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authorLinus Torvalds <torvalds@linux-foundation.org>2024-06-28 16:11:02 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2024-06-28 16:11:02 -0700
commitb75f94727023c9d362eb875609dcc71a88a67480 (patch)
treecdd8d4f6434f04902b6e02c1b6a1ab3ccb9b6fc1 /arch/x86/include/asm
parent093d9603b60093a9aaae942db56107f6432a5dca (diff)
parent1c07c9be87dd3dd0634033bf08728b32465f08fb (diff)
Merge tag 'hardening-v6.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening fixes from Kees Cook: - Remove invalid tty __counted_by annotation (Nathan Chancellor) - Add missing MODULE_DESCRIPTION()s for KUnit string tests (Jeff Johnson) - Remove non-functional per-arch kstack entropy filtering * tag 'hardening-v6.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: tty: mxser: Remove __counted_by from mxser_board.ports[] randomize_kstack: Remove non-functional per-arch entropy filtering string: kunit: add missing MODULE_DESCRIPTION() macros
Diffstat (limited to 'arch/x86/include/asm')
-rw-r--r--arch/x86/include/asm/entry-common.h15
1 files changed, 6 insertions, 9 deletions
diff --git a/arch/x86/include/asm/entry-common.h b/arch/x86/include/asm/entry-common.h
index 7e523bb3d2d3..fb2809b20b0a 100644
--- a/arch/x86/include/asm/entry-common.h
+++ b/arch/x86/include/asm/entry-common.h
@@ -73,19 +73,16 @@ static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
#endif
/*
- * Ultimately, this value will get limited by KSTACK_OFFSET_MAX(),
- * but not enough for x86 stack utilization comfort. To keep
- * reasonable stack head room, reduce the maximum offset to 8 bits.
- *
- * The actual entropy will be further reduced by the compiler when
- * applying stack alignment constraints (see cc_stack_align4/8 in
+ * This value will get limited by KSTACK_OFFSET_MAX(), which is 10
+ * bits. The actual entropy will be further reduced by the compiler
+ * when applying stack alignment constraints (see cc_stack_align4/8 in
* arch/x86/Makefile), which will remove the 3 (x86_64) or 2 (ia32)
* low bits from any entropy chosen here.
*
- * Therefore, final stack offset entropy will be 5 (x86_64) or
- * 6 (ia32) bits.
+ * Therefore, final stack offset entropy will be 7 (x86_64) or
+ * 8 (ia32) bits.
*/
- choose_random_kstack_offset(rdtsc() & 0xFF);
+ choose_random_kstack_offset(rdtsc());
}
#define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare