From ed0d9c66f97c6865e87fa6e3631bbc3919a31ad6 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Wed, 10 Mar 2021 17:46:46 +0000 Subject: [PATCH] powerpc/uaccess: Call might_fault() inconditionaly Commit 6bfd93c32a50 ("powerpc: Fix incorrect might_sleep in __get_user/__put_user on kernel addresses") added a check to not call might_sleep() on kernel addresses. This was to enable the use of __get_user() in the alignment exception handler for any address. Then commit 95156f0051cb ("lockdep, mm: fix might_fault() annotation") added a check of the address space in might_fault(), based on set_fs() logic. But this didn't solve the powerpc alignment exception case as it didn't call set_fs(KERNEL_DS). Nowadays, set_fs() is gone, previous patch fixed the alignment exception handler and __get_user/__put_user are not supposed to be used anymore to read kernel memory. Therefore the is_kernel_addr() check has become useless and can be removed. Signed-off-by: Christophe Leroy Reviewed-by: Daniel Axtens Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/e0a980a4dc7a2551183dd5cb30f46eafdbee390c.1615398265.git.christophe.leroy@csgroup.eu --- arch/powerpc/include/asm/uaccess.h | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index 8b81535e68d49..ce3dc3f407ac7 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -77,8 +77,7 @@ __pu_failed: \ __typeof__(*(ptr)) __pu_val = (x); \ __typeof__(size) __pu_size = (size); \ \ - if (!is_kernel_addr((unsigned long)__pu_addr)) \ - might_fault(); \ + might_fault(); \ __chk_user_ptr(__pu_addr); \ __put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err); \ \ @@ -238,12 +237,12 @@ do { \ __typeof__(size) __gu_size = (size); \ \ __chk_user_ptr(__gu_addr); \ - if (do_allow && !is_kernel_addr((unsigned long)__gu_addr)) \ + if (do_allow) { \ might_fault(); \ - if (do_allow) \ __get_user_size(__gu_val, __gu_addr, __gu_size, __gu_err); \ - else \ + } else { \ __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \ + } \ (x) = (__typeof__(*(ptr)))__gu_val; \ \ __gu_err; \ -- GitLab