kernel.git/arch/riscv/kernel/vdso.c, branch linux-6.0.y

riscv: vdso: fix NULL deference in vdso_join_timens() when vfork

2022-10-21T10:37:39Z

commit a8616d2dc193b6becc36b5f3cfeaa9ac7a5762f9 upstream. Testing tools/testing/selftests/timens/vfork_exec.c got below kernel log: [ 6.838454] Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000000020 [ 6.842255] Oops [#1] [ 6.842871] Modules linked in: [ 6.844249] CPU: 1 PID: 64 Comm: vfork_exec Not tainted 6.0.0-rc3-rt15+ #8 [ 6.845861] Hardware name: riscv-virtio,qemu (DT) [ 6.848009] epc : vdso_join_timens+0xd2/0x110 [ 6.850097] ra : vdso_join_timens+0xd2/0x110 [ 6.851164] epc : ffffffff8000635c ra : ffffffff8000635c sp : ff6000000181fbf0 [ 6.852562] gp : ffffffff80cff648 tp : ff60000000fdb700 t0 : 3030303030303030 [ 6.853852] t1 : 0000000000000030 t2 : 3030303030303030 s0 : ff6000000181fc40 [ 6.854984] s1 : ff60000001e6c000 a0 : 0000000000000010 a1 : ffffffff8005654c [ 6.856221] a2 : 00000000ffffefff a3 : 0000000000000000 a4 : 0000000000000000 [ 6.858114] a5 : 0000000000000000 a6 : 0000000000000008 a7 : 0000000000000038 [ 6.859484] s2 : ff60000001e6c068 s3 : ff6000000108abb0 s4 : 0000000000000000 [ 6.860751] s5 : 0000000000001000 s6 : ffffffff8089dc40 s7 : ffffffff8089dc38 [ 6.862029] s8 : ffffffff8089dc30 s9 : ff60000000fdbe38 s10: 000000000000005e [ 6.863304] s11: ffffffff80cc3510 t3 : ffffffff80d1112f t4 : ffffffff80d1112f [ 6.864565] t5 : ffffffff80d11130 t6 : ff6000000181fa00 [ 6.865561] status: 0000000000000120 badaddr: 0000000000000020 cause: 000000000000000d [ 6.868046] [] timens_commit+0x38/0x11a [ 6.869089] [] timens_on_fork+0x72/0xb4 [ 6.870055] [] begin_new_exec+0x3c6/0x9f0 [ 6.871231] [] load_elf_binary+0x628/0x1214 [ 6.872304] [] bprm_execve+0x1f2/0x4e4 [ 6.873243] [] do_execveat_common+0x16e/0x1ee [ 6.874258] [] sys_execve+0x3c/0x48 [ 6.875162] [] ret_from_syscall+0x0/0x2 [ 6.877484] ---[ end trace 0000000000000000 ]--- This is because the mm->context.vdso_info is NULL in vfork case. From another side, mm->context.vdso_info either points to vdso info for RV64 or vdso info for compat, there's no need to bloat riscv's mm_context_t, we can handle the difference when setup the additional page for vdso. Signed-off-by: Jisheng Zhang Suggested-by: Palmer Dabbelt Fixes: 3092eb456375 ("riscv: compat: vdso: Add setup additional pages implementation") Link: https://lore.kernel.org/r/20220924070737.3048-1-jszhang@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt Signed-off-by: Greg Kroah-Hartman

riscv: compat: Using seperated vdso_maps for compat_vdso_info

2022-05-26T00:24:06Z

This is a fixup for vdso implementation which caused musl to fail. [ 11.600082] Run /sbin/init as init process [ 11.628561] init[1]: unhandled signal 11 code 0x1 at 0x0000000000000000 in libc.so[ffffff8ad39000+a4000] [ 11.629398] CPU: 0 PID: 1 Comm: init Not tainted 5.18.0-rc7-next-20220520 #1 [ 11.629462] Hardware name: riscv-virtio,qemu (DT) [ 11.629546] epc : 00ffffff8ada1100 ra : 00ffffff8ada13c8 sp : 00ffffffc58199f0 [ 11.629586] gp : 00ffffff8ad39000 tp : 00ffffff8ade0998 t0 : ffffffffffffffff [ 11.629598] t1 : 00ffffffc5819fd0 t2 : 0000000000000000 s0 : 00ffffff8ade0cc0 [ 11.629610] s1 : 00ffffff8ade0cc0 a0 : 0000000000000000 a1 : 00ffffffc5819a00 [ 11.629622] a2 : 0000000000000001 a3 : 000000000000001e a4 : 00ffffffc5819b00 [ 11.629634] a5 : 00ffffffc5819b00 a6 : 0000000000000000 a7 : 0000000000000000 [ 11.629645] s2 : 00ffffff8ade0ac8 s3 : 00ffffff8ade0ec8 s4 : 00ffffff8ade0728 [ 11.629656] s5 : 00ffffff8ade0a90 s6 : 0000000000000000 s7 : 00ffffffc5819e40 [ 11.629667] s8 : 00ffffff8ade0ca0 s9 : 00ffffff8addba50 s10: 0000000000000000 [ 11.629678] s11: 0000000000000000 t3 : 0000000000000002 t4 : 0000000000000001 [ 11.629688] t5 : 0000000000020000 t6 : ffffffffffffffff [ 11.629699] status: 0000000000004020 badaddr: 0000000000000000 cause: 000000000000000d The last __vdso_init(&compat_vdso_info) replaces the data in normal vdso_info. This is an obvious bug. Reported-by: Guenter Roeck Signed-off-by: Guo Ren Signed-off-by: Guo Ren Tested-by: Heiko Stuebner Tested-by: Guenter Roeck Link: https://lore.kernel.org/r/20220525160404.2930984-1-guoren@kernel.org Fixes: 3092eb456375 ("riscv: compat: vdso: Add setup additional pages implementation") Signed-off-by: Palmer Dabbelt

