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authorClément Léger <cleger@rivosinc.com>2023-10-04 18:14:05 +0300
committerPalmer Dabbelt <palmer@rivosinc.com>2023-11-01 18:34:59 +0300
commit9f23a5d2f6b01c2ab91d791109731a0d87ec2239 (patch)
tree17fd1a240636a03de468a1f01b0ca407f099de28 /arch/riscv/include/asm
parent71c54b3d169db5569655cbd2a3616bc701fd5eec (diff)
downloadlinux-9f23a5d2f6b01c2ab91d791109731a0d87ec2239.tar.xz
riscv: add support for PR_SET_UNALIGN and PR_GET_UNALIGN
Now that trap support is ready to handle misalignment errors in S-mode, allow the user to control the behavior of misaligned accesses using prctl(PR_SET_UNALIGN). Add an align_ctl flag in thread_struct which will be used to determine if we should SIGBUS the process or not on such fault. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20231004151405.521596-9-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/include/asm')
-rw-r--r--arch/riscv/include/asm/processor.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index 3e23e1786d05..adbe520d07c5 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -8,6 +8,7 @@
#include <linux/const.h>
#include <linux/cache.h>
+#include <linux/prctl.h>
#include <vdso/processor.h>
@@ -82,6 +83,7 @@ struct thread_struct {
unsigned long bad_cause;
unsigned long vstate_ctrl;
struct __riscv_v_ext_state vstate;
+ unsigned long align_ctl;
};
/* Whitelist the fstate from the task_struct for hardened usercopy */
@@ -94,6 +96,7 @@ static inline void arch_thread_struct_whitelist(unsigned long *offset,
#define INIT_THREAD { \
.sp = sizeof(init_stack) + (long)&init_stack, \
+ .align_ctl = PR_UNALIGN_NOPRINT, \
}
#define task_pt_regs(tsk) \
@@ -134,6 +137,12 @@ extern long riscv_v_vstate_ctrl_set_current(unsigned long arg);
extern long riscv_v_vstate_ctrl_get_current(void);
#endif /* CONFIG_RISCV_ISA_V */
+extern int get_unalign_ctl(struct task_struct *tsk, unsigned long addr);
+extern int set_unalign_ctl(struct task_struct *tsk, unsigned int val);
+
+#define GET_UNALIGN_CTL(tsk, addr) get_unalign_ctl((tsk), (addr))
+#define SET_UNALIGN_CTL(tsk, val) set_unalign_ctl((tsk), (val))
+
#endif /* __ASSEMBLY__ */
#endif /* _ASM_RISCV_PROCESSOR_H */