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authorLinus Torvalds <torvalds@linux-foundation.org>2025-05-05 08:14:53 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2025-05-05 08:14:53 -0700
commit01f95500a162fca88cefab9ed64ceded5afabc12 (patch)
tree3f6feaf0408a604fed9b2e45734a3d7465c58d6e
parent7b26feb436d2ef5db1e8ba82c7ecb4c1cc869502 (diff)
parent68025adfc13e6cd15eebe2293f77659f47daf13b (diff)
Merge tag 'uml-for-linux-6.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux
Pull uml fix from Johannes Berg: "There's just a single fix here for the _nofault changes that were causing issues with clang, and then when we looked at it some other issues seemed to exist" * tag 'uml-for-linux-6.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: um: fix _nofault accesses
-rw-r--r--arch/um/include/asm/uaccess.h2
-rw-r--r--arch/um/kernel/trap.c26
-rw-r--r--arch/x86/um/shared/sysdep/faultinfo_32.h2
-rw-r--r--arch/x86/um/shared/sysdep/faultinfo_64.h2
4 files changed, 17 insertions, 15 deletions
diff --git a/arch/um/include/asm/uaccess.h b/arch/um/include/asm/uaccess.h
index 3a08f9029a3f..1c6e0ae41b0c 100644
--- a/arch/um/include/asm/uaccess.h
+++ b/arch/um/include/asm/uaccess.h
@@ -55,6 +55,7 @@ do { \
goto err_label; \
} \
*((type *)dst) = get_unaligned((type *)(src)); \
+ barrier(); \
current->thread.segv_continue = NULL; \
} while (0)
@@ -66,6 +67,7 @@ do { \
if (__faulted) \
goto err_label; \
put_unaligned(*((type *)src), (type *)(dst)); \
+ barrier(); \
current->thread.segv_continue = NULL; \
} while (0)
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index ce073150dc20..ef2272e92a43 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -225,20 +225,20 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
panic("Failed to sync kernel TLBs: %d", err);
goto out;
}
- else if (current->mm == NULL) {
- if (current->pagefault_disabled) {
- if (!mc) {
- show_regs(container_of(regs, struct pt_regs, regs));
- panic("Segfault with pagefaults disabled but no mcontext");
- }
- if (!current->thread.segv_continue) {
- show_regs(container_of(regs, struct pt_regs, regs));
- panic("Segfault without recovery target");
- }
- mc_set_rip(mc, current->thread.segv_continue);
- current->thread.segv_continue = NULL;
- goto out;
+ else if (current->pagefault_disabled) {
+ if (!mc) {
+ show_regs(container_of(regs, struct pt_regs, regs));
+ panic("Segfault with pagefaults disabled but no mcontext");
}
+ if (!current->thread.segv_continue) {
+ show_regs(container_of(regs, struct pt_regs, regs));
+ panic("Segfault without recovery target");
+ }
+ mc_set_rip(mc, current->thread.segv_continue);
+ current->thread.segv_continue = NULL;
+ goto out;
+ }
+ else if (current->mm == NULL) {
show_regs(container_of(regs, struct pt_regs, regs));
panic("Segfault with no mm");
}
diff --git a/arch/x86/um/shared/sysdep/faultinfo_32.h b/arch/x86/um/shared/sysdep/faultinfo_32.h
index ab5c8e47049c..9193a7790a71 100644
--- a/arch/x86/um/shared/sysdep/faultinfo_32.h
+++ b/arch/x86/um/shared/sysdep/faultinfo_32.h
@@ -31,8 +31,8 @@ struct faultinfo {
#define ___backtrack_faulted(_faulted) \
asm volatile ( \
- "mov $0, %0\n" \
"movl $__get_kernel_nofault_faulted_%=,%1\n" \
+ "mov $0, %0\n" \
"jmp _end_%=\n" \
"__get_kernel_nofault_faulted_%=:\n" \
"mov $1, %0;" \
diff --git a/arch/x86/um/shared/sysdep/faultinfo_64.h b/arch/x86/um/shared/sysdep/faultinfo_64.h
index 26fb4835d3e9..61e4ca1e0ab5 100644
--- a/arch/x86/um/shared/sysdep/faultinfo_64.h
+++ b/arch/x86/um/shared/sysdep/faultinfo_64.h
@@ -31,8 +31,8 @@ struct faultinfo {
#define ___backtrack_faulted(_faulted) \
asm volatile ( \
- "mov $0, %0\n" \
"movq $__get_kernel_nofault_faulted_%=,%1\n" \
+ "mov $0, %0\n" \
"jmp _end_%=\n" \
"__get_kernel_nofault_faulted_%=:\n" \
"mov $1, %0;" \