riscv: compat: vdso: Add setup additional pages implementation

2022-04-26T20:36:59Z

Reconstruct __setup_additional_pages() by appending vdso info pointer argument to meet compat_vdso_info requirement. And change vm_special_mapping *dm, *cm initialization into static. Signed-off-by: Guo Ren Signed-off-by: Guo Ren Reviewed-by: Palmer Dabbelt Tested-by: Heiko Stuebner Link: https://lore.kernel.org/r/20220405071314.3225832-18-guoren@kernel.org Signed-off-by: Palmer Dabbelt

riscv/vdso: Add support for time namespaces

2021-10-04T21:16:43Z

Implement generic vdso time namespace support which also enables time namespaces for riscv. This is quite similar to what arm64 does. selftest/timens test result: 1..10 ok 1 Passed for CLOCK_BOOTTIME (syscall) ok 2 Passed for CLOCK_BOOTTIME (vdso) ok 3 # SKIP CLOCK_BOOTTIME_ALARM isn't supported ok 4 # SKIP CLOCK_BOOTTIME_ALARM isn't supported ok 5 Passed for CLOCK_MONOTONIC (syscall) ok 6 Passed for CLOCK_MONOTONIC (vdso) ok 7 Passed for CLOCK_MONOTONIC_COARSE (syscall) ok 8 Passed for CLOCK_MONOTONIC_COARSE (vdso) ok 9 Passed for CLOCK_MONOTONIC_RAW (syscall) ok 10 Passed for CLOCK_MONOTONIC_RAW (vdso) # Totals: pass:8 fail:0 xfail:0 xpass:0 skip:2 error:0 Signed-off-by: Tong Tiangen Signed-off-by: Palmer Dabbelt

riscv/vdso: make arch_setup_additional_pages wait for mmap_sem for write killable

2021-10-02T20:42:26Z

riscv architectures relying on mmap_sem for write in their arch_setup_additional_pages. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. Signed-off-by: Tong Tiangen Reviewed-by: Kefeng Wang Fixes: 76d2a0493a17 ("RISC-V: Init and Halt Code") Signed-off-by: Palmer Dabbelt

riscv/vdso: Move vdso data page up front

2021-10-02T20:42:25Z

As commit 601255ae3c98 ("arm64: vdso: move data page before code pages"), the same issue exists on riscv, testcase is shown below, make sure that vdso.so is bigger than page size, struct timespec tp; clock_gettime(5, &tp); printf("tv_sec: %ld, tv_nsec: %ld\n", tp.tv_sec, tp.tv_nsec); without this patch, test result : tv_sec: 0, tv_nsec: 0 with this patch, test result : tv_sec: 1629271537, tv_nsec: 748000000 Move the vdso data page in front of the VDSO area to fix the issue. Fixes: ad5d1122b82fb ("riscv: use vDSO common flow to reduce the latency of the time-related functions") Signed-off-by: Tong Tiangen Reviewed-by: Kefeng Wang Signed-off-by: Palmer Dabbelt

riscv/vdso: Refactor asm/vdso.h

2021-10-02T20:42:23Z

The asm/vdso.h will be included in vdso.lds.S in the next patch, the following cleanup is needed to avoid syntax error: 1.the declaration of sys_riscv_flush_icache() is moved into asm/syscall.h. 2.the definition of struct vdso_data is moved into kernel/vdso.c. 2.the definition of VDSO_SYMBOL is placed under "#ifndef __ASSEMBLY__". Also remove the redundant linux/types.h include. Signed-off-by: Tong Tiangen Reviewed-by: Kefeng Wang Signed-off-by: Palmer Dabbelt

riscv: Mark some global variables __ro_after_init

2021-04-26T15:25:08Z

All of these are never modified after init, so they can be __ro_after_init. Signed-off-by: Jisheng Zhang Signed-off-by: Palmer Dabbelt

riscv: Fixup CONFIG_GENERIC_TIME_VSYSCALL

2021-01-13T04:34:44Z

The patch fix commit: ad5d112 ("riscv: use vDSO common flow to reduce the latency of the time-related functions"). The GENERIC_TIME_VSYSCALL should be CONFIG_GENERIC_TIME_VSYSCALL or vgettimeofday won't work. Signed-off-by: Guo Ren Reviewed-by: Pekka Enberg Fixes: ad5d1122b82f ("riscv: use vDSO common flow to reduce the latency of the time-related functions") Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt

Merge tag 'riscv-for-linus-5.8-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2020-06-11T19:55:20Z

Pull more RISC-V updates from Palmer Dabbelt: - Kconfig select statements are now sorted alphanumerically - first-level interrupts are now handled via a full irqchip driver - CPU hotplug is fixed - vDSO calls now use the common vDSO infrastructure * tag 'riscv-for-linus-5.8-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: set the permission of vdso_data to read-only riscv: use vDSO common flow to reduce the latency of the time-related functions riscv: fix build warning of missing prototypes RISC-V: Don't mark init section as non-executable RISC-V: Force select RISCV_INTC for CONFIG_RISCV RISC-V: Remove do_IRQ() function clocksource/drivers/timer-riscv: Use per-CPU timer interrupt irqchip: RISC-V per-HART local interrupt controller driver RISC-V: Rename and move plic_find_hart_id() to arch directory RISC-V: self-contained IPI handling routine RISC-V: Sort select statements alphanumerically