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authorLinus Torvalds <torvalds@linux-foundation.org>2016-03-15 10:02:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-03-15 10:02:25 -0700
commit42576bee6eacda29a3193e97961ab3583a324850 (patch)
tree850f5f50941e800bd457cda268d650565ac746d6 /arch
parentba33ea811e1ff6726abb7f8f96df38c2d7b50304 (diff)
parent25b4caf7c50e8c501310e8c515d8518b1850c948 (diff)
Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 boot updates from Ingo Molnar: "Early command line options parsing enhancements from Dave Hansen, plus minor cleanups and enhancements" * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/boot: Remove unused 'is_big_kernel' variable x86/boot: Use proper array element type in memset() size calculation x86/boot: Pass in size to early cmdline parsing x86/boot: Simplify early command line parsing x86/boot: Fix early command-line parsing when partial word matches x86/boot: Fix early command-line parsing when matching at end x86/boot: Simplify kernel load address alignment check x86/boot: Micro-optimize reset_early_page_tables()
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/boot/tools/build.c1
-rw-r--r--arch/x86/kernel/head64.c14
-rw-r--r--arch/x86/kernel/head_64.S4
-rw-r--r--arch/x86/lib/cmdline.c60
4 files changed, 47 insertions, 32 deletions
diff --git a/arch/x86/boot/tools/build.c b/arch/x86/boot/tools/build.c
index a7661c430cd9..0702d2531bc7 100644
--- a/arch/x86/boot/tools/build.c
+++ b/arch/x86/boot/tools/build.c
@@ -49,7 +49,6 @@ typedef unsigned int u32;
/* This must be large enough to hold the entire setup */
u8 buf[SETUP_SECT_MAX*512];
-int is_big_kernel;
#define PECOFF_RELOC_RESERVE 0x20
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 2c0f3407bd1f..1f4422d5c8d0 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -40,13 +40,8 @@ pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX);
/* Wipe all early page tables except for the kernel symbol map */
static void __init reset_early_page_tables(void)
{
- unsigned long i;
-
- for (i = 0; i < PTRS_PER_PGD-1; i++)
- early_level4_pgt[i].pgd = 0;
-
+ memset(early_level4_pgt, 0, sizeof(pgd_t)*(PTRS_PER_PGD-1));
next_early_pgt = 0;
-
write_cr3(__pa_nodebug(early_level4_pgt));
}
@@ -54,7 +49,6 @@ static void __init reset_early_page_tables(void)
int __init early_make_pgtable(unsigned long address)
{
unsigned long physaddr = address - __PAGE_OFFSET;
- unsigned long i;
pgdval_t pgd, *pgd_p;
pudval_t pud, *pud_p;
pmdval_t pmd, *pmd_p;
@@ -81,8 +75,7 @@ again:
}
pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++];
- for (i = 0; i < PTRS_PER_PUD; i++)
- pud_p[i] = 0;
+ memset(pud_p, 0, sizeof(*pud_p) * PTRS_PER_PUD);
*pgd_p = (pgdval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
}
pud_p += pud_index(address);
@@ -97,8 +90,7 @@ again:
}
pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++];
- for (i = 0; i < PTRS_PER_PMD; i++)
- pmd_p[i] = 0;
+ memset(pmd_p, 0, sizeof(*pmd_p) * PTRS_PER_PMD);
*pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
}
pmd = (physaddr & PMD_MASK) + early_pmd_flags;
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 2e974680f5ad..22fbf9df61bb 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -75,9 +75,7 @@ startup_64:
subq $_text - __START_KERNEL_map, %rbp
/* Is the address not 2M aligned? */
- movq %rbp, %rax
- andl $~PMD_PAGE_MASK, %eax
- testl %eax, %eax
+ testl $~PMD_PAGE_MASK, %ebp
jnz bad_address
/*
diff --git a/arch/x86/lib/cmdline.c b/arch/x86/lib/cmdline.c
index 422db000d727..5cc78bf57232 100644
--- a/arch/x86/lib/cmdline.c
+++ b/arch/x86/lib/cmdline.c
@@ -21,12 +21,16 @@ static inline int myisspace(u8 c)
* @option: option string to look for
*
* Returns the position of that @option (starts counting with 1)
- * or 0 on not found.
+ * or 0 on not found. @option will only be found if it is found
+ * as an entire word in @cmdline. For instance, if @option="car"
+ * then a cmdline which contains "cart" will not match.
*/
-int cmdline_find_option_bool(const char *cmdline, const char *option)
+static int
+__cmdline_find_option_bool(const char *cmdline, int max_cmdline_size,
+ const char *option)
{
char c;
- int len, pos = 0, wstart = 0;
+ int pos = 0, wstart = 0;
const char *opptr = NULL;
enum {
st_wordstart = 0, /* Start of word/after whitespace */
@@ -37,11 +41,11 @@ int cmdline_find_option_bool(const char *cmdline, const char *option)
if (!cmdline)
return -1; /* No command line */
- len = min_t(int, strlen(cmdline), COMMAND_LINE_SIZE);
- if (!len)
- return 0;
-
- while (len--) {
+ /*
+ * This 'pos' check ensures we do not overrun
+ * a non-NULL-terminated 'cmdline'
+ */
+ while (pos < max_cmdline_size) {
c = *(char *)cmdline++;
pos++;
@@ -58,18 +62,35 @@ int cmdline_find_option_bool(const char *cmdline, const char *option)
/* fall through */
case st_wordcmp:
- if (!*opptr)
+ if (!*opptr) {
+ /*
+ * We matched all the way to the end of the
+ * option we were looking for. If the
+ * command-line has a space _or_ ends, then
+ * we matched!
+ */
if (!c || myisspace(c))
return wstart;
- else
- state = st_wordskip;
- else if (!c)
+ /*
+ * We hit the end of the option, but _not_
+ * the end of a word on the cmdline. Not
+ * a match.
+ */
+ } else if (!c) {
+ /*
+ * Hit the NULL terminator on the end of
+ * cmdline.
+ */
return 0;
- else if (c != *opptr++)
- state = st_wordskip;
- else if (!len) /* last word and is matching */
- return wstart;
- break;
+ } else if (c == *opptr++) {
+ /*
+ * We are currently matching, so continue
+ * to the next character on the cmdline.
+ */
+ break;
+ }
+ state = st_wordskip;
+ /* fall through */
case st_wordskip:
if (!c)
@@ -82,3 +103,8 @@ int cmdline_find_option_bool(const char *cmdline, const char *option)
return 0; /* Buffer overrun */
}
+
+int cmdline_find_option_bool(const char *cmdline, const char *option)
+{
+ return __cmdline_find_option_bool(cmdline, COMMAND_LINE_SIZE, option);
+}