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author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-09-17 11:13:37 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-09-17 11:13:37 -0700 |
commit | e789286468a9ea7acb5aae09a11bdfc7d46874ec (patch) | |
tree | 4384de117d5fed773e6df2ace6eee6ed53b26829 | |
parent | e5a710d13247975444c9a18e28413e566c334271 (diff) | |
parent | 75b2f7e4c9e0fd750a5a27ca9736d1daa7a3762a (diff) | |
download | lwn-e789286468a9ea7acb5aae09a11bdfc7d46874ec.tar.gz lwn-e789286468a9ea7acb5aae09a11bdfc7d46874ec.zip |
Merge tag 'x86-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"Misc fixes:
- Fix an UV boot crash
- Skip spurious ENDBR generation on _THIS_IP_
- Fix ENDBR use in putuser() asm methods
- Fix corner case boot crashes on 5-level paging
- and fix a false positive WARNING on LTO kernels"
* tag 'x86-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/purgatory: Remove LTO flags
x86/boot/compressed: Reserve more memory for page tables
x86/ibt: Avoid duplicate ENDBR in __put_user_nocheck*()
x86/ibt: Suppress spurious ENDBR
x86/platform/uv: Use alternate source for socket to node data
-rw-r--r-- | arch/x86/boot/compressed/ident_map_64.c | 8 | ||||
-rw-r--r-- | arch/x86/include/asm/boot.h | 45 | ||||
-rw-r--r-- | arch/x86/include/asm/linkage.h | 8 | ||||
-rw-r--r-- | arch/x86/kernel/apic/x2apic_uv_x.c | 11 | ||||
-rw-r--r-- | arch/x86/lib/putuser.S | 4 | ||||
-rw-r--r-- | arch/x86/purgatory/Makefile | 4 | ||||
-rw-r--r-- | include/linux/instruction_pointer.h | 5 |
7 files changed, 61 insertions, 24 deletions
diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c index bcc956c17872..08f93b0401bb 100644 --- a/arch/x86/boot/compressed/ident_map_64.c +++ b/arch/x86/boot/compressed/ident_map_64.c @@ -59,6 +59,14 @@ static void *alloc_pgt_page(void *context) return NULL; } + /* Consumed more tables than expected? */ + if (pages->pgt_buf_offset == BOOT_PGT_SIZE_WARN) { + debug_putstr("pgt_buf running low in " __FILE__ "\n"); + debug_putstr("Need to raise BOOT_PGT_SIZE?\n"); + debug_putaddr(pages->pgt_buf_offset); + debug_putaddr(pages->pgt_buf_size); + } + entry = pages->pgt_buf + pages->pgt_buf_offset; pages->pgt_buf_offset += PAGE_SIZE; diff --git a/arch/x86/include/asm/boot.h b/arch/x86/include/asm/boot.h index 4ae14339cb8c..b3a7cfb0d99e 100644 --- a/arch/x86/include/asm/boot.h +++ b/arch/x86/include/asm/boot.h @@ -40,23 +40,40 @@ #ifdef CONFIG_X86_64 # define BOOT_STACK_SIZE 0x4000 +/* + * Used by decompressor's startup_32() to allocate page tables for identity + * mapping of the 4G of RAM in 4-level paging mode: + * - 1 level4 table; + * - 1 level3 table; + * - 4 level2 table that maps everything with 2M pages; + * + * The additional level5 table needed for 5-level paging is allocated from + * trampoline_32bit memory. + */ # define BOOT_INIT_PGT_SIZE (6*4096) -# ifdef CONFIG_RANDOMIZE_BASE + /* - * Assuming all cross the 512GB boundary: - * 1 page for level4 - * (2+2)*4 pages for kernel, param, cmd_line, and randomized kernel - * 2 pages for first 2M (video RAM: CONFIG_X86_VERBOSE_BOOTUP). - * Total is 19 pages. + * Total number of page tables kernel_add_identity_map() can allocate, + * including page tables consumed by startup_32(). + * + * Worst-case scenario: + * - 5-level paging needs 1 level5 table; + * - KASLR needs to map kernel, boot_params, cmdline and randomized kernel, + * assuming all of them cross 256T boundary: + * + 4*2 level4 table; + * + 4*2 level3 table; + * + 4*2 level2 table; + * - X86_VERBOSE_BOOTUP needs to map the first 2M (video RAM): + * + 1 level4 table; + * + 1 level3 table; + * + 1 level2 table; + * Total: 28 tables + * + * Add 4 spare table in case decompressor touches anything beyond what is + * accounted above. Warn if it happens. */ -# ifdef CONFIG_X86_VERBOSE_BOOTUP -# define BOOT_PGT_SIZE (19*4096) -# else /* !CONFIG_X86_VERBOSE_BOOTUP */ -# define BOOT_PGT_SIZE (17*4096) -# endif -# else /* !CONFIG_RANDOMIZE_BASE */ -# define BOOT_PGT_SIZE BOOT_INIT_PGT_SIZE -# endif +# define BOOT_PGT_SIZE_WARN (28*4096) +# define BOOT_PGT_SIZE (32*4096) #else /* !CONFIG_X86_64 */ # define BOOT_STACK_SIZE 0x1000 diff --git a/arch/x86/include/asm/linkage.h b/arch/x86/include/asm/linkage.h index 97a3de7892d3..5ff49fd67732 100644 --- a/arch/x86/include/asm/linkage.h +++ b/arch/x86/include/asm/linkage.h @@ -8,6 +8,14 @@ #undef notrace #define notrace __attribute__((no_instrument_function)) +#ifdef CONFIG_64BIT +/* + * The generic version tends to create spurious ENDBR instructions under + * certain conditions. + */ +#define _THIS_IP_ ({ unsigned long __here; asm ("lea 0(%%rip), %0" : "=r" (__here)); __here; }) +#endif + #ifdef CONFIG_X86_32 #define asmlinkage CPP_ASMLINKAGE __attribute__((regparm(0))) #endif /* CONFIG_X86_32 */ diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c index d9f5d7492f83..205cee567629 100644 --- a/arch/x86/kernel/apic/x2apic_uv_x.c +++ b/arch/x86/kernel/apic/x2apic_uv_x.c @@ -1533,7 +1533,7 @@ static void __init build_socket_tables(void) { struct uv_gam_range_entry *gre = uv_gre_table; int nums, numn, nump; - int cpu, i, lnid; + int i, lnid, apicid; int minsock = _min_socket; int maxsock = _max_socket; int minpnode = _min_pnode; @@ -1584,15 +1584,14 @@ static void __init build_socket_tables(void) /* Set socket -> node values: */ lnid = NUMA_NO_NODE; - for_each_possible_cpu(cpu) { - int nid = cpu_to_node(cpu); - int apicid, sockid; + for (apicid = 0; apicid < ARRAY_SIZE(__apicid_to_node); apicid++) { + int nid = __apicid_to_node[apicid]; + int sockid; - if (lnid == nid) + if ((nid == NUMA_NO_NODE) || (lnid == nid)) continue; lnid = nid; - apicid = per_cpu(x86_cpu_to_apicid, cpu); sockid = apicid >> uv_cpuid.socketid_shift; if (_socket_to_node[sockid - minsock] == SOCK_EMPTY) diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S index 1451e0c4ae22..235bbda6fc82 100644 --- a/arch/x86/lib/putuser.S +++ b/arch/x86/lib/putuser.S @@ -56,7 +56,6 @@ SYM_FUNC_END(__put_user_1) EXPORT_SYMBOL(__put_user_1) SYM_FUNC_START(__put_user_nocheck_1) - ENDBR ASM_STAC 2: movb %al,(%_ASM_CX) xor %ecx,%ecx @@ -76,7 +75,6 @@ SYM_FUNC_END(__put_user_2) EXPORT_SYMBOL(__put_user_2) SYM_FUNC_START(__put_user_nocheck_2) - ENDBR ASM_STAC 4: movw %ax,(%_ASM_CX) xor %ecx,%ecx @@ -96,7 +94,6 @@ SYM_FUNC_END(__put_user_4) EXPORT_SYMBOL(__put_user_4) SYM_FUNC_START(__put_user_nocheck_4) - ENDBR ASM_STAC 6: movl %eax,(%_ASM_CX) xor %ecx,%ecx @@ -119,7 +116,6 @@ SYM_FUNC_END(__put_user_8) EXPORT_SYMBOL(__put_user_8) SYM_FUNC_START(__put_user_nocheck_8) - ENDBR ASM_STAC 9: mov %_ASM_AX,(%_ASM_CX) #ifdef CONFIG_X86_32 diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index c2a29be35c01..08aa0f25f12a 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -19,6 +19,10 @@ CFLAGS_sha256.o := -D__DISABLE_EXPORTS -D__NO_FORTIFY # optimization flags. KBUILD_CFLAGS := $(filter-out -fprofile-sample-use=% -fprofile-use=%,$(KBUILD_CFLAGS)) +# When LTO is enabled, llvm emits many text sections, which is not supported +# by kexec. Remove -flto=* flags. +KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS)) + # When linking purgatory.ro with -r unresolved symbols are not checked, # also link a purgatory.chk binary without -r to check for unresolved symbols. PURGATORY_LDFLAGS := -e purgatory_start -z nodefaultlib diff --git a/include/linux/instruction_pointer.h b/include/linux/instruction_pointer.h index cda1f706eaeb..aa0b3ffea935 100644 --- a/include/linux/instruction_pointer.h +++ b/include/linux/instruction_pointer.h @@ -2,7 +2,12 @@ #ifndef _LINUX_INSTRUCTION_POINTER_H #define _LINUX_INSTRUCTION_POINTER_H +#include <asm/linkage.h> + #define _RET_IP_ (unsigned long)__builtin_return_address(0) + +#ifndef _THIS_IP_ #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) +#endif #endif /* _LINUX_INSTRUCTION_POINTER_H */ |