[PATCH 3/3] fs/core/vmcore: Move sev_active() reference to x86 arch code
From: Thiago Jung Bauermann <hidden>
Date: 2019-07-12 05:41:54
Also in:
linux-fsdevel, linux-iommu, linux-s390, lkml
Subsystem:
filesystems (vfs and infrastructure), kdump, proc filesystem, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Alexander Viro, Christian Brauner, Andrew Morton, Baoquan He, Mike Rapoport, Pasha Tatashin, Pratyush Yadav, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Secure Encrypted Virtualization is an x86-specific feature, so it shouldn't appear in generic kernel code because it forces non-x86 architectures to define the sev_active() function, which doesn't make a lot of sense. To solve this problem, add an x86 elfcorehdr_read() function to override the generic weak implementation. To do that, it's necessary to make read_from_oldmem() public so that it can be used outside of vmcore.c. Signed-off-by: Thiago Jung Bauermann <redacted> --- arch/x86/kernel/crash_dump_64.c | 5 +++++ fs/proc/vmcore.c | 8 ++++---- include/linux/crash_dump.h | 14 ++++++++++++++ include/linux/mem_encrypt.h | 1 - 4 files changed, 23 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c
index 22369dd5de3b..045e82e8945b 100644
--- a/arch/x86/kernel/crash_dump_64.c
+++ b/arch/x86/kernel/crash_dump_64.c@@ -70,3 +70,8 @@ ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize, { return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, true); } + +ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos) +{ + return read_from_oldmem(buf, count, ppos, 0, sev_active()); +}
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 57957c91c6df..ca1f20bedd8c 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c@@ -100,9 +100,9 @@ static int pfn_is_ram(unsigned long pfn) } /* Reads a page from the oldmem device from given offset. */ -static ssize_t read_from_oldmem(char *buf, size_t count, - u64 *ppos, int userbuf, - bool encrypted) +ssize_t read_from_oldmem(char *buf, size_t count, + u64 *ppos, int userbuf, + bool encrypted) { unsigned long pfn, offset; size_t nr_bytes;
@@ -166,7 +166,7 @@ void __weak elfcorehdr_free(unsigned long long addr) */ ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos) { - return read_from_oldmem(buf, count, ppos, 0, sev_active()); + return read_from_oldmem(buf, count, ppos, 0, false); } /*
diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h
index f774c5eb9e3c..4664fc1871de 100644
--- a/include/linux/crash_dump.h
+++ b/include/linux/crash_dump.h@@ -115,4 +115,18 @@ static inline int vmcore_add_device_dump(struct vmcoredd_data *data) return -EOPNOTSUPP; } #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ + +#ifdef CONFIG_PROC_VMCORE +ssize_t read_from_oldmem(char *buf, size_t count, + u64 *ppos, int userbuf, + bool encrypted); +#else +static inline ssize_t read_from_oldmem(char *buf, size_t count, + u64 *ppos, int userbuf, + bool encrypted) +{ + return -EOPNOTSUPP; +} +#endif /* CONFIG_PROC_VMCORE */ + #endif /* LINUX_CRASHDUMP_H */
diff --git a/include/linux/mem_encrypt.h b/include/linux/mem_encrypt.h
index f2e399fb626b..a3747fcae466 100644
--- a/include/linux/mem_encrypt.h
+++ b/include/linux/mem_encrypt.h@@ -21,7 +21,6 @@ #else /* !CONFIG_ARCH_HAS_MEM_ENCRYPT */ -static inline bool sev_active(void) { return false; } static inline bool mem_encrypt_active(void) { return false; } #endif /* CONFIG_ARCH_HAS_MEM_ENCRYPT */