong KUAP fault for IO_URING
From: Zorro Lang @ 2021-01-28 15:20 UTC (permalink / raw)
To: Christophe Leroy; +Cc: Jens Axboe, linuxppc-dev, Nicholas Piggin
In-Reply-To: <17ae2706-fe95-a5de-b9da-e3480800daf7@csgroup.eu>
On Thu, Jan 28, 2021 at 03:44:21PM +0100, Christophe Leroy wrote:
>
>
> Le 28/01/2021 à 15:42, Jens Axboe a écrit :
> > On 1/28/21 6:52 AM, Zorro Lang wrote:
> > > On Wed, Jan 27, 2021 at 08:06:37PM -0700, Jens Axboe wrote:
> > > > On 1/27/21 8:13 PM, Zorro Lang wrote:
> > > > > On Thu, Jan 28, 2021 at 10:18:07AM +1000, Nicholas Piggin wrote:
> > > > > > Excerpts from Jens Axboe's message of January 28, 2021 5:29 am:
> > > > > > > On 1/27/21 9:38 AM, Christophe Leroy wrote:
> > > > > > > >
> > > > > > > >
> > > > > > > > Le 27/01/2021 à 15:56, Zorro Lang a écrit :
> > > > > > > > > On powerpc, io_uring test hit below KUAP fault on __do_page_fault.
> > > > > > > > > The fail source line is:
> > > > > > > > >
> > > > > > > > > if (unlikely(!is_user && bad_kernel_fault(regs, error_code, address, is_write)))
> > > > > > > > > return SIGSEGV;
> > > > > > > > >
> > > > > > > > > The is_user() is based on user_mod(regs) only. This's not suit for
> > > > > > > > > io_uring, where the helper thread can assume the user app identity
> > > > > > > > > and could perform this fault just fine. So turn to use mm to decide
> > > > > > > > > if this is valid or not.
> > > > > > > >
> > > > > > > > I don't understand why testing is_user would be an issue. KUAP purpose
> > > > > > > > it to block any unallowed access from kernel to user memory
> > > > > > > > (Equivalent to SMAP on x86). So it really must be based on MSR_PR bit,
> > > > > > > > that is what is_user provides.
> > > > > > > >
> > > > > > > > If the kernel access is legitimate, kernel should have opened
> > > > > > > > userspace access then you shouldn't get this "Bug: Read fault blocked
> > > > > > > > by KUAP!".
> > > > > > > >
> > > > > > > > As far as I understand, the fault occurs in
> > > > > > > > iov_iter_fault_in_readable() which calls fault_in_pages_readable() And
> > > > > > > > fault_in_pages_readable() uses __get_user() so it is a legitimate
> > > > > > > > access and you really should get a KUAP fault.
> > > > > > > >
> > > > > > > > So the problem is somewhere else, I think you proposed patch just
> > > > > > > > hides the problem, it doesn't fix it.
> > > > > > >
> > > > > > > If we do kthread_use_mm(), can we agree that the user access is valid?
> > > > > >
> > > > > > Yeah the io uring code is fine, provided it uses the uaccess primitives
> > > > > > like any other kernel code. It's looking more like a an arch/powerpc bug.
> > > > > >
> > > > > > > We should be able to copy to/from user space, and including faults, if
> > > > > > > that's been done and the new mm assigned. Because it really should be.
> > > > > > > If SMAP was a problem on x86, we would have seen it long ago.
> > > > > > >
> > > > > > > I'm assuming this may be breakage related to the recent uaccess changes
> > > > > > > related to set_fs and friends? Or maybe recent changes on the powerpc
> > > > > > > side?
> > > > > > >
> > > > > > > Zorro, did 5.10 work?
> > > > > >
> > > > > > Would be interesting to know.
> > > > >
> > > > > Sure Nick and Jens, which 5.10 rc? version do you want to know ? Or any git
> > > > > commit(be the HEAD) in 5.10 phase?
> > > >
> > > > I forget which versions had what series of this, but 5.10 final - and if
> > > > that fails, then 5.9 final. IIRC, 5.9 was pre any of these changes, and
> > > > 5.10 definitely has them.
> > >
> > > I justed built linux v5.10 with same .config file, and gave it same test.
> > > v5.10 (HEAD=2c85ebc57b Linux 5.10) can't reproduce this bug:
> > >
> > > # ./check generic/013 generic/051
> > > FSTYP -- xfs (non-debug)
> > > PLATFORM -- Linux/ppc64le ibm-p9z-xxx-xxxx 5.10.0 #3 SMP Thu Jan 28 04:12:14 EST 2021
> > > MKFS_OPTIONS -- -f -m crc=1,finobt=1,reflink=1,rmapbt=1,bigtime=1,inobtcount=1 /dev/sda3
> > > MOUNT_OPTIONS -- -o context=system_u:object_r:root_t:s0 /dev/sda3 /mnt/xfstests/scratch
> > >
> > > generic/013 138s ... 77s
> > > generic/051 103s ... 143s
> > > Ran: generic/013 generic/051
> > > Passed all 2 tests
> >
> > Thanks for testing that, so I think it's safe to conclude that there's a
> > regression in powerpc fault handling for kthreads that use
> > kthread_use_mm in this release. A bisect would definitely find it, but
> > might be pointless if Christophe or Nick already have an idea of what it
> > is.
> >
>
> I don't have any idea yet, but I'd be curious to see the vmlinux binary matching the reported Oops.
OK, I don't have the vmlinux matching that bug report now, I can help to prepare a new one, but
I need lots of time (about 10+ hours).
Thanks,
Zorro
>
> Christophe
>
^ permalink raw reply
* Re: [PATCH] powerpc/fault: fix wrong KUAP fault for IO_URING
From: Christophe Leroy @ 2021-01-28 14:44 UTC (permalink / raw)
To: Jens Axboe, Zorro Lang, Nicholas Piggin; +Cc: linuxppc-dev
In-Reply-To: <aedb880b-da2b-ec29-3b66-66f01733be9b@kernel.dk>
Le 28/01/2021 à 15:42, Jens Axboe a écrit :
> On 1/28/21 6:52 AM, Zorro Lang wrote:
>> On Wed, Jan 27, 2021 at 08:06:37PM -0700, Jens Axboe wrote:
>>> On 1/27/21 8:13 PM, Zorro Lang wrote:
>>>> On Thu, Jan 28, 2021 at 10:18:07AM +1000, Nicholas Piggin wrote:
>>>>> Excerpts from Jens Axboe's message of January 28, 2021 5:29 am:
>>>>>> On 1/27/21 9:38 AM, Christophe Leroy wrote:
>>>>>>>
>>>>>>>
>>>>>>> Le 27/01/2021 à 15:56, Zorro Lang a écrit :
>>>>>>>> On powerpc, io_uring test hit below KUAP fault on __do_page_fault.
