| Message ID | 20250127213310.2496133-4-wnliu@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | unwind, arm64: add sframe unwinder for kernel | expand |
On 28-01-2025 03:03, Weinan Liu wrote: > Add sframe header so that we know how to access the sframe section > generated by compilers. > > This is the sframe header file borrowed from the patchset [1] > Josh Poimboeuf according to sframe v2 spec [2]. > > [1]: https://lore.kernel.org/lkml/42c0a99236af65c09c8182e260af7bcf5aa1e158.1730150953.git.jpoimboe@kernel.org/ > [2]: https://sourceware.org/binutils/docs/sframe-spec.html > > Signed-off-by: Weinan Liu <wnliu@google.com> > --- > kernel/sframe.h | 215 ++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 215 insertions(+) > create mode 100644 kernel/sframe.h > > diff --git a/kernel/sframe.h b/kernel/sframe.h > new file mode 100644 > index 000000000000..11b9be7ad82e > --- /dev/null > +++ b/kernel/sframe.h > @@ -0,0 +1,215 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later */ > +/* > + * Copyright (C) 2023, Oracle and/or its affiliates. > + * > + * This file contains definitions for the SFrame stack tracing format, which is > + * documented at https://sourceware.org/binutils/docs > + */ > +#ifndef _SFRAME_H > +#define _SFRAME_H > + > +#include <linux/types.h> > + > +#define SFRAME_VERSION_1 1 > +#define SFRAME_VERSION_2 2 > +#define SFRAME_MAGIC 0xdee2 > + > +/* Function Descriptor Entries are sorted on PC. */ > +#define SFRAME_F_FDE_SORTED 0x1 > +/* Frame-pointer based stack tracing. Defined, but not set. */ > +#define SFRAME_F_FRAME_POINTER 0x2 > + > +#define SFRAME_CFA_FIXED_FP_INVALID 0 > +#define SFRAME_CFA_FIXED_RA_INVALID 0 > + > +/* Supported ABIs/Arch. */ > +#define SFRAME_ABI_AARCH64_ENDIAN_BIG 1 /* AARCH64 big endian. */ > +#define SFRAME_ABI_AARCH64_ENDIAN_LITTLE 2 /* AARCH64 little endian. */ > +#define SFRAME_ABI_AMD64_ENDIAN_LITTLE 3 /* AMD64 little endian. */ > + > +/* SFrame FRE types. */ > +#define SFRAME_FRE_TYPE_ADDR1 0 > +#define SFRAME_FRE_TYPE_ADDR2 1 > +#define SFRAME_FRE_TYPE_ADDR4 2 > + > +/* > + * SFrame Function Descriptor Entry types. > + * > + * The SFrame format has two possible representations for functions. The > + * choice of which type to use is made according to the instruction patterns > + * in the relevant program stub. > + */ > + > +/* Unwinders perform a (PC >= FRE_START_ADDR) to look up a matching FRE. */ > +#define SFRAME_FDE_TYPE_PCINC 0 > +/* > + * Unwinders perform a (PC & FRE_START_ADDR_AS_MASK >= FRE_START_ADDR_AS_MASK) > + * to look up a matching FRE. Typical usecases are pltN entries, trampolines > + * etc. > + */ > +#define SFRAME_FDE_TYPE_PCMASK 1 > + > +/** > + * struct sframe_preamble - SFrame Preamble. > + * @magic: Magic number (SFRAME_MAGIC). > + * @version: Format version number (SFRAME_VERSION). > + * @flags: Various flags. > + */ > +struct sframe_preamble { > + u16 magic; > + u8 version; > + u8 flags; > +} __packed; > + > +/** > + * struct sframe_header - SFrame Header. > + * @preamble: SFrame preamble. > + * @abi_arch: Identify the arch (including endianness) and ABI. > + * @cfa_fixed_fp_offset: Offset for the Frame Pointer (FP) from CFA may be > + * fixed for some ABIs ((e.g, in AMD64 when -fno-omit-frame-pointer is > + * used). When fixed, this field specifies the fixed stack frame offset > + * and the individual FREs do not need to track it. When not fixed, it > + * is set to SFRAME_CFA_FIXED_FP_INVALID, and the individual FREs may > + * provide the applicable stack frame offset, if any. > + * @cfa_fixed_ra_offset: Offset for the Return