Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
[watchdog] hpwdt: fix use of inline assembly
The inline assembly in drivers/watchdog/hpwdt.c was incredibly broken,
and included all the function prologue and epilogue stuff, even though
it was itself then inside a C function where the compiler would add its
own prologue and epilogue on top of it all.
This then just _happened_ to work if you had exactly the right compiler
version and exactly the right compiler flags, so that gcc just happened
to not create any prologue at all (the gcc-generated epilogue wouldn't
matter, since it would never be reached).
But the more proper way to fix it is to simply not do this. Move the
inline asm to the top level, with no surrounding function at all (the
better alternative would be to remove the prologue and make it actually
use proper description of the arguments to the inline asm, but that's a
bigger change than the one I'm willing to make right now).
Tested-by: S.Çağlar Onur <caglar@pardus.org.tr>
Acked-by: Thomas Mingarelli <Thomas.Mingarelli@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+80
-75
drivers/watchdog/hpwdt.c
+80
-75
drivers/watchdog/hpwdt.c
···
140
};
141
MODULE_DEVICE_TABLE(pci, hpwdt_devices);
142
143
#ifndef CONFIG_X86_64
144
/* --32 Bit Bios------------------------------------------------------------ */
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#define HPWDT_ARCH 32
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148
-
asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
149
-
unsigned long *pRomEntry)
150
-
{
151
-
asm("pushl %ebp \n\t"
152
-
"movl %esp, %ebp \n\t"
153
-
"pusha \n\t"
154
-
"pushf \n\t"
155
-
"push %es \n\t"
156
-
"push %ds \n\t"
157
-
"pop %es \n\t"
158
-
"movl 8(%ebp),%eax \n\t"
159
-
"movl 4(%eax),%ebx \n\t"
160
-
"movl 8(%eax),%ecx \n\t"
161
-
"movl 12(%eax),%edx \n\t"
162
-
"movl 16(%eax),%esi \n\t"
163
-
"movl 20(%eax),%edi \n\t"
164
-
"movl (%eax),%eax \n\t"
165
-
"push %cs \n\t"
166
-
"call *12(%ebp) \n\t"
167
-
"pushf \n\t"
168
-
"pushl %eax \n\t"
169
-
"movl 8(%ebp),%eax \n\t"
170
-
"movl %ebx,4(%eax) \n\t"
171
-
"movl %ecx,8(%eax) \n\t"
172
-
"movl %edx,12(%eax) \n\t"
173
-
"movl %esi,16(%eax) \n\t"
174
-
"movl %edi,20(%eax) \n\t"
175
-
"movw %ds,24(%eax) \n\t"
176
-
"movw %es,26(%eax) \n\t"
177
-
"popl %ebx \n\t"
178
-
"movl %ebx,(%eax) \n\t"
179
-
"popl %ebx \n\t"
180
-
"movl %ebx,28(%eax) \n\t"
181
-
"pop %es \n\t"
182
-
"popf \n\t"
183
-
"popa \n\t"
184
-
"leave \n\t" "ret");
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-
}
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/*
188
* cru_detect
···
337
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#define HPWDT_ARCH 64
339
340
-
asmlinkage void asminline_call(struct cmn_registers *pi86Regs,
341
-
unsigned long *pRomEntry)
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-
{
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-
asm("pushq %rbp \n\t"
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-
"movq %rsp, %rbp \n\t"
345
-
"pushq %rax \n\t"
346
-
"pushq %rbx \n\t"
347
-
"pushq %rdx \n\t"
348
-
"pushq %r12 \n\t"
349
-
"pushq %r9 \n\t"
350
-