>>>>>>>> The fail source line is:
>>>>>>>>
>>>>>>>> if (unlikely(!is_user && bad_kernel_fault(regs, error_code, address, is_write)))
>>>>>>>> return SIGSEGV;
>>>>>>>>
>>>>>>>> The is_user() is based on user_mod(regs) only. This's not suit for
>>>>>>>> io_uring, where the helper thread can assume the user app identity
>>>>>>>> and could perform this fault just fine. So turn to use mm to decide
>>>>>>>> if this is valid or not.
>>>>>>>
>>>>>>> I don't understand why testing is_user would be an issue. KUAP purpose
>>>>>>> it to block any unallowed access from kernel to user memory
>>>>>>> (Equivalent to SMAP on x86). So it really must be based on MSR_PR bit,
>>>>>>> that is what is_user provides.
>>>>>>>
>>>>>>> If the kernel access is legitimate, kernel should have opened
>>>>>>> userspace access then you shouldn't get this "Bug: Read fault blocked
>>>>>>> by KUAP!".
>>>>>>>
>>>>>>> As far as I understand, the fault occurs in
>>>>>>> iov_iter_fault_in_readable() which calls fault_in_pages_readable() And
>>>>>>> fault_in_pages_readable() uses __get_user() so it is a legitimate
>>>>>>> access and you really should get a KUAP fault.
>>>>>>>
>>>>>>> So the problem is somewhere else, I think you proposed patch just
>>>>>>> hides the problem, it doesn't fix it.
>>>>>>
>>>>>> If we do kthread_use_mm(), can we agree that the user access is valid?
>>>>>
>>>>> Yeah the io uring code is fine, provided it uses the uaccess primitives
>>>>> like any other kernel code. It's looking more like a an arch/powerpc bug.
>>>>>
>>>>>> We should be able to copy to/from user space, and including faults, if
>>>>>> that's been done and the new mm assigned. Because it really should be.
>>>>>> If SMAP was a problem on x86, we would have seen it long ago.
>>>>>>
>>>>>> I'm assuming this may be breakage related to the recent uaccess changes
>>>>>> related to set_fs and friends? Or maybe recent changes on the powerpc
>>>>>> side?
>>>>>>
>>>>>> Zorro, did 5.10 work?
>>>>>
>>>>> Would be interesting to know.
>>>>
>>>> Sure Nick and Jens, which 5.10 rc? version do you want to know ? Or any git
>>>> commit(be the HEAD) in 5.10 phase?
>>>
>>> I forget which versions had what series of this, but 5.10 final - and if
>>> that fails, then 5.9 final. IIRC, 5.9 was pre any of these changes, and
>>> 5.10 definitely has them.
>>
>> I justed built linux v5.10 with same .config file, and gave it same test.
>> v5.10 (HEAD=2c85ebc57b Linux 5.10) can't reproduce this bug:
>>
>> # ./check generic/013 generic/051
>> FSTYP -- xfs (non-debug)
>> PLATFORM -- Linux/ppc64le ibm-p9z-xxx-xxxx 5.10.0 #3 SMP Thu Jan 28 04:12:14 EST 2021
>> MKFS_OPTIONS -- -f -m crc=1,finobt=1,reflink=1,rmapbt=1,bigtime=1,inobtcount=1 /dev/sda3
>> MOUNT_OPTIONS -- -o context=system_u:object_r:root_t:s0 /dev/sda3 /mnt/xfstests/scratch
>>
>> generic/013 138s ... 77s
>> generic/051 103s ... 143s
>> Ran: generic/013 generic/051
>> Passed all 2 tests
>
> Thanks for testing that, so I think it's safe to conclude that there's a
> regression in powerpc fault handling for kthreads that use
> kthread_use_mm in this release. A bisect would definitely find it, but
> might be pointless if Christophe or Nick already have an idea of what it
> is.
>
I don't have any idea yet, but I'd be curious to see the vmlinux binary matching the reported Oops.
Christophe
^ permalink raw reply
* Re: [PATCH] powerpc/fault: fix wrong KUAP fault for IO_URING
From: Jens Axboe @ 2021-01-28 14:42 UTC (permalink / raw)
To: Zorro Lang, Nicholas Piggin; +Cc: linuxppc-dev
In-Reply-To: <20210128135220.GQ14354@localhost.localdomain>
On 1/28/21 6:52 AM, Zorro Lang wrote:
> On Wed, Jan 27, 2021 at 08:06:37PM -0700, Jens Axboe wrote:
>> On 1/27/21 8:13 PM, Zorro Lang wrote:
>>> On Thu, Jan 28, 2021 at 10:18:07AM +1000, Nicholas Piggin wrote:
>>>> Excerpts from Jens Axboe's message of January 28, 2021 5:29 am:
>>>>> On 1/27/21 9:38 AM, Christophe Leroy wrote:
>>>>>>
>>>>>>
>>>>>> Le 27/01/2021 à 15:56, Zorro Lang a écrit :
>>>>>>> On powerpc, io_uring test hit below KUAP fault on __do_page_fault.
>>>>>>> The fail source line is:
>>>>>>>
>>>>>>> if (unlikely(!is_user && bad_kernel_fault(regs, error_code, address, is_write)))
>>>>>>> return SIGSEGV;
>>>>>>>
>>>>>>> The is_user() is based on user_mod(regs) only. This's not suit for
>>>>>>> io_uring, where the helper thread can assume the user app identity
>>>>>>> and could perform this fault just fine. So turn to use mm to decide
>>>>>>> if this is valid or not.
>>>>>>
>>>>>> I don't understand why testing is_user would be an issue. KUAP purpose
>>>>>> it to block any unallowed access from kernel to user memory
>>>>>> (Equivalent to SMAP on x86). So it really must be based on MSR_PR bit,
>>>>>> that is what is_user provides.
>>>>>>
>>>>>> If the kernel access is legitimate, kernel should have opened
>>>>>> userspace access then you shouldn't get this "Bug: Read fault blocked
>>>>>> by KUAP!".
>>>>>>
>>>>>> As far as I understand, the fault occurs in
>>>>>> iov_iter_fault_in_readable() which calls fault_in_pages_readable() And
>>>>>> fault_in_pages_readable() uses __get_user() so it is a legitimate
>>>>>> access and you really should get a KUAP fault.
