From b76dd9302af7803aac62243ae94d53067fc819b4 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 25 Jun 2021 10:34:34 +0200 Subject: um: make PCI emulation driver init/exit static The functions aren't used elsewhere, so they can be static. Reported-by: kernel test robot Fixes: 68f5d3f3b654 ("um: add PCI over virtio emulation driver") Signed-off-by: Johannes Berg Acked-By: Anton Ivanov Signed-off-by: Richard Weinberger --- arch/um/drivers/virt-pci.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/um/drivers/virt-pci.c b/arch/um/drivers/virt-pci.c index 0b802834f40a..70c17de16662 100644 --- a/arch/um/drivers/virt-pci.c +++ b/arch/um/drivers/virt-pci.c @@ -810,7 +810,7 @@ void *pci_root_bus_fwnode(struct pci_bus *bus) return um_pci_fwnode; } -int um_pci_init(void) +static int um_pci_init(void) { int err, i; @@ -884,7 +884,7 @@ free: } module_init(um_pci_init); -void um_pci_exit(void) +static void um_pci_exit(void) { unregister_virtio_driver(&um_pci_virtio_driver); irq_domain_remove(um_pci_msi_domain); -- cgit v1.2.3 From 21976f2b747edd9350336cdd6700b792a3bc2170 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 25 Jun 2021 10:34:36 +0200 Subject: um: virtio_uml: include linux/virtio-uml.h This fixes a sparse warning, since the function defined here should have a declaration (or be static). Reported-by: kernel test robot Fixes: 43c590cb8666 ("um: virtio/pci: enable suspend/resume") Signed-off-by: Johannes Berg Acked-By: Anton Ivanov Signed-off-by: Richard Weinberger --- arch/um/drivers/virtio_uml.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch') diff --git a/arch/um/drivers/virtio_uml.c b/arch/um/drivers/virtio_uml.c index 4412d6febade..cb79fe33d84e 100644 --- a/arch/um/drivers/virtio_uml.c +++ b/arch/um/drivers/virtio_uml.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include #include -- cgit v1.2.3 From 7ad28e0df7ee9dbcb793bb88dd81d4d22bb9a10e Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 25 Jun 2021 10:34:37 +0200 Subject: um: virtio_uml: fix memory leak on init failures If initialization fails, e.g. because the connection failed, we leak the 'vu_dev'. Fix that. Reported by smatch. Fixes: 5d38f324993f ("um: drivers: Add virtio vhost-user driver") Signed-off-by: Johannes Berg Acked-By: Anton Ivanov Signed-off-by: Richard Weinberger --- arch/um/drivers/virtio_uml.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/um/drivers/virtio_uml.c b/arch/um/drivers/virtio_uml.c index cb79fe33d84e..d51e445df797 100644 --- a/arch/um/drivers/virtio_uml.c +++ b/arch/um/drivers/virtio_uml.c @@ -1140,7 +1140,7 @@ static int virtio_uml_probe(struct platform_device *pdev) rc = os_connect_socket(pdata->socket_path); } while (rc == -EINTR); if (rc < 0) - return rc; + goto error_free; vu_dev->sock = rc; spin_lock_init(&vu_dev->sock_lock); @@ -1161,6 +1161,8 @@ static int virtio_uml_probe(struct platform_device *pdev) error_init: os_close_file(vu_dev->sock); +error_free: + kfree(vu_dev); return rc; } -- cgit v1.2.3 From 4a22c4cebd61f67bd8a2c79f8dae10df074f62b9 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 11 Aug 2021 16:58:25 +0200 Subject: um: virt-pci: don't do DMA from stack When enabling VMAP_STACK, SG helpers immediately complained that we were doing DMA from stack. Use per-CPU variables to avoid that. