1d8f739b07
__builtin_constant_p() always return 0 for pointers, so on RADIX we always end up opening both direction (by writing 0 in SPR29): 0000000000000170 <._copy_to_user>: ... 1b0: 4c 00 01 2c isync 1b4: 39 20 00 00 li r9,0 1b8: 7d 3d 03 a6 mtspr 29,r9 1bc: 4c 00 01 2c isync 1c0: 48 00 00 01 bl 1c0 <._copy_to_user+0x50> 1c0: R_PPC64_REL24 .__copy_tofrom_user ... 0000000000000220 <._copy_from_user>: ... 2ac: 4c 00 01 2c isync 2b0: 39 20 00 00 li r9,0 2b4: 7d 3d 03 a6 mtspr 29,r9 2b8: 4c 00 01 2c isync 2bc: 7f c5 f3 78 mr r5,r30 2c0: 7f 83 e3 78 mr r3,r28 2c4: 48 00 00 01 bl 2c4 <._copy_from_user+0xa4> 2c4: R_PPC64_REL24 .__copy_tofrom_user ... Use an explicit parameter for direction selection, so that GCC is able to see it is a constant: 00000000000001b0 <._copy_to_user>: ... 1f0: 4c 00 01 2c isync 1f4: 3d 20 40 00 lis r9,16384 1f8: 79 29 07 c6 rldicr r9,r9,32,31 1fc: 7d 3d 03 a6 mtspr 29,r9 200: 4c 00 01 2c isync 204: 48 00 00 01 bl 204 <._copy_to_user+0x54> 204: R_PPC64_REL24 .__copy_tofrom_user ... 0000000000000260 <._copy_from_user>: ... 2ec: 4c 00 01 2c isync 2f0: 39 20 ff ff li r9,-1 2f4: 79 29 00 04 rldicr r9,r9,0,0 2f8: 7d 3d 03 a6 mtspr 29,r9 2fc: 4c 00 01 2c isync 300: 7f c5 f3 78 mr r5,r30 304: 7f 83 e3 78 mr r3,r28 308: 48 00 00 01 bl 308 <._copy_from_user+0xa8> 308: R_PPC64_REL24 .__copy_tofrom_user ... Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Spell out the directions, s/KUAP_R/KUAP_READ/ etc.] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/f4e88ec4941d5facb35ce75026b0112f980086c3.1579866752.git.christophe.leroy@c-s.fr
94 lines
2.2 KiB
C
94 lines
2.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_POWERPC_KUP_H_
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#define _ASM_POWERPC_KUP_H_
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#define KUAP_READ 1
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#define KUAP_WRITE 2
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#define KUAP_READ_WRITE (KUAP_READ | KUAP_WRITE)
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#ifdef CONFIG_PPC64
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#include <asm/book3s/64/kup-radix.h>
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#endif
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#ifdef CONFIG_PPC_8xx
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#include <asm/nohash/32/kup-8xx.h>
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#endif
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#ifdef CONFIG_PPC_BOOK3S_32
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#include <asm/book3s/32/kup.h>
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#endif
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#ifdef __ASSEMBLY__
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#ifndef CONFIG_PPC_KUAP
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.macro kuap_save_and_lock sp, thread, gpr1, gpr2, gpr3
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.endm
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.macro kuap_restore sp, current, gpr1, gpr2, gpr3
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.endm
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.macro kuap_check current, gpr
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.endm
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#endif
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#else /* !__ASSEMBLY__ */
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#include <asm/pgtable.h>
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void setup_kup(void);
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#ifdef CONFIG_PPC_KUEP
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void setup_kuep(bool disabled);
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#else
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static inline void setup_kuep(bool disabled) { }
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#endif /* CONFIG_PPC_KUEP */
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#ifdef CONFIG_PPC_KUAP
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void setup_kuap(bool disabled);
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#else
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static inline void setup_kuap(bool disabled) { }
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static inline void allow_user_access(void __user *to, const void __user *from,
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unsigned long size, unsigned long dir) { }
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static inline void prevent_user_access(void __user *to, const void __user *from,
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unsigned long size, unsigned long dir) { }
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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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return false;
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}
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#endif /* CONFIG_PPC_KUAP */
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static inline void allow_read_from_user(const void __user *from, unsigned long size)
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{
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allow_user_access(NULL, from, size, KUAP_READ);
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}
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static inline void allow_write_to_user(void __user *to, unsigned long size)
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{
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allow_user_access(to, NULL, size, KUAP_WRITE);
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}
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static inline void allow_read_write_user(void __user *to, const void __user *from,
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unsigned long size)
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{
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allow_user_access(to, from, size, KUAP_READ_WRITE);
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}
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static inline void prevent_read_from_user(const void __user *from, unsigned long size)
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{
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prevent_user_access(NULL, from, size, KUAP_READ);
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}
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static inline void prevent_write_to_user(void __user *to, unsigned long size)
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{
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prevent_user_access(to, NULL, size, KUAP_WRITE);
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}
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static inline void prevent_read_write_user(void __user *to, const void __user *from,
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unsigned long size)
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{
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prevent_user_access(to, from, size, KUAP_READ_WRITE);
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}
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#endif /* !__ASSEMBLY__ */
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#endif /* _ASM_POWERPC_KUAP_H_ */
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