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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/include/asm/frame.h
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/include/asm/frame.h')
-rw-r--r--arch/x86/include/asm/frame.h113
1 files changed, 113 insertions, 0 deletions
diff --git a/arch/x86/include/asm/frame.h b/arch/x86/include/asm/frame.h
new file mode 100644
index 000000000..fb42659f6
--- /dev/null
+++ b/arch/x86/include/asm/frame.h
@@ -0,0 +1,113 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_FRAME_H
+#define _ASM_X86_FRAME_H
+
+#include <asm/asm.h>
+
+/*
+ * These are stack frame creation macros. They should be used by every
+ * callable non-leaf asm function to make kernel stack traces more reliable.
+ */
+
+#ifdef CONFIG_FRAME_POINTER
+
+#ifdef __ASSEMBLY__
+
+.macro FRAME_BEGIN
+ push %_ASM_BP
+ _ASM_MOV %_ASM_SP, %_ASM_BP
+.endm
+
+.macro FRAME_END
+ pop %_ASM_BP
+.endm
+
+#ifdef CONFIG_X86_64
+/*
+ * This is a sneaky trick to help the unwinder find pt_regs on the stack. The
+ * frame pointer is replaced with an encoded pointer to pt_regs. The encoding
+ * is just setting the LSB, which makes it an invalid stack address and is also
+ * a signal to the unwinder that it's a pt_regs pointer in disguise.
+ *
+ * NOTE: This macro must be used *after* PUSH_AND_CLEAR_REGS because it corrupts
+ * the original rbp.
+ */
+.macro ENCODE_FRAME_POINTER ptregs_offset=0
+ leaq 1+\ptregs_offset(%rsp), %rbp
+.endm
+#else /* !CONFIG_X86_64 */
+/*
+ * This is a sneaky trick to help the unwinder find pt_regs on the stack. The
+ * frame pointer is replaced with an encoded pointer to pt_regs. The encoding
+ * is just clearing the MSB, which makes it an invalid stack address and is also
+ * a signal to the unwinder that it's a pt_regs pointer in disguise.
+ *
+ * NOTE: This macro must be used *after* SAVE_ALL because it corrupts the
+ * original ebp.
+ */
+.macro ENCODE_FRAME_POINTER
+ mov %esp, %ebp
+ andl $0x7fffffff, %ebp
+.endm
+#endif /* CONFIG_X86_64 */
+
+#else /* !__ASSEMBLY__ */
+
+#define FRAME_BEGIN \
+ "push %" _ASM_BP "\n" \
+ _ASM_MOV "%" _ASM_SP ", %" _ASM_BP "\n"
+
+#define FRAME_END "pop %" _ASM_BP "\n"
+
+#ifdef CONFIG_X86_64
+
+#define ENCODE_FRAME_POINTER \
+ "lea 1(%rsp), %rbp\n\t"
+
+static inline unsigned long encode_frame_pointer(struct pt_regs *regs)
+{
+ return (unsigned long)regs + 1;
+}
+
+#else /* !CONFIG_X86_64 */
+
+#define ENCODE_FRAME_POINTER \
+ "movl %esp, %ebp\n\t" \
+ "andl $0x7fffffff, %ebp\n\t"
+
+static inline unsigned long encode_frame_pointer(struct pt_regs *regs)
+{
+ return (unsigned long)regs & 0x7fffffff;
+}
+
+#endif /* CONFIG_X86_64 */
+
+#endif /* __ASSEMBLY__ */
+
+#define FRAME_OFFSET __ASM_SEL(4, 8)
+
+#else /* !CONFIG_FRAME_POINTER */
+
+#ifdef __ASSEMBLY__
+
+.macro ENCODE_FRAME_POINTER ptregs_offset=0
+.endm
+
+#else /* !__ASSEMBLY */
+
+#define ENCODE_FRAME_POINTER
+
+static inline unsigned long encode_frame_pointer(struct pt_regs *regs)
+{
+ return 0;
+}
+
+#endif
+
+#define FRAME_BEGIN
+#define FRAME_END
+#define FRAME_OFFSET 0
+
+#endif /* CONFIG_FRAME_POINTER */
+
+#endif /* _ASM_X86_FRAME_H */