# git rev-parse -q --verify d02d2129641d6cd22492ddc85e11d112eb0d5a6f^{commit} d02d2129641d6cd22492ddc85e11d112eb0d5a6f already have revision, skipping fetch # git checkout -q -f -B kisskb d02d2129641d6cd22492ddc85e11d112eb0d5a6f # git clean -qxdf # < git log -1 # commit d02d2129641d6cd22492ddc85e11d112eb0d5a6f # Author: Russell Currey # Date: Fri Mar 1 01:49:17 2019 +1100 # # powerpc/64s: Implement KUAP for Radix MMU # # Kernel Userspace Access Prevention utilises a feature of the Radix MMU # which disallows read and write access to userspace addresses. By # utilising this, the kernel is prevented from accessing user data from # outside of trusted paths that perform proper safety checks, such as # copy_{to/from}_user() and friends. # # Userspace access is disabled from early boot and is only enabled when # performing an operation like copy_{to/from}_user(). The register that # controls this (AMR) does not prevent userspace from accessing itself, # so there is no need to save and restore when entering and exiting # userspace. # # This feature has a slight performance impact which I roughly measured # to be 3% slower in the worst case (performing 1GB of 1 byte # read()/write() syscalls), and is gated behind the CONFIG_PPC_KUAP # option for performance-critical builds. # # This feature can be tested by using the lkdtm driver (CONFIG_LKDTM=y) # and performing the following: # # # (echo ACCESS_USERSPACE) > [debugfs]/provoke-crash/DIRECT # # If enabled, this should send SIGSEGV to the thread. # # mpe: Drop the unused paca flags. Zero the UAMOR to be safe. Save the # AMR when we enter the kernel from the kernel and then lock it again. # Restore on the way back to the kernel. This means we handle nesting of # interrupts properly, ie. we are protected inside the page fault # handler caused by a user access. Add paranoid checking of AMR in # switch and syscall return. Add an isync() to prevent_user_access() # # Signed-off-by: Russell Currey # Signed-off-by: Michael Ellerman # < /opt/cross/kisskb/gcc-4.6.3-nolibc/sh4-linux/bin/sh4-linux-gcc --version # < /opt/cross/kisskb/gcc-4.6.3-nolibc/sh4-linux/bin/sh4-linux-ld --version # < git log --format=%s --max-count=1 d02d2129641d6cd22492ddc85e11d112eb0d5a6f # < make -s -j 120 ARCH=sh O=/kisskb/build/powerpc-next_sh-defconfig_sh4 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/sh4-linux/bin/sh4-linux- defconfig # make -s -j 120 ARCH=sh O=/kisskb/build/powerpc-next_sh-defconfig_sh4 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/sh4-linux/bin/sh4-linux- Generating include/generated/machtypes.h :1318:2: warning: #warning syscall pkey_mprotect not implemented [-Wcpp] :1321:2: warning: #warning syscall pkey_alloc not implemented [-Wcpp] :1324:2: warning: #warning syscall pkey_free not implemented [-Wcpp] :1327:2: warning: #warning syscall statx not implemented [-Wcpp] :1333:2: warning: #warning syscall io_pgetevents not implemented [-Wcpp] :1336:2: warning: #warning syscall rseq not implemented [-Wcpp] /kisskb/src/arch/sh/kernel/cpu/sh4/../sh3/../../entry-common.S: Assembler messages: /kisskb/src/arch/sh/kernel/cpu/sh4/../sh3/../../entry-common.S:385: Warning: overflow in branch to syscall_exit_work; converted into longer instruction sequence /kisskb/src/arch/sh/kernel/cpu/sh4/../sh3/../../entry-common.S:388: Warning: overflow in branch to syscall_exit_work; converted into longer instruction sequence /kisskb/src/kernel/rcu/srcutree.c: In function 'init_srcu_struct_fields': /kisskb/src/kernel/rcu/srcutree.c:152:32: warning: 'levelspread[]' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/rcu/srcutree.c:100:6: note: 'levelspread[]' was declared here /kisskb/src/kernel/cgroup/cgroup-v1.c: In function 'cgroup1_mount': /kisskb/src/kernel/cgroup/cgroup-v1.c:1263:20: warning: 'root' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c: In function 'proc_reg_open': /kisskb/src/include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c:339:21: note: 'pdeo' was declared here /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:186:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/i2c/i2c-core-base.c: In function 'i2c_generic_scl_recovery': /kisskb/src/drivers/i2c/i2c-core-base.c:235:5: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/sh/clk/cpg.c: In function 'r8': /kisskb/src/drivers/sh/clk/cpg.c:41:2: warning: passing argument 1 of 'ioread8' discards 'const' qualifier from pointer target type [enabled by default] /kisskb/src/include/asm-generic/iomap.h:29:21: note: expected 'void *' but argument is of type 'const void *' /kisskb/src/drivers/sh/clk/cpg.c: In function 'r16': /kisskb/src/drivers/sh/clk/cpg.c:46:2: warning: passing argument 1 of 'ioread16' discards 'const' qualifier from pointer target type [enabled by default] /kisskb/src/include/asm-generic/iomap.h:30:21: note: expected 'void *' but argument is of type 'const void *' /kisskb/src/drivers/sh/clk/cpg.c: In function 'r32': /kisskb/src/drivers/sh/clk/cpg.c:51:2: warning: passing argument 1 of 'ioread32' discards 'const' qualifier from pointer target type [enabled by default] /kisskb/src/include/asm-generic/iomap.h:32:21: note: expected 'void *' but argument is of type 'const void *' /kisskb/src/kernel/trace/trace_dynevent.c: In function 'create_dyn_event': /kisskb/src/kernel/trace/trace_dynevent.c:89:5: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2594:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write': /kisskb/src/drivers/base/regmap/regmap.c:1855:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/mm/vmstat.c: In function 'sysctl_vm_numa_stat_handler': /kisskb/src/mm/vmstat.c:89:5: warning: 'oldval' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/ipv6/ip6_output.c: In function '__ip6_append_data.isra.12': /kisskb/src/include/linux/skbuff.h:1338:6: warning: 'extra_uref' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/ipv6/ip6_output.c:1270:14: note: 'extra_uref' was declared here /kisskb/src/net/ipv4/ip_output.c: In function '__ip_append_data': /kisskb/src/include/linux/skbuff.h:1338:6: warning: 'extra_uref' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/ipv4/ip_output.c:885:14: note: 'extra_uref' was declared here /kisskb/src/fs/mpage.c: In function 'do_mpage_readpage': /kisskb/src/fs/mpage.c:338:1: warning: the frame size of 1108 bytes is larger than 1024 bytes [-Wframe-larger-than=] /kisskb/src/fs/mpage.c: In function '__mpage_writepage': /kisskb/src/fs/mpage.c:690:1: warning: the frame size of 1148 bytes is larger than 1024 bytes [-Wframe-larger-than=] /kisskb/src/fs/ext4/readpage.c: In function 'ext4_mpage_readpages': /kisskb/src/fs/ext4/readpage.c:295:1: warning: the frame size of 1200 bytes is larger than 1024 bytes [-Wframe-larger-than=] /kisskb/src/mm/hugetlb.c: In function 'alloc_pool_huge_page': /kisskb/src/mm/hugetlb.c:1434:5: warning: 'page' may be used uninitialized in this function [-Wuninitialized] Kernel: arch/sh/boot/zImage is ready Completed OK # rm -rf /kisskb/build/powerpc-next_sh-defconfig_sh4 # Build took: 0:00:27.433163