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[24.130.93.68]) by smtp.gmail.com with ESMTPSA id x1-20020aa79a41000000b00536b2483aedsm6873603pfj.199.2022.09.13.18.26.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Sep 2022 18:26:26 -0700 (PDT) From: Max Filippov To: linux-xtensa@linux-xtensa.org Cc: Chris Zankel , linux-kernel@vger.kernel.org, Eric Biederman , Kees Cook , Alexander Viro , linux-mm@kvack.org, Max Filippov Subject: [PATCH] xtensa: add FDPIC and static PIE support for noMMU Date: Tue, 13 Sep 2022 18:26:10 -0700 Message-Id: <20220914012610.2734108-1-jcmvbkbc@gmail.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Define ELFOSABI_XTENSA_FDPIC and Use is as an OSABI tag in the ELF header to distinguish FDPIC ELF files from regular ELF files. Define ELF_FDPIC_PLAT_INIT and put executable map, interpreter map and executable dynamic section addresses into registers a4..a6. Update start_thread macro to preserve register values in the current register window. Add definitions for PTRACE_GETFDPIC, PTRACE_GETFDPIC_EXEC and PTRACE_GETFDPIC_INTERP. Signed-off-by: Max Filippov --- arch/xtensa/include/asm/elf.h | 11 +++++++++++ arch/xtensa/include/asm/processor.h | 3 +++ arch/xtensa/include/uapi/asm/ptrace.h | 4 ++++ fs/Kconfig.binfmt | 2 +- 4 files changed, 19 insertions(+), 1 deletion(-) diff --git a/arch/xtensa/include/asm/elf.h b/arch/xtensa/include/asm/elf.h index 9c21897c6992..ffcf1ada19c6 100644 --- a/arch/xtensa/include/asm/elf.h +++ b/arch/xtensa/include/asm/elf.h @@ -93,6 +93,10 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG]; #define elf_check_arch(x) ( ( (x)->e_machine =3D=3D EM_XTENSA ) || \ ( (x)->e_machine =3D=3D EM_XTENSA_OLD ) ) =20 +#define ELFOSABI_XTENSA_FDPIC 65 +#define elf_check_fdpic(x) ((x)->e_ident[EI_OSABI] =3D=3D ELFOSABI_XTENSA_= FDPIC) +#define ELF_FDPIC_CORE_EFLAGS 0 + /* * These are used to set parameters in the core dumps. */ @@ -164,6 +168,13 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG]; (_r)->areg[14] =3D 0; (_r)->areg[15] =3D 0; \ } while (0) =20 +#define ELF_FDPIC_PLAT_INIT(_r, _exec_map_addr, _interp_map_addr, dynamic_= addr) \ + do { \ + (_r)->areg[4] =3D _exec_map_addr; \ + (_r)->areg[5] =3D _interp_map_addr; \ + (_r)->areg[6] =3D dynamic_addr; \ + } while (0) + typedef struct { xtregs_opt_t opt; xtregs_user_t user; diff --git a/arch/xtensa/include/asm/processor.h b/arch/xtensa/include/asm/= processor.h index 76bc63127c66..b75ba16ec080 100644 --- a/arch/xtensa/include/asm/processor.h +++ b/arch/xtensa/include/asm/processor.h @@ -205,9 +205,12 @@ struct thread_struct { #define start_thread(regs, new_pc, new_sp) \ do { \ unsigned long syscall =3D (regs)->syscall; \ + unsigned long current_aregs[16]; \ + memcpy(current_aregs, (regs)->areg, sizeof(current_aregs)); \ memset((regs), 0, sizeof(*(regs))); \ (regs)->pc =3D (new_pc); \ (regs)->ps =3D USER_PS_VALUE; \ + memcpy((regs)->areg, current_aregs, sizeof(current_aregs)); \ (regs)->areg[1] =3D (new_sp); \ (regs)->areg[0] =3D 0; \ (regs)->wmask =3D 1; \ diff --git a/arch/xtensa/include/uapi/asm/ptrace.h b/arch/xtensa/include/ua= pi/asm/ptrace.h index 50db3e0a6341..9115e86ebc75 100644 --- a/arch/xtensa/include/uapi/asm/ptrace.h +++ b/arch/xtensa/include/uapi/asm/ptrace.h @@ -37,6 +37,10 @@ #define PTRACE_SETXTREGS 19 #define PTRACE_GETHBPREGS 20 #define PTRACE_SETHBPREGS 21 +#define PTRACE_GETFDPIC 22 + +#define PTRACE_GETFDPIC_EXEC 0 +#define PTRACE_GETFDPIC_INTERP 1 =20 #ifndef __ASSEMBLY__ =20 diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt index 21e154516bf2..9d131a54226f 100644 --- a/fs/Kconfig.binfmt +++ b/fs/Kconfig.binfmt @@ -58,7 +58,7 @@ config ARCH_USE_GNU_PROPERTY config BINFMT_ELF_FDPIC bool "Kernel support for FDPIC ELF binaries" default y if !BINFMT_ELF - depends on ARM || ((M68K || SUPERH) && !MMU) + depends on ARM || ((M68K || SUPERH || XTENSA) && !MMU) select ELFCORE help ELF FDPIC binaries are based on ELF, but allow the individual load --=20 2.30.2