From a846f47962e4643b33847c9a0b2b6387f02a93be Mon Sep 17 00:00:00 2001 From: KarimAllah Ahmed Date: Tue, 30 Jun 2015 14:57:39 -0700 Subject: x86/kexec: prepend elfcorehdr instead of appending it to the crash-kernel command-line. Any parameter passed after '--' in the kernel command-line will not be parsed by the kernel at all, instead it will be passed directly to init process. Currently the kernel appends elfcorehdr= to the cmdline passed from kexec load, and if this command-line is used to pass parameters to init process this means that 'elfcorehdr' will not be parsed as a kernel parameter at all which will be a problem for vmcore subsystem since it will know nothing about the location of the ELF structure! Prepending 'elfcorehdr' instead of appending it fixes this problem since it ensures that it always comes before '--' and so it's always parsed as a kernel command-line parameter. Even with this patch things can still go wrong if 'CONFIG_CMDLINE' was also used to embedd a command-line to the crash dump kernel and this command-line contains '--' since the current behavior of the kernel is to actually append the boot loader command-line to the embedded command-line. Signed-off-by: KarimAllah Ahmed Cc: Thomas Gleixner Cc: Ingo Molnar Cc: H. Peter Anvin Acked-by: Vivek Goyal Cc: Haren Myneni Cc: Eric Biederman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/kernel/kexec-bzimage64.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c index ca05f86481aa..ca83f7ac388b 100644 --- a/arch/x86/kernel/kexec-bzimage64.c +++ b/arch/x86/kernel/kexec-bzimage64.c @@ -72,15 +72,16 @@ static int setup_cmdline(struct kimage *image, struct boot_params *params, unsigned long cmdline_len) { char *cmdline_ptr = ((char *)params) + cmdline_offset; - unsigned long cmdline_ptr_phys, len; + unsigned long cmdline_ptr_phys, len = 0; uint32_t cmdline_low_32, cmdline_ext_32; - memcpy(cmdline_ptr, cmdline, cmdline_len); if (image->type == KEXEC_TYPE_CRASH) { - len = sprintf(cmdline_ptr + cmdline_len - 1, - " elfcorehdr=0x%lx", image->arch.elf_load_addr); - cmdline_len += len; + len = sprintf(cmdline_ptr, + "elfcorehdr=0x%lx ", image->arch.elf_load_addr); } + memcpy(cmdline_ptr + len, cmdline, cmdline_len); + cmdline_len += len; + cmdline_ptr[cmdline_len - 1] = '\0'; pr_debug("Final command line is: %s\n", cmdline_ptr); -- cgit v1.2.3 From c1bd55f922a2df6038060ed48a82d146d301ca12 Mon Sep 17 00:00:00 2001 From: Josh Triplett Date: Tue, 30 Jun 2015 15:00:00 -0700 Subject: x86: opt into HAVE_COPY_THREAD_TLS, for both 32-bit and 64-bit For 32-bit userspace on a 64-bit kernel, this requires modifying stub32_clone to actually swap the appropriate arguments to match CONFIG_CLONE_BACKWARDS, rather than just leaving the C argument for tls broken. Patch co-authored by Josh Triplett and Thiago Macieira. Signed-off-by: Josh Triplett Acked-by: Andy Lutomirski Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Thiago Macieira Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/Kconfig | 1 + arch/x86/kernel/process_32.c | 6 +++--- arch/x86/kernel/process_64.c | 8 ++++---- 3 files changed, 8 insertions(+), 7 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 47365c7b9f47..55bced17dc95 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -88,6 +88,7 @@ config X86 select HAVE_CMPXCHG_DOUBLE select HAVE_CMPXCHG_LOCAL select HAVE_CONTEXT_TRACKING if X86_64 + select HAVE_COPY_THREAD_TLS select HAVE_C_RECORDMCOUNT select HAVE_DEBUG_KMEMLEAK select HAVE_DEBUG_STACKOVERFLOW diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index c09c99ccf3e3..f73c962fe636 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -128,8 +128,8 @@ void release_thread(struct task_struct *dead_task) release_vm86_irqs(dead_task); } -int copy_thread(unsigned long clone_flags, unsigned long sp, - unsigned long arg, struct task_struct *p) +int copy_thread_tls(unsigned long clone_flags, unsigned long sp, + unsigned long arg, struct task_struct *p, unsigned long tls) { struct pt_regs *childregs = task_pt_regs(p); struct task_struct *tsk; @@ -184,7 +184,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, */ if (clone_flags & CLONE_SETTLS) err = do_set_thread_area(p, -1, - (struct user_desc __user *)childregs->si, 0); + (struct user_desc __user *)tls, 0); if (err && p->thread.io_bitmap_ptr) { kfree(p->thread.io_bitmap_ptr); diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 843f92e4c711..71d7849a07f7 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -150,8 +150,8 @@ static inline u32 read_32bit_tls(struct task_struct *t, int tls) return get_desc_base(&t->thread.tls_array[tls]); } -int copy_thread(unsigned long clone_flags, unsigned long sp, - unsigned long arg, struct task_struct *p) +int copy_thread_tls(unsigned long clone_flags, unsigned long sp, + unsigned long arg, struct task_struct *p, unsigned long tls) { int err; struct pt_regs *childregs; @@ -207,10 +207,10 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, #ifdef CONFIG_IA32_EMULATION if (is_ia32_task()) err = do_set_thread_area(p, -1, - (struct user_desc __user *)childregs->si, 0); + (struct user_desc __user *)tls, 0); else #endif - err = do_arch_prctl(p, ARCH_SET_FS, childregs->r8); + err = do_arch_prctl(p, ARCH_SET_FS, tls); if (err) goto out; } -- cgit v1.2.3