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger --- arch/um/drivers/virt-pci.c | 104 +++++++++++++++++++++++++++++++++------------ 1 file changed, 78 insertions(+), 26 deletions(-) (limited to 'arch') diff --git a/arch/um/drivers/virt-pci.c b/arch/um/drivers/virt-pci.c index 70c17de16662..c08066633023 100644 --- a/arch/um/drivers/virt-pci.c +++ b/arch/um/drivers/virt-pci.c @@ -56,6 +56,13 @@ static unsigned long um_pci_msi_used[BITS_TO_LONGS(MAX_MSI_VECTORS)]; #define UM_VIRT_PCI_MAXDELAY 40000 +struct um_pci_message_buffer { + struct virtio_pcidev_msg hdr; + u8 data[8]; +}; + +static struct um_pci_message_buffer __percpu *um_pci_msg_bufs; + static int um_pci_send_cmd(struct um_pci_device *dev, struct virtio_pcidev_msg *cmd, unsigned int cmd_size, @@ -68,11 +75,12 @@ static int um_pci_send_cmd(struct um_pci_device *dev, [1] = extra ? &extra_sg : &in_sg, [2] = extra ? &in_sg : NULL, }; + struct um_pci_message_buffer *buf; int delay_count = 0; int ret, len; bool posted; - if (WARN_ON(cmd_size < sizeof(*cmd))) + if (WARN_ON(cmd_size < sizeof(*cmd) || cmd_size > sizeof(*buf))) return -EINVAL; switch (cmd->op) { @@ -88,6 +96,9 @@ static int um_pci_send_cmd(struct um_pci_device *dev, break; } + buf = get_cpu_var(um_pci_msg_bufs); + memcpy(buf, cmd, cmd_size); + if (posted) { u8 *ncmd = kmalloc(cmd_size + extra_size, GFP_ATOMIC); @@ -102,7 +113,10 @@ static int um_pci_send_cmd(struct um_pci_device *dev, } else { /* try without allocating memory */ posted = false; + cmd = (void *)buf; } + } else { + cmd = (void *)buf; } sg_init_one(&out_sg, cmd, cmd_size); @@ -118,11 +132,12 @@ static int um_pci_send_cmd(struct um_pci_device *dev, posted ? cmd : HANDLE_NO_FREE(cmd), GFP_ATOMIC); if (ret) - return ret; + goto out; if (posted) { virtqueue_kick(dev->cmd_vq); - return 0; + ret = 0; + goto out; } /* kick and poll for getting a response on the queue */ @@ -148,6 +163,8 @@ static int um_pci_send_cmd(struct um_pci_device *dev, } clear_bit(UM_PCI_STAT_WAITING, &dev->status); +out: + put_cpu_var(um_pci_msg_bufs); return ret; } @@ -161,12 +178,17 @@ static unsigned long um_pci_cfgspace_read(void *priv, unsigned int offset, .size = size, .addr = offset, }; - /* maximum size - we may only use parts of it */ - u8 data[8]; + /* buf->data is maximum size - we may only use parts of it */ + struct um_pci_message_buffer *buf; + u8 *data; + unsigned long ret = ~0ULL; if (!dev) return ~0ULL; + buf = get_cpu_var(um_pci_msg_bufs); + data = buf->data; + memset(data, 0xff, sizeof(data)); switch (size) { @@ -179,27 +201,34 @@ static unsigned long um_pci_cfgspace_read(void *priv, unsigned int offset, break; default: WARN(1, "invalid config space read size %d\n", size); - return ~0ULL; + goto out; } - if (um_pci_send_cmd(dev, &hdr, sizeof(hdr), NULL, 0, - data, sizeof(data))) - return ~0ULL; + if (um_pci_send_cmd(dev, &hdr, sizeof(hdr), NULL, 0, data, 8)) + goto out; switch (size) { case 1: - return data[0]; + ret = data[0]; + break; case 2: - return le16_to_cpup((void *)data); + ret = le16_to_cpup((void *)data); + break; case 4: - return le32_to_cpup((void *)data); + ret = le32_to_cpup((void *)data); + break; #ifdef CONFIG_64BIT case 8: - return le64_to_cpup((void *)data); + ret = le64_to_cpup((void *)data); + break; #endif default: - return ~0ULL; + break; } + +out: + put_cpu_var(um_pci_msg_bufs); + return ret; } static void um_pci_cfgspace_write(void *priv, unsigned int offset, int size, @@ -272,8 +301,13 @@ static void um_pci_bar_copy_from(void *priv, void *buffer, static unsigned long um_pci_bar_read(void *priv, unsigned int offset, int size) { - /* maximum size - we may only use parts of it */ - u8 data[8]; + /* buf->data is maximum size - we may only use parts of it */ + struct um_pci_message_buffer *buf; + u8 *data; + unsigned long ret = ~0ULL; + + buf = get_cpu_var(um_pci_msg_bufs); + data = buf->data; switch (size) { case 1: @@ -285,25 +319,33 @@ static unsigned long um_pci_bar_read(void *priv, unsigned int offset, break; default: WARN(1, "invalid config space read size %d\n", size); - return ~0ULL; + goto out; } um_pci_bar_copy_from(priv, data, offset, size); switch (size) { case 1: - return data[0]; + ret = data[0]; + break; case 2: - return le16_to_cpup((void *)data); + ret = le16_to_cpup((void *)data); + break; case 4: - return le32_to_cpup((void *)data); + ret = le32_to_cpup((void *)data); + break; #ifdef CONFIG_64BIT case 8: - return le64_to_cpup((void *)data); + ret = le64_to_cpup((void *)data); + break; #endif default: - return ~0ULL; + break; } + +out: + put_cpu_var(um_pci_msg_bufs); + return ret; } static void um_pci_bar_copy_to(void *priv, unsigned int offset, @@ -823,10 +865,16 @@ static int um_pci_init(void) "No virtio device ID configured for PCI - no PCI support\n")) return 0; - bridge = pci_alloc_host_bridge(0); - if (!bridge) + um_pci_msg_bufs = alloc_percpu(struct um_pci_message_buffer); + if (!um_pci_msg_bufs) return -ENOMEM; + bridge = pci_alloc_host_bridge(0); + if (!bridge) { + err = -ENOMEM; + goto free; + } + um_pci_fwnode = irq_domain_alloc_named_fwnode("um-pci"); if (!um_pci_fwnode) { err = -ENOMEM; @@ -878,8 +926,11 @@ free: irq_domain_remove(um_pci_inner_domain); if (um_pci_fwnode) irq_domain_free_fwnode(um_pci_fwnode); - pci_free_resource_list(&bridge->windows); - pci_free_host_bridge(bridge); + if (bridge) { + pci_free_resource_list(&bridge->windows); + pci_free_host_bridge(bridge); + } + free_percpu(um_pci_msg_bufs); return err; } module_init(um_pci_init); @@ -891,5 +942,6 @@ static void um_pci_exit(void) irq_domain_remove(um_pci_inner_domain); pci_free_resource_list(&bridge->windows); pci_free_host_bridge(bridge); + free_percpu(um_pci_msg_bufs); } module_exit(um_pci_exit); -- cgit v1.2.3 From bc5c49d79206b40ad16e055837a33b6dc6160bed Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 11 Aug 2021 16:58:26 +0200 Subject: um: enable VMAP_STACK This works just fine, so select HAVE_ARCH_VMAP_STACK to let users enable VMAP_STACK if desired. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger --- arch/um/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'arch') diff --git a/arch/um/Kconfig b/arch/um/Kconfig index 0561b73cfd9a..389c9f5bcb2b 100644 --- a/arch/um/Kconfig +++ b/arch/um/Kconfig @@ -21,6 +21,7 @@ config UML select HAVE_GCC_PLUGINS select SET_FS select TTY # Needed for line.c + select HAVE_ARCH_VMAP_STACK config MMU bool -- cgit v1.2.3 From adf9ae0d159d3dc94f58d788fc4757c8749ac0df Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 13 Jul 2021 23:47:10 +0200 Subject: um: fix stub location calculation