159 lines
3.8 KiB
C
159 lines
3.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_POWERPC_BOOK3S_32_KUP_H
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#define _ASM_POWERPC_BOOK3S_32_KUP_H
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#include <asm/book3s/32/mmu-hash.h>
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#ifdef __ASSEMBLY__
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.macro kuep_update_sr gpr1, gpr2 /* NEVER use r0 as gpr2 due to addis */
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101: mtsrin \gpr1, \gpr2
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addi \gpr1, \gpr1, 0x111 /* next VSID */
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rlwinm \gpr1, \gpr1, 0, 0xf0ffffff /* clear VSID overflow */
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addis \gpr2, \gpr2, 0x1000 /* address of next segment */
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bdnz 101b
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isync
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.endm
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.macro kuep_lock gpr1, gpr2
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#ifdef CONFIG_PPC_KUEP
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li \gpr1, NUM_USER_SEGMENTS
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li \gpr2, 0
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mtctr \gpr1
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mfsrin \gpr1, \gpr2
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oris \gpr1, \gpr1, SR_NX@h /* set Nx */
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kuep_update_sr \gpr1, \gpr2
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#endif
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.endm
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.macro kuep_unlock gpr1, gpr2
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#ifdef CONFIG_PPC_KUEP
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li \gpr1, NUM_USER_SEGMENTS
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li \gpr2, 0
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mtctr \gpr1
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mfsrin \gpr1, \gpr2
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rlwinm \gpr1, \gpr1, 0, ~SR_NX /* Clear Nx */
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kuep_update_sr \gpr1, \gpr2
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#endif
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.endm
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#ifdef CONFIG_PPC_KUAP
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.macro kuap_update_sr gpr1, gpr2, gpr3 /* NEVER use r0 as gpr2 due to addis */
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101: mtsrin \gpr1, \gpr2
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addi \gpr1, \gpr1, 0x111 /* next VSID */
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rlwinm \gpr1, \gpr1, 0, 0xf0ffffff /* clear VSID overflow */
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addis \gpr2, \gpr2, 0x1000 /* address of next segment */
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cmplw \gpr2, \gpr3
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blt- 101b
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isync
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.endm
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.macro kuap_save_and_lock sp, thread, gpr1, gpr2, gpr3
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lwz \gpr2, KUAP(\thread)
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rlwinm. \gpr3, \gpr2, 28, 0xf0000000
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stw \gpr2, STACK_REGS_KUAP(\sp)
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beq+ 102f
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li \gpr1, 0
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stw \gpr1, KUAP(\thread)
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mfsrin \gpr1, \gpr2
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oris \gpr1, \gpr1, SR_KS@h /* set Ks */
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kuap_update_sr \gpr1, \gpr2, \gpr3
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102:
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.endm
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.macro kuap_restore sp, current, gpr1, gpr2, gpr3
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lwz \gpr2, STACK_REGS_KUAP(\sp)
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rlwinm. \gpr3, \gpr2, 28, 0xf0000000
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stw \gpr2, THREAD + KUAP(\current)
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beq+ 102f
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mfsrin \gpr1, \gpr2
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rlwinm \gpr1, \gpr1, 0, ~SR_KS /* Clear Ks */
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kuap_update_sr \gpr1, \gpr2, \gpr3
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102:
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.endm
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.macro kuap_check current, gpr
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#ifdef CONFIG_PPC_KUAP_DEBUG
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lwz \gpr2, KUAP(thread)
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999: twnei \gpr, 0
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EMIT_BUG_ENTRY 999b, __FILE__, __LINE__, (BUGFLAG_WARNING | BUGFLAG_ONCE)
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#endif
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.endm
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#endif /* CONFIG_PPC_KUAP */
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#else /* !__ASSEMBLY__ */
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#ifdef CONFIG_PPC_KUAP
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#include <linux/sched.h>
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static inline void kuap_update_sr(u32 sr, u32 addr, u32 end)
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{
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addr &= 0xf0000000; /* align addr to start of segment */
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barrier(); /* make sure thread.kuap is updated before playing with SRs */
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while (addr < end) {
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mtsrin(sr, addr);
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sr += 0x111; /* next VSID */
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sr &= 0xf0ffffff; /* clear VSID overflow */
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addr += 0x10000000; /* address of next segment */
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}
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isync(); /* Context sync required after mtsrin() */
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}
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static __always_inline void allow_user_access(void __user *to, const void __user *from,
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u32 size, unsigned long dir)
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{
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u32 addr, end;
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BUILD_BUG_ON(!__builtin_constant_p(dir));
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if (!(dir & KUAP_WRITE))
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return;
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addr = (__force u32)to;
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if (!addr || addr >= TASK_SIZE || !size)
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return;
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end = min(addr + size, TASK_SIZE);
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current->thread.kuap = (addr & 0xf0000000) | ((((end - 1) >> 28) + 1) & 0xf);
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kuap_update_sr(mfsrin(addr) & ~SR_KS, addr, end); /* Clear Ks */
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}
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static __always_inline void prevent_user_access(void __user *to, const void __user *from,
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u32 size, unsigned long dir)
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{
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u32 addr = (__force u32)to;
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u32 end = min(addr + size, TASK_SIZE);
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BUILD_BUG_ON(!__builtin_constant_p(dir));
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if (!(dir & KUAP_WRITE))
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return;
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if (!addr || addr >= TASK_SIZE || !size)
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return;
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current->thread.kuap = 0;
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kuap_update_sr(mfsrin(addr) | SR_KS, addr, end); /* set Ks */
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}
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static inline bool
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bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
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{
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unsigned long begin = regs->kuap & 0xf0000000;
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unsigned long end = regs->kuap << 28;
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if (!is_write)
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return false;
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return WARN(address < begin || address >= end,
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"Bug: write fault blocked by segment registers !");
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}
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#endif /* CONFIG_PPC_KUAP */
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#endif /* __ASSEMBLY__ */
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#endif /* _ASM_POWERPC_BOOK3S_32_KUP_H */
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