Address from CFA is fixed for > + * some ABIs. When fixed, this field specifies the fixed stack frame > + * offset and the individual FREs do not need to track it. When not > + * fixed, it is set to SFRAME_CFA_FIXED_FP_INVALID. > + * @auxhdr_len: Number of bytes making up the auxiliary header, if any. > + * Some ABI/arch, in the future, may use this space for extending the > + * information in SFrame header. Auxiliary header is contained in bytes > + * sequentially following the sframe_header. > + * @num_fdes: Number of SFrame FDEs in this SFrame section. > + * @num_fres: Number of SFrame Frame Row Entries. > + * @fre_len: Number of bytes in the SFrame Frame Row Entry section. > + * @fdes_off: Offset of SFrame Function Descriptor Entry section. > + * @fres_off: Offset of SFrame Frame Row Entry section. > + */ > +struct sframe_header { > + struct sframe_preamble preamble; > + u8 abi_arch; > + s8 cfa_fixed_fp_offset; > + s8 cfa_fixed_ra_offset; > + u8 auxhdr_len; > + u32 num_fdes; > + u32 num_fres; > + u32 fre_len; > + u32 fdes_off; > + u32 fres_off; > +} __packed; > + > +#define SFRAME_HDR_SIZE(sframe_hdr) \ > + ((sizeof(struct sframe_header) + (sframe_hdr).auxhdr_len)) > + > +/* Two possible keys for executable (instruction) pointers signing. */ > +#define SFRAME_AARCH64_PAUTH_KEY_A 0 /* Key A. */ > +#define SFRAME_AARCH64_PAUTH_KEY_B 1 /* Key B. */ > + > +/** > + * struct sframe_fde - SFrame Function Descriptor Entry. > + * @start_addr: Function start address. Encoded as a signed offset, > + * relative to the current FDE. > + * @size: Size of the function in bytes. > + * @fres_off: Offset of the first SFrame Frame Row Entry of the function, > + * relative to the beginning of the SFrame Frame Row Entry sub-section. > + * @fres_num: Number of frame row entries for the function. > + * @info: Additional information for deciphering the stack trace > + * information for the function. Contains information about SFrame FRE > + * type, SFrame FDE type, PAC authorization A/B key, etc. > + * @rep_size: Block size for SFRAME_FDE_TYPE_PCMASK > + * @padding: Unused > + */ > +struct sframe_fde { > + s32 start_addr; > + u32 size; > + u32 fres_off; > + u32 fres_num; > + u8 info; > + u8 rep_size; > + u16 padding; > +} __packed; > + > +/* > + * 'func_info' in SFrame FDE contains additional information for deciphering > + * the stack trace information for the function. In V1, the information is > + * organized as follows: > + * - 4-bits: Identify the FRE type used for the function. > + * - 1-bit: Identify the FDE type of the function - mask or inc. > + * - 1-bit: PAC authorization A/B key (aarch64). > + * - 2-bits: Unused. > + * --------------------------------------------------------------------- > + * | Unused | PAC auth A/B key (aarch64) | FDE type | FRE type | > + * | | Unused (amd64) | | | > + * --------------------------------------------------------------------- > + * 8 6 5 4 0 > + */ > + > +/* Note: Set PAC auth key to SFRAME_AARCH64_PAUTH_KEY_A by default. */ > +#define SFRAME_FUNC_INFO(fde_type, fre_enc_type) \ > + (((SFRAME_AARCH64_PAUTH_KEY_A & 0x1) << 5) | \ > + (((fde_type) & 0x1) << 4) | ((fre_enc_type) & 0xf)) > + > +#define SFRAME_FUNC_FRE_TYPE(data) ((data) & 0xf) > +#define SFRAME_FUNC_FDE_TYPE(data) (((data) >> 4) & 0x1) > +#define SFRAME_FUNC_PAUTH_KEY(data) (((data) >> 5) & 0x1) > + > +/* > + * Size of stack frame offsets in an SFrame Frame Row Entry. A single > + * SFrame FRE has all offsets of the same size. Offset size may vary > + * across frame row entries. > + */ > +#define SFRAME_FRE_OFFSET_1B 0 > +#define