Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge branch 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm
Pull ARM fix from Russell King:
"Last ARM fix for 4.14.
This plugs a hole in dump_instr(), which, with certain conditions
satisfied, can dump instructions from kernel space"
* 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm:
ARM: 8720/1: ensure dump_instr() checks addr_limit
+18
-10
+18
-10
arch/arm/kernel/traps.c
+18
-10
arch/arm/kernel/traps.c
···
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set_fs(fs);
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155
}
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157
-
static void dump_instr(const char *lvl, struct pt_regs *regs)
157
+
static void __dump_instr(const char *lvl, struct pt_regs *regs)
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158
{
159
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unsigned long addr = instruction_pointer(regs);
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const int thumb = thumb_mode(regs);
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161
const int width = thumb ? 4 : 8;
162
-
mm_segment_t fs;
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162
char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
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int i;
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164
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165
/*
167
-
* We need to switch to kernel mode so that we can use __get_user
168
-
* to safely read from kernel space. Note that we now dump the
169
-
* code first, just in case the backtrace kills us.
166
+
* Note that we now dump the code first, just in case the backtrace
167
+
* kills us.
170
168
*/
171
-
fs = get_fs();
172
-
set_fs(KERNEL_DS);
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169
174
170
for (i = -4; i < 1 + !!thumb; i++) {
175
171
unsigned int val, bad;
176
172
177
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if (thumb)
178
-
bad = __get_user(val, &((u16 *)addr)[i]);
174
+
bad = get_user(val, &((u16 *)addr)[i]);
179
175
else
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-
bad = __get_user(val, &((u32 *)addr)[i]);
176
+
bad = get_user(val, &((u32 *)addr)[i]);
181
177
182
178
if (!bad)
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179
p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ",
···
184
188
}
185
189
}
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190
printk("%sCode: %s\n", lvl, str);
191
+
}
187
192
188
-
set_fs(fs);
193
+
static void dump_instr(const char *lvl, struct pt_regs *regs)
194
+
{
195
+
mm_segment_t fs;
196
+
197
+
if (!user_mode(regs)) {
198
+
fs = get_fs();
199
+
set_fs(KERNEL_DS);
200
+
__dump_instr(lvl, regs);
201
+
set_fs(fs);
202
+
} else {
203
+
__dump_instr(lvl, regs);
204
+
}
189
205
}
190
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207
#ifdef CONFIG_ARM_UNWIND