>>>>>>
>>>>>> So the problem is somewhere else, I think you proposed patch just
>>>>>> hides the problem, it doesn't fix it.
>>>>>
>>>>> If we do kthread_use_mm(), can we agree that the user access is valid?
>>>>
>>>> Yeah the io uring code is fine, provided it uses the uaccess primitives
>>>> like any other kernel code. It's looking more like a an arch/powerpc bug.
>>>>
>>>>> We should be able to copy to/from user space, and including faults, if
>>>>> that's been done and the new mm assigned. Because it really should be.
>>>>> If SMAP was a problem on x86, we would have seen it long ago.
>>>>>
>>>>> I'm assuming this may be breakage related to the recent uaccess changes
>>>>> related to set_fs and friends? Or maybe recent changes on the powerpc
>>>>> side?
>>>>>
>>>>> Zorro, did 5.10 work?
>>>>
>>>> Would be interesting to know.
>>>
>>> Sure Nick and Jens, which 5.10 rc? version do you want to know ? Or any git
>>> commit(be the HEAD) in 5.10 phase?
>>
>> I forget which versions had what series of this, but 5.10 final - and if
>> that fails, then 5.9 final. IIRC, 5.9 was pre any of these changes, and
>> 5.10 definitely has them.
>
> I justed built linux v5.10 with same .config file, and gave it same test.
> v5.10 (HEAD=2c85ebc57b Linux 5.10) can't reproduce this bug:
>
> # ./check generic/013 generic/051
> FSTYP -- xfs (non-debug)
> PLATFORM -- Linux/ppc64le ibm-p9z-xxx-xxxx 5.10.0 #3 SMP Thu Jan 28 04:12:14 EST 2021
> MKFS_OPTIONS -- -f -m crc=1,finobt=1,reflink=1,rmapbt=1,bigtime=1,inobtcount=1 /dev/sda3
> MOUNT_OPTIONS -- -o context=system_u:object_r:root_t:s0 /dev/sda3 /mnt/xfstests/scratch
>
> generic/013 138s ... 77s
> generic/051 103s ... 143s
> Ran: generic/013 generic/051
> Passed all 2 tests
Thanks for testing that, so I think it's safe to conclude that there's a
regression in powerpc fault handling for kthreads that use
kthread_use_mm in this release. A bisect would definitely find it, but
might be pointless if Christophe or Nick already have an idea of what it
is.
--
Jens Axboe
^ permalink raw reply
* Re: [PATCH] powerpc/fault: fix wrong KUAP fault for IO_URING
From: Zorro Lang @ 2021-01-28 13:52 UTC (permalink / raw)
To: Jens Axboe, Nicholas Piggin; +Cc: linuxppc-dev
In-Reply-To: <66061f75-c8de-c1eb-aaaf-9594a31be790@kernel.dk>
On Wed, Jan 27, 2021 at 08:06:37PM -0700, Jens Axboe wrote:
> On 1/27/21 8:13 PM, Zorro Lang wrote:
> > On Thu, Jan 28, 2021 at 10:18:07AM +1000, Nicholas Piggin wrote:
> >> Excerpts from Jens Axboe's message of January 28, 2021 5:29 am:
> >>> On 1/27/21 9:38 AM, Christophe Leroy wrote:
> >>>>
> >>>>
> >>>> Le 27/01/2021 à 15:56, Zorro Lang a écrit :
> >>>>> On powerpc, io_uring test hit below KUAP fault on __do_page_fault.
> >>>>> The fail source line is:
> >>>>>
> >>>>> if (unlikely(!is_user && bad_kernel_fault(regs, error_code, address, is_write)))
> >>>>> return SIGSEGV;
> >>>>>
> >>>>> The is_user() is based on user_mod(regs) only. This's not suit for
> >>>>> io_uring, where the helper thread can assume the user app identity
> >>>>> and could perform this fault just fine. So turn to use mm to decide
> >>>>> if this is valid or not.
> >>>>
> >>>> I don't understand why testing is_user would be an issue. KUAP purpose
> >>>> it to block any unallowed access from kernel to user memory
> >>>> (Equivalent to SMAP on x86). So it really must be based on MSR_PR bit,
> >>>> that is what is_user provides.
> >>>>
> >>>> If the kernel access is legitimate, kernel should have opened
> >>>> userspace access then you shouldn't get this "Bug: Read fault blocked
> >>>> by KUAP!".
> >>>>
> >>>> As far as I understand, the fault occurs in
> >>>> iov_iter_fault_in_readable() which calls fault_in_pages_readable() And
> >>>> fault_in_pages_readable() uses __get_user() so it is a legitimate
> >>>> access and you really should get a KUAP fault.
> >>>>
> >>>> So the problem is somewhere else, I think you proposed patch just
> >>>> hides the problem, it doesn't fix it.
> >>>
> >>> If we do kthread_use_mm(), can we agree that the user access is valid?
> >>
> >> Yeah the io uring code is fine, provided it uses the uaccess primitives
> >> like any other kernel code. It's looking more like a an arch/powerpc bug.
> >>
> >>> We should be able to copy to/from user space, and including faults, if
> >>> that's been done and the new mm assigned. Because it really should be.
> >>> If SMAP was a problem on x86, we would have seen it long ago.
> >>>
> >>> I'm assuming this may be breakage related to the recent uaccess changes
> >>> related to set_fs and friends? Or maybe recent changes on the powerpc
> >>> side?
> >>>
> >>> Zorro, did 5.10 work?
> >>
> >> Would be interesting to know.
> >
> > Sure Nick and Jens, which 5.10 rc? version do you want to know ? Or any git
> > commit(be the HEAD) in 5.10 phase?
>
> I forget which versions had what series of this, but 5.10 final - and if
> that fails, then 5.9 final. IIRC, 5.9 was pre any of these changes, and
> 5.10 definitely has them.
I justed built linux v5.10 with same .config file, and gave it same test.
v5.10 (HEAD=2c85ebc57b Linux 5.10) can't reproduce this bug:
# ./check generic/013 generic/051
FSTYP -- xfs (non-debug)
PLATFORM -- Linux/ppc64le ibm-p9z-xxx-xxxx 5.10.0 #3 SMP Thu Jan 28 04:12:14 EST 2021
MKFS_OPTIONS -- -f -m crc=1,finobt=1,reflink=1,rmapbt=1,bigtime=1,inobtcount=1 /dev/sda3
MOUNT_OPTIONS -- -o context=system_u:object_r:root_t:s0 /dev/sda3 /mnt/xfstests/scratch
generic/013 138s ... 77s
generic/051 103s ... 143s
Ran: generic/013 generic/051
Passed all 2 tests
>
> --
> Jens Axboe
>
^ permalink raw reply
* [PATCH 1/3] sched: Remove MAX_USER_RT_PRIO
From: Dietmar Eggemann @ 2021-01-28 13:10 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra, Jeremy Kerr, Arnd Bergmann,
Michael Ellerman
Cc: Juri Lelli, Hillf Danton, Vincent Guittot, linux-kernel,
Steven Rostedt, linuxppc-dev
In-Reply-To: <20210128131040.296856-1-dietmar.eggemann@arm.com>
Commit d46523ea32a7 ("[PATCH] fix MAX_USER_RT_PRIO and MAX_RT_PRIO")
was introduced due to a a small time period in which the realtime patch
set was using different values for MAX_USER_RT_PRIO and MAX_RT_PRIO.
