The branch stable/14 has been updated by wulf:
URL:
https://cgit.FreeBSD.org/src/commit/?id=6d4b6edcf381809d07abb2031288943a597f9f86
commit 6d4b6edcf381809d07abb2031288943a597f9f86
Author: Vladimir Kondratyev <w...@freebsd.org>
AuthorDate: 2024-02-10 22:01:50 +0000
Commit: Vladimir Kondratyev <w...@freebsd.org>
CommitDate: 2024-02-17 20:58:39 +0000
LinuxKPI: Allow kmalloc to be called when FPU protection is enabled
Amdgpu driver does a lot of memory allocations in FPU-protected sections
of code for certain display cores, e.g. for DCN30. This does not work
on FreeBSD as its malloc function can not be run within a critical
section. Check this condition and temporally exit from FPU-protected
context to workaround issue and reduce source code patching.
Sponsored by: Serenity Cyber Security, LLC
Reviewed by: manu (previous version)
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D42822
(cherry picked from commit c0b8047bdc13040eafb162c4b7b5dba11034ff4b)
---
sys/compat/linuxkpi/common/include/linux/compat.h | 10 ++++++--
sys/compat/linuxkpi/common/include/linux/slab.h | 5 ++--
sys/compat/linuxkpi/common/src/linux_fpu.c | 28 ++++++++++++++++++++++-
sys/compat/linuxkpi/common/src/linux_slab.c | 24 +++++++++++++++++++
4 files changed, 62 insertions(+), 5 deletions(-)
diff --git a/sys/compat/linuxkpi/common/include/linux/compat.h
b/sys/compat/linuxkpi/common/include/linux/compat.h
index d1a02f612f42..8a5a6918bb7c 100644
--- a/sys/compat/linuxkpi/common/include/linux/compat.h
+++ b/sys/compat/linuxkpi/common/include/linux/compat.h
@@ -41,17 +41,20 @@ extern int linux_alloc_current(struct thread *, int flags);
extern void linux_free_current(struct task_struct *);
extern struct domainset *linux_get_vm_domain_set(int node);
+#define __current_unallocated(td) \
+ __predict_false((td)->td_lkpi_task == NULL)
+
static inline void
linux_set_current(struct thread *td)
{
- if (__predict_false(td->td_lkpi_task == NULL))
+ if (__current_unallocated(td))
lkpi_alloc_current(td, M_WAITOK);
}
static inline int
linux_set_current_flags(struct thread *td, int flags)
{
- if (__predict_false(td->td_lkpi_task == NULL))
+ if (__current_unallocated(td))
return (lkpi_alloc_current(td, flags));
return (0);
}
@@ -59,4 +62,7 @@ linux_set_current_flags(struct thread *td, int flags)
#define compat_ptr(x) ((void *)(uintptr_t)x)
#define ptr_to_compat(x) ((uintptr_t)x)
+typedef void fpu_safe_exec_cb_t(void *ctx);
+void lkpi_fpu_safe_exec(fpu_safe_exec_cb_t func, void *ctx);
+
#endif /* _LINUXKPI_LINUX_COMPAT_H_ */
diff --git a/sys/compat/linuxkpi/common/include/linux/slab.h
b/sys/compat/linuxkpi/common/include/linux/slab.h
index 8557f831bb60..298306b6ea05 100644
--- a/sys/compat/linuxkpi/common/include/linux/slab.h
+++ b/sys/compat/linuxkpi/common/include/linux/slab.h
@@ -41,6 +41,7 @@
MALLOC_DECLARE(M_KMALLOC);
+#define kmalloc(size, flags) lkpi_kmalloc(size, flags)
#define kvmalloc(size, flags) kmalloc(size, flags)
#define kvzalloc(size, flags) kmalloc(size, (flags) |
__GFP_ZERO)
#define kvcalloc(n, size, flags) kvmalloc_array(n, size, (flags)
| __GFP_ZERO)
@@ -53,7 +54,6 @@ MALLOC_DECLARE(M_KMALLOC);
