From: guoren@kernel.org
To: guoren@kernel.org, palmer@dabbelt.com, arnd@arndb.de,
anup@brainfault.org, gregkh@linuxfoundation.org, hch@lst.de
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-riscv@lists.infradead.org, linux-csky@vger.kernel.org,
linux-s390@vger.kernel.org, sparclinux@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org, linux-parisc@vger.kernel.org,
linux-mips@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
x86@kernel.org, heiko@sntech.de,
Guo Ren <guoren@linux.alibaba.com>
Subject: [PATCH V8 15/20] riscv: compat: Add hw capability check for elf
Date: Wed, 16 Mar 2022 15:03:12 +0800 [thread overview]
Message-ID: <20220316070317.1864279-16-guoren@kernel.org> (raw)
In-Reply-To: <20220316070317.1864279-1-guoren@kernel.org>
From: Guo Ren <guoren@linux.alibaba.com>
Detect hardware COMPAT (32bit U-mode) capability in rv64. If not
support COMPAT mode in hw, compat_elf_check_arch would return
false by compat_binfmt_elf.c
Add CLASS to enhance (compat_)elf_check_arch to distinguish
32BIT/64BIT elf.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
---
arch/riscv/include/asm/elf.h | 6 ++++--
arch/riscv/kernel/process.c | 28 ++++++++++++++++++++++++++++
2 files changed, 32 insertions(+), 2 deletions(-)
diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
index a234656cfb5d..754fdb8cee96 100644
--- a/arch/riscv/include/asm/elf.h
+++ b/arch/riscv/include/asm/elf.h
@@ -33,9 +33,11 @@
/*
* This is used to ensure we don't load something for the wrong architecture.
*/
-#define elf_check_arch(x) ((x)->e_machine == EM_RISCV)
+#define elf_check_arch(x) (((x)->e_machine == EM_RISCV) && \
+ ((x)->e_ident[EI_CLASS] == ELF_CLASS))
-#define compat_elf_check_arch(x) ((x)->e_machine == EM_RISCV)
+extern bool compat_elf_check_arch(Elf32_Ehdr *hdr);
+#define compat_elf_check_arch compat_elf_check_arch
#define CORE_DUMP_USE_REGSET
#define ELF_EXEC_PAGESIZE (PAGE_SIZE)
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index 8c7665481a9f..203fdaa3f9e2 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -83,6 +83,34 @@ void show_regs(struct pt_regs *regs)
dump_backtrace(regs, NULL, KERN_DEFAULT);
}
+#ifdef CONFIG_COMPAT
+static bool compat_mode_supported __read_mostly;
+
+bool compat_elf_check_arch(Elf32_Ehdr *hdr)
+{
+ return compat_mode_supported &&
+ hdr->e_machine == EM_RISCV &&
+ hdr->e_ident[EI_CLASS] == ELFCLASS32;
+}
+
+static int __init compat_mode_detect(void)
+{
+ unsigned long tmp = csr_read(CSR_STATUS);
+
+ csr_write(CSR_STATUS, (tmp & ~SR_UXL) | SR_UXL_32);
+ compat_mode_supported =
+ (csr_read(CSR_STATUS) & SR_UXL) == SR_UXL_32;
+
+ csr_write(CSR_STATUS, tmp);
+
+ pr_info("riscv: ELF compat mode %s",
+ compat_mode_supported ? "supported" : "failed");
+
+ return 0;
+}
+early_initcall(compat_mode_detect);
+#endif
+
void start_thread(struct pt_regs *regs, unsigned long pc,
unsigned long sp)
{
--
2.25.1
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next prev parent reply other threads:[~2022-03-16 7:16 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-16 7:02 [PATCH V8 00/20] riscv: compat: Add COMPAT Kbuild skeletal support guoren
2022-03-16 7:02 ` [PATCH V8 01/20] uapi: simplify __ARCH_FLOCK{,64}_PAD a little guoren
2022-03-16 7:02 ` [PATCH V8 02/20] uapi: always define F_GETLK64/F_SETLK64/F_SETLKW64 in fcntl.h guoren
2022-03-16 7:03 ` [PATCH V8 03/20] compat: consolidate the compat_flock{, 64} definition guoren
2022-03-16 7:03 ` [PATCH V8 04/20] kconfig: Add SYSVIPC_COMPAT for all architectures guoren
2022-03-16 7:03 ` [PATCH V8 05/20] fs: stat: compat: Add __ARCH_WANT_COMPAT_STAT guoren
2022-03-16 7:03 ` [PATCH V8 06/20] asm-generic: compat: Cleanup duplicate definitions guoren
2022-03-16 7:03 ` [PATCH V8 07/20] syscalls: compat: Fix the missing part for __SYSCALL_COMPAT guoren
2022-03-16 7:03 ` [PATCH V8 08/20] riscv: Fixup difference with defconfig guoren
2022-03-16 7:03 ` [PATCH V8 09/20] riscv: compat: Add basic compat data type implementation guoren
2022-03-16 7:03 ` [PATCH V8 10/20] riscv: compat: Re-implement TASK_SIZE for COMPAT_32BIT guoren
2022-03-21 0:22 ` Guo Ren
2022-03-16 7:03 ` [PATCH V8 11/20] riscv: compat: syscall: Add compat_sys_call_table implementation guoren
2022-03-16 7:03 ` [PATCH V8 12/20] riscv: compat: syscall: Add entry.S implementation guoren
2022-03-16 7:03 ` [PATCH V8 13/20] riscv: compat: process: Add UXL_32 support in start_thread guoren
2022-03-16 7:03 ` [PATCH V8 14/20] riscv: compat: Add elf.h implementation guoren
2022-03-16 7:03 ` guoren [this message]
2022-03-16 7:03 ` [PATCH V8 16/20] riscv: compat: vdso: Add COMPAT_VDSO base code implementation guoren
2022-03-16 7:03 ` [PATCH V8 17/20] riscv: compat: vdso: Add setup additional pages implementation guoren
2022-03-16 7:03 ` [PATCH V8 18/20] riscv: compat: signal: Add rt_frame implementation guoren
2022-03-16 7:03 ` [PATCH V8 19/20] riscv: compat: ptrace: Add compat_arch_ptrace implement guoren
2022-03-16 7:03 ` [PATCH V8 20/20] riscv: compat: Add COMPAT Kbuild skeletal support guoren
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