This is no longer true, i.e. now MAX_RT_PRIO == MAX_USER_RT_PRIO.
Get rid of MAX_USER_RT_PRIO and make everything use MAX_RT_PRIO
instead.
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
---
include/linux/sched/prio.h | 9 +--------
kernel/sched/core.c | 7 +++----
2 files changed, 4 insertions(+), 12 deletions(-)
diff --git a/include/linux/sched/prio.h b/include/linux/sched/prio.h
index 7d64feafc408..d111f2fd77ea 100644
--- a/include/linux/sched/prio.h
+++ b/include/linux/sched/prio.h
@@ -11,16 +11,9 @@
* priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
* tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
* values are inverted: lower p->prio value means higher priority.
- *
- * The MAX_USER_RT_PRIO value allows the actual maximum
- * RT priority to be separate from the value exported to
- * user-space. This allows kernel threads to set their
- * priority to a value higher than any user task. Note:
- * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
*/
-#define MAX_USER_RT_PRIO 100
-#define MAX_RT_PRIO MAX_USER_RT_PRIO
+#define MAX_RT_PRIO 100
#define MAX_PRIO (MAX_RT_PRIO + NICE_WIDTH)
#define DEFAULT_PRIO (MAX_RT_PRIO + NICE_WIDTH / 2)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 06b449942adf..625ec1e12064 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5897,11 +5897,10 @@ static int __sched_setscheduler(struct task_struct *p,
/*
* Valid priorities for SCHED_FIFO and SCHED_RR are
- * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL,
+ * 1..MAX_RT_PRIO-1, valid priority for SCHED_NORMAL,
* SCHED_BATCH and SCHED_IDLE is 0.
*/
- if ((p->mm && attr->sched_priority > MAX_USER_RT_PRIO-1) ||
- (!p->mm && attr->sched_priority > MAX_RT_PRIO-1))
+ if (attr->sched_priority > MAX_RT_PRIO-1)
return -EINVAL;
if ((dl_policy(policy) && !__checkparam_dl(attr)) ||
(rt_policy(policy) != (attr->sched_priority != 0)))
@@ -6969,7 +6968,7 @@ SYSCALL_DEFINE1(sched_get_priority_max, int, policy)
switch (policy) {
case SCHED_FIFO:
case SCHED_RR:
- ret = MAX_USER_RT_PRIO-1;
+ ret = MAX_RT_PRIO-1;
break;
case SCHED_DEADLINE:
case SCHED_NORMAL:
--
2.25.1
^ permalink raw reply related
* [PATCH 0/3] sched: Task priority related cleanups
From: Dietmar Eggemann @ 2021-01-28 13:10 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra, Jeremy Kerr, Arnd Bergmann,
Michael Ellerman
Cc: Juri Lelli, Hillf Danton, Vincent Guittot, linux-kernel,
Steven Rostedt, linuxppc-dev
(1) Removing MAX_USER_RT_PRIO was already discussed here in April 2020:
https://lkml.kernel.org/r/20200423094403.6f1d2b8d@gandalf.local.home
(2) USER_PRIO() and related macros are not used anymore except in one
case for powerpc where MAX_USER_PRIO can be replaced by NICE_WIDTH.
Set_load_weight(), task_prio(), cpu_weight_nice_write_s64(),
__update_max_tr() don't use USER_PRIO() but priority - MAX_RT_PRIO.
(3) The function header of task_prio() needs an update. It looks
ancient since it mentions a prio space [-16 ... 15] for mormal
tasks. I can't figure out why this range is mentioned here? Maybe
the influence of the 'sleep-bonus interactivity' feature which was
removed by commit f3479f10c5d6 ("sched: remove the sleep-bonus
interactivity code")?
Dietmar Eggemann (3):
sched: Remove MAX_USER_RT_PRIO
sched: Remove USER_PRIO, TASK_USER_PRIO and MAX_USER_PRIO
sched/core: Update task_prio() function header
arch/powerpc/platforms/cell/spufs/sched.c | 2 +-
include/linux/sched/prio.h | 18 +-----------------
kernel/sched/core.c | 15 +++++++++------
kernel/sched/sched.h | 2 +-
4 files changed, 12 insertions(+), 25 deletions(-)
--
2.25.1
^ permalink raw reply
* [PATCH 2/3] sched: Remove USER_PRIO, TASK_USER_PRIO and MAX_USER_PRIO
From: Dietmar Eggemann @ 2021-01-28 13:10 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra, Jeremy Kerr, Arnd Bergmann,
Michael Ellerman
Cc: Juri Lelli, Hillf Danton, Vincent Guittot, linux-kernel,
Steven Rostedt, linuxppc-dev
In-Reply-To: <20210128131040.296856-1-dietmar.eggemann@arm.com>
The only remaining use of MAX_USER_PRIO (and USER_PRIO) is the
SCALE_PRIO() definition in the PowerPC Cell architecture's Synergistic
Processor Unit (SPU) scheduler. TASK_USER_PRIO isn't used anymore.
Commit fe443ef2ac42 ("[POWERPC] spusched: Dynamic timeslicing for
SCHED_OTHER") copied SCALE_PRIO() from the task scheduler in v2.6.23.
Commit a4ec24b48dde ("sched: tidy up SCHED_RR") removed it from the task
scheduler in v2.6.24.
Commit 3ee237dddcd8 ("sched/prio: Add 3 macros of MAX_NICE, MIN_NICE and
NICE_WIDTH in prio.h") introduced NICE_WIDTH much later.
With:
MAX_USER_PRIO = USER_PRIO(MAX_PRIO)
= MAX_PRIO - MAX_RT_PRIO
MAX_PRIO = MAX_RT_PRIO + NICE_WIDTH
MAX_USER_PRIO = MAX_RT_PRIO + NICE_WIDTH - MAX_RT_PRIO
MAX_USER_PRIO = NICE_WIDTH
MAX_USER_PRIO can be replaced by NICE_WIDTH to be able to remove all the
{*_}USER_PRIO defines.
