5.15-stable review patch. If anyone has any objections, please let me know.
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From: Uros Bizjak ubizjak@gmail.com
[ Upstream commit ac9c408ed19d535289ca59200dd6a44a6a2d6036 ]
RDPID instruction outputs to a word-sized register (64-bit on x86_64 and 32-bit on x86_32). Use an unsigned long variable to store the correct size.
LSL outputs to 32-bit register, use %k operand prefix to always print the 32-bit name of the register.
Use RDPID insn mnemonic while at it as the minimum binutils version of 2.30 supports it.
[ bp: Merge two patches touching the same function into a single one. ]
Fixes: ffebbaedc861 ("x86/vdso: Introduce helper functions for CPU and node number") Signed-off-by: Uros Bizjak ubizjak@gmail.com Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Link: https://lore.kernel.org/20250616095315.230620-1-ubizjak@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/include/asm/segment.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h index 8dd8e8ec9fa55..879be4ffa06c7 100644 --- a/arch/x86/include/asm/segment.h +++ b/arch/x86/include/asm/segment.h @@ -242,7 +242,7 @@ static inline unsigned long vdso_encode_cpunode(int cpu, unsigned long node)
static inline void vdso_read_cpunode(unsigned *cpu, unsigned *node) { - unsigned int p; + unsigned long p;
/* * Load CPU and node number from the GDT. LSL is faster than RDTSCP @@ -252,10 +252,10 @@ static inline void vdso_read_cpunode(unsigned *cpu, unsigned *node) * * If RDPID is available, use it. */ - alternative_io ("lsl %[seg],%[p]", - ".byte 0xf3,0x0f,0xc7,0xf8", /* RDPID %eax/rax */ + alternative_io ("lsl %[seg],%k[p]", + "rdpid %[p]", X86_FEATURE_RDPID, - [p] "=a" (p), [seg] "r" (__CPUNODE_SEG)); + [p] "=r" (p), [seg] "r" (__CPUNODE_SEG));
if (cpu) *cpu = (p & VDSO_CPUNODE_MASK);