"movq %rsi, %r12 \n\t"
351
-
"movq %rdi, %r9 \n\t"
352
-
"movl 4(%r9),%ebx \n\t"
353
-
"movl 8(%r9),%ecx \n\t"
354
-
"movl 12(%r9),%edx \n\t"
355
-
"movl 16(%r9),%esi \n\t"
356
-
"movl 20(%r9),%edi \n\t"
357
-
"movl (%r9),%eax \n\t"
358
-
"call *%r12 \n\t"
359
-
"pushfq \n\t"
360
-
"popq %r12 \n\t"
361
-
"popfq \n\t"
362
-
"movl %eax, (%r9) \n\t"
363
-
"movl %ebx, 4(%r9) \n\t"
364
-
"movl %ecx, 8(%r9) \n\t"
365
-
"movl %edx, 12(%r9) \n\t"
366
-
"movl %esi, 16(%r9) \n\t"
367
-
"movl %edi, 20(%r9) \n\t"
368
-
"movq %r12, %rax \n\t"
369
-
"movl %eax, 28(%r9) \n\t"
370
-
"popq %r9 \n\t"
371
-
"popq %r12 \n\t"
372
-
"popq %rdx \n\t"
373
-
"popq %rbx \n\t"
374
-
"popq %rax \n\t"
375
-
"leave \n\t" "ret");
376
-
}
377
378
/*
379
* dmi_find_cru
···
140
};
141
MODULE_DEVICE_TABLE(pci, hpwdt_devices);
142
143
+
extern asmlinkage void asminline_call(struct cmn_registers *pi86Regs, unsigned long *pRomEntry);
144
+
145
#ifndef CONFIG_X86_64
146
/* --32 Bit Bios------------------------------------------------------------ */
147
148
#define HPWDT_ARCH 32
149
150
+
asm(".text \n\t"
151
+
".align 4 \n"
152
+
"asminline_call: \n\t"
153
+
"pushl %ebp \n\t"
154
+
"movl %esp, %ebp \n\t"
155
+
"pusha \n\t"
156
+
"pushf \n\t"
157
+
"push %es \n\t"
158
+
"push %ds \n\t"
159
+
"pop %es \n\t"
160
+
"movl 8(%ebp),%eax \n\t"
161
+
"movl 4(%eax),%ebx \n\t"
162
+
"movl 8(%eax),%ecx \n\t"
163
+
"movl 12(%eax),%edx \n\t"
164
+
"movl 16(%eax),%esi \n\t"
165
+
"movl 20(%eax),%edi \n\t"
166
+
"movl (%eax),%eax \n\t"
167
+
"push %cs \n\t"
168
+
"call *12(%ebp) \n\t"
169
+
"pushf \n\t"
170
+
"pushl %eax \n\t"
171
+
"movl 8(%ebp),%eax \n\t"
172
+
"movl %ebx,4(%eax) \n\t"
173
+
"movl %ecx,8(%eax) \n\t"
174
+
"movl %edx,12(%eax) \n\t"
175
+
"movl %esi,16(%eax) \n\t"
176
+
"movl %edi,20(%eax) \n\t"
177
+
"movw %ds,24(%eax) \n\t"
178
+
"movw %es,26(%eax) \n\t"
179
+
"popl %ebx \n\t"
180
+
"movl %ebx,(%eax) \n\t"
181
+
"popl %ebx \n\t"
182
+
"movl %ebx,28(%eax) \n\t"
183
+
"pop %es \n\t"
184
+
"popf \n\t"
185
+
"popa \n\t"
186
+
"leave \n\t"
187
+
"ret \n\t"
188
+
".previous");
189
+
190
191
/*
192
* cru_detect
···
333
334
#define HPWDT_ARCH 64
335
336
+
asm(".text \n\t"
337
+
".align 4 \n"
338
+
"asminline_call: \n\t"
339
+
"pushq %rbp \n\t"
340
+
"movq %rsp, %rbp \n\t"
341
+
"pushq %rax \n\t"
342
+
"pushq %rbx \n\t"
343
+
"pushq %rdx \n\t"
344
+
"pushq %r12 \n\t"
345
+
"pushq %r9 \n\t"
346
+
"movq %rsi, %r12 \n\t"
347
+
"movq %rdi, %r9 \n\t"
348
+
"movl 4(%r9),%ebx \n\t"
349
+
"movl 8(%r9),%ecx \n\t"
350
+
"movl 12(%r9),%edx \n\t"
351
+
"movl 16(%r9),%esi \n\t"
352
+
"movl 20(%r9),%edi \n\t"
353
+
"movl (%r9),%eax \n\t"
354
+
"call *%r12 \n\t"
355
+
"pushfq \n\t"
356
+
"popq %r12 \n\t"
357
+
"popfq \n\t"
358
+
"movl %eax, (%r9) \n\t"
359
+
"movl %ebx, 4(%r9) \n\t"
360
+
"movl %ecx, 8(%r9) \n\t"
361
+
"movl %edx, 12(%r9) \n\t"
362
+
"movl %esi, 16(%r9) \n\t"
363
+
"movl %edi, 20(%r9) \n\t"
364
+
"movq %r12, %rax \n\t"
365
+
"movl %eax, 28(%r9) \n\t"
366
+
"popq %r9 \n\t"
367
+
"popq %r12 \n\t"
368
+
"popq %rdx \n\t"
369
+
"popq %rbx \n\t"
370
+
"popq %rax \n\t"
371
+
"leave \n\t"
372
+
"ret \n\t"
373
+
".previous");
374
375
/*
376
* dmi_find_cru