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
---
arch/powerpc/platforms/cell/spufs/sched.c | 2 +-
include/linux/sched/prio.h | 9 ---------
kernel/sched/sched.h | 2 +-
3 files changed, 2 insertions(+), 11 deletions(-)
diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index f18d5067cd0f..aeb7f3922106 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -72,7 +72,7 @@ static struct timer_list spuloadavg_timer;
#define DEF_SPU_TIMESLICE (100 * HZ / (1000 * SPUSCHED_TICK))
#define SCALE_PRIO(x, prio) \
- max(x * (MAX_PRIO - prio) / (MAX_USER_PRIO / 2), MIN_SPU_TIMESLICE)
+ max(x * (MAX_PRIO - prio) / (NICE_WIDTH / 2), MIN_SPU_TIMESLICE)
/*
* scale user-nice values [ -20 ... 0 ... 19 ] to time slice values:
diff --git a/include/linux/sched/prio.h b/include/linux/sched/prio.h
index d111f2fd77ea..ab83d85e1183 100644
--- a/include/linux/sched/prio.h
+++ b/include/linux/sched/prio.h
@@ -26,15 +26,6 @@
#define NICE_TO_PRIO(nice) ((nice) + DEFAULT_PRIO)
#define PRIO_TO_NICE(prio) ((prio) - DEFAULT_PRIO)
-/*
- * 'User priority' is the nice value converted to something we
- * can work with better when scaling various scheduler parameters,
- * it's a [ 0 ... 39 ] range.
- */
-#define USER_PRIO(p) ((p)-MAX_RT_PRIO)
-#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
-#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
-
/*
* Convert nice value [19,-20] to rlimit style value [1,40].
*/
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 045b01064c1e..6edc67df3554 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -140,7 +140,7 @@ extern void call_trace_sched_update_nr_running(struct rq *rq, int count);
* scale_load() and scale_load_down(w) to convert between them. The
* following must be true:
*
- * scale_load(sched_prio_to_weight[USER_PRIO(NICE_TO_PRIO(0))]) == NICE_0_LOAD
+ * scale_load(sched_prio_to_weight[NICE_TO_PRIO(0)-MAX_RT_PRIO]) == NICE_0_LOAD
*
*/
#define NICE_0_LOAD (1L << NICE_0_LOAD_SHIFT)
--
2.25.1
^ permalink raw reply related
* [PATCH 3/3] sched/core: Update task_prio() function header
From: Dietmar Eggemann @ 2021-01-28 13:10 UTC (permalink / raw)
To: Ingo Molnar, Peter Zijlstra, Jeremy Kerr, Arnd Bergmann,
Michael Ellerman
Cc: Juri Lelli, Hillf Danton, Vincent Guittot, linux-kernel,
Steven Rostedt, linuxppc-dev
In-Reply-To: <20210128131040.296856-1-dietmar.eggemann@arm.com>
The description of the RT offset and the values for 'normal' tasks needs
update. Moreover there are DL tasks now.
task_prio() has to stay like it is to guarantee compatibility with the
/proc/<pid>/stat priority field:
# cat /proc/<pid>/stat | awk '{ print $18; }'
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
---
kernel/sched/core.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 625ec1e12064..be3a956c2d23 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5602,8 +5602,12 @@ SYSCALL_DEFINE1(nice, int, increment)
* @p: the task in question.
*
* Return: The priority value as seen by users in /proc.
- * RT tasks are offset by -200. Normal tasks are centered
- * around 0, value goes from -16 to +15.
+ *
+ * sched policy return value kernel prio user prio/nice
+ *
+ * normal, batch, idle [0 ... 39] [100 ... 139] 0/[-20 ... 19]
+ * fifo, rr [-2 ... -100] [98 ... 0] [1 ... 99]
+ * deadline -101 -1 0
*/
int task_prio(const struct task_struct *p)
{
--
2.25.1
^ permalink raw reply related
* Re: [PATCH v4 02/10] powerpc/signal: Add unsafe_copy_{vsx, fpr}_from_user()
From: Christophe Leroy @ 2021-01-28 12:05 UTC (permalink / raw)
To: David Laight, 'Christopher M. Riedl',
linuxppc-dev@lists.ozlabs.org
In-Reply-To: <6a6ce1a53fcf4669a9848114d3460fef@AcuMS.aculab.com>
Le 28/01/2021 à 11:38, David Laight a écrit :
> From: Christopher M. Riedl
>> Sent: 28 January 2021 04:04
>>
>> Reuse the "safe" implementation from signal.c except for calling
>> unsafe_copy_from_user() to copy into a local buffer.
>>
>> Signed-off-by: Christopher M. Riedl <cmr@codefail.de>
>> ---
>> arch/powerpc/kernel/signal.h | 33 +++++++++++++++++++++++++++++++++
>> 1 file changed, 33 insertions(+)
>>
>> diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
>> index 2559a681536e..c18402d625f1 100644
>> --- a/arch/powerpc/kernel/signal.h
>> +++ b/arch/powerpc/kernel/signal.h
>> @@ -53,6 +53,33 @@ unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user *from);
>> &buf[i], label);\
>> } while (0)
>>
>> +#define unsafe_copy_fpr_from_user(task, from, label) do { \
>> + struct task_struct *__t = task; \
>> + u64 __user *__f = (u64 __user *)from; \
>> + u64 buf[ELF_NFPREG]; \
>
> How big is that buffer?
#define ELF_NFPREG 33
So that's 264 bytes.
That's a bit big but still reasonable I think.
Christophe
> Isn't is likely to be reasonably large compared to a reasonable
> kernel stack frame.
> Especially since this isn't even a leaf function.
>
>> + int i; \
>> + \
>> + unsafe_copy_from_user(buf, __f, ELF_NFPREG * sizeof(double), \
>
> That really ought to be sizeof(buf).