#define vmalloc_node(size, node) __vmalloc_node(size,
GFP_KERNEL, node)
#define vmalloc_user(size) __vmalloc(size, GFP_KERNEL |
__GFP_ZERO, 0)
#define vmalloc(size) __vmalloc(size, GFP_KERNEL, 0)
-#define __kmalloc(...) kmalloc(__VA_ARGS__)
/*
* Prefix some functions with linux_ to avoid namespace conflict
@@ -107,7 +107,7 @@ linux_check_m_flags(gfp_t flags)
}
static inline void *
-kmalloc(size_t size, gfp_t flags)
+__kmalloc(size_t size, gfp_t flags)
{
return (malloc(MAX(size, sizeof(struct llist_node)), M_KMALLOC,
linux_check_m_flags(flags)));
@@ -218,6 +218,7 @@ ksize(const void *ptr)
return (malloc_usable_size(ptr));
}
+extern void *lkpi_kmalloc(size_t size, gfp_t flags);
extern struct linux_kmem_cache *linux_kmem_cache_create(const char *name,
size_t size, size_t align, unsigned flags, linux_kmem_ctor_t *ctor);
extern void *lkpi_kmem_cache_alloc(struct linux_kmem_cache *, gfp_t);
diff --git a/sys/compat/linuxkpi/common/src/linux_fpu.c
b/sys/compat/linuxkpi/common/src/linux_fpu.c
index b26dce98774b..4e40a2b004bb 100644
--- a/sys/compat/linuxkpi/common/src/linux_fpu.c
+++ b/sys/compat/linuxkpi/common/src/linux_fpu.c
@@ -30,11 +30,13 @@
#include <sys/proc.h>
#include <sys/kernel.h>
+#include <linux/compat.h>
#include <linux/sched.h>
#include <asm/fpu/api.h>
-#if defined(__aarch64__) || defined(__amd64__) || defined(__i386__)
+#if defined(__aarch64__) || defined(__arm__) || defined(__amd64__) || \
+ defined(__i386__) || defined(__powerpc64__)
#include <machine/fpu.h>
@@ -58,6 +60,24 @@ lkpi_kernel_fpu_end(void)
fpu_kern_leave(curthread, NULL);
}
+void
+lkpi_fpu_safe_exec(fpu_safe_exec_cb_t func, void *ctx)
+{
+ unsigned int save_fpu_level;
+
+ save_fpu_level =
+ __current_unallocated(curthread) ? 0 : current->fpu_ctx_level;
+ if (__predict_false(save_fpu_level != 0)) {
+ current->fpu_ctx_level = 1;
+ kernel_fpu_end();
+ }
+ func(ctx);
+ if (__predict_false(save_fpu_level != 0)) {
+ kernel_fpu_begin();
+ current->fpu_ctx_level = save_fpu_level;
+ }
+}
+
#else
void
@@ -70,4 +90,10 @@ lkpi_kernel_fpu_end(void)
{
}
+void
+lkpi_fpu_safe_exec(fpu_safe_exec_cb_t func, void *ctx)
+{
+ func(ctx);
+}
+
#endif
diff --git a/sys/compat/linuxkpi/common/src/linux_slab.c
b/sys/compat/linuxkpi/common/src/linux_slab.c
index 72097c55f94c..68117d1c9fa7 100644
--- a/sys/compat/linuxkpi/common/src/linux_slab.c
+++ b/sys/compat/linuxkpi/common/src/linux_slab.c
@@ -25,6 +25,7 @@
*/
#include <sys/cdefs.h>
+#include <linux/compat.h>
#include <linux/slab.h>
#include <linux/rcupdate.h>
#include <linux/kernel.h>
@@ -206,6 +207,29 @@ linux_kmem_cache_destroy(struct linux_kmem_cache *c)
free(c, M_KMALLOC);
}
+struct lkpi_kmalloc_ctx {
+ size_t size;
+ gfp_t flags;
+ void *addr;
+};
+
+static void
+lkpi_kmalloc_cb(void *ctx)
+{
+ struct lkpi_kmalloc_ctx *lmc = ctx;
+
+ lmc->addr = __kmalloc(lmc->size, lmc->flags);
+}
+
+void *
+lkpi_kmalloc(size_t size, gfp_t flags)
+{
+ struct lkpi_kmalloc_ctx lmc = { .size = size, .flags = flags };
+
+ lkpi_fpu_safe_exec(&lkpi_kmalloc_cb, &lmc);
+ return(lmc.addr);
+}
+
static void
linux_kfree_async_fn(void *context, int pending)
{
