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Peter Anvin" Subject: [PATCH -tip v2 1/2] x86/ptrace: Use savesegment() in get_segment_reg() instead of inline asm Date: Wed, 8 Apr 2026 10:22:11 +0200 Message-ID: <20260408082814.60213-1-ubizjak@gmail.com> X-Mailer: git-send-email 2.53.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Replace direct 'movl' instructions for DS, ES, FS, and GS read in get_segment_reg() with the savesegment() helper. This improves readability, consistency, and ensures proper handling of segment registers on x86_64. No functional change intended. Signed-off-by: Uros Bizjak Acked-by: Oleg Nesterov Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: "H. Peter Anvin" --- arch/x86/kernel/ptrace.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 3dcadc13f09a..4cb00aa0645f 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -251,32 +251,31 @@ static u16 get_segment_reg(struct task_struct *task, unsigned long offset) /* * Returning the value truncates it to 16 bits. */ - unsigned int seg; + unsigned int retval; switch (offset) { case offsetof(struct user_regs_struct, fs): if (task == current) { - /* Older gas can't assemble movq %?s,%r?? */ - asm("movl %%fs,%0" : "=r" (seg)); - return seg; + savesegment(fs, retval); + return retval; } return task->thread.fsindex; case offsetof(struct user_regs_struct, gs): if (task == current) { - asm("movl %%gs,%0" : "=r" (seg)); - return seg; + savesegment(gs, retval); + return retval; } return task->thread.gsindex; case offsetof(struct user_regs_struct, ds): if (task == current) { - asm("movl %%ds,%0" : "=r" (seg)); - return seg; + savesegment(ds, retval); + return retval; } return task->thread.ds; case offsetof(struct user_regs_struct, es): if (task == current) { - asm("movl %%es,%0" : "=r" (seg)); - return seg; + savesegment(es, retval); + return retval; } return task->thread.es; -- 2.53.0