>
> David
>
>
>> + label); \
>> + for (i = 0; i < ELF_NFPREG - 1; i++) \
>> + __t->thread.TS_FPR(i) = buf[i]; \
>> + __t->thread.fp_state.fpscr = buf[i]; \
>> +} while (0)
>> +
>> +#define unsafe_copy_vsx_from_user(task, from, label) do { \
>> + struct task_struct *__t = task; \
>> + u64 __user *__f = (u64 __user *)from; \
>> + u64 buf[ELF_NVSRHALFREG]; \
>> + int i; \
>> + \
>> + unsafe_copy_from_user(buf, __f, \
>> + ELF_NVSRHALFREG * sizeof(double), \
>> + label); \
>> + for (i = 0; i < ELF_NVSRHALFREG ; i++) \
>> + __t->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i]; \
>> +} while (0)
>> +
>> +
>> #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
>> #define unsafe_copy_ckfpr_to_user(to, task, label) do { \
>> struct task_struct *__t = task; \
>> @@ -80,6 +107,10 @@ unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user *from);
>> unsafe_copy_to_user(to, (task)->thread.fp_state.fpr, \
>> ELF_NFPREG * sizeof(double), label)
>>
>> +#define unsafe_copy_fpr_from_user(task, from, label) \
>> + unsafe_copy_from_user((task)->thread.fp_state.fpr, from, \
>> + ELF_NFPREG * sizeof(double), label)
>> +
>> static inline unsigned long
>> copy_fpr_to_user(void __user *to, struct task_struct *task)
>> {
>> @@ -115,6 +146,8 @@ copy_ckfpr_from_user(struct task_struct *task, void __user *from)
>> #else
>> #define unsafe_copy_fpr_to_user(to, task, label) do { } while (0)
>>
>> +#define unsafe_copy_fpr_from_user(task, from, label) do { } while (0)
>> +
>> static inline unsigned long
>> copy_fpr_to_user(void __user *to, struct task_struct *task)
>> {
>> --
>> 2.26.1
>
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> Registration No: 1397386 (Wales)
>
^ permalink raw reply
* [PATCH] ASoC: fsl_spdif: Utilize the defined parameter to clear code
From: Tang Bin @ 2021-01-28 11:27 UTC (permalink / raw)
To: broonie, timur, nicoleotsuka, Xiubo.Lee, lgirdwood, perex, tiwai
Cc: alsa-devel, linuxppc-dev, linux-kernel, Tang Bin
Utilize the defined parameter 'dev' to make the code cleaner.
Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
---
sound/soc/fsl/fsl_spdif.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/sound/soc/fsl/fsl_spdif.c b/sound/soc/fsl/fsl_spdif.c
index 455f96908..b6d5563df 100644
--- a/sound/soc/fsl/fsl_spdif.c
+++ b/sound/soc/fsl/fsl_spdif.c
@@ -1215,7 +1215,7 @@ static int fsl_spdif_probe_txclk(struct fsl_spdif_priv *spdif_priv,
for (i = 0; i < STC_TXCLK_SRC_MAX; i++) {
sprintf(tmp, "rxtx%d", i);
- clk = devm_clk_get(&pdev->dev, tmp);
+ clk = devm_clk_get(dev, tmp);
if (IS_ERR(clk)) {
dev_err(dev, "no rxtx%d clock in devicetree\n", i);
return PTR_ERR(clk);
@@ -1237,14 +1237,14 @@ static int fsl_spdif_probe_txclk(struct fsl_spdif_priv *spdif_priv,
break;
}
- dev_dbg(&pdev->dev, "use rxtx%d as tx clock source for %dHz sample rate\n",
+ dev_dbg(dev, "use rxtx%d as tx clock source for %dHz sample rate\n",
spdif_priv->txclk_src[index], rate[index]);
- dev_dbg(&pdev->dev, "use txclk df %d for %dHz sample rate\n",
+ dev_dbg(dev, "use txclk df %d for %dHz sample rate\n",
spdif_priv->txclk_df[index], rate[index]);
if (clk_is_match(spdif_priv->txclk[index], spdif_priv->sysclk))
- dev_dbg(&pdev->dev, "use sysclk df %d for %dHz sample rate\n",
+ dev_dbg(dev, "use sysclk df %d for %dHz sample rate\n",
spdif_priv->sysclk_df[index], rate[index]);
- dev_dbg(&pdev->dev, "the best rate for %dHz sample rate is %dHz\n",
+ dev_dbg(dev, "the best rate for %dHz sample rate is %dHz\n",
rate[index], spdif_priv->txrate[index]);
return 0;
--
2.20.1.windows.1
^ permalink raw reply related
* [PATCH v5 2/2] powerpc/mce: Remove per cpu variables from MCE handlers
From: Ganesh Goudar @ 2021-01-28 10:41 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Ganesh Goudar, mahesh, npiggin
In-Reply-To: <20210128104143.70668-1-ganeshgr@linux.ibm.com>
Access to per-cpu variables requires translation to be enabled on
pseries machine running in hash mmu mode, Since part of MCE handler
runs in realmode and part of MCE handling code is shared between ppc
architectures pseries and powernv, it becomes difficult to manage
these variables differently on different architectures, So have
these variables in paca instead of having them as per-cpu variables
to avoid complications.
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
---
v2: Dynamically allocate memory for machine check event info.
v3: Remove check for hash mmu lpar, use memblock_alloc_try_nid
to allocate memory.
v4: Spliting the patch into two.
v5: Fix build error for PPC32.
