This is a note to let you know that I've just added the patch titled powerpc/fixmap: Use __fix_to_virt() instead of fix_to_virt() to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: powerpc-fixmap-use-__fix_to_virt-instead-of-fix_to_v.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 9c0c89e51eba1aa705320992ede5c0d16d81fecf Author: Christophe Leroy <christophe.leroy@xxxxxx> Date: Thu Sep 12 13:49:42 2019 +0000 powerpc/fixmap: Use __fix_to_virt() instead of fix_to_virt() [ Upstream commit 77693a5fb57be4606a6024ec8e3076f9499b906b ] Modify back __set_fixmap() to using __fix_to_virt() instead of fix_to_virt() otherwise the following happens because it seems GCC doesn't see idx as a builtin const. CC mm/early_ioremap.o In file included from ./include/linux/kernel.h:11:0, from mm/early_ioremap.c:11: In function â??fix_to_virtâ??, inlined from â??__set_fixmapâ?? at ./arch/powerpc/include/asm/fixmap.h:87:2, inlined from â??__early_ioremapâ?? at mm/early_ioremap.c:156:4: ./include/linux/compiler.h:350:38: error: call to â??__compiletime_assert_32â?? declared with attribute error: BUILD_BUG_ON failed: idx >= __end_of_fixed_addresses _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) ^ ./include/linux/compiler.h:331:4: note: in definition of macro â??__compiletime_assertâ?? prefix ## suffix(); \ ^ ./include/linux/compiler.h:350:2: note: in expansion of macro â??_compiletime_assertâ?? _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) ^ ./include/linux/build_bug.h:39:37: note: in expansion of macro â??compiletime_assertâ?? #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) ^ ./include/linux/build_bug.h:50:2: note: in expansion of macro â??BUILD_BUG_ON_MSGâ?? BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) ^ ./include/asm-generic/fixmap.h:32:2: note: in expansion of macro â??BUILD_BUG_ONâ?? BUILD_BUG_ON(idx >= __end_of_fixed_addresses); ^ Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx> Fixes: 4cfac2f9c7f1 ("powerpc/mm: Simplify __set_fixmap()") Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/f4984c615f90caa3277775a68849afeea846850d.1568295907.git.christophe.leroy@xxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/powerpc/include/asm/fixmap.h b/arch/powerpc/include/asm/fixmap.h index 0cfc365d814b..722289a1d000 100644 --- a/arch/powerpc/include/asm/fixmap.h +++ b/arch/powerpc/include/asm/fixmap.h @@ -77,7 +77,12 @@ enum fixed_addresses { static inline void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags) { - map_kernel_page(fix_to_virt(idx), phys, flags); + if (__builtin_constant_p(idx)) + BUILD_BUG_ON(idx >= __end_of_fixed_addresses); + else if (WARN_ON(idx >= __end_of_fixed_addresses)) + return; + + map_kernel_page(__fix_to_virt(idx), phys, flags); } #endif /* !__ASSEMBLY__ */