[PATCH 17/35] x86, boot: Move checking of cmd_line_ptr out of common path

[Yinghai Lu]

cmdline.c::__cmdline_find_option... are shared between 16-bit setup code
and 32/64 bit decompressor code.

for 32/64 only path via kexec, we should not check if ptr is less 1M.
as those cmdline could be put above 1M, or even 4G.

Move out accessible checking out of __cmdline_find_option()
So decompressor in misc.c can parse cmdline correctly.

Signed-off-by: Yinghai Lu <ying...@kernel.org>
---
 arch/x86/boot/boot.h    |   14 ++++++++++++--
 arch/x86/boot/cmdline.c |    8 ++++----
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h
index 18997e5..7fadf80 100644
--- a/arch/x86/boot/boot.h
+++ b/arch/x86/boot/boot.h
@@ -289,12 +289,22 @@ int __cmdline_find_option(u32 cmdline_ptr, const char 
*option, char *buffer, int
 int __cmdline_find_option_bool(u32 cmdline_ptr, const char *option);
 static inline int cmdline_find_option(const char *option, char *buffer, int 
bufsize)
 {
-       return __cmdline_find_option(boot_params.hdr.cmd_line_ptr, option, 
buffer, bufsize);
+       u32 cmd_line_ptr = boot_params.hdr.cmd_line_ptr;
+
+       if (cmd_line_ptr >= 0x100000)
+               return -1;      /* inaccessible */
+
+       return __cmdline_find_option(cmd_line_ptr, option, buffer, bufsize);
 }
 
 static inline int cmdline_find_option_bool(const char *option)
 {
-       return __cmdline_find_option_bool(boot_params.hdr.cmd_line_ptr, option);
+       u32 cmd_line_ptr = boot_params.hdr.cmd_line_ptr;
+
+       if (cmd_line_ptr >= 0x100000)
+               return -1;      /* inaccessible */
+
+       return __cmdline_find_option_bool(cmd_line_ptr, option);
 }
 
 
diff --git a/arch/x86/boot/cmdline.c b/arch/x86/boot/cmdline.c
index 6b3b6f7..768f00f 100644
--- a/arch/x86/boot/cmdline.c
+++ b/arch/x86/boot/cmdline.c
@@ -41,8 +41,8 @@ int __cmdline_find_option(u32 cmdline_ptr, const char 
*option, char *buffer, int
                st_bufcpy       /* Copying this to buffer */
        } state = st_wordstart;
 
-       if (!cmdline_ptr || cmdline_ptr >= 0x100000)
-               return -1;      /* No command line, or inaccessible */
+       if (!cmdline_ptr)
+               return -1;      /* No command line */
 
        cptr = cmdline_ptr & 0xf;
        set_fs(cmdline_ptr >> 4);
@@ -111,8 +111,8 @@ int __cmdline_find_option_bool(u32 cmdline_ptr, const char 
*option)
                st_wordskip,    /* Miscompare, skip */
        } state = st_wordstart;
 
-       if (!cmdline_ptr || cmdline_ptr >= 0x100000)
-               return -1;      /* No command line, or inaccessible */
+       if (!cmdline_ptr)
+               return -1;      /* No command line */
 
        cptr = cmdline_ptr & 0xf;
        set_fs(cmdline_ptr >> 4);
-- 
1.7.10.4

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