---
arch/powerpc/include/asm/mce.h | 18 +++++++
arch/powerpc/include/asm/paca.h | 4 ++
arch/powerpc/kernel/mce.c | 79 ++++++++++++++++++------------
arch/powerpc/kernel/setup-common.c | 2 +
4 files changed, 71 insertions(+), 32 deletions(-)
diff --git a/arch/powerpc/include/asm/mce.h b/arch/powerpc/include/asm/mce.h
index 7d8b6679ec68..331d944280b8 100644
--- a/arch/powerpc/include/asm/mce.h
+++ b/arch/powerpc/include/asm/mce.h
@@ -206,6 +206,17 @@ struct mce_error_info {
#define MAX_MC_EVT 10
+struct mce_info {
+ int mce_nest_count;
+ struct machine_check_event mce_event[MAX_MC_EVT];
+ /* Queue for delayed MCE events. */
+ int mce_queue_count;
+ struct machine_check_event mce_event_queue[MAX_MC_EVT];
+ /* Queue for delayed MCE UE events. */
+ int mce_ue_count;
+ struct machine_check_event mce_ue_event_queue[MAX_MC_EVT];
+};
+
/* Release flags for get_mce_event() */
#define MCE_EVENT_RELEASE true
#define MCE_EVENT_DONTRELEASE false
@@ -234,4 +245,11 @@ long __machine_check_early_realmode_p8(struct pt_regs *regs);
long __machine_check_early_realmode_p9(struct pt_regs *regs);
long __machine_check_early_realmode_p10(struct pt_regs *regs);
#endif /* CONFIG_PPC_BOOK3S_64 */
+
+#ifdef CONFIG_PPC_BOOK3S_64
+void mce_init(void);
+#else
+static inline void mce_init(void) { };
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
#endif /* __ASM_PPC64_MCE_H__ */
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index 9454d29ff4b4..38e0c55e845d 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -29,6 +29,7 @@
#include <asm/hmi.h>
#include <asm/cpuidle.h>
#include <asm/atomic.h>
+#include <asm/mce.h>
#include <asm-generic/mmiowb_types.h>
@@ -273,6 +274,9 @@ struct paca_struct {
#ifdef CONFIG_MMIOWB
struct mmiowb_state mmiowb_state;
#endif
+#ifdef CONFIG_PPC_BOOK3S_64
+ struct mce_info *mce_info;
+#endif /* CONFIG_PPC_BOOK3S_64 */
} ____cacheline_aligned;
extern void copy_mm_to_paca(struct mm_struct *mm);
diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
index 9f3e133b57b7..6ec5c68997ed 100644
--- a/arch/powerpc/kernel/mce.c
+++ b/arch/powerpc/kernel/mce.c
@@ -17,22 +17,13 @@
#include <linux/irq_work.h>
#include <linux/extable.h>
#include <linux/ftrace.h>
+#include <linux/memblock.h>
#include <asm/machdep.h>
#include <asm/mce.h>
#include <asm/nmi.h>
-static DEFINE_PER_CPU(int, mce_nest_count);
-static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event);
-
-/* Queue for delayed MCE events. */
-static DEFINE_PER_CPU(int, mce_queue_count);
-static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event_queue);
-
-/* Queue for delayed MCE UE events. */
-static DEFINE_PER_CPU(int, mce_ue_count);
-static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT],
- mce_ue_event_queue);
+#include "setup.h"
static void machine_check_process_queued_event(struct irq_work *work);
static void machine_check_ue_irq_work(struct irq_work *work);
@@ -103,9 +94,10 @@ void save_mce_event(struct pt_regs *regs, long handled,
struct mce_error_info *mce_err,
uint64_t nip, uint64_t addr, uint64_t phys_addr)
{
- int index = __this_cpu_inc_return(mce_nest_count) - 1;
- struct machine_check_event *mce = this_cpu_ptr(&mce_event[index]);
+ int index = local_paca->mce_info->mce_nest_count++;
+ struct machine_check_event *mce;
+ mce = &local_paca->mce_info->mce_event[index];
/*
* Return if we don't have enough space to log mce event.
* mce_nest_count may go beyond MAX_MC_EVT but that's ok,
@@ -191,7 +183,7 @@ void save_mce_event(struct pt_regs *regs, long handled,
*/
int get_mce_event(struct machine_check_event *mce, bool release)
{
- int index = __this_cpu_read(mce_nest_count) - 1;
+ int index = local_paca->mce_info->mce_nest_count - 1;
struct machine_check_event *mc_evt;
int ret = 0;
@@ -201,7 +193,7 @@ int get_mce_event(struct machine_check_event *mce, bool release)
/* Check if we have MCE info to process. */
if (index < MAX_MC_EVT) {
- mc_evt = this_cpu_ptr(&mce_event[index]);
+ mc_evt = &local_paca->mce_info->mce_event[index];
/* Copy the event structure and release the original */
if (mce)
*mce = *mc_evt;
@@ -211,7 +203,7 @@ int get_mce_event(struct machine_check_event *mce, bool release)
}
/* Decrement the count to free the slot. */
if (release)
- __this_cpu_dec(mce_nest_count);
+ local_paca->mce_info->mce_nest_count--;
return ret;
}
@@ -233,13 +225,14 @@ static void machine_check_ue_event(struct machine_check_event *evt)
{
int index;
- index = __this_cpu_inc_return(mce_ue_count) - 1;
+ index = local_paca->mce_info->mce_ue_count++;
/* If queue is full, just return for now. */
if (index >= MAX_MC_EVT) {
- __this_cpu_dec(mce_ue_count);
+ local_paca->mce_info->mce_ue_count--;
return;
}
- memcpy(this_cpu_ptr(&mce_ue_event_queue[index]), evt, sizeof(*evt));
+ memcpy(&local_paca->mce_info->mce_ue_event_queue[index],
+ evt, sizeof(*evt));
/* Queue work to process this event later. */
irq_work_queue(&mce_ue_event_irq_work);
@@ -256,13 +249,14 @@ void machine_check_queue_event(void)
if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
return;
- index = __this_cpu_inc_return(mce_queue_count) - 1;
+ index = local_paca->mce_info->mce_queue_count++;
/* If queue is full, just return for now. */
if (index >= MAX_MC_EVT) {
- __this_cpu_dec(mce_queue_count);
+ local_paca->mce_info->mce_queue_count--;
return;
}
- memcpy(this_cpu_ptr(&mce_event_queue[index]), &evt, sizeof(evt));
+ memcpy(&local_paca->mce_info->mce_event_queue[index],
+ &evt, sizeof(evt));
/* Queue irq work to process this event later. */
irq_work_queue(&mce_event_process_work);
@@ -289,9 +283,9 @@ static void machine_process_ue_event(struct work_struct *work)
int index;
struct machine_check_event *evt;
- while (__this_cpu_read(mce_ue_count) > 0) {
- index = __this_cpu_read(mce_ue_count) - 1;
- evt = this_cpu_ptr(&mce_ue_event_queue[index]);
+ while (local_paca->mce_info->mce_ue_count > 0) {
+ index = local_paca->mce_info->mce_ue_count - 1;
+ evt = &local_paca->mce_info->mce_ue_event_queue[index];
blocking_notifier_call_chain(&mce_notifier_list, 0, evt);
#ifdef CONFIG_MEMORY_FAILURE
/*
@@ -304,7 +298,7 @@ static void machine_process_ue_event(struct work_struct *work)
*/
if (evt->error_type == MCE_ERROR_TYPE_UE) {
if (evt->u.ue_error.ignore_event) {
- __this_cpu_dec(mce_ue_count);
+ local_paca->mce_info->mce_ue_count--;
continue;
}
@@ -320,7 +314,7 @@ static void machine_process_ue_event(struct work_struct *work)
"was generated\n");
}
#endif
- __this_cpu_dec(mce_ue_count);
+ local_paca->mce_info->mce_ue_count--;
}
}
/*
@@ -338,17 +332,17 @@ static void machine_check_process_queued_event(struct irq_work *work)
* For now just print it to console.
* TODO: log this error event to FSP or nvram.