SFRAME_FRE_OFFSET_2B 1 > +#define SFRAME_FRE_OFFSET_4B 2 > + > +/* An SFrame Frame Row Entry can be SP or FP based. */ > +#define SFRAME_BASE_REG_FP 0 > +#define SFRAME_BASE_REG_SP 1 > + > +/* > + * The index at which a specific offset is presented in the variable length > + * bytes of an FRE. > + */ > +#define SFRAME_FRE_CFA_OFFSET_IDX 0 > +/* > + * The RA stack offset, if present, will always be at index 1 in the variable > + * length bytes of the FRE. > + */ > +#define SFRAME_FRE_RA_OFFSET_IDX 1 > +/* > + * The FP stack offset may appear at offset 1 or 2, depending on the ABI as RA > + * may or may not be tracked. > + */ > +#define SFRAME_FRE_FP_OFFSET_IDX 2 > + > +/* > + * 'fre_info' in SFrame FRE contains information about: > + * - 1 bit: base reg for CFA > + * - 4 bits: Number of offsets (N). A value of up to 3 is allowed to track > + * all three of CFA, FP and RA (fixed implicit order). > + * - 2 bits: information about size of the offsets (S) in bytes. > + * Valid values are SFRAME_FRE_OFFSET_1B, SFRAME_FRE_OFFSET_2B, > + * SFRAME_FRE_OFFSET_4B > + * - 1 bit: Mangled RA state bit (aarch64 only). > + * --------------------------------------------------------------- > + * | Mangled-RA (aarch64) | Size of | Number of | base_reg | > + * | Unused (amd64) | offsets | offsets | | > + * --------------------------------------------------------------- > + * 8 7 5 1 0 > + */ > + > +/* Note: Set mangled_ra_p to zero by default. */ > +#define SFRAME_FRE_INFO(base_reg_id, offset_num, offset_size) \ > + (((0 & 0x1) << 7) | (((offset_size) & 0x3) << 5) | \ > + (((offset_num) & 0xf) << 1) | ((base_reg_id) & 0x1)) > + > +/* Set the mangled_ra_p bit as indicated. */ > +#define SFRAME_FRE_INFO_UPDATE_MANGLED_RA_P(mangled_ra_p, fre_info) \ > + ((((mangled_ra_p) & 0x1) << 7) | ((fre_info) & 0x7f)) > + > +#define SFRAME_FRE_CFA_BASE_REG_ID(data) ((data) & 0x1) > +#define SFRAME_FRE_OFFSET_COUNT(data) (((data) >> 1) & 0xf) > +#define SFRAME_FRE_OFFSET_SIZE(data) (((data) >> 5) & 0x3) > +#define SFRAME_FRE_MANGLED_RA_P(data) (((data) >> 7) & 0x1) > + > +#endif /* _SFRAME_H */ Looks good to me. Reviewed-by: Prasanna Kumar T S M <ptsm@linux.microsoft.com>.
diff --git a/kernel/sframe.h b/kernel/sframe.h new file mode 100644 index 000000000000..11b9be7ad82e --- /dev/null +++ b/kernel/sframe.h @@ -0,0 +1,215 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2023, Oracle and/or its affiliates. + * + * This file contains definitions for the SFrame stack tracing format, which is + * documented at https://sourceware.org/binutils/docs + */ +#ifndef _SFRAME_H +#define _SFRAME_H + +#include <linux/types.h> + +#define SFRAME_VERSION_1 1 +#define SFRAME_VERSION_2 2 +#define SFRAME_MAGIC 0xdee2 + +/* Function Descriptor Entries are sorted on PC. */ +#define SFRAME_F_FDE_SORTED 0x1 +/* Frame-pointer based stack tracing. Defined, but not set. */ +#define SFRAME_F_FRAME_POINTER 0x2 + +#define SFRAME_CFA_FIXED_FP_INVALID 0 +#define SFRAME_CFA_FIXED_RA_INVALID 0 + +/* Supported ABIs/Arch. */ +#define SFRAME_ABI_AARCH64_ENDIAN_BIG 1 /* AARCH64 big endian. */ +#define SFRAME_ABI_AARCH64_ENDIAN_LITTLE 2 /* AARCH64 little endian. */ +#define SFRAME_ABI_AMD64_ENDIAN_LITTLE 3 /* AMD64 little endian. */ + +/* SFrame FRE types. */ +#define SFRAME_FRE_TYPE_ADDR1 0 +#define SFRAME_FRE_TYPE_ADDR2 1 +#define SFRAME_FRE_TYPE_ADDR4 2 + +/* + * SFrame Function Descriptor Entry types. + * + * The SFrame format has two possible representations for functions. The + * choice of which type to use is made according to the instruction patterns + * in the relevant