From: Luis Machado Date: Tue, 7 Feb 2023 09:47:27 +0000 (+0000) Subject: sme: Signal frame support X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=f62b3d21ec1f8c62905c55b76543d49666e2f717;p=binutils-gdb.git sme: Signal frame support Teach gdb about the ZA/SSVE state on signal frames and how to restore the contents of the registers. There is a new ZA_MAGIC context that the Linux Kernel uses to communicate the ZA register state to gdb. The SVE_MAGIC context has also been adjusted to contain a flag indicating whether it is a SVE or SSVE state. Regression-tested on aarch64-linux Ubuntu 22.04/20.04. Reviewed-by: Thiago Jung Bauermann --- diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c index bdd5cb05c10..f76d1888072 100644 --- a/gdb/aarch64-linux-tdep.c +++ b/gdb/aarch64-linux-tdep.c @@ -48,6 +48,7 @@ #include "linux-record.h" #include "arch/aarch64-mte-linux.h" +#include "arch/aarch64-scalable-linux.h" #include "arch-utils.h" #include "value.h" @@ -152,6 +153,7 @@ #define AARCH64_EXTRA_MAGIC 0x45585401 #define AARCH64_FPSIMD_MAGIC 0x46508001 #define AARCH64_SVE_MAGIC 0x53564501 +#define AARCH64_ZA_MAGIC 0x54366345 /* Defines for the extra_context that follows an AARCH64_EXTRA_MAGIC. */ #define AARCH64_EXTRA_DATAP_OFFSET 8 @@ -164,13 +166,23 @@ /* Defines for the sve structure that follows an AARCH64_SVE_MAGIC. */ #define AARCH64_SVE_CONTEXT_VL_OFFSET 8 +#define AARCH64_SVE_CONTEXT_FLAGS_OFFSET 10 #define AARCH64_SVE_CONTEXT_REGS_OFFSET 16 #define AARCH64_SVE_CONTEXT_P_REGS_OFFSET(vq) (32 * vq * 16) #define AARCH64_SVE_CONTEXT_FFR_OFFSET(vq) \ (AARCH64_SVE_CONTEXT_P_REGS_OFFSET (vq) + (16 * vq * 2)) #define AARCH64_SVE_CONTEXT_SIZE(vq) \ (AARCH64_SVE_CONTEXT_FFR_OFFSET (vq) + (vq * 2)) +/* Flag indicating the SVE Context describes streaming mode. */ +#define SVE_SIG_FLAG_SM 0x1 +/* SME constants. */ +#define AARCH64_SME_CONTEXT_SVL_OFFSET 8 +#define AARCH64_SME_CONTEXT_REGS_OFFSET 16 +#define AARCH64_SME_CONTEXT_ZA_SIZE(svq) \ + ((sve_vl_from_vq (svq) * sve_vl_from_vq (svq))) +#define AARCH64_SME_CONTEXT_SIZE(svq) \ + (AARCH64_SME_CONTEXT_REGS_OFFSET + AARCH64_SME_CONTEXT_ZA_SIZE (svq)) /* Read an aarch64_ctx, returning the magic value, and setting *SIZE to the size, or return 0 on error. */ @@ -324,7 +336,10 @@ aarch64_linux_sigframe_init (const struct tramp_frame *self, CORE_ADDR section_end = section + AARCH64_SIGCONTEXT_RESERVED_SIZE; CORE_ADDR fpsimd = 0; CORE_ADDR sve_regs = 0; + CORE_ADDR za_state = 0; + uint64_t svcr = 0; uint32_t size, magic; + size_t vq = 0, svq = 0; bool extra_found = false; int num_regs = gdbarch_num_regs (gdbarch); @@ -360,7 +375,7 @@ aarch64_linux_sigframe_init (const struct tramp_frame *self, /* Check if the section is followed by a full SVE dump, and set sve_regs if it is. */ gdb_byte buf[4]; - uint16_t vq; + uint16_t flags; if (!tdep->has_sve ()) break; @@ -373,9 +388,23 @@ aarch64_linux_sigframe_init (const struct tramp_frame *self, } vq = sve_vq_from_vl (extract_unsigned_integer (buf, 2, byte_order)); - if (vq != tdep->vq) - error (_("Invalid vector length in signal frame %d vs %s."), vq, - pulongest (tdep->vq)); + /* If SME is supported, also read the flags