*/
- while (__this_cpu_read(mce_queue_count) > 0) {
- index = __this_cpu_read(mce_queue_count) - 1;
- evt = this_cpu_ptr(&mce_event_queue[index]);
+ while (local_paca->mce_info->mce_queue_count > 0) {
+ index = local_paca->mce_info->mce_queue_count - 1;
+ evt = &local_paca->mce_info->mce_event_queue[index];
if (evt->error_type == MCE_ERROR_TYPE_UE &&
evt->u.ue_error.ignore_event) {
- __this_cpu_dec(mce_queue_count);
+ local_paca->mce_info->mce_queue_count--;
continue;
}
machine_check_print_event_info(evt, false, false);
- __this_cpu_dec(mce_queue_count);
+ local_paca->mce_info->mce_queue_count--;
}
}
@@ -741,3 +735,24 @@ long hmi_exception_realmode(struct pt_regs *regs)
return 1;
}
+
+void __init mce_init(void)
+{
+ struct mce_info *mce_info;
+ u64 limit;
+ int i;
+
+ limit = min(ppc64_bolted_size(), ppc64_rma_size);
+ for_each_possible_cpu(i) {
+ mce_info = memblock_alloc_try_nid(sizeof(*mce_info),
+ __alignof__(*mce_info),
+ MEMBLOCK_LOW_LIMIT,
+ limit, cpu_to_node(i));
+ if (!mce_info)
+ goto err;
+ paca_ptrs[i]->mce_info = mce_info;
+ }
+ return;
+err:
+ panic("Failed to allocate memory for MCE event data\n");
+}
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 71f38e9248be..d480f091e0ad 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -64,6 +64,7 @@
#include <asm/mmu_context.h>
#include <asm/cpu_has_feature.h>
#include <asm/kasan.h>
+#include <asm/mce.h>
#include "setup.h"
@@ -938,6 +939,7 @@ void __init setup_arch(char **cmdline_p)
exc_lvl_early_init();
emergency_stack_init();
+ mce_init();
smp_release_cpus();
initmem_init();
--
2.26.2
^ permalink raw reply related
* [PATCH v5 1/2] powerpc/mce: Reduce the size of event arrays
From: Ganesh Goudar @ 2021-01-28 10:41 UTC (permalink / raw)
To: linuxppc-dev, mpe; +Cc: Ganesh Goudar, mahesh, npiggin
Maximum recursive depth of MCE is 4, Considering the maximum depth
allowed reduce the size of event to 10 from 100. This saves us ~19kB
of memory and has no fatal consequences.
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
---
v4: This patch is a fragment of the orignal patch which is
split into two.
v5: No changes.
---
arch/powerpc/include/asm/mce.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/mce.h b/arch/powerpc/include/asm/mce.h
index e6c27ae843dc..7d8b6679ec68 100644
--- a/arch/powerpc/include/asm/mce.h
+++ b/arch/powerpc/include/asm/mce.h
@@ -204,7 +204,7 @@ struct mce_error_info {
bool ignore_event;
};
-#define MAX_MC_EVT 100
+#define MAX_MC_EVT 10
/* Release flags for get_mce_event() */
#define MCE_EVENT_RELEASE true
--
2.26.2
^ permalink raw reply related
* RE: [PATCH v4 02/10] powerpc/signal: Add unsafe_copy_{vsx, fpr}_from_user()
From: David Laight @ 2021-01-28 10:38 UTC (permalink / raw)
To: 'Christopher M. Riedl', linuxppc-dev@lists.ozlabs.org
In-Reply-To: <20210128040424.12720-3-cmr@codefail.de>
From: Christopher M. Riedl
> Sent: 28 January 2021 04:04
>
> Reuse the "safe" implementation from signal.c except for calling
> unsafe_copy_from_user() to copy into a local buffer.
>
> Signed-off-by: Christopher M. Riedl <cmr@codefail.de>
> ---
> arch/powerpc/kernel/signal.h | 33 +++++++++++++++++++++++++++++++++
> 1 file changed, 33 insertions(+)
>
> diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
> index 2559a681536e..c18402d625f1 100644
> --- a/arch/powerpc/kernel/signal.h
> +++ b/arch/powerpc/kernel/signal.h
> @@ -53,6 +53,33 @@ unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user *from);
> &buf[i], label);\
> } while (0)
>
> +#define unsafe_copy_fpr_from_user(task, from, label) do { \
> + struct task_struct *__t = task; \
> + u64 __user *__f = (u64 __user *)from; \
> + u64 buf[ELF_NFPREG]; \
How big is that buffer?
Isn't is likely to be reasonably large compared to a reasonable
kernel stack frame.
Especially since this isn't even a leaf function.
> + int i; \
> + \
> + unsafe_copy_from_user(buf, __f, ELF_NFPREG * sizeof(double), \
That really ought to be sizeof(buf).
David
> + label); \
> + for (i = 0; i < ELF_NFPREG - 1; i++) \
> + __t->thread.TS_FPR(i) = buf[i]; \
> + __t->thread.fp_state.fpscr = buf[i]; \
> +} while (0)
> +
> +#define unsafe_copy_vsx_from_user(task, from, label) do { \
> + struct task_struct *__t = task; \
> + u64 __user *__f = (u64 __user *)from; \
> + u64 buf[ELF_NVSRHALFREG]; \
> + int i; \
> + \
> + unsafe_copy_from_user(buf, __f, \
> + ELF_NVSRHALFREG * sizeof(double), \
> + label); \
> + for (i = 0; i < ELF_NVSRHALFREG ; i++) \
> + __t->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i]; \
> +} while (0)
> +
> +
> #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
> #define unsafe_copy_ckfpr_to_user(to, task, label) do { \
> struct task_struct *__t = task; \
> @@ -80,6 +107,10 @@ unsigned long copy_ckfpr_from_user(struct task_struct *task, void __user *from);
> unsafe_copy_to_user(to, (task)->thread.fp_state.fpr, \
> ELF_NFPREG * sizeof(double), label)
>
> +#define unsafe_copy_fpr_from_user(task, from, label) \
> + unsafe_copy_from_user((task)->thread.fp_state.fpr, from, \
> + ELF_NFPREG * sizeof(double), label)
> +
> static inline unsigned long
> copy_fpr_to_user(void __user *to, struct task_struct *task)
> {
> @@ -115,6 +146,8 @@ copy_ckfpr_from_user(struct task_struct *task, void __user *from)
> #else
> #define unsafe_copy_fpr_to_user(to, task, label) do { } while (0)
>
> +#define unsafe_copy_fpr_from_user(task, from, label) do { } while (0)
> +
> static inline unsigned long
> copy_fpr_to_user(void __user *to, struct task_struct *task)
> {
> --
> 2.26.1
-
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Registration No: 1397386 (Wales)
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