program stub. + */ + +/* Unwinders perform a (PC >= FRE_START_ADDR) to look up a matching FRE. */ +#define SFRAME_FDE_TYPE_PCINC 0 +/* + * Unwinders perform a (PC & FRE_START_ADDR_AS_MASK >= FRE_START_ADDR_AS_MASK) + * to look up a matching FRE. Typical usecases are pltN entries, trampolines + * etc. + */ +#define SFRAME_FDE_TYPE_PCMASK 1 + +/** + * struct sframe_preamble - SFrame Preamble. + * @magic: Magic number (SFRAME_MAGIC). + * @version: Format version number (SFRAME_VERSION). + * @flags: Various flags. + */ +struct sframe_preamble { + u16 magic; + u8 version; + u8 flags; +} __packed; + +/** + * struct sframe_header - SFrame Header. + * @preamble: SFrame preamble. + * @abi_arch: Identify the arch (including endianness) and ABI. + * @cfa_fixed_fp_offset: Offset for the Frame Pointer (FP) from CFA may be + * fixed for some ABIs ((e.g, in AMD64 when -fno-omit-frame-pointer is + * used). When fixed, this field specifies the fixed stack frame offset + * and the individual FREs do not need to track it. When not fixed, it + * is set to SFRAME_CFA_FIXED_FP_INVALID, and the individual FREs may + * provide the applicable stack frame offset, if any. + * @cfa_fixed_ra_offset: Offset for the Return Address from CFA is fixed for + * some ABIs. When fixed, this field specifies the fixed stack frame + * offset and the individual FREs do not need to track it. When not + * fixed, it is set to SFRAME_CFA_FIXED_FP_INVALID. + * @auxhdr_len: Number of bytes making up the auxiliary header, if any. + * Some ABI/arch, in the future, may use this space for extending the + * information in SFrame header. Auxiliary header is contained in bytes + * sequentially following the sframe_header. + * @num_fdes: Number of SFrame FDEs in this SFrame section. + * @num_fres: Number of SFrame Frame Row Entries. + * @fre_len: Number of bytes in the SFrame Frame Row Entry section. + * @fdes_off: Offset of SFrame Function Descriptor Entry section. + * @fres_off: Offset of SFrame Frame Row Entry section. + */ +struct sframe_header { + struct sframe_preamble preamble; + u8 abi_arch; + s8 cfa_fixed_fp_offset; + s8 cfa_fixed_ra_offset; + u8 auxhdr_len; + u32 num_fdes; + u32 num_fres; + u32 fre_len; + u32 fdes_off; + u32 fres_off; +} __packed; + +#define SFRAME_HDR_SIZE(sframe_hdr) \ + ((sizeof(struct sframe_header) + (sframe_hdr).auxhdr_len)) + +/* Two possible keys for executable (instruction) pointers signing. */ +#define SFRAME_AARCH64_PAUTH_KEY_A 0 /* Key A. */ +#define SFRAME_AARCH64_PAUTH_KEY_B 1 /* Key B. */ + +/** + * struct sframe_fde - SFrame Function Descriptor Entry. + * @start_addr: Function start address. Encoded as a signed offset, + * relative to the current FDE. + * @size: Size of the function in bytes. + * @fres_off: Offset of the first SFrame Frame Row Entry of the function, + * relative to the beginning of the SFrame Frame Row Entry sub-section. + * @fres_num: Number of frame row entries for the function. + * @info: Additional information for deciphering the stack trace + * information for the function. Contains information about SFrame FRE + * type, SFrame FDE type, PAC authorization A/B key, etc. + * @rep_size: Block size for SFRAME_FDE_TYPE_PCMASK + * @padding: Unused + */ +struct sframe_fde { + s32 start_addr; + u32 size; + u32 fres_off; + u32 fres_num; + u8 info; + u8 rep_size; + u16 padding; +} __packed; + +/* + * 'func_info' in SFrame FDE contains additional information for deciphering + * the stack trace information for the function. In V1, the information is + * organized as follows: + * - 4-bits: Identify the FRE type used for the function. + * - 1-bit: Identify the FDE type of the function - mask or inc. + * - 1-bit: PAC authorization A/B key (aarch64). + * - 2-bits: Unused. + * --------------------------------------------------------------------- + * | Unused | PAC auth A/B key (aarch64) | FDE type | FRE type | + * | | Unused (amd64) | | | + * --------------------------------------------------------------------- + * 8 6 5 4 0 + */ + +/* Note: Set PAC auth key to SFRAME_AARCH64_PAUTH_KEY_A by default. */ +#define SFRAME_FUNC_INFO(fde_type, fre_enc_type) \ + (((SFRAME_AARCH64_PAUTH_KEY_A & 0x1) << 5) | \ + (((fde_type) & 0x1) << 4) | ((fre_enc_type) & 0xf)) + +#define SFRAME_FUNC_FRE_TYPE(data) ((data) & 0xf) +#define SFRAME_FUNC_FDE_TYPE(data) (((data) >> 4) & 0x1) +#define SFRAME_FUNC_PAUTH_KEY(data) (((data) >> 5) & 0x1) + +/* + * Size of stack frame offsets in an SFrame Frame Row Entry. A single + * SFrame FRE has all offsets of the same size. Offset size may vary + * across frame row entries. + */ +#define SFRAME_FRE_OFFSET_1B 0 +#define SFRAME_FRE_OFFSET_2B 1 +#define SFRAME_FRE_OFFSET_4B 2 + +/* An SFrame Frame Row Entry can be SP or FP based. */ +#define SFRAME_BASE_REG_FP 0 +#define SFRAME_BASE_REG_SP 1 + +/* + * The index at which a specific offset is presented in the variable length + * bytes of an FRE. + */ +#define SFRAME_FRE_CFA_OFFSET_IDX 0 +/* + * The RA stack offset, if present, will always be at index 1 in the variable + * length bytes of the FRE. + */ +#define SFRAME_FRE_RA_OFFSET_IDX 1 +/* + * The FP stack offset may appear at offset 1 or 2, depending on the ABI as RA + * may or may not be tracked. + */ +#define SFRAME_FRE_FP_OFFSET_IDX 2 + +/* + * 'fre_info' in SFrame FRE contains information about: + * - 1 bit: base reg for CFA + * - 4 bits: Number of offsets (N). A value of up to 3 is allowed to track + * all three of CFA, FP and RA (fixed implicit order). + * - 2 bits: information about size of the offsets (S) in bytes. + * Valid values are SFRAME_FRE_OFFSET_1B, SFRAME_FRE_OFFSET_2B, + * SFRAME_FRE_OFFSET_4B + * - 1 bit: Mangled RA state bit (aarch64 only). + * --------------------------------------------------------------- + * | Mangled-RA (aarch64) | Size of | Number of | base_reg | + * | Unused (amd64) | offsets | offsets | | + * --------------------------------------------------------------- + * 8 7 5 1 0 + */ + +/* Note: Set mangled_ra_p to zero by default. */ +#define SFRAME_FRE_INFO(base_reg_id, offset_num, offset_size) \ + (((0 & 0x1) << 7) | (((offset_size) & 0x3) << 5) | \ + (((offset_num) & 0xf) << 1) | ((base_reg_id) & 0x1)) + +/* Set the mangled_ra_p bit as indicated. */ +#define SFRAME_FRE_INFO_UPDATE_MANGLED_RA_P(mangled_ra_p, fre_info) \ + ((((mangled_ra_p) & 0x1) << 7) | ((fre_info) & 0x7f)) + +#define SFRAME_FRE_CFA_BASE_REG_ID(data) ((data) & 0x1) +#define SFRAME_FRE_OFFSET_COUNT(data) (((data) >> 1) & 0xf) +#define SFRAME_FRE_OFFSET_SIZE(data) (((data) >> 5) & 0x3) +#define SFRAME_FRE_MANGLED_RA_P(data) (((data) >> 7) & 0x1) + +#endif /* _SFRAME_H */
Add sframe header so that we know how to access the sframe section generated by compilers. This is the sframe header file borrowed from the patchset [1] Josh Poimboeuf according to sframe v2 spec [2]. [1]: https://lore.kernel.org/lkml/42c0a99236af65c09c8182e260af7bcf5aa1e158.1730150953.git.jpoimboe@kernel.org/ [2]: https://sourceware.org/binutils/docs/sframe-spec.html Signed-off-by: Weinan Liu <wnliu@google.com> --- kernel/sframe.h | 215 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 215 insertions(+) create mode 100644 kernel/sframe.h