field. It may + indicate if this SVE context is for streaming mode (SSVE). */ + if (tdep->has_sme ()) + { + if (target_read_memory (section + + AARCH64_SVE_CONTEXT_FLAGS_OFFSET, + buf, 2) != 0) + { + section += size; + break; + } + flags = extract_unsigned_integer (buf, 2, byte_order); + + /* Is this SSVE data? If so, enable the SM bit in SVCR. */ + if (flags & SVE_SIG_FLAG_SM) + svcr |= SVCR_SM_BIT; + } if (size >= AARCH64_SVE_CONTEXT_SIZE (vq)) sve_regs = section + AARCH64_SVE_CONTEXT_REGS_OFFSET; @@ -384,6 +413,38 @@ aarch64_linux_sigframe_init (const struct tramp_frame *self, break; } + case AARCH64_ZA_MAGIC: + { + if (!tdep->has_sme ()) + { + section += size; + break; + } + + /* Check if the section is followed by a full ZA dump, and set + za_state if it is. */ + gdb_byte buf[2]; + + if (target_read_memory (section + AARCH64_SME_CONTEXT_SVL_OFFSET, + buf, 2) != 0) + { + section += size; + break; + } + svq = sve_vq_from_vl (extract_unsigned_integer (buf, 2, + byte_order)); + + if (size >= AARCH64_SME_CONTEXT_SIZE (svq)) + { + za_state = section + AARCH64_SME_CONTEXT_REGS_OFFSET; + /* We have ZA data. Enable the ZA bit in SVCR. */ + svcr |= SVCR_ZA_BIT; + } + + section += size; + break; + } + case AARCH64_EXTRA_MAGIC: { /* Extra is always the last valid section in reserved and points to @@ -422,7 +483,7 @@ aarch64_linux_sigframe_init (const struct tramp_frame *self, for (int i = 0; i < 32; i++) { - offset = sve_regs + (i * tdep->vq * 16); + offset = sve_regs + (i * vq * 16); trad_frame_set_reg_addr (this_cache, AARCH64_SVE_Z0_REGNUM + i, offset); trad_frame_set_reg_addr (this_cache, @@ -440,12 +501,12 @@ aarch64_linux_sigframe_init (const struct tramp_frame *self, offset); } - offset = sve_regs + AARCH64_SVE_CONTEXT_P_REGS_OFFSET (tdep->vq); + offset = sve_regs + AARCH64_SVE_CONTEXT_P_REGS_OFFSET (vq); for (int i = 0; i < 16; i++) trad_frame_set_reg_addr (this_cache, AARCH64_SVE_P0_REGNUM + i, - offset + (i * tdep->vq * 2)); + offset + (i * vq * 2)); - offset = sve_regs + AARCH64_SVE_CONTEXT_FFR_OFFSET (tdep->vq); + offset = sve_regs + AARCH64_SVE_CONTEXT_FFR_OFFSET (vq); trad_frame_set_reg_addr (this_cache, AARCH64_SVE_FFR_REGNUM, offset); } @@ -461,6 +522,17 @@ aarch64_linux_sigframe_init (const struct tramp_frame *self, aarch64_linux_restore_vregs (gdbarch, this_cache, fpsimd); } + if (za_state != 0) + { + /* Restore the ZA state. */ + trad_frame_set_reg_addr (this_cache, tdep->sme_za_regnum, + za_state); + } + + /* If SME is supported, set SVCR as well. */ + if (tdep->has_sme ()) + trad_frame_set_reg_value (this_cache, tdep->sme_svcr_regnum, svcr); + trad_frame_set_id (this_cache, frame_id_build (sp, func)); } diff --git a/gdb/nat/aarch64-scalable-linux-sigcontext.h b/gdb/nat/aarch64-scalable-linux-sigcontext.h index 74407bd266a..18623443744 100644 --- a/gdb/nat/aarch64-scalable-linux-sigcontext.h +++ b/gdb/nat/aarch64-scalable-linux-sigcontext.h @@ -30,7 +30,10 @@ struct sve_context { struct _aarch64_ctx head; __u16 vl; - __u16 __reserved[3]; + /* Holds flags. This field was defined for SME support. Prior to it, + this used to be a reserved 16-bit value. */ + __u16 flags; + __u16 __reserved[2]; }; /*