In commit 9f0b4807a44f ("um: rework userspace stubs to not hard-code stub location") I changed stub_segv_handler() to do a calculation with a pointer to a stack variable to find the data page that we're using for the stack and the rest of the data. This same commit was meant to do it as well for stub_clone_handler(), but the change inadvertently went into commit 84b2789d6115 ("um: separate child and parent errors in clone stub") instead. This was reported to not be compiled correctly by gcc 5, causing the code to crash here. I'm not sure why, perhaps it's UB because the var isn't initialized? In any case, this trick always seemed bad, so just create a new inline function that does the calculation in assembly. Reported-by: subashab@codeaurora.org Fixes: 9f0b4807a44f ("um: rework userspace stubs to not hard-code stub location") Fixes: 84b2789d6115 ("um: separate child and parent errors in clone stub") Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger --- arch/um/kernel/skas/clone.c | 3 +-- arch/x86/um/shared/sysdep/stub_32.h | 12 ++++++++++++ arch/x86/um/shared/sysdep/stub_64.h | 12 ++++++++++++ arch/x86/um/stub_segv.c | 3 +-- 4 files changed, 26 insertions(+), 4 deletions(-) (limited to 'arch') diff --git a/arch/um/kernel/skas/clone.c b/arch/um/kernel/skas/clone.c index 5afac0fef24e..ff5061f29167 100644 --- a/arch/um/kernel/skas/clone.c +++ b/arch/um/kernel/skas/clone.c @@ -24,8 +24,7 @@ void __attribute__ ((__section__ (".__syscall_stub"))) stub_clone_handler(void) { - int stack; - struct stub_data *data = (void *) ((unsigned long)&stack & ~(UM_KERN_PAGE_SIZE - 1)); + struct stub_data *data = get_stub_page(); long err; err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD, diff --git a/arch/x86/um/shared/sysdep/stub_32.h b/arch/x86/um/shared/sysdep/stub_32.h index b95db9daf0e8..4c6c2be0c899 100644 --- a/arch/x86/um/shared/sysdep/stub_32.h +++ b/arch/x86/um/shared/sysdep/stub_32.h @@ -101,4 +101,16 @@ static inline void remap_stack_and_trap(void) "memory"); } +static __always_inline void *get_stub_page(void) +{ + unsigned long ret; + + asm volatile ( + "movl %%esp,%0 ;" + "andl %1,%0" + : "=a" (ret) + : "g" (~(UM_KERN_PAGE_SIZE - 1))); + + return (void *)ret; +} #endif diff --git a/arch/x86/um/shared/sysdep/stub_64.h b/arch/x86/um/shared/sysdep/stub_64.h index 6e2626b77a2e..e9c4b2b38803 100644 --- a/arch/x86/um/shared/sysdep/stub_64.h +++ b/arch/x86/um/shared/sysdep/stub_64.h @@ -108,4 +108,16 @@ static inline void remap_stack_and_trap(void) __syscall_clobber, "r10", "r8", "r9"); } +static __always_inline void *get_stub_page(void) +{ + unsigned long ret; + + asm volatile ( + "movq %%rsp,%0 ;" + "andq %1,%0" + : "=a" (ret) + : "g" (~(UM_KERN_PAGE_SIZE - 1))); + + return (void *)ret; +} #endif diff --git a/arch/x86/um/stub_segv.c b/arch/x86/um/stub_segv.c index 21836eaf1725..f7eefba034f9 100644 --- a/arch/x86/um/stub_segv.c +++ b/arch/x86/um/stub_segv.c @@ -11,9 +11,8 @@ void __attribute__ ((__section__ (".__syscall_stub"))) stub_segv_handler(int sig, siginfo_t *info, void *p) { - int stack; + struct faultinfo *f = get_stub_page(); ucontext_t *uc = p; - struct faultinfo *f = (void *)(((unsigned long)&stack) & ~(UM_KERN_PAGE_SIZE - 1)); GET_FAULTINFO_FROM_MC(*f, &uc->uc_mcontext); trap_myself